Category: Hem/Onc Updates

Expert Perspectives on MRD Testing in Multiple Myeloma

RR

Learn how leading oncologists use MRD to inform treatment strategy and predict relapse risk

Written by: Dr. Gary Simmons & Dr. Kashif Ali
This educational opportunity is sponsored by Adaptive Biotechnologies

Measurable residual disease (MRD) testing has become a valuable tool across the multiple myeloma disease continuum, offering unprecedented insight into disease burden, treatment response, and relapse risk.  NCCN guidelines define MRD negativity as the absence of clonal plasma cells by next generation flow cytometry or next generation sequencing (NGS), at a sensitivity of at least 1 in 10-5 cells, and recommend assessing MRD status after induction, post-transplant, post-consolidation and during maintenance therapy.1  MRD results are shaping key decisions ranging from the role and timing of autologous stem cell transplant to strategies for monitoring and treatment adjustment.  Notably, MRD may be measured from bone marrow or peripheral blood, with data indicating that blood-based testing complements – but does not replace – bone marrow-based testing.2  In this dual-perspective Thought Leader Article, Dr. Gary Simmons (Virginia Oncology Associates) explores how MRD guides transplant decision-making, and Dr. Kashif Ali (Maryland Oncology Hematology) examines the value of blood-based MRD in monitoring response and predicting relapse in multiple myeloma.

The Role of MRD in Informing Autologous Stem Cell Transplant Decision-Making

Despite remarkable advances in multiple myeloma therapy, autologous stem cell transplant still plays a role in the treatment of many patients.  Traditionally, clinical decision-making around transplant was limited to weighing patient-specific factors such as age, comorbidities, and the limited methods that existed to gauge response to induction therapy.  MRD testing provides unprecedented, personalized insight into the induction response achieved by each patient, which directly influences the decision of whether to follow up with transplant.  MRD does not diminish the value of transplant but is rather a stratification tool to identify patients who would derive additional benefit from transplant, from those for which monitoring would suffice.  Several clinical trials including Determination, Perseus and GMMG-HD7 have demonstrated that transplant increases achievement and duration of MRD negativity.3,4,5 Thus, there is a bi-directional relationship in which MRD negativity supports the therapeutic value of transplant, and MRD results help to ensure that patients receive the minimal level of treatment required to achieve optimal outcomes.

In my practice, I evaluate MRD status alongside several variables including patient age, comorbidities, and standard- vs high-risk cytogenetics per the International Myeloma Working Group, when deciding on upfront vs deferred vs no transplant following induction therapy.  In many cases, patient-specific factors significantly influence the weight of MRD results in guiding transplant decision-making.  Notable among these is patient age.  I tend to recommend transplant in young patients, even those who are MRD negative, given data showing a substantially increased disease-free survival6 and improved clinical outcomes in younger fit patients.7  Conversely, there are populations in which MRD negativity would lead me to defer upfront transplant, especially in patients demanding a conservative approach, such as those greater than 75-years-old and/or those with significant comorbidities.  In these patients, MRD negativity often leads me to delay transplant, with the understanding that if/when the patient relapses, there are alternative treatment options to pursue, such as CAR T-cell therapy.  In general, I encourage most standard-risk myeloma patients that if they are MRD negative over the next 5 years, the disease-free is similar with or without transplant; that is encouraging to patients.

As myeloma testing and treatment options rapidly evolve, it’s increasingly important to stay abreast of the gold standard MRD testing options and latest clinical guidelines, to ensure optimal patient outcomes.  We’re always reviewing the options and the depth of MRD testing in our myeloma patients.  At this point, I tend to exclusively use the clonoSEQ assay, as it has a depth of 1×10-6 cells.  We know that depth of MRD and duration of MRD are related to improved clinical outcomes.  Therefore, despite the clinical trials using a MRD cutoff of 1×10-5 cells, we prefer the increased sensitivity offered by clonoSEQ of 1×10-6, for optimal assurance that negativity accurately identifies patients who are truly “MRD negative”.  While this piece is focused on the value of MRD in guiding transplant decisions, it’s worth nothing that assay depth and sensitivity also come to be very important post-stem cell transplant – as MRD negativity after a few years of maintenance can be used to determine if patients can stop maintenance therapy.  In the MASTER trial, MRD status and cytogenetics could predict risk of relapse in two years, highlighting the utility of MRD to help guide continuing maintenance or identify patients who may be able to stop.8 Altogether, these insights underscore how MRD drives personalized care from transplant decision-making to maintenance, ensuring optimal outcomes for patients with multiple myeloma.

The Role of Peripheral Blood-Based MRD Assessment in Monitoring Disease Response

While bone marrow evaluation remains the standard method for MRD assessment, peripheral blood-based MRD testing is an increasingly valuable approach for guiding treatment decisions and monitoring response in multiple myeloma.  MRD negativity by both peripheral blood and bone marrow is associated with an improved progression-free survival (PFS) compared to one modality alone, underscoring their complementary nature.2 Notably, peripheral blood MRD positivity has a 100% positive predictive value of bone marrow MRD positivity.10  Understandably, the negative predictive value of peripheral blood MRD is lower, demonstrating that peripheral blood MRD negativity does not exclude bone marrow disease.11 Therefore, in my practice, blood-based MRD positivity does not prompt confirmatory bone marrow testing, whereas blood-based MRD negativity should be confirmed by bone marrow biopsy, if the goal is to alter treatment.

Confidence in blood-based MRD results is influenced by several factors, including myeloma disease biology and timing.  Patients who present with circulating plasma cells at diagnosis have more aggressive disease and worse outcomes.12,13,14 In the post-transplant setting, studies have shown that patients negative for circulating DNA at three months post-transplant had significantly better PFS (84 vs 31 months) with a positive predictive value of 93.3%.15,16 Those who achieve a complete response will have no detectable plasma cells, as opposed to those who have a relapse, and blood-based MRD testing opens the door to uncover previously undetectable levels of circulating plasma cells.  There are also situations, such as patients with patchy bone marrow involvement or extramedullary disease17, in which MRD assessment of blood is more informative and bone marrow testing alone would be insufficient.18

Timing is another important consideration.  The concordance between bone marrow and blood-based MRD is lowest early after transplant and increases with time, suggesting enhanced reliability of peripheral blood MRD during maintenance.19 Peripheral blood MRD is well suited for longitudinal monitoring post-induction, post-transplant, and especially during maintenance in situations where repeated bone marrow biopsies would not be feasible.10,20 I routinely incorporate peripheral blood MRD testing at these timepoints and find it to be a less invasive alternative that enables more frequent assessment of patients who are reluctant to undergo repeat bone marrow biopsies.20,21 When the goal is to continue maintenance treatment, I utilize serial peripheral blood MRD testing and myeloma-related lab tests.  In these scenarios, I would only check a bone marrow biopsy if the goal were to discontinue or de-escalate treatment.  In the case of a blood-based MRD positivity, given the high concordance between peripheral blood and bone marrow, I would not mandate that an unwilling patient also undergo bone marrow-based MRD.  In my practice and outside of a clinical trial, most patients with blood-based MRD positivity, after hearing about data on concordance, decide not to undergo bone marrow confirmation although I do offer it to them.  Together, the expanding clinical utility of MRD assessment by blood and bone marrow underscores its value for guiding treatment decisions, monitoring response and prognosticating outcomes in multiple myeloma.

References:

  1. National Comprehensive Cancer Network. Multiple Myeloma. Updated 2025-11-26.
  2. Langerhorst P, Noori S, Zajec M, et al. Multiple Myeloma Minimal Residual Disease Detection: Targeted Mass Spectrometry in Blood vs Next-Generation Sequencing in Bone Marrow. Clinical Chemistry.  2021;67(12):1689-1698.  doi:10.1093/clinchem/hvab187.
  3. Richardson PG, Jacobus SJ, Weller EA, et al. Triplet Therapy, Transplantation, and Maintenance until Progression in Myeloma.  The New England Journal of Medicine.  2022;387(2):132–147. doi:10.1056/NEJMoa2204925.
  4. Sonneveld P, Dimopoulos MA, Boccadoro M, et al. Daratumumab, Bortezomib, Lenalidomide, and Dexamethasone for Multiple Myeloma. The New England Journal of Medicine.  2024;390(4):301-313.   doi:10.1056/NEJMoa2312054.
  5. Goldschmidt H, Bertch U, Pozek E, et al. Isatuximab, Lenalidomide, Bortezomib and Dexamethasone Induction Therapy for Transplant-Eligible Patients with Newly Diagnosed Multiple Myeloma: Final Progression-Free Survival Analysis of Part 1 of an Open-Label, Multicenter, Randomized, Phase 3 Trial (GMMG-HD7). Blood.  2024;144(Supplement 1): 769.  doi: https://doi.org/10.1182/blood-2024-193308.
  6. Ebraheem M, Kumar SK, Dispenzieri A, et al. Deepening Responses after Upfront Autologous Stem Cell Transplantation in Patients with Newly Diagnosed Multiple Myeloma in the Era of Novel Agent Induction Therapy. Transplant Cell Ther.  2022;28(11):760.e1-760.e5.  doi:10.1016/j.jtct.2022.07.030.
  7. Liu J, Yan W, Fan H, et al. Clinical Benefit of Autologous Stem Cell Transplantation for Patients with Multiple Myeloma Achieving Undetectable Minimal Residual Disease after Induction Treatment. Cancer Res Commun.  2023;3(9):1770-1780.  doi:10.1158/2767-9764.CRC-23-0185.
  8. Costa LJ, Chhabra S, Medvedova E, et al. Daratumumab, Carfilzomib, Lenalidomide, and Dexamethasone With Minimal Residual Disease Response-Adapted Therapy in Newly Diagnosed Multiple Myeloma. J Clin Oncol.  2022;40(25):2901-2912.  doi:10.1200/JCO.21.01935.
  9. Terpos E, Malandrakis P, Ntanasis-Stathopoulos I, et al. Sustained bone marrow and imaging MRD negativity for 3 years drives discontinuation of maintenance post-ASCT in myeloma. Blood.  2025;145(20):2353-2360.  doi:10.1182/blood.2024027686.
  10. Lasa M, Notarfranchi L, Agullo C, et al. Minimally Invasive Assessment of Peripheral Residual Disease During Maintenance or Observation in Transplant-Eligible Patients With Multiple Myeloma. J Clin Oncol.  2025;43(2):125-132.  doi:10.1200/JCO.24.00635.
  11. Chandhok NS, Sekeres MA. Measurable residual disease in hematologic malignancies: a biomarker in search of a standard. EClinicalMedicine.  2025;86:103348.  doi:10.1016/j.eclinm.2025.103348.
  12. Bertamini L, Oliva S, Rota-Scalabrini D, et al. High Levels of Circulating Tumor Plasma Cells as a Key Hallmark of Aggressive Disease in Transplant-Eligible Patients With Newly Diagnosed Multiple Myeloma. J Clin Oncol.  2022;40(27):3120-3131.  doi:10.1200/JCO.21.01393.
  13. Li Q, Ai L, Zuo L, et al. Circulating plasma cells as a predictive biomarker in Multiple myeloma: an updated systematic review and meta-analysis. Ann Med.  2024;56(1):2338604.  doi:10.1080/07853890.2024.2338604.
  14. Li J, Wang N, Tesfaluul N, Gao X, Liu S, Yue B. Prognostic value of circulating plasma cells in patients with multiple myeloma: A meta-analysis. PLoS One.  2017;12(7):e0181447.  doi:10.1371/journal.pone.0181447.
  15. Dhakal B, Sharma S, Balcioglu M, et al. Assessment of Molecular Residual Disease Using Circulating Tumor DNA to Identify Multiple Myeloma Patients at High Risk of Relapse. Frontiers in Oncology.  2022;12:786451.  doi:10.3389/fonc.2022.786451.
  16. Dhakal B, Sharma S, Shchegrova S, et al. Personalized, ctDNA analysis to detect minimal residual disease and identify patients at high risk of relapse with multiple myeloma. Journal of Clinical Oncology.  2021;39(Suppl 15):8029.  doi:10.1200/JCO.2021.39.15_suppl.8029.
  17. van de Donk NWCJ, Pawlyn C, Yong KL. Multiple myeloma. Lancet.  2021;397(10272):410-427.  doi:10.1016/S0140-6736(21)00135-5.
  18. Manasanch EE. What to do with minimal residual disease testing in myeloma. Hematology Am Soc Hematol Educ Program.  2019;2019(1):137-141.  doi:10.1182/hematology.2019000080.
  19. Kubicki T, Dytfeld D, Barnidge D, et al. Mass spectrometry-based assessment of M protein in peripheral blood during maintenance therapy in multiple myeloma. Blood.  2024;144(9):955-963.  doi:10.1182/blood.2024024041.
  20. Wijnands C, Noori S, Donk NWCJV, VanDuijn MM, Jacobs JFM. Advances in minimal residual disease monitoring in multiple myeloma. Crit Rev Clin Lab Sci.  2023;60(7):518-534.  doi:10.1080/10408363.2023.2209652.
  21. Kumar S, Paiva B, Anderson KC, et al. International Myeloma Working Group Consensus Criteria for Response and Minimal Residual Disease Assessment in Multiple Myeloma. Lancet Oncology.  2016;17(8):e328-e346.  doi:10.1016/S1470-2045(16)30206-6.

FDA Approves CALQUENCE® with VENCLEXTA® for Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

RR

SUMMARY: The FDA on February 19, 2026, approved Acalabrutinib (CALQUENCE®) in combination with Venetoclax (VENCLEXTA®) for adults with Chronic Lymphocytic Leukemia (CLL) or Small Lymphocytic Lymphoma (SLL).

The American Cancer Society estimates that for 2026, about 22,760 new cases of Chronic Lymphocytic Leukemia (CLL) will be diagnosed in the US and 4350 patients will die of the disease. CLL accounts for about one-quarter of the new cases of leukemia. The average age of patients diagnosed with CLL is around 70 years, and CLL is rarely seen in people under age 40, and is extremely rare in children. Patients with CLL often receive continuous therapy with either Brutons Tyrosine Kinase (BTK) inhibitor, time limited therapy with BCL2 inhibitor Venetoclax given along with anti-CD20 antibody Obinutuzumab (GAZYVA®), or under certain circumstances, chemoimmunotherapy.

Brutons Tyrosine Kinase (BTK) is a member of the Tec family of kinases, downstream of the B-cell receptor, and is predominantly expressed in B-cells. It is a mediator of B-cell receptor signaling in normal and transformed B-cells. BTK inhibitors inhibit cell proliferation and promote programmed cell death (Apoptosis) by blocking B-cell activation and signaling. BTK is a validated molecular target found across numerous B-cell leukemias and lymphomas including CLL, Mantle Cell Lymphoma (MCL), and Waldenstrom Macroglobulinemia (WM). Four BTK inhibitors are presently approved by the FDA. They include first generation Ibrutinib (IMBRUVICA®) and second generation agents such as Acalabrutinib (CALQUENCE®), Zanubrutinib (BRUKINSA®) and non-covalent BTKi, Pirtobrutinib (JAYPIRCA®).

The pro-survival (anti-apoptotic) protein BCL2 is over expressed by CLL cells and regulates clonal selection and cell survival. Venetoclax is a second generation, oral, selective, small molecule inhibitor of BCL2 and restores the apoptotic processes in tumor cells. Venetoclax is frequently combined with the infusion-based drug Obinutuzumab, which can impose a logistical burden on patients. The combination of Acalabrutinib plus Venetoclax, were noted to be synergistic.

The AMPLIFY trial is a randomized, global, multi-center, open-label Phase III study designed to assess the efficacy and safety of Acalabrutinib in combination with Venetoclax, with or without Obinutuzumab, compared to investigators choice of standard chemoimmunotherapy. In this study, 867 patients (N=867) across 171 locations worldwide with previously untreated CLL were randomized 1:1:1 to receive a fixed-duration regimen of Acalabrutinib and Venetoclax with Obinutuzumab (AVO; N=286), Acalabrutinib and Venetoclax without Obinutuzumab (AV; N=291), or Standard-of-Care chemoimmunotherapy with either Fludarabine plus Cyclophosphamide and Rituximab (FCR) or Bendamustine plus Rituximab (BR) (FCR/BR; N=290). The median patient age was 61 years, 64.5% were male, and 58.6% had CLL with unmutated IGHV. Eligible patients had an ECOG performance status of 0 to 2 and active disease, requiring treatment as per the International Workshop on CLL 2018 criteria. Patients with prior CLL-specific treatments, 17p deletions, TP53 mutations, transformation of CLL to aggressive Non-Hodgkin Lymphoma, Central Nervous System involvement, or a history of Progressive Multifocal Leukoencephalopathy were excluded. The Primary endpoint of the trial was Progression Free Survival (PFS) as assessed by an Independent Review Committee (IRC). Key Secondary endpoints included PFS assessed by investigators, undetectable Minimal Residual Disease (uMRD; 10-4 cutoff) rate assessed in peripheral blood in the treatment groups, Overall Survival (OS), Overall Response Rate (ORR), Duration of Response, and Time to next treatment.

Efficacy Outcomes (Median Follow-Up: 41 Months)

Progression-Free Survival (PFS) — BICR Assessed

  • AVO vs FCR/BR
    • HR: 0.42
    • P < 0.0001
    • 58% reduction in risk of progression or death
  • AV vs FCR/BR
    • HR: 0.65
    • P = 0.0038
    • 35% reduction in risk of progression or death
  • 36-Month PFS Rates
    • AVO: 83%
    • AV: 76.8%
    • FCR/BR: 66.5%
  • Median PFS
    • AVO: Not reached
    • AV: Not reached
    • FCR/BR: 47.6 months

Overall Response Rate (ORR) — BICR Assessed

  • AVO: 92.7%
  • AV: 92.8%
  • FCR/BR: 75.2%
  • P < 0.0001 for both AVO vs FCR/BR and AV vs FCR/BR

Overall Survival (OS)

  • AV vs FCR/BR
    • HR: 0.33
    • P < 0.0001
    • Demonstrated a strong trend toward improved Overall Survival

Serious Adverse Events occurred in 38.4% (AVO group), 24.7% of patients (AV group), and 27.4% (FCR/BR group). Grade 3 or more neutropenia among the treatment groups, was noted in 35.2%, 26.8% and 32.4%, respectively. COVID-19-related deaths affected 25 patients in the AVO group, 10 patients in the AV group, and 21 patients in the FCR/BR group.

Conclusion

The AMPLIFY study met its Primary endpoint, demonstrating superior Progression-Free Survival (PFS) with both AVO and AV compared with standard chemoimmunotherapy.

Key Takeaways

  • Both combinations produced deep and durable responses
  • Represent a more effective, fixed-duration treatment strategy
  • Offer a shift away from traditional chemoimmunotherapy

Clinical Distinction Between Regimens

AV (Acalabrutinib + Venetoclax):

  • First all-oral, fixed-duration regimen
  • Designed for fit, treatment-naïve CLL patients
  • Provides meaningful convenience
  • Demonstrates a manageable safety profile

AVO (Acalabrutinib + Venetoclax + Obinutuzumab):

  • Further improved efficacy outcomes
  • Associated with:
    • Higher rates of serious adverse events
    • Increased COVID-19–related deaths

 

Fixed-Duration Acalabrutinib Combinations in Untreated Chronic Lymphocytic Leukemia. Brown JR, Seymour JF, Wojciech Jurczak, et al. for the AMPLIFY investigators. N Engl J Med 2025;392:748-762

FDA Approves KEYTRUDA® with Paclitaxel for Platinum-Resistant Epithelial Ovarian, Fallopian tube, or Primary Peritoneal Carcinoma

RR

SUMMARY: The FDA on February 10, 2026, approved Pembrolizumab (KEYTRUDA®) as well as Pembrolizumab and Berahyaluronidase alfa-pmph (KEYTRUDA QLEX®) in combination with Paclitaxel, with or without Bevacizumab (AVASTIN®), for adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS≥1) as determined by an FDA-authorized test, and who have received one or two prior systemic treatment regimens. The FDA also approved the PD-L1 IHC 22C3 pharmDx as a companion diagnostic device to identify patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS≥1) for treatment with Pembrolizumab.

It is estimated that in the United States, approximately 21,010 women will be diagnosed with ovarian cancer in 2026 and 12,450 women will die of the disease. Ovarian cancer ranks fifth in cancer deaths among women. It accounts for more deaths than any other cancer of the female reproductive system. Approximately 75% of the ovarian cancer patients are diagnosed with advanced disease. Approximately 85% of all ovarian cancers are epithelial in origin, and approximately 70% of all epithelial ovarian cancers are High-Grade Serous adenocarcinomas. Patients with newly diagnosed advanced ovarian cancer are often treated with platinum-based chemotherapy following primary surgical cytoreduction. Approximately 70% of these patients will relapse within the subsequent 3 years and are incurable, with a 5-year Overall Survival rate of about 20-30%.

Platinum-resistant recurrent ovarian cancer therefore remains a significant therapeutic challenge, with historically limited options and modest improvements in survival. Previous studies, such as the Phase III AURELIA trial, established weekly Paclitaxel with Bevacizumab as an effective chemotherapy regimen. The potential for chemotherapy to enhance antitumor immune responses provided the rationale for combining Pembrolizumab, an anti–PD-1 antibody, with Paclitaxel, with or without Bevacizumab, in this patient population.

Trial Design

The ENGOT-ov65/KEYNOTE-B96 trial (NCT05116189) was a multicenter, randomized, double-blind, placebo-controlled Phase III study that enrolled 643 patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma. Eligible patients had received one to two prior systemic therapies, including at least one platinum-based regimen, and had evidence of disease progression within six months after platinum therapy. Patients with primary platinum-refractory disease were excluded.

Participants were randomized 1:1 to receive Pembrolizumab 400 mg every six weeks or placebo, in combination with weekly Paclitaxel 80 mg/m² on days 1, 8, and 15 of each 3-week cycle, with or without Bevacizumab 10 mg/kg every 2 weeks. Prior use of PARP inhibitors, Bevacizumab, or PD-1/PD-L1 agents was allowed. Patients had an ECOG performance status of 0–1, with a median age of 61–62 years and predominance of high-grade serous histology (86%). Approximately one-third of patients had PD-L1 CPS ≥10.

Efficacy Results

The Primary endpoint was Progression-Free Survival (PFS) per RECIST v1.1, with Overall Survival (OS) as a key Secondary endpoint.

  • First interim analysis (median follow-up 15.6 months):
    • Overall population: median PFS 8.3 months with Pembrolizumab vs 6.4 months with placebo (HR 0.70; P<0.0001).
    • PD-L1 CPS ≥1 population: median PFS 8.3 months vs 7.2 months (HR 0.72; P=0.0014).
  • Second interim analysis (median follow-up 26.6 months):
    • PD-L1 CPS ≥1 population: OS improved to 18.2 months with Pembrolizumab vs 14.0 months with placebo (HR 0.76; P=0.0053).
    • Benefits were observed across subgroups, including older patients, prior PARP inhibitor exposure, and short platinum-free interval.
    • Objective Response Rates were higher with Pembrolizumab (53.0% vs 46.6% in PD-L1 CPS ≥1 patients) with longer Duration of Response.

The PFS and OS improvements were consistent regardless of Bevacizumab use, supporting both doublet and triplet strategies in routine practice.

Safety Profile

Pembrolizumab combined with weekly Paclitaxel, with or without Bevacizumab, demonstrated a manageable safety profile. Adverse events were consistent with known toxicities of checkpoint inhibitors and chemotherapy, including immune-mediated events, infusion reactions, and myelosuppression. No unexpected safety signals were reported, confirming the feasibility of this regimen in a platinum-resistant population.

Clinical Implications

KEYNOTE-B96 demonstrates a clinically meaningful improvement in both Progression-Free and Overall Survival, representing one of the longest reported OS durations in platinum-resistant ovarian cancer. The regimen leverages the immune-modulating effects of weekly Paclitaxel and the potential vascular-normalizing and immunosuppressive effects of Bevacizumab, addressing multiple barriers to effective immune activation.

These results support PD-L1 CPS as a predictive biomarker while emphasizing the importance of integrating immunotherapy with established chemotherapy backbones. The findings provide a foundation for sequencing this strategy alongside emerging therapies, including antibody-drug conjugates and other targeted agents, in this difficult-to-treat population.

Conclusion

KEYNOTE-B96 establishes Pembrolizumab plus weekly Paclitaxel, with or without Bevacizumab, as a viable and effective treatment option for patients with platinum-resistant ovarian cancer, delivering meaningful improvements in survival with a manageable safety profile. This trial highlights the potential of immunotherapy combinations in a disease historically considered immunologically “cold” and provides a new evidence-based option in a setting of high unmet need.

Pembrolizumab vs placebo plus weekly paclitaxel ± bevacizumab in platinum-resistant recurrent ovarian cancer: Results from the randomized double-blind phase 3 ENGOT-ov65/KEYNOTE-B96 study. Colombo N, Zsiros E, Sebastianelli A, et al. Presented at: European Society of Medical Oncology Congress 2025; October 17–20, 2025; Berlin, Germany. Abstract LBA3.

TRODELVY® plus KEYTRUDA® in Metastatic Triple Negative Breast Cancer

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that in the US, approximately 321,910 new cases of female breast cancer will be diagnosed in 2026, and about 42,140 women will die of the disease, largely due to metastatic recurrence.

The Persistent Therapeutic Gap in Metastatic TNBC

Triple-Negative Breast Cancer (TNBC) which accounts for roughly 10-15% of breast cancers remains one of the most biologically aggressive breast cancer subtypes, defined by the absence of estrogen and progesterone receptor expression and lack of HER2 overexpression. Despite therapeutic advances, metastatic TNBC carries a dismal prognosis, with 5-year relative survival rates near 15%.

Approximately 40% of TNBC tumors express PD-L1 (combined positive score [CPS] ≥10). Based on results from KEYNOTE-355, the combination of Pembrolizumab (KEYTRUDA®) and chemotherapy (Taxane or Gemcitabine–Carboplatin backbone) became the standard first-line regimen for PD-L1–positive metastatic TNBC, improving both Progression-Free Survival (PFS) and Overall Survival (OS), compared with chemotherapy alone.

However, Real-World Data suggest that nearly half of patients with metastatic TNBC do not receive therapy beyond first line due to rapid progression or early mortality. This underscores the importance of maximizing disease control early in the treatment course.

The Rationale for ADC–Immunotherapy Combination

Sacituzumab govitecan (TRODELVY®) is a Trop-2–directed Antibody–Drug Conjugate (ADC) delivering the topoisomerase I inhibitor SN-38 via a hydrolyzable linker. It previously demonstrated significant survival benefit over chemotherapy in heavily pretreated metastatic TNBC (ASCENT), as well as significantly prolonged Progression-Free Survival compared with standard chemotherapy in the first-line treatment of advanced or metastatic TNBC among patients who are not candidates for PD-1/PD-L1 inhibitors (ASCENT-03).

Given the complementary mechanisms of cytotoxic payload delivery and immune checkpoint inhibition, combining Sacituzumab govitecan with Pembrolizumab represents a biologically compelling strategy to deepen and prolong response in earlier lines of therapy.

ASCENT-04/KEYNOTE-D19: Trial Design

ASCENT-04/KEYNOTE-D19 is a global, randomized, open-label Phase 3 trial conducted across 186 sites in 28 countries.

Eligible patients included:

  • Adults with locally advanced unresectable or metastatic TNBC
  • No prior therapy for advanced disease
  • PD-L1–positive tumors (CPS ≥10, centrally confirmed using PD-L1 IHC 22C3 pharmDx assay)

A total of 443 patients were randomized 1:1:

  • Sacituzumab govitecan (10 mg/kg IV days 1 and 8, q21 days) plus Pembrolizumab (200 mg IV q3 weeks)
  • Physician’s choice chemotherapy plus Pembrolizumab

Stratification factors included:

  • Disease status (de novo metastatic vs. early relapse)
  • Geographic region
  • Prior exposure to anti–PD-1/PD-L1 therapy in curative-intent setting

The Primary endpoint was PFS by Blinded Independent Central Review. Secondary endpoints included OS, Objective Response Rate (ORR), Duration of Response (DoR), and Safety.

Efficacy Outcomes

At a median follow-up of 14 months, the study met its Primary endpoint.

  • Median PFS:
    • 11.2 months with Sacituzumab govitecan plus Pembrolizumab
    • 7.8 months with chemotherapy plus Pembrolizumab
  • Hazard Ratio for progression or death: 0.65 (95% CI, 0.51–0.84; P<0.001)

Investigator-assessed PFS results were concordant. The PFS benefit was consistent across predefined subgroups, including patients with liver metastases and those with early relapse (6–12 months after curative-intent therapy). Notably, median PFS approached one year with the ADC–immunotherapy combination, exceeding historical benchmarks from chemo-immunotherapy trials in this setting.

  • ORR:
    • 60% with Sacituzumab govitecan plus Pembrolizumab
    • 53% with chemotherapy plus Pembrolizumab
  • Complete Response rate: 13% vs. 8%
  • Median Duration of Response:
    • 16.5 months vs. 9.2 months

Although formal hypothesis testing was not performed for secondary endpoints, responses with the ADC combination were notably more durable. Importantly, despite a higher-than-expected ORR in the control arm, responses with chemotherapy were less sustained, likely explaining the PFS separation.

OS data remain immature at this analysis (26% event rate), with medians not yet reached in either arm.

Safety and Treatment Adherence

Grade ≥3 adverse events occurred at similar rates in both groups (about 70%). However, treatment discontinuation due to adverse events was substantially lower with the ADC combination (12% vs. 31%). This difference may reflect the nature of toxicities. ADC-associated events such as diarrhea are generally manageable with supportive care, whereas chemotherapy-related toxicities such as neuropathy may be cumulative and less reversible. Adverse events leading to death occurred in 3% of patients in each arm.

Clinical Interpretation

ASCENT-04/KEYNOTE-D19 establishes the first positive Phase 3 data evaluating an ADC combined with immunotherapy in the frontline treatment of PD-L1–positive metastatic TNBC.

The magnitude of PFS benefit (HR 0.65), prolonged response durability, and lower discontinuation rate suggest that Sacituzumab govitecan plus Pembrolizumab may represent an evolution of first-line therapy in this population.

Given that many patients will not reach subsequent lines of treatment, intensifying effective therapy upfront is clinically meaningful. The ADC backbone may offer sustained tumor control beyond what is achievable with chemotherapy-based combinations.

Limitations and Ongoing Questions

Key limitations include:

  • Open-label design
  • Crossover to Sacituzumab govitecan in the control arm
  • Immature OS data
  • Limited representation of patients previously treated with adjuvant immunotherapy

Future analyses will clarify survival impact and optimal sequencing, particularly as additional ADCs enter earlier lines of therapy. Ongoing trials such as ASCENT-05 (NCT05633654) and SASCIA (NCT04595565) are evaluating Sacituzumab govitecan in high-risk early-stage settings, potentially broadening its therapeutic footprint.

Bottom Line for Practice

For patients with previously untreated, PD-L1–positive, locally advanced unresectable or metastatic TNBC, Sacituzumab govitecan plus Pembrolizumab significantly prolongs Progression-Free Survival compared with chemotherapy plus Pembrolizumab, with durable responses and manageable toxicity.

These findings position ADC–immunotherapy combinations as a potential new backbone strategy in frontline TNBC management, pending maturation of Overall Survival data.

Sacituzumab Govitecan plus Pembrolizumab for Advanced Triple-Negative Breast Cancer. Tolaney SM, de Azambuja E, Kalinsky K, et al. for the ASCENT-04/KEYNOTE-D19 Clinical Trial Investigators. N Engl J Med 2026;394:354-366.

Final Overall Survival Results from the EMBARK trial: Practice-Changing Evidence in High-Risk Biochemical Recurrence

RR

SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with Prostate cancer during their lifetime. It is estimated that in the United States, about 333,830 new cases of Prostate cancer will be diagnosed in 2026 and 36,320 men will die of the disease. Androgen Deprivation Therapy (ADT) or testosterone suppression has been the cornerstone of treatment of advanced Prostate cancer, and is the first treatment intervention.

The major source of PSA (Prostate Specific Antigen) is the prostate gland, and the PSA levels are therefore undetectable within 6 weeks after Radical Prostatectomy. Similarly, following radiation therapy there is a gradual decline in PSA, before reaching a post treatment nadir. A detectable PSA level after Radical Prostatectomy, or a rising PSA level following radiation therapy, is considered PSA failure or biochemical recurrence. Approximately 35% of the patients with prostate cancer will experience PSA only relapse within 10 years of their primary treatment, and a third of these patients will develop documented metastatic disease within 8 years following PSA only relapse. Rising PSA is therefore a sign of recurrent disease. Patients with biochemically relapsed prostate cancer following local therapy, and a short PSA doubling time, are at risk for distant metastases.

Enzalutamide (XTANDI®) is a potent oral Androgen Receptor Pathway Inhibitor with demonstrated efficacy in patients with both localized and advanced prostate cancer.

EMBARK is a randomized, double-blind, placebo-controlled, multi-national, Phase III trial, conducted to evaluate the efficacy and safety of Enzalutamide plus Leuprolide and Enzalutamide monotherapy, as compared with Leuprolide alone, in patients with non-metastatic Hormone/Castration-Sensitive Prostate Cancer (nmHSPC or nmCSPC) prostate cancer, who have had high-risk biochemical recurrence. In this study, a total of 1068 eligible patients were randomly assigned 1:1:1 to receive Enzalutamide at 160 mg orally once daily plus Leuprolide IM every 12 weeks (N=355), single agent Enzalutamide at 160 mg orally once daily (N=355) or Leuprolide alone (N=358). All patients had received prior definitive therapy with radical prostatectomy and/or radiotherapy with curative intent. High risk disease was defined as a PSA doubling time of 9 months or less and a PSA level of 2 ng/ml above nadir after radiation therapy, or 1 ng/ml or more after radical prostatectomy with or without postoperative radiation therapy. The baseline characteristics were well balanced among the treatment groups. The median age was 69 years, the median PSA doubling time was 4.9 months and the median PSA level was 5.2 ng/ml. The Primary end point was Metastasis-Free Survival (MFS), as assessed by Blinded Independent Central Review (BICR) in the combination group, as compared with the Leuprolide-alone group. MFS is defined as the duration of time in months between randomization and the earliest objective evidence of radiographic progression by central imaging or death due to any cause, whichever occurred first. Secondary end points included MFS in the Enzalutamide monotherapy group, as compared with the Leuprolide-alone group, Overall Survival (OS), Patient-Reported Outcomes and Safety.

At a median follow up 60.7 months, the 5 year MFS was 87.3% in the Enzalutamide combination group and 71.4% with Leuprolide alone (HR for metastasis or death 0.42; P<0.001). This represented a 58% lower risk of metastasis or death in the combination group than Leuprolide alone among patients with biochemically recurrent prostate cancer. At the time of this analysis, Overall Survival data were immature.

In this publication, the final Overall Survival (OS) analysis of the Phase 3 EMBARK trial provided compelling long-term evidence supporting intensified Androgen-Receptor Pathway Inhibition in patients with high-risk biochemical recurrence of prostate cancer and no evidence of metastasis on conventional imaging. At the time of this final analysis, 277 deaths had occurred: 73 in the combination arm, 111 in the Leuprolide-alone arm, and 93 in the Enzalutamide monotherapy arm. Median follow-up exceeded 93 months across all treatment groups, offering a robust long-term perspective on survival outcomes.

Overall Survival: Durable and Clinically Meaningful Benefit

The combination of Enzalutamide plus Leuprolide demonstrated a statistically and clinically significant improvement in OS compared with Leuprolide alone:

  • 8-year OS:
    • 78.9% (95% CI, 73.9–83.1) with combination therapy
    • 69.5% (95% CI, 64.0–74.3) with Leuprolide alone
  • Hazard ratio for death: 0.60 (95% CI, 0.44–0.80; P<0.001)

This 40% relative reduction in mortality risk translates into an absolute improvement of nearly 10% at 8 years, a notable achievement in a population historically managed with Androgen Deprivation Therapy (ADT) alone.

By contrast, Enzalutamide monotherapy did not significantly improve OS relative to Leuprolide alone:

  • 8-year OS: 73.1% (95% CI, 67.6–77.9)
  • Hazard ratio: 0.83 (95% CI, 0.63–1.10; P=0.19)

While monotherapy previously demonstrated improvements in key Secondary endpoints, including Metastasis-Free Survival, it did not confer a statistically significant survival advantage in this final OS analysis.

Descriptive updates of Secondary endpoints were consistent with earlier reports. Time to first use of new antineoplastic therapy and time to first symptomatic skeletal event continued to favor combination therapy.

Although fractures were numerically more frequent in the combination arm, this reflected a broader category of bone and joint injuries. Importantly, the time to first symptomatic skeletal event was prolonged with Enzalutamide plus Leuprolide compared with Leuprolide alone, suggesting lower clinically meaningful skeletal morbidity despite the higher overall reporting of fractures.

Safety Profile: No New Signals

The long-term safety data remained consistent with earlier analyses. No new safety signals emerged, and the adverse-event profile of Enzalutamide, whether used in combination or as monotherapy, aligned with prior experience in metastatic castration-resistant and metastatic castration-sensitive prostate cancer settings.

Clinical Context: Imaging Evolution and Treatment Implications

Interpretation of these results must consider the evolving imaging landscape. At the time of trial enrollment, staging relied on CT or MRI for soft-tissue assessment and radionuclide bone scans for osseous disease. With the increasing use of PSMA PET imaging, it is likely that a proportion of patients categorized as nonmetastatic in the trial may have harbored occult locoregional or oligometastatic disease detectable by more sensitive modalities. Nevertheless, the study reflects real-world practice standards at the time and provides a pragmatic framework for treatment decision-making in high-risk biochemical recurrence.

Treatment Suspension Strategy: A Unique Feature

An important protocol component was treatment suspension at week 37 for patients achieving undetectable PSA (<0.2 ng/mL), with reinitiation upon PSA rise to predefined thresholds. This strategy aimed to mitigate toxicity and preserve quality of life. Notably, the OS benefit of combination therapy was achieved despite these mandated treatment interruptions.

Future research should clarify:

  • Which patients may safely undergo treatment suspension,
  • Whether continuous therapy could further optimize outcomes in select populations,
  • And how molecular imaging findings should inform early intensification strategies.

Positioning in the Treatment Paradigm

The final OS data reinforce earlier MFS findings and establish Enzalutamide plus ADT as a preferred standard of care for patients with Castration-Sensitive Prostate Cancer and high-risk biochemical recurrence without conventional radiographic metastases.

Although Enzalutamide monotherapy remains a reasonable option, particularly for patients prioritizing preservation of sexual function based on patient-reported outcomes, shared decision-making remains essential, balancing efficacy, toxicity, and quality-of-life considerations.

Conclusion

With nearly eight years of follow-up, the EMBARK trial confirms that intensification of Androgen-Receptor Pathway Inhibition with Enzalutamide plus Leuprolide delivers a durable Overall Survival advantage in high-risk biochemical recurrence. These findings extend the survival benefits observed with Enzalutamide across earlier disease states and further reshape management strategies in this evolving therapeutic space.

Improved Survival with Enzalutamide in Biochemically Recurrent Prostate Cancer. Shore ND, Luz MA, Giorgi UD, et al. N Engl J Med 2026;394:563-575.

Redefining First-Line Maintenance in HR-Positive, HER2-Positive Metastatic Breast Cancer

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that in the US, approximately 321,910 new cases of female breast cancer will be diagnosed in 2026, and about 42,140 women will die of the disease, largely due to metastatic recurrence.

Breast cancer remains a biologically heterogeneous disease, with approximately 70% of tumors expressing estrogen receptors (ER) and/or progesterone receptors (PR). Among patients with metastatic disease, Hormone Receptor (HR)–positive, HER2-negative tumors represent the most common subtype. However, 15%–20% of primary breast cancers overexpress HER2, a historically aggressive phenotype. Notably, more than half of HER2-positive tumors also coexpress hormone receptors, creating a biologically distinct subgroup characterized by signaling interplay between the HER2 and estrogen receptor pathways.

For patients with HR-positive, HER2-positive metastatic breast cancer, the current first-line standard consists of induction chemotherapy combined with dual HER2 blockade (Trastuzumab-HERCEPTIN® and Pertuzumab-PERJETA®), followed by maintenance HER2-targeted therapy plus endocrine therapy. While this approach has significantly improved outcomes, resistance remains inevitable for most patients. Preclinical data have consistently demonstrated bidirectional crosstalk between HER2 and ER signaling, as well as persistent activation of the cyclin D1–CDK4/6 axis, which may drive resistance to both endocrine and HER2-directed therapies. These mechanistic insights provided the scientific rationale for evaluating triple pathway inhibition, simultaneous targeting of HER2, ER, and CDK4/6 in this population.

Biological Rationale for CDK4/6 Inhibition

Cyclin-Dependent Kinases 4 and 6 (CDK4/6) regulate orderly progression from the G1 to S phase of the cell cycle through phosphorylation of the retinoblastoma (RB) protein. Aberrant activation of this pathway is implicated in tumor proliferation and therapeutic resistance across multiple breast cancer subtypes, including HER2-positive disease.

Palbociclib (IBRANCE®), an oral selective CDK4/6 inhibitor, suppresses RB phosphorylation and arrests cell-cycle progression. Preclinical HER2-positive models have demonstrated that sustained cyclin D1–CDK4/6 activity contributes to resistance to HER2-targeted therapies, and dual inhibition of CDK4/6 and HER2 has shown synergistic antitumor effects. Early-phase clinical studies further suggested that combining CDK4/6 inhibition with HER2-directed and endocrine therapy was feasible and potentially additive in efficacy. These findings led to the Phase 3 PATINA trial.

The PATINA Trial: Study Design

PATINA was an open-label, randomized Phase 3 study evaluating whether adding Palbociclib to maintenance therapy could extend disease control in patients with HR-positive, HER2-positive metastatic breast cancer.

Eligibility and Treatment Approach

Patients were enrolled after completing 4 to 8 cycles of induction chemotherapy plus HER2-targeted therapy without disease progression. Key eligibility criteria included:

  • HR positivity (≥1% nuclear staining by IHC)
  • HER2 positivity (IHC 3+ or ISH amplification per ASCO/CAP guidelines)
  • No prior systemic therapy for metastatic disease beyond induction
  • A disease-free interval ≥6 months after prior adjuvant HER2 therapy

A total of 518 patients were randomized 1:1:

  • Palbociclib arm (n=261): Maintenance HER2-targeted therapy + endocrine therapy + Palbociclib (125 mg orally, 21 days on/7 days off; dose reductions permitted)
  • Standard arm (n=257): Maintenance HER2-targeted therapy + endocrine therapy

Baseline characteristics were balanced. The median age was 53.4 years; 99% were female; 61.8% were postmenopausal. Importantly, 54.4% had de novo metastatic disease. The Primary endpoint was investigator-assessed Progression-Free Survival (PFS). Secondary endpoints included Objective Response, clinical benefit, safety, and Overall Survival.

Efficacy Outcomes: A Meaningful Extension of Disease Control

At a median follow-up of 53.5 months, the addition of Palbociclib resulted in a statistically and clinically significant improvement in PFS. The median PFS was 44.3 months in the Palbociclib group and 29.1 months in the standard therapy group (HR=0.75; P=0.02). The estimated PFS rates favored the Palbociclib arm over standard therapy at all measured time points and was 84.9% versus 73.2% at 12 months, 65,2% versus 55.3% at 24 months, and 46.5% versus 38.3% at 48 months respectively.

The depth and durability of response were also enhanced:

  • Confirmed response rate: 32.9% vs. 24.8%
  • Complete response rate: 14.3% vs. 11.3%
  • Median duration of confirmed response: 44.9 vs. 30.8 months

Importantly, when the induction phase is included, total first-line disease control in the Palbociclib arm extended beyond four years. Early mortality was uncommon, with 6-month Overall Survival exceeding 99% in both groups, reflecting favorable biology among patients who completed induction therapy.

The control arm’s median PFS of 29 months exceeded initial projections, likely reflecting mandated endocrine therapy use and the exclusion of patients who progressed during induction, factors that enriched the study population for more favorable disease biology.

Safety Profile

The safety findings were consistent with known toxicities of Palbociclib and HER2-targeted therapies. Neutropenia was the predominant toxicity and febrile neutropenia was rare. Grade 3 and Grade 4 adverse events were 79.7% and 10% in the Palbociclib group versus 30.6% and 3.6% in the standard therapy group.

Clinical Implications

The PATINA trial supports a paradigm shift in the maintenance setting for HR-positive, HER2-positive metastatic breast cancer. By targeting HER2, Estrogen Receptor signaling, and CDK4/6-mediated cell-cycle progression concurrently, this strategy addresses key resistance mechanisms.

Achieving a median PFS exceeding 44 months represents a meaningful advance in a disease subtype historically associated with aggressive biology. While antibody–drug conjugates and other potent HER2-directed agents remain appropriate for selected high-risk patients, this chemotherapy-sparing maintenance intensification strategy provides durable disease control in a substantial proportion of patients.

The open-label design and limited racial diversity are important considerations. Additional analyses evaluating patient-reported outcomes, biomarker correlates, and central nervous system outcomes are ongoing and may further refine patient selection.

Conclusion

The addition of Palbociclib to maintenance anti-HER2 and endocrine therapy significantly prolongs Progression-Free Survival in patients with HR-positive, HER2-positive advanced breast cancer, albeit with increased, but manageable, hematologic toxicity. Triple pathway inhibition targeting HER2, estrogen receptor, and CDK4/6 signaling may now represent a compelling first-line maintenance strategy capable of extending disease control beyond four years in appropriately selected patients.

Palbociclib for Hormone-Receptor–Positive, HER2-Positive Advanced Breast Cancer. Metzger O, Mandrekar S, Goel S, et al. N Engl J Med 2026;394:451-462

Late Breaking Abstract – 2026 ASCO GI Symposium: Redefining First-Line Therapy in HER2-Positive Gastroesophageal Adenocarcinoma with Zanidatamab-Based Combinations

RR

SUMMARY: The American Cancer Society estimates that in the US, about 31,510 new cases of Gastric cancer will be diagnosed in 2026 and about 10,740 people will die of the disease. It is one of the leading causes of cancer-related deaths in the world. Several hereditary syndromes such as Hereditary Diffuse Gastric Cancer (HDGC), Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer) and Familial Adenomatous Polyposis (FAP) have been associated with a predisposition for stomach cancer. Additionally, one of the strongest risk factor for Gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium.

Persistent Unmet Need in HER2-Positive Disease

The Human Epidermal growth factor Receptor (HER) or erbB family of receptors, consist of HER1, HER2, HER3 and HER4. Approximately 20% of patients with GastroEsophageal Adenocarcinoma (GEA), encompassing gastric, gastroesophageal junction, and esophageal adenocarcinomas, harbor HER2-positive tumors. Despite the incorporation of HER2-directed therapy into first-line management more than a decade ago, long-term outcomes remain suboptimal. With Trastuzumab (HERCEPTIN®) plus chemotherapy, median Progression-Free Survival (PFS) has historically hovered around 10 months, and median Overall Survival (OS) around 20 months.

More recently, the addition of immune checkpoint inhibition has modestly improved outcomes in selected patients. Based on KEYNOTE-811, Pembrolizumab (KEYTRUDA®) plus Trastuzumab and chemotherapy is now standard for PD-L1–positive tumors. However, early relapse, often within the first year, remains common, underscoring the need for more effective HER2-targeted strategies.

Zanidatamab: A Next-Generation HER2-Targeted Approach

Preclinical and clinical data suggest greater antibody saturation on HER2-expressing tumor cells than with Trastuzumab or Pertuzumab (PERJETA®).

Zanidatamab (ZIIHERA®) is a novel, humanized IgG1 bispecific monoclonal antibody designed to bind two non-overlapping extracellular domains of HER2 (ECD2 and ECD4). This biparatopic binding leads to enhanced HER2 receptor clustering, internalization, and downregulation, resulting in more complete inhibition of HER2 signaling compared with single-epitope antibodies. Beyond direct signal blockade, Zanidatamab’s unique binding geometry promotes robust immune-mediated antitumor activity, including Complement-Dependent Cytotoxicity (CDC), Antibody-Dependent Cellular Cytotoxicity (ADCC), and Antibody-Dependent Cellular Phagocytosis (ADCP).

Zanidatamab’s clinical momentum was reinforced by its FDA accelerated approval in November 2024 for previously treated, unresectable or metastatic HER2-positive biliary tract cancer, highlighting the platform’s broader relevance across HER2-driven gastrointestinal malignancies.

Rationale for Combining HER2 Blockade and Immunotherapy

The HERIZON-GEA-01 trial also explored synergy between dual HER2 targeting and immune checkpoint inhibition. Tislelizumab (TEVIMBRA®), a humanized IgG4 anti-PD-1 monoclonal antibody, is engineered to minimize Fc-gamma receptor binding on macrophages, potentially reducing antibody-dependent clearance of activated T cells. Tislelizumab received FDA approval in March 2024 for previously treated metastatic esophageal Squamous Cell Carcinoma, supporting its activity in upper gastrointestinal cancers.

HERIZON-GEA-01: Trial Design and Patient Population

HERIZON-GEA-01 (NCT05152147) is a global, open-label, Phase III study evaluating Zanidatamab-based regimens versus standard Trastuzumab plus chemotherapy in the first-line setting for HER2-positive metastatic GEA (GastroEsophageal Adenocarcinoma).

A total of 914 patients with unresectable, locally advanced, recurrent, or metastatic disease were enrolled between December 2021 and February 2025. More than two-thirds had gastric primaries. Patients had received no prior systemic therapy, HER2-targeted therapy, or immunotherapy in this setting.

Participants were randomized 1:1:1 to:

  • Arm A: Trastuzumab plus chemotherapy
  • Arm B: Zanidatamab plus chemotherapy
  • Arm C: Zanidatamab plus Tislelizumab plus chemotherapy

CAPOX was the chemotherapy backbone in approximately 90% of patients. Zanidatamab-based regimens in Arm B and Arm C were compared with standard Trastuzumab plus chemotherapy in Arm A. The dual Primary endpoints were PFS by Blinded Independent Review and OS.

Efficacy Results: Clinically Meaningful and Practice-Changing

At the interim analysis (data cutoff October 2025; median follow-up 26 months), there was a clear and consistent improvement in Progression-Free Survival with Zanidatamab-based therapy compared with Trastuzumab plus chemotherapy. Median PFS reached 12.4 months with Zanidatamab plus chemotherapy and 12.4 months with Zanidatamab plus Tislelizumab and chemotherapy, compared with 8.1–8.2 months in the Trastuzumab control arm. These gains translated into a 35–37% reduction in the risk of disease progression or death, with Hazard Ratios of 0.65 for Zanidatamab plus chemotherapy and 0.63 for the triplet regimen (both P <0.0001). Importantly, the separation of the PFS curves was maintained over time, highlighting the durability of benefit. The 1-year PFS was 38.0% with Zanidatamab plus chemotherapy and 43.9% with the triplet, versus 20.9% and 38.2% respectively with Trastuzumab-based therapy. The 2-year PFS was 31.5% and 20.9%, respectively, compared with 15.6% in the Trastuzumab group. These findings mark the first time a majority of patients receiving first-line HER2-targeted therapy remain progression-free at one year, a notable advance in a disease historically characterized by early relapse.

Median OS improved from 19.2 months with Trastuzumab plus chemotherapy to 24.4 months with Zanidatamab plus chemotherapy and 26.4 months with Zanidatamab plus Tislelizumab and chemotherapy. The addition of Tislelizumab yielded a statistically significant 28% reduction in the risk of death (HR 0.72; P =0.0043). While OS data for Zanidatamab plus chemotherapy alone were not yet statistically significant at this interim analysis (HR 0.80; P =0.0564), the observed survival extension of more than five months suggests meaningful clinical activity, with further analyses planned as follow-up matures. The 2-year OS was 50.3% with Zanidatamab plus chemotherapy and 54.3% with the triplet, versus 42.2% and 43.8% respectively with Trastuzumab-based therapy. The 30-month OS was 38.8% and 43.8%, respectively, compared with 30.0% in the Trastuzumab group.

Notably, the triplet regimen is the first HER2-directed first-line strategy to achieve median Overall Survival exceeding two years in a randomized phase III trial. Further, the benefits in both PFS and OS were consistent across key subgroups, including geographic region and PD-L1 status, an especially notable finding given that checkpoint inhibitor benefit has traditionally been restricted to PD-L1–positive tumors.

Depth and Durability of Response

Zanidatamab-based regimens also produced deeper and more durable responses. Confirmed Objective Response Rates approached 70% in both Zanidatamab arms, with Complete Response rates nearing 20% when Tislelizumab was added. Median duration of response was particularly striking, exceeding 20 months with the triplet regimen and substantially longer than the 8-month duration observed with Trastuzumab plus chemotherapy.

Safety and Tolerability

The safety profiles of Zanidatamab and Tislelizumab were consistent with their known toxicities. Grade ≥3 treatment-related adverse events occurred in approximately 59% of patients receiving Zanidatamab plus chemotherapy and 72% with the addition of Tislelizumab, compared with 60% in the Trastuzumab arm.

Diarrhea was the most common toxicity across all arms, typically occurring early and resolving within several weeks. Rates of HER2-targeted therapy discontinuation due to adverse events were higher with Zanidatamab-based regimens but remained manageable, with no new safety signals identified.

Clinical Implications and Future Directions

HERIZON-GEA-01 represents a landmark study in HER2-positive gastroesophageal adenocarcinoma. It is the first phase III trial to demonstrate superiority of a novel HER2-targeted agent over Trastuzumab in the first-line metastatic setting, and the first to achieve median PFS beyond one year and median OS beyond two years in this population.

While cross-trial comparisons should be interpreted cautiously, outcomes with Zanidatamab plus Tislelizumab and chemotherapy compare favorably with historical results from KEYNOTE-811. The observation of benefit irrespective of PD-L1 status further broadens the potential impact of this strategy.

As longer follow-up matures and guideline bodies evaluate these data, Zanidatamab, particularly in combination with immunotherapy appears poised to redefine the standard of care for HER2-positive metastatic gastroesophageal adenocarcinoma, offering patients a meaningful extension of disease control and survival.

Zanidatamab + chemotherapy ± tislelizumab for first-line HER2-positive locally advanced, unresectable, or metastatic gastroesophageal adenocarcinoma: Primary analysis from HERIZON-GEA-01. Elimova E, Rha SY, Shitara K, et al. 2026 ASCO Gastrointestinal Cancers Symposium. Abstract LBA285. Presented January 8, 2026.

Reconsidering Menopausal Hormone Therapy in BRCA1/2 Carriers: Emerging Evidence Challenges Longstanding Concerns

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that in the US, approximately 321,910 new cases of female breast cancer will be diagnosed in 2026, and about 42,140 women will die of the disease, largely due to metastatic recurrence.

The tumor suppressor genes such as BRCA1 and BRCA2 help repair damaged DNA and thus play an important role in maintaining cellular genetic integrity, failing which these genetic aberrations can result in malignancies. Mutations in BRCA1 and BRCA2 account for about 20 to 25 percent of hereditary breast cancers and about 5 to 10 percent of all breast cancers. These mutations can be inherited from either of the parents and a child has a 50 percent chance of inheriting this mutation, and the deleterious effects of the mutations are seen even when a second copy of the gene in an individual is normal. Women with germline BRCA1 or BRCA2 mutations face markedly elevated lifetime risks of breast cancer, estimated at up to 70%. More than half of these cancers occur before the age of 50, underscoring the importance of informed counseling regarding risk-modifying exposures. 

For much of the latter half of the 20th century, Hormone Replacement Therapy (HRT) was widely prescribed to alleviate menopausal symptoms and protect against long-term complications such as osteoporosis. This practice shifted dramatically in 2002, when the Women’s Health Initiative reported increased risks of cardiovascular events and breast cancer associated with hormone therapy in older, postmenopausal women. In the aftermath, both patients and clinicians largely retreated from Menopausal Hormone Therapy (MHT), and its use declined sharply.

While those findings reshaped care in the general population, their applicability to women with hereditary cancer predisposition, particularly carriers of pathogenic BRCA1 or BRCA2 variants, has remained uncertain. These women face markedly elevated risks of ovarian and fallopian tube cancers and are therefore advised to undergo risk-reducing bilateral salpingo-oophorectomy at relatively young ages. The procedure is effective for cancer prevention but induces abrupt surgical menopause, often decades earlier than natural menopause, with well-documented short- and long-term consequences including vasomotor symptoms, sexual dysfunction, bone loss, and adverse cardiovascular and cognitive effects.

Menopausal Hormone Therapy (MHT) is the most effective intervention for mitigating these outcomes of early menopause. However, concerns that hormone exposure could further increase breast cancer risk in BRCA carriers have led to substantial hesitation, misinformation, and, in many cases, prolonged untreated symptoms. Researchers have emphasized, recommending premenopausal oophorectomy without offering a safe strategy to manage its consequences creates an untenable clinical dilemma.

Study Design: Emulating a Trial in a High-Risk Population

To address this evidence gap, investigators conducted the largest prospective matched analysis to date examining MHT use and breast cancer risk in BRCA1 and BRCA2 carriers. Using data from a longitudinal cohort, the study sought to emulate a randomized clinical trial by carefully matching women who initiated MHT after menopause, predominantly surgical menopause, to those who did not.

Eligible participants had no prior cancer history, no bilateral mastectomy, and had entered menopause. A total of 676 matched pairs were created, matched one-to-one by gene mutation (BRCA1 or BRCA2), year of birth, and age at menopause. Participants ranged in age from 22 to 76 years, with a mean age of 43.8 years. MHT formulations initiated after menopause included estrogen-only therapy, combined estrogen–progestogen therapy, progestogen alone, tibolone, and conjugated equine estrogen plus bazedoxifene. Cox proportional hazards models were used to estimate breast cancer risk.

Results: No Signal of Increased Breast Cancer Risk

After a mean follow-up of 5.6 years from the date of first MHT use, breast cancer incidence was significantly lower among women who used MHT compared with their matched, unexposed counterparts. Incident breast cancer occurred in 12.9% of MHT users versus 18.9% of non-users (P = 0.002).

Notably, estrogen-only therapy was associated with a substantial reduction in breast cancer risk, corresponding to a 63% relative decrease compared with non-users. In contrast, no increased or decreased risk was observed with combined estrogen–progestogen therapy, progestogen monotherapy, or tibolone. Among the 43 women who received conjugated equine estrogen plus bazedoxifene, no breast cancer diagnoses were reported during follow-up, an exploratory finding that warrants further investigation. Importantly, risk estimates were consistent across BRCA1 and BRCA2 carriers, underscoring the relevance of these findings across mutation subtypes.

Clinical Implications

These data provide critical reassurance for clinicians managing young women with hereditary breast and ovarian cancer syndromes. In contrast to earlier studies conducted in the general population, MHT use in BRCA1/2 carriers was not associated with an increased risk of breast cancer, regardless of formulation. Estrogen-only regimens, in particular, appeared protective, although causality cannot be inferred.

While limitations include a relatively modest follow-up duration and small numbers in certain subgroups, this prospective analysis offers the strongest evidence to date supporting the safety of MHT in this high-risk population. The findings reinforce the need for individualized, evidence-based counseling that balances cancer risk reduction with quality-of-life preservation.

Moving Forward

As MHT formulations continue to evolve, ongoing research will be essential to refine risk stratification and optimize menopause management strategies in BRCA mutation carriers. For now, these results support a personalized approach to MHT use in women experiencing surgical or natural menopause after risk-reducing oophorectomy, provided there are no contraindications. For many patients, informed use of MHT may offer not only symptom relief, but also a path toward improved long-term health and wellbeing without compromising breast cancer risk.

GS3-01. Menopausal Hormone Therapy and the Risk of Breast Cancer in Women with a Pathogenic Variant in BRCA1 or BRCA2. Kotsopoulos J, Seca M, Jacek G, et al. Presented at the 2025 San Antonio Breast Cancer Symposium (SABCS; Abstract GS3-01). 

Exploring GLP-1 Receptor Agonists as a Novel Adjunct in Sickle Cell Disease

RR

SUMMARY: Sickle Cell Disease (SCD) or Sickle Cell anemia is an Autosomal Recessive disorder caused by mutations in the hemoglobin beta-globin gene, and affects approximately 100,000 Americans. It is estimated that it affects 1 out of every 365 African-American births and 1 out of every 16,300 Hispanic-American births. The average life expectancy for patients with Sickle Cell Disease in the US is approximately 40-60 years.

HbSS disease or Sickle Cell anemia is the most common Sickle Cell Disease genotype and is associated with the most severe manifestations. HbSS disease is caused by a mutation substituting thymine for adenine in the sixth codon of the beta-globin chain gene. This in turn affects the hemoglobin’s ability to carry oxygen and causes it to polymerize. This results in decreased solubility thereby distorting the shape of the red blood cells, increasing their rigidity and resulting in red blood cells that are sickle shaped rather than biconcave. These sickle shaped red blood cells limit oxygen delivery to the tissues by restricting the flow in blood vessels, leading to severe pain and organ damage (Vaso-Occlusive Crises). Oxidative stress is an important contributing factor to hemoglobin polymerization with polymer formation occurring only in the deoxy state. HbS/b-0 Thalassemia (double heterozygote for HbS and b-0 Thalassemia) is clinically indistinguishable from HbSS disease. Management of Sickle Cell Disease includes pain control, transfusion support and Hydroxyurea. None of the presently available therapies addresses the underlying cause of this disease nor do they fully ameliorate disease manifestations. Allogeneic bone marrow transplantation can cure this genetic disorder, but less than 20% of eligible patients have a related HLA-matched donor. There is therefore a great unmet need to find new therapies for Sickle Cell Disease.

Background: Inflammation and Vasculopathy at the Core of SCD

Sickle cell disease (SCD) is defined by chronic hemolysis, recurrent vaso-occlusion, and a persistent thrombo-inflammatory state. These processes drive episodic pain crises, progressive end-organ damage, cardiopulmonary complications, and premature mortality. Despite advances in disease-directed therapies, vascular dysfunction, oxidative stress, and systemic inflammation remain central, and incompletely addressed features of SCD pathophysiology.

Glucagon-Like Peptide-1 receptor agonists (GLP-1a), widely used in metabolic disease, have demonstrated pleiotropic effects beyond glycemic control. Preclinical and translational studies suggest GLP-1a exert anti-inflammatory, endothelial-protective, and antithrombotic effects through modulation of NF-κB, ERK/AMPK, and JAK/STAT signaling pathways, suppression of oxidative stress, macrophage polarization, and reduced platelet aggregation. Importantly, GLP-1 receptor activation in monocytes, macrophages, and neutrophils has been shown to attenuate NF-κB signaling and limit NLRP3 inflammasome priming, mechanisms highly relevant to SCD biology. Given these overlapping pathways of vascular injury and inflammation in SCD, investigators hypothesized that GLP-1a therapy could favorably modify the vascular and inflammatory milieu in SCD.

Study Design: Real-World Evidence from a Global Cohort

To explore this hypothesis, researchers conducted a retrospective, Propensity Score–Matched cohort study using the TriNetX Analytics Network, a global research platform aggregating de-identified data from more than 275 million patients worldwide.

The analysis identified over 238,000 individuals treated for SCD between 2005 and 2022, including 5,638 patients exposed to GLP-1a therapy. After 1:1 Propensity Score Matching, accounting for demographics, SCD-directed therapies, comorbidities, laboratory values (including HbA1c), and cardiovascular medications, 4,807 matched pairs were included in the final analysis.

The cohorts were well balanced, with a mean age in the early 50s, 73% female representation, and similar racial distribution. Comorbidities such as hypertension, diabetes, and overweight/obesity were comparable between groups. Mean follow-up was 3 years, and the average duration of GLP-1a exposure among users was approximately 136 days.

Primary outcomes included all-cause mortality, sickle cell crisis, ischemic stroke or Transient Ischemic Attack (TIA), and Venous ThromboEmbolism (VTE). Secondary outcomes encompassed health care utilization and major organ complications, including hospitalization, ICU admission, Acute kidney injury (AKI), thrombocytopenia, Heart Failure (HF), Pulmonary Fibrosis (PF), Pulmonary Hypertension (PH), and Myocardial Infarction (MI).

Results: Consistent Risk Reduction Across Clinical Endpoints

GLP-1a use was associated with significant reductions across all primary outcomes. Most notably, patients receiving GLP-1a experienced a markedly lower risk of all-cause mortality compared with non-users (2.5% vs. 7.0%; OR 0.33; 95% CI, 0.27–0.41). Rates of sickle cell crisis were also reduced (3.5% vs. 4.3%), as were ischemic stroke/TIA and VTE events.

Beyond these Primary endpoints, GLP-1a therapy was linked to broad reductions in secondary outcomes and health care utilization. Patients receiving GLP-1a demonstrated lower rates of hospitalization and ICU admission, along with significantly reduced risks of AKI, thrombocytopenia, HF, PH, PF, and MI. Collectively, these findings suggest potential benefits spanning hematologic, cardiovascular, renal, and pulmonary domains.

Clinical Interpretation: A Potential Disease-Modifying Signal

While causality cannot be established due to the retrospective, observational design, the consistency and magnitude of benefit across multiple clinically meaningful outcomes are notable. Investigators acknowledged limitations inherent to Real-World Data, including reliance on ICD coding and limited clinical granularity, which precluded detailed phenotyping or assessment of disease severity and treatment sequencing.

Importantly, concerns surrounding GLP-1a–associated dehydration and its theoretical potential to exacerbate sickling were not reflected in increased crisis rates; in fact, sickle cell crises were less frequent among GLP-1a users. The observed reductions in cardiopulmonary complications may reflect downstream benefits of attenuated inflammation, reduced vaso-occlusion, and improved endothelial function.

Implications and Future Directions

These findings provide compelling, hypothesis-generating evidence that GLP-1 receptor agonists may confer disease-modifying benefits in SCD when used as an adjunct to existing therapies. Beyond individual patient outcomes, reductions in hospitalization and ICU utilization suggest a meaningful impact on overall health care burden.

Prospective, randomized clinical trials will be essential to confirm these observations, clarify optimal patient selection, and define safety considerations specific to the SCD population. If validated, GLP-1a therapy could represent a novel strategy targeting the inflammatory and vasculopathic underpinnings of sickle cell disease.

Key Takeaways

  • GLP-1 receptor agonist use was associated with significantly lower all-cause mortality in patients with SCD.
  • Reduced risks of sickle cell crisis, ischemic stroke/TIA, and Venous Thromboembolism were observed.
  • GLP-1a therapy was linked to fewer hospitalizations, ICU admissions, and cardiopulmonary complications.
  • Findings support prospective trials to evaluate GLP-1a as a potential disease-modifying adjunct in SCD management.

Targeting inflammation in sickle cell disease: Association of GLP-1 agonist use with improved survival and reduced sickle cell crisis and cardiopulmonary complications. Cheema AY, Munir M, Mandala A, et al. Presented at: ASH Annual Meeting and Exposition; Dec. 6-9, 2025; Orlando. Abstract 2970.

FDA Approves First Line ENHERTU® plus PERJETA® for HER2-Positive Metastatic Breast Cancer

RR

SUMMARY: The FDA on December 15, 2025, approved ENHERTU® in combination with Pertuzumab for the first-line treatment of adults with unresectable or metastatic HER2-positive (IHC 3+ or ISH+) breast cancer as determined by an FDA-approved test.

Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that in the US, approximately 321,910 new cases of female breast cancer will be diagnosed in 2026, and about 42,140 women will die of the disease, largely due to metastatic recurrence.

The HER or erbB family of receptors consist of HER1, HER2, HER3 and HER4. Approximately 15%-20% of invasive breast cancers overexpress HER2/neu oncogene, which is a negative predictor of outcomes without systemic therapy. Trastuzumab (HERCEPTIN®) is a humanized monoclonal antibody targeting HER2. Trastuzumab binds to subdomain IV of the HER2 extracellular domain and blocks the downstream cell signaling pathways (PI3K-AKT pathway) and induces Antibody Dependent Cellular Cytotoxicity (ADCC). Pertuzumab (PERJETA®) is a recombinant humanized monoclonal antibody that binds to the HER2 at a different epitope of the HER2 extracellular domain (subdomain II) compared to Trastuzumab, and prevents the dimerization of HER2 with HER3 receptor. Pertuzumab stimulates ADCC similar to Trastuzumab. By combining Trastuzumab and Pertuzumab, a more comprehensive blockade of HER2 signaling can be accomplished, as these two agents bind to different HER2 epitopes and may complement each other and improve efficacy.

Trastuzumab deruxtecan (T-DXd) (ENHERTU®) is a next-generation Antibody-Drug Conjugate (ADC) composed of a humanized monoclonal antibody specifically targeting HER2, with the amino acid sequence similar to Trastuzumab, a cleavable tetrapeptide-based linker, and a potent cytotoxic Topoisomerase I inhibitor as the cytotoxic drug (payload). T-DXd has a favorable pharmacokinetic profile and the tetrapeptide-based linker is stable in the plasma and is selectively cleaved by cathepsins that are up-regulated in tumor cells. Unlike  ado-Trastuzumab emtansine, another ADC targeting HER2, T-DXd has a higher drug-to-antibody ratio (8 versus 4), released payload easily crosses the cell membrane with resulting potent cytotoxic effect on neighboring tumor cells regardless of target expression, and the released cytotoxic agent (payload) has a short half-life, thus minimizing systemic exposure.

Background and Clinical Rationale
Trastuzumab deruxtecan (T-DXd) has demonstrated potent antitumor activity in HER2-positive breast cancer across multiple treatment lines. However, prior to the DESTINY-Breast09 study, all approved indications for T-DXd required patients to have received prior systemic therapy in either the metastatic or adjuvant setting. With the longstanding CLEOPATRA regimen, Docetaxel, Trastuzumab, and Pertuzumab (THP) established over a decade ago as the first-line standard of care, the oncology community has been eager to evaluate whether T-DXd could improve frontline outcomes.

Study Design and Patient Population
DESTINY-Breast09 (NCT04784715) is a randomized, global Phase 3 study designed to evaluate the efficacy and safety of first-line T-DXd with or without Pertuzumab, versus Taxane plusTrastuzumab plus Pertuzumab (THP), in patients with HER2-positive advanced/metastatic breast cancer. A total of 1,157 patients were enrolled across 283 sites worldwide. Eligible patients had centrally confirmed HER2-positive disease (IHC 3+ or ISH+), no prior chemotherapy or HER2-targeted therapy in the metastatic setting, and ≤1 prior line of endocrine therapy. Patients were stratified by Hormone Receptor (HR) status, PIK3CA mutation status, and de novo vs recurrent disease, and randomized 1:1:1 to:

  • T-DXd + placebo – N=387
  • T-DXd + Pertuzumab (T-DXd + P) – N=383
  • THP (control arm) – N=387

The interim analysis presented at ASCO 2025 focused on the comparison between T-DXd + P and THP. The T-DXd monotherapy arm remains blinded until the final PFS analysis.

The Primary endpoint was Progression-Free Survival (PFS) by Blinded Independent Central Review (BICR) in the intent-to-treat population. Secondary endpoints included Overall Survival (OS), PFS by investigator (INV), Objective Response Rate (ORR), Duration of Response (DOR), and Safety.

Efficacy Outcomes: Progression-Free Survival and Response
At a median follow-up of 29 months, T-DXd + P demonstrated a statistically significant and clinically meaningful improvement in PFS compared to THP:

  • Median PFS by BICR:
    • T-DXd + P: 40.7 months
    • THP: 26.9 months
    • HR: 0.56; P <0.00001
  • PFS by Investigator Assessment:
    • Median: 40.7 months vs 20.7 months
    • HR: 0.49 (95% CI: 0.39–0.61)
  • Overall Response Rate (ORR):
    • T-DXd + P: 85.1%
    • THP: 78.6%
  • Complete Response Rate:
    • T-DXd + P: 15.1%
    • THP: 8.5%
  • Median Duration of Response:
    • T-DXd + P: 39.2 months
    • THP: 26.4 months

The PFS benefit was consistent across all patient subgroups, including HR status and PIK3CA mutation.

Safety Profile and Adverse Events
The safety profile of T-DXd + P in the frontline setting was consistent with known toxicities of T-DXd, with no new safety signals. Adjudicated drug-related Interstitial Lung Disease/pneumonitis occurred in 12.1% of patients receiving T-DXd + P (mostly grade 1 and 2) in contrast to only 1.0% among patients receiving THP. Other treatment-related toxicities such as nausea, vomiting, and constipation were more common with T-DXd + P, possibly due to longer median treatment exposure (~3.5 years).

Clinical Implications and Emerging Questions
The marked 13.8-month PFS improvement positions T-DXd + P as a strong candidate to replace THP as the first-line standard for HER2-positive advanced metastatic breast cancer. These results mirror the transformative impact of T-DXd seen in the second-line DESTINY-Breast03 trial comparing T-DXd with ado-Trastuzumab emtansine, where it yielded a median PFS of 28.8 months.

However, while efficacy is unquestionable, questions remain around treatment sequencing, duration, and long-term quality of life:

  • Could T-DXd be reserved for second-line therapy in select patients with less aggressive disease?
  • Might a strategy of T-DXd + P induction followed by de-escalation to maintenance Trastuzumab/Pertuzumab reduce toxicity?
  • Can biomarker-driven personalization, refine who should receive first-line T-DXd?

The researchers of this study emphasized that these results represent a paradigm shift in first-line treatment of advanced HER2-positive breast cancer.

Conclusion
DESTINY-Breast09 demonstrates that T-DXd + Pertuzumab significantly improves PFS compared to THP, with durable responses and manageable toxicity. The findings suggest a potential new first-line standard for HER2-positive metastatic breast cancer. While overall survival and long-term safety data are still maturing, the study sets a new benchmark in the frontline treatment landscape and invites critical dialogue on optimizing sequencing, duration, and patient-centered outcomes.

Trastuzumab Deruxtecan plus Pertuzumab for HER2-Positive Metastatic Breast Cancer. Tolaney SM, Jiang Z, Zhang Q, et al. for the DESTINY-Breast09 Trial Investigators. N Engl J Med. DOI: 10.1056/NEJMoa2508668