Category: Meeting Updates

Fixed-Duration vs Continuous Targeted Therapy in Frontline CLL: Insights from the Phase III CLL17 Trial

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SUMMARY: 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 is rarely seen in people under age 40, and is extremely rare in children.

Evolving Treatment Paradigms in CLL            

The therapeutic landscape of CLL has undergone a profound transformation over the past decade, moving away from chemoimmunotherapy toward mechanism-based targeted agents. Brutons Tyrosine Kinase (BTK) inhibitors and the BCL2 inhibitor Venetoclax have become foundational therapies, delivering durable disease control across biologic risk groups. Historically, BTK inhibitors were administered continuously until progression or intolerance, whereas Venetoclax-based combinations introduced the possibility of time-limited treatment.

The rationale for fixed-duration therapy stems from the observation that rational combinations can induce deeper remissions, including undetectable Minimal Residual Disease (MRD), potentially allowing for treatment-free intervals and reduced cumulative toxicity. While Venetoclax–Rituximab in relapsed disease and Venetoclax–Obinutuzumab in the frontline setting validated this concept, the relative efficacy of fixed-duration regimens compared with continuous BTK inhibition remained an unanswered question, until now.

Trial Design and Patient Population

CLL17 is an international, investigator-initiated, Phase III randomized trial designed to directly compare fixed-duration and continuous targeted treatment strategies, in previously untreated CLL patients. A total of 909 treatment-naïve patients were enrolled across 174 centers in 13 countries and randomly assigned in a 1:1:1 ratio to receive:

Fixed-duration Venetoclax plus Obinutuzumab (N=303)

Fixed-duration Venetoclax plus Ibrutinib (N=305)

Continuous Ibrutinib monotherapy (N=301)

Randomization was stratified by fitness status, IGHV mutation status, and the presence of del(17p) and/or TP53 mutation. The study population reflected real-world heterogeneity, with a median age of 66 years, 44% classified as unfit (based on CIRS scores greater than 6, a creatinine clearance of less than 70 ml per minute, or both), more than half harboring unmutated IGHV, 7.6% of the patients with del(17p) or TP53 mutation (or both), and nearly 20% exhibiting complex karyotypes. High- and very high-risk disease by the CLL International Prognostic Index was present in more than 60% of patients, underscoring the clinical relevance of the cohort. The Primary endpoint was investigator-assessed Progression-Free Survival (PFS), with the trial powered to test the noninferiority of each fixed-duration regimen versus continuous Ibrutinib. Key Secondary endpoints included Overall Survival (OS), MRD negativity, Response Rates, and Safety.

Efficacy Outcomes: Noninferiority Achieved

At a median follow-up of 34.2 months, in this prespecified interim analysis, both fixed-duration strategies met the prespecified criteria for noninferiority compared with continuous Ibrutinib. Three-year PFS rates were remarkably similar across treatment arms:

81.1% with Venetoclax–Obinutuzumab

79.4% with Venetoclax–Ibrutinib

81.0% with continuous Ibrutinib

Hazard ratios for progression or death favored neither continuous nor fixed-duration therapy, providing the first prospective evidence that time-limited targeted regimens can match the disease control achieved with indefinite BTK inhibition in the frontline setting.

Overall Survival at three years exceeded 90% in all groups, with no meaningful differences observed at this interim analysis. Longer follow-up will be required to determine whether survival curves diverge with time, particularly in biologically high-risk subgroups.

Depth of Remission and MRD Dynamics

Marked differences emerged in depth of response. Undetectable MRD in peripheral blood at the end of treatment was achieved in:

73.3% of patients treated with Venetoclax–Obinutuzumab

47.2% of those receiving Venetoclax–Ibrutinib

0% of patients on continuous Ibrutinib

These findings reinforce the well-established limitation of single-agent BTK inhibition in achieving deep molecular remissions and highlight a key advantage of Venetoclax-based combinations. While end-of-treatment MRD has been associated with long-term outcomes in fixed-duration regimens, its prognostic value relative to continuous BTK inhibition remains less clear. Ongoing longitudinal MRD assessments in CLL17 may help clarify whether differences in MRD depth ultimately translate into durable clinical benefit.

Safety and Tolerability Considerations

Adverse events were common across all treatment arms, reflecting the immunocompromised nature of the CLL population. Infections affected nearly 80% of patients overall, with serious and fatal infections occurring more frequently in the Venetoclax–Obinutuzumab arm. Importantly, trial enrollment coincided with the COVID-19 pandemic, and approximately 10% of patients experienced severe COVID-19–related infections.

Cytopenias, particularly neutropenia, were more frequent with combination regimens, especially Venetoclax–Obinutuzumab. However, these events were largely confined to the first year of therapy and resolved after treatment completion. In contrast, cardiac toxicities, including atrial fibrillation and hypertension, were more commonly associated with Ibrutinib-containing regimens, consistent with prior experience.

Tumor lysis syndrome was infrequent (<5%) across Venetoclax-containing arms, demonstrating that standard ramp-up strategies and debulking approaches effectively mitigate this risk, even in older and unfit patients.

Subgroup Insights and Clinical Implications

Fixed-duration therapy performed well across most biologic subgroups. Notably, patients with unmutated IGHV did not experience inferior outcomes with time-limited treatment compared with continuous Ibrutinib, supporting broader use of fixed-duration strategies. Patients with mutated IGHV achieved particularly favorable outcomes with Venetoclax–Obinutuzumab, consistent with the more indolent biology of this subgroup.

For patients with del(17p) or TP53 mutations, outcomes were encouraging with BTK inhibitor–containing regimens, although the small sample size and limited follow-up preclude definitive conclusions. Continuous therapy did not clearly outperform fixed-duration Venetoclax–Ibrutinib in this population, highlighting the need for ongoing observation and biomarker-driven analyses.

Positioning CLL17 in the Current Treatment Landscape

The results of CLL17 complement and extend findings from earlier studies such as CLL13, CLL14, CAPTIVATE, and GLOW, while providing the first direct, randomized comparison between fixed-duration and continuous targeted therapy. Importantly, the trial was conducted during the emergence of next-generation BTK inhibitors with improved cardiac safety profiles, suggesting that the central question addressed by CLL17, time-limited versus continuous therapy, will remain clinically relevant regardless of the specific BTK inhibitor chosen.

Conclusions

The first analysis of the Phase III CLL17 trial demonstrates that fixed-duration Venetoclax–Obinutuzumab and Venetoclax–Ibrutinib are noninferior to continuous Ibrutinib in previously untreated CLL, with comparable Progression-Free Survival and excellent Overall Survival. These findings provide high-level evidence supporting fixed-duration therapy as a viable frontline strategy for most patients, offering the advantages of treatment-free intervals and deep remissions without compromising efficacy. As follow-up matures, CLL17 will further inform patient selection, remission durability, and the long-term significance of MRD. For now, the trial marks a pivotal step toward more personalized, time-limited treatment strategies in CLL.

Fixed-Duration versus Continuous Treatment for Chronic Lymphocytic Leukemia. Al-Sawaf O, Stumpf J,  Zhang C, et al. for the CLL17 Trial Investigators. Published December 6, 2025. DOI: 10.1056/NEJMoa2515458.

Neoadjuvant Niraparib Plus Dostarlimab in BRCA or PALB2-Mutated Triple Negative Breast Cancer: Phase II TBCRC 056 Results

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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 316,950 new cases of female breast cancer were diagnosed in 2025, and about 42,170 women died of the disease, largely due to metastatic recurrence.

Rationale for a Chemotherapy-Free Neoadjuvant Strategy

Patients with germline BRCA1/2 or PALB2–mutated breast cancer represent a biologically distinct population with heightened sensitivity to PARP inhibition. Beyond synthetic lethality, accumulating preclinical evidence suggests that PARP inhibitors activate the cGAS/STING pathway, increasing intratumoral inflammation, recruiting CD8+ T cells, and potentially priming tumors for immune checkpoint blockade.

While prior studies have not demonstrated a clear benefit for combining PARP inhibitors with immunotherapy in the advanced TNBC (Triple-Negative Breast Cancer) setting, investigators hypothesized that the early-stage, neoadjuvant context, characterized by less immune exhaustion and lower tumor burden, might offer a more permissive environment for synergy.

Study Design and Patient Population

TBCRC 056 is a randomized, Phase II study evaluating the PARP inhibitor Niraparib (ZEJULA&reg;) in combination with the anti–PD-1 antibody Dostarlimab (JEMPERLI&reg;) as neoadjuvant therapy for patients with HER2-negative breast cancer harboring germline BRCA1/2 or PALB2 mutations. The trial includes cohorts for both triple-negative and Estrogen Receptor (ER) positive disease. The current analysis focuses on TNBC cohorts (Arms A and B). Participants with ER positive breast cancer will be placed directly into Arm C. There is no randomization for these participants.

Eligible patients were ≥18 years old with Stage I–III TNBC, primary tumors ≥1.0 cm, HER2-negative disease, and confirmed germline BRCA1/2 or PALB2 mutations. Patients were randomized to:

  • Arm A: Niraparib 200 mg orally once daily plus Dostarlimab 500 mg IV every 3 weeks for 18 weeks
  • Arm B: Niraparib monotherapy for 3 weeks followed by Niraparib plus Dostarlimab for 15 weeks

Tumor biopsies were obtained at baseline and week 3 to assess immune modulation. Surgery followed 18 weeks of therapy, with optional additional neoadjuvant treatment at investigator discretion if residual disease was detected.

RCB (Residual Cancer Burden in the breast tissue and axillary lymph nodes) Categories:

  • RCB 0:No invasive cancer cells found (pCR).
  • RCB I (Minimal):Very small amount of residual disease.
  • RCB II (Moderate):Moderate amount of residual disease.
  • RCB III (Extensive):Significant amount of residual disease.

Endpoints and Statistical Considerations

The Primary endpoints were:

  • Pathologic Complete Response (pCR; RCB-0) rate in Arms A and B combined
  • Change in stromal Tumor-Infiltrating Lymphocytes (sTILs) from baseline to week 3

The study was powered to detect a pCR rate of ≥50%, allowing rejection of a null hypothesis pCR rate <30%.

Baseline Characteristics

A total of 46 patients with TNBC were enrolled across Arms A and B. The median age was 39.3 years, reflecting the young demographic typical of germline BRCA-associated disease. Most patients were White (84.8%), with representation from Black, Asian, and Hispanic populations. Clinically, 37.0% had Stage I disease, 45.7% Stage II, and 17.4% Stage III. The majority had node-negative and high-grade (grade 3) tumors. BRCA1 mutations predominated (82.6%), with the remainder harboring BRCA2 mutations. No PALB2-mutated TNBC patients were enrolled in this cohort.

Efficacy Outcomes: pCR and Residual Disease

Neoadjuvant Niraparib plus Dostarlimab achieved a pCR rate of 50.0% (90% CI, 37.1%–62.9%) among evaluable patients, meeting and exceeding the study’s predefined efficacy threshold.

Notably:

  • pCR rates were identical in both treatment strategies, at 50% in Arm A (concurrent therapy) and Arm B (niraparib lead-in)
  • The combined RCB-0/I rate was 60.0%, suggesting meaningful tumor eradication or minimal residual disease in a majority of patients
  • Approximately 24% of patients crossed over to additional preoperative therapy, reflecting real-world decision-making when residual disease is identified

These findings support the robustness of the regimen regardless of initial PARP inhibitor lead-in.

Immune Modulation and Biomarker Insights

A key translational objective of TBCRC 056 was to characterize early immune changes within the tumor microenvironment.

Both treatment arms demonstrated statistically significant increases in sTILs from baseline to week 3:

  • Arm A: Mean sTILs increased from 16% to 27.4%
  • Arm B: Mean sTILs increased from 19.5% to 42.1%, suggesting a pronounced immune activation following PARP inhibitor exposure

Importantly, patients who achieved pCR had higher baseline sTIL levels than those who did not, underscoring the prognostic relevance of preexisting immune infiltration. Baseline sTILs were also associated with achieving RCB-0/I.

In contrast, baseline PD-L1 expression, estrogen receptor status (ER-0 vs ER-low), and short-term changes in sTILs were not independently associated with pCR, highlighting the complexity of immune–genomic interactions in BRCA-driven TNBC.

Safety and Tolerability

The safety profile of Niraparib plus Dostarlimab was consistent with known toxicities of PARP inhibition and immune checkpoint blockade.

  • Grade ≥2 treatment-related adverse events occurred in 82.6% of patients
  • Grade 3 events were reported in 26.1%, and grade 4 events were rare (2.2%)
  • The most common higher-grade toxicities included anemia, fatigue, hypertension, hypothyroidism, and neutropenia

Treatment discontinuation occurred in 13% of patients, with discontinuations split between Niraparib and Dostarlimab, suggesting manageable but clinically relevant toxicity in a neoadjuvant setting.

Key Takeaways for Oncology Practice

  • TBCRC 056 demonstrates that a chemotherapy-free neoadjuvant therapy with Niraparib combined with Dostarlimab achieved a 50% pathologic Complete Response (pCR) rate in patients with germline BRCA-mutated early-stage TNBC, exceeding the study’s predefined efficacy threshold.
  • pCR rates were identical whether Dostarlimab was administered concurrently with Niraparib or following a short PARP inhibitor lead-in, suggesting flexibility in treatment sequencing.
  • Treatment was associated with a significant increase in stromal Tumor-Infiltrating Lymphocytes (sTILs) within 3 weeks, supporting biologic synergy between PARP inhibition and PD-1 blockade in early-stage disease.
  • Higher baseline sTIL levels were associated with both pCR and minimal residual disease (RCB-0/I), whereas baseline PD-L1 expression and ER-low status were not predictive.
  • These findings support further investigation of biomarker-driven, non-chemotherapy neoadjuvant strategies in genetically defined TNBC populations.

TBCRC-056: A phase II study of neoadjuvant niraparib with dostarlimab for patients with BRCA- or PALB2-mutated breast cancer: results from the TNBC cohorts. Mayer EL, Graham N, Leon-Ferre RA, et al. Presented at: 2025 San Antonio Breast Cancer Symposium; December 9-12, 2025; San Antonio, TX. Abstract RF5-02.

 

 

 

 

Late Breaking Abstract – ASH 2025: Teclistamab Plus Daratumumab Redefines Outcomes in Early Relapsed Multiple Myeloma

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SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 36,110 new cases will be diagnosed in 2025, and 12,030 patients are expected to die of the disease. Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The introduction of Proteasome Inhibitors, Immunomodulatory agents and CD38 targeted therapies has resulted in higher Response Rates, as well as longer Progression Free Survival (PFS) and Overall Survival (OS), with the median survival for patients with myeloma approaching 10 years or more. Nonetheless, multiple myeloma in 2025 remains an incurable disease.

Relapsed or Refractory Multiple Myeloma (RRMM) remains a complex clinical challenge, even as therapeutic options continue to expand. Progressive immune dysfunction, cumulative treatment toxicity, and repeated relapses often limit the durability of benefit with conventional salvage regimens. Moreover, the increasingly effective frontline landscape has raised the bar for second- and later-line therapy, leaving fewer highly active, well-tolerated options for patients early in relapse.

BCMA-directed therapies have transformed expectations in advanced disease, particularly with CAR-T cell approaches demonstrating deep responses and prolonged disease control. However, manufacturing timelines, resource intensity, and patient fitness requirements limit universal access. Consequently, there is a critical need for off-the-shelf, immunotherapy-based regimens that deliver CAR-T–like efficacy with broader applicability.

Teclistamab (TECVAYLI&reg;), a bispecific T-cell engaging antibody targeting CD3 on T cells and BCMA on myeloma cells, has previously shown meaningful and durable responses in heavily pretreated RRMM. Daratumumab (DARZALEX&reg;), an anti-CD38 monoclonal antibody, remains a foundational therapy across all disease stages, offering both direct antimyeloma activity and immune modulation. Preclinical and clinical observations suggest that Daratumumab-mediated depletion of immunosuppressive cellular subsets enhances T-cell fitness, providing a strong biological rationale for combination with BCMA-directed bispecific antibodies.

The MajesTEC-3 trial was designed to test whether combining Teclistamab with Daratumumab could improve outcomes compared with established Daratumumab-based regimens in patients with earlier-line RRMM.

Study Design and Patient Population

MajesTEC-3 (NCT05083169) is an ongoing, randomized, open-label, Phase 3 trial conducted across 150 centers in 20 countries. Eligible patients had relapsed or refractory multiple myeloma after one to three prior lines of therapy, including prior exposure to both an immunomodulatory agent and a proteasome inhibitor. Patients with prior BCMA-directed therapy or anti-CD38–refractory disease were excluded.

A total of 587 patients were randomized 1:1 to receive either:

  • Teclistamab plus subcutaneous Daratumumab, or
  • Investigator’s choice of standard Daratumumab-based therapy, consisting of Daratumumab and Dexamethasone combined with either Pomalidomide (DPd) or Bortezomib (DVd).

Randomization was stratified by choice of control regimen, International Staging System stage, prior exposure to anti-CD38 antibodies, and number of prior treatment lines. The median patient age was approximately 64–65 years, with a median of two prior lines of therapy. Importantly, more than one-third of enrolled patients had high-risk cytogenetic features, reflecting a clinically relevant population.

Treatment Administration: A Patient-Centered, Steroid-Sparing Approach

Patients in the investigational arm received subcutaneous Teclistamab using a step-up dosing strategy, followed by a progressively extended dosing interval, transitioning to monthly administration from cycle 7 onward. Daratumumab was administered subcutaneously according to its approved schedule.

Notably, the regimen became steroid-free after cycle 1, an important quality-of-life consideration for patients requiring long-term therapy. Infection prophylaxis, immunoglobulin supplementation, and monitoring of IgG levels were mandated, with protocol amendments reinforcing best practices for infection prevention during BCMA-directed therapy. The Primary end point was Progression-Free Survival (PFS), as assessed by an Independent Review Committee.

Primary Endpoint: Striking Improvement in Progression-Free Survival

At a median follow-up of 34.5 months, Teclistamab plus Daratumumab demonstrated a highly significant and clinically transformative improvement in PFS compared with DPd or DVd.

  • The estimated 36-month PFS rate was 83.4% with Teclistamab–Daratumumab versus 29.7% with standard Daratumumab-based therapy.
  • This translated into an 83% reduction in the risk of disease progression or death (HR 0.17; 95% CI, 0.12–0.23; P<0.001).
  • The prespecified boundary for superiority was crossed at the first interim analysis.

Importantly, the PFS advantage was consistent across all prespecified and clinically relevant subgroups, including patients with high-risk cytogenetics and those treated in earlier versus later relapse.

Depth and Durability of Response

Beyond delaying progression, Teclistamab–Daratumumab induced exceptionally deep and durable responses:

  • Complete Response or better was achieved in 81.8% of patients receiving the combination, compared with 32.1% in the control arm.
  • Overall Response Rates were also higher (89.0% vs. 75.3%).
  • Rates of Minimal Residual Disease negativity at a sensitivity of 10⁻⁵ were more than threefold higher with Teclistamab–Daratumumab (58.4% vs. 17.1%).

Responses occurred rapidly, with a median time to first response of just over one month, and deepened over time. At three years, nearly 90% of responders in the investigational arm remained in response, suggesting the emergence of a plateau in disease control.

Overall Survival and Symptom Outcomes

Although follow-up for overall survival continues, early analyses favored Teclistamab–Daratumumab, with a high proportion of patients remaining alive beyond two years. Improvements were also observed in time to worsening of myeloma-related symptoms, underscoring the regimen’s clinical and patient-reported benefit.

Safety and Tolerability: Manageable With Established Protocols

The safety profile of Teclistamab–Daratumumab was consistent with the known risks of BCMA-directed bispecific antibodies and Daratumumab. Serious adverse events occurred more frequently in the investigational arm, driven primarily by cytopenias and infections.

  • Cytokine Release Syndrome was common but predominantly low grade and largely confined to the step-up dosing period.
  • Importantly, the incidence of CRS was lower than that reported with Teclistamab monotherapy, supporting a favorable interaction between the two agents.
  • Fatal adverse events were infrequent and decreased following protocol-reinforced infection-prevention strategies.

The trial highlights the critical importance of early immunoglobulin replacement, antimicrobial prophylaxis, and vigilant monitoring, now well established in guidelines for patients receiving BCMA-targeted therapies.

Context Within the Evolving Treatment Landscape

The magnitude of benefit observed with Teclistamab–Daratumumab is particularly notable given the strong performance of the control arm, which exceeded historical expectations from prior DPd and DVd studies. Even in this context, the combination delivered superior depth, durability, and consistency of response. As CAR-T therapies move earlier in the disease course, off-the-shelf immunotherapies such as Teclistamab–Daratumumab offer a complementary strategy, one that combines accessibility, scalability, and sustained disease control. Monthly dosing after the initial treatment phase further supports feasibility in community oncology settings.

Clinical Implications

The MajesTEC-3 trial establishes Teclistamab plus Daratumumab as a highly effective immunotherapy-based option for patients with early relapsed multiple myeloma, delivering unprecedented Progression-Free Survival and deep molecular responses without the logistical barriers of cellular therapy. With appropriate supportive care and infection-prevention strategies, this regimen may meaningfully reset expectations for long-term disease control in a population historically characterized by inevitable relapse.

Conclusion

In patients with multiple myeloma who had received one to three prior lines of therapy, Teclistamab combined with Daratumumab significantly outperformed established Daratumumab-based regimens, offering durable disease control, deep responses, and a manageable safety profile. These findings position Teclistamab–Daratumumab as a potential new standard in earlier-line Relapsed or Refractory Multiple Myeloma, and signal continued progress toward prolonged survival in this traditionally incurable disease.

Teclistamab plus Daratumumab in Relapsed or Refractory Multiple Myeloma. Costa LJ,  Bahlis NJ, Perrot A, et al. for the MajesTEC-3 Trial Investigators. N Engl J Med. Published December 9, 2025. DOI: 10.1056/NEJMoa2514663

 

 

 

 

Late Breaking Abstract – ESMO 2025: Advancing First-Line Therapy in High-Risk NMIBC: Final Results from the Phase III POTOMAC Trial

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SUMMARY: The American Cancer Society estimates that 84,870 new cases of bladder cancer will be diagnosed in 2025 and 17,420 will die of the disease. Bladder cancer is the fourth most common cancer in men but is less common in women and the average age at the time of diagnosis is 73 years. Caucasians are more likely to be diagnosed with bladder cancer than African Americans or Hispanic Americans.

Persistent Unmet Need in BCG-Naïve High-Risk NMIBC

High-risk Non–Muscle-Invasive Bladder Cancer (NMIBC) remains a clinically challenging disease despite decades of experience with intravesical Bacillus Calmette-Guérin (BCG). Standard management consists of complete TransUrethral Resection of Bladder Tumor (TURBT) followed by BCG induction and maintenance, However, up to 40% of patients experience early recurrence or progression within two years. For those with high-risk recurrence, radical cystectomy is frequently recommended, an intervention associated with substantial morbidity and quality-of-life implications. These limitations have driven interest in immunotherapy-based strategies aimed at improving disease control earlier in the treatment course and potentially delaying or avoiding radical surgery.

Rationale for Combining PD-L1 Blockade with BCG

Durvalumab (IMFINZI&reg;), a monoclonal antibody targeting Programmed Death-Ligand 1 (PD-L1), has demonstrated clinically meaningful benefit in bladder cancer, most notably in the perioperative setting for muscle-invasive disease. Biologic rationale for combining immune checkpoint inhibition with BCG includes immune priming within the bladder microenvironment and the observation that PD-L1 expression may increase with disease progression or BCG resistance. Introducing checkpoint blockade earlier, before immune escape is fully established, may therefore enhance the durability of response to BCG.

POTOMAC Trial Design and Patient Population

POTOMAC (NCT03528694) was a global, randomized, open-label Phase III trial evaluating whether adding Durvalumab to standard BCG therapy improves outcomes in patients with BCG-naïve, high-risk NMIBC. A total of 1,018 patients from more than 120 centers across 12 countries were randomized 1:1:1 following TURBT to one of three treatment arms:

  • Durvalumab plus BCG induction and maintenance (N=339)
  • Durvalumab plus BCG induction alone (N=339)
  • BCG induction and maintenance alone (control– N=340)

Durvalumab was administered at 1,500 mg IV every four weeks for 13 cycles (one year), while intravesical BCG induction therapy was weekly for 6 weeks and maintenance therapy consisted of three doses at weekly intervals at 3, 6, 12, 18, and 24 months. Patients were stratified by Carcinoma in Situ (CIS) and higher-risk papillary disease. The Primary endpoint was investigator-assessed Disease-Free Survival (DFS) comparing Durvalumab plus BCG induction and maintenance versus BCG alone.

Durable Improvement in Disease-Free Survival

At a median follow-up of 60.7 months, POTOMAC met its primary endpoint. The addition of one year of Durvalumab to BCG induction and maintenance resulted in a 32% reduction in the risk of high-risk disease recurrence or death compared with BCG alone (HR=0.68; P=0.015). Disease-free survival curves separated early and remained consistently apart over time, underscoring both early and sustained benefit. The median DFS was not reached in either arm. Importantly, Durvalumab combined with BCG induction alone, without maintenance BCG, did not improve outcomes, reinforcing the central role of adequate BCG exposure in disease control.

Overall Survival and Long-Term Follow-Up

Although the study was not powered to detect Overall Survival differences, extended follow-up showed no evidence of harm associated with Durvalumab. Descriptive analyses suggested numerically favorable survival outcomes with the combination regimen, providing reassurance regarding long-term safety in this curative-intent population.

Safety Profile and Treatment Tolerability

The safety profile of Durvalumab plus BCG was consistent with the known toxicities of each agent. Grade 3 or 4 treatment-related adverse events occurred more frequently with combination therapy than with BCG alone, but these events were generally manageable. No treatment-related deaths were reported. Common adverse effects reflected expected urinary and immune-related events, supporting the feasibility of integrating systemic immunotherapy into NMIBC management.

Context within the Evolving NMIBC Landscape

POTOMAC represents one of the longest follow-up datasets evaluating immune checkpoint inhibition in NMIBC and adds to a growing body of evidence supporting this strategy. Together with prior positive trials exploring PD-1/PD-L1 inhibitors alongside BCG, the data suggest that immune checkpoint blockade can meaningfully augment standard therapy when combined with full-course BCG. Differences among trials highlight the importance of patient selection, adequate maintenance therapy, and sufficient duration of treatment exposure.

Clinical Implications for Practice

The POTOMAC findings reinforce several key principles for clinicians:

  • Maintenance BCG remains essential and should not be replaced by systemic immunotherapy alone
  • Early integration of immune checkpoint blockade can improve disease control in carefully selected high-risk patients
  • Long-term follow-up matters, particularly in NMIBC where durable bladder preservation is a primary goal

Conclusion

For patients with BCG-naïve, high-risk NMIBC, the addition of one year of Durvalumab to standard BCG induction and maintenance delivers a statistically significant and clinically meaningful improvement in Disease-Free Survival with a manageable safety profile. POTOMAC raises the bar for first-line NMIBC therapy and positions combined systemic and intravesical immunotherapy as a compelling new option for this high-risk population.

Durvalumab in combination with BCG for BCG-naive, high-risk, non-muscle-invasive bladder cancer (POTOMAC): final analysis of a randomised, open-label, phase 3 trial. De Santis M, Redorta JP, Nishiyama H, et al. The Lancet. 2025;406:2221-2234.

HER2CLIMB-05: Redefining First-Line Maintenance Therapy in HER2-Positive Metastatic Breast Cancer

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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 316,950 new cases of female breast cancer will be diagnosed in 2025, and about 42,170 women will die of the disease, largely due to metastatic recurrence.

Approximately 15-20% of invasive breast cancers overexpress HER2/neu oncogene, which is a negative predictor of outcomes without systemic therapy. Patients with HER2-positive metastatic breast cancer are often treated with anti-HER2 targeted therapy along with chemotherapy, irrespective of hormone receptor status, and this has resulted in significantly improved treatment outcomes. With advances in systemic therapies for this patient population, the incidence of brain metastases as a sanctuary site has increased. Approximately 50% of patients with HER2-positive metastatic breast cancer develop brain metastases. However, systemic HER2-targeted agents, including Tyrosine Kinase Inhibitors, as well as chemotherapy have limited antitumor activity in the brain. Local therapeutic interventions for brain metastases include neurosurgical resection and Stereotactic or Whole-Brain Radiation Therapy. There is a high unmet need for systemic treatment options to treat established brain metastases and reduce the risk for progression in the Central Nervous System (CNS).

Expanding Options Beyond Standard Maintenance

Despite major advances in the management of Human Epidermal growth factor Receptor 2–positive (HER2+) metastatic breast cancer (MBC), disease progression during maintenance therapy remains a persistent challenge. The long-standing first-line (1L) standard of care, induction with Trastuzumab, Pertuzumab, and a Taxane followed by Trastuzumab plus Pertuzumab maintenance, has delivered durable benefit, yet most patients ultimately relapse within two years. This unmet need is particularly relevant in a modern population increasingly exposed to HER2-targeted therapy in the early-stage setting and enriched for de novo metastatic disease.

HER2CLIMB-05 was designed to test whether intensifying HER2 blockade during the maintenance phase, by adding the highly selective oral HER2 tyrosine kinase inhibitor (TKI) Tucatinib (TUKYSA®), could further delay disease progression while preserving tolerability and quality of life.

Study Design and Patient Population

HER2CLIMB-05 (NCT05132582) is a randomized, double-blind, placebo-controlled, International Phase 3 trial enrolling patients with centrally confirmed HER2+ unresectable locally advanced or metastatic breast cancer. Eligible patients had no evidence of disease progression following 4 to 8 cycles of standard 1L induction therapy with Trastuzumab, Pertuzumab, and a taxane, an ECOG performance status of 0 or 1, and no or asymptomatic brain metastases.

A total of 654 patients were randomized 1:1 to receive Tucatinib (300 mg PO twice daily) or placebo, in combination with Trastuzumab and Pertuzumab administered IV every 21 days. Randomization was stratified by de novo versus recurrent disease, Hormone Receptor (HR) status, and presence or history of brain metastases. Endocrine therapy was permitted for patients with HR-positive disease. The Primary endpoint was investigator-assessed Progression-Free Survival (PFS) per RECIST v1.1. Key Secondary endpoints included Overall Survival (OS), PFS by Blinded Independent Central Review (BICR), Central Nervous System (CNS) PFS, safety, and Patient-Reported Outcomes.

The enrolled population reflects current real-world patterns of HER2+ MBC. All patients were female, with a median age of 54 years. Nearly 70% presented with de novo metastatic disease, over half had HR-positive tumors, and 12.4% had a presence or history of brain metastases at baseline. Most patients had excellent performance status, with nearly two-thirds classified as ECOG 0.

Primary Endpoint Met: Significant and Clinically Meaningful PFS Improvement

At a median follow-up of approximately 23 months, HER2CLIMB-05 met its Primary endpoint. The addition of Tucatinib to Trastuzumab and Pertuzumab resulted in a statistically significant and clinically meaningful improvement in PFS compared with standard maintenance therapy alone. Median PFS was 24.9 months in the Tucatinib arm versus 16.3 months in the control arm, corresponding to a 36% reduction in the risk of disease progression or death (Hazard Ratio [HR], 0.64; P < 0.0001). Results from BICR were consistent, reinforcing the robustness of the primary analysis.

Importantly, the PFS benefit was observed across all prespecified subgroups, including patients with and without brain metastases and those with HR-positive or HR-negative disease. This consistency highlights the broad applicability of Tucatinib-based maintenance therapy in HER2+ MBC.

Early Signals in Overall Survival and CNS Outcomes

Overall Survival data remain immature, with approximately 20% of the required events observed at the time of this primary analysis. Median OS has not yet been reached in either arm, with no evidence of detriment associated with Tucatinib and a favorable trend observed.

While CNS-PFS was not reached in the overall population, patients with baseline brain metastases experienced a numerical improvement with Tucatinib, with median CNS-PFS nearly doubling compared with control (8.5 vs 4.3 months). Although preliminary, these findings align with prior HER2CLIMB data supporting Tucatinib’s activity in CNS disease.

Safety Profile: Consistent and Manageable

The safety profile of Tucatinib in combination with Trastuzumab and Pertuzumab was consistent with known toxicities of HER2-directed regimens. Diarrhea, nausea, and transaminase elevations were the most common treatment-emergent adverse events in the Tucatinib arm, the majority of which were low grade and manageable with supportive care and dose modifications.

Grade ≥3 adverse events were more frequent with Tucatinib, particularly elevated ALT and AST; however, hepatic events were generally asymptomatic, reversible, and occurred early in treatment. Discontinuation of Tucatinib due to adverse events occurred in 13.5% of patients, underscoring the importance of proactive monitoring and toxicity management in clinical practice. No new safety signals were identified.

Positioning HER2CLIMB-05 in an Evolving Treatment Landscape

HER2CLIMB-05 adds to a growing body of evidence supporting maintenance intensification strategies in HER2+ MBC. Alongside recent Phase 3 trials such as PATINA and DESTINY-Breast09, these data emphasize that meaningful improvements in disease control can be achieved beyond traditional chemotherapy-based induction regimens.

Unlike antibody–drug conjugate based approaches, Tucatinib-based maintenance offers a chemotherapy-free option that targets HER2 both extracellularly and intracellularly, with particular relevance for patients with brain metastases or those who may not be ideal candidates for prolonged cytotoxic therapy.

Clinical Implications

The HER2CLIMB-05 primary analysis demonstrates that adding Tucatinib to Trastuzumab and Pertuzumab as 1L maintenance therapy significantly prolongs PFS, extending disease control to more than two years in patients with HER2+ metastatic breast cancer. The benefit was consistent across key subgroups, including HR status and CNS involvement, and was achieved with a manageable and familiar safety profile.

As the HER2+ metastatic treatment paradigm continues to evolve, Tucatinib-based maintenance represents an important new option that may delay progression and postpone the need for subsequent cytotoxic therapy. Ongoing follow-up will clarify the impact on Overall Survival, CNS outcomes, and patient-reported Quality of Life, further informing individualized treatment decisions.

HER2CLIMB-05: A Phase 3 Study of Tucatinib Versus Placebo in Combination with Trastuzumab and Pertuzumab as First-line Maintenance Therapy for HER2+ Metastatic Breast Cancer. Dieras V, Curigliano G, Martin M, et al. on behalf of the HER2CLIMB-05 investigators. J Clin Oncol. DOI: 10.1200/JCO-25-02600

Late Breaking Abstract – ESMO 2025: Early Radioligand Intensification in mHSPC: Key Findings from the Phase III PSMAddition Trial

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SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 8 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 313,780 new cases of prostate cancer will be diagnosed in 2025 and 35,770 men will die of the disease.

Metastatic Hormone-Sensitive Prostate Cancer (mHSPC) remains a challenging disease state, even with modern intensification strategies. Androgen-Deprivation Therapy (ADT) combined with an Androgen Receptor Pathway Inhibitor (ARPI) is a widely adopted standard of care. Yet many patients continue to progress and long-term disease control remains elusive.

Prostate-Specific Membrane Antigen (PSMA) is a Type II cell membrane glycoprotein that is selectively expressed in prostate cells, with high levels of expression in prostatic adenocarcinoma. PSMA is a therefore an excellent target for molecular imaging and therapeutics, due to its high specificity for prostate cancer. The emergence of PSMA-targeted radioligand therapy validated in metastatic Castration-Resistant Prostate Cancer (mCRPC) through the VISION and PSMAfore studies, has prompted investigation of earlier integration.

Lutetium Lu 177 vipivotide tetraxetan (PLUVICTO®) is a radiopharmaceutical that targets PSMA. It is comprised of Lutetium-177, a cytotoxic radionuclide, linked to the ligand PSMA-617, a small molecule designed to bind with high affinity to PSMA. Radioligand therapy with PLUVICTO® targets PSMA and releases its payload of lethal beta radiation into the prostate cancer cell.

The Phase III PSMAddition trial represents the first randomized effort to evaluate a targeted radionuclide therapy in the hormone-sensitive setting.

Study Design and Patient Population

PSMAddition enrolled 1,144 men with treatment-naïve or minimally treated (≤45 days of hormonal therapy) mHSPC. All patients had PSMA-positive metastatic disease confirmed by 68Ga-PSMA-11 PET/CT, defined as at least one lesion with uptake exceeding liver activity. Participants were randomized 1:1 to:

  • Experimental arm: 177Lu-PSMA-617 (7.4 GBq every 6 weeks for up to six cycles) + ADT + an ARPI of physician’s choice
  • Control arm: ADT + ARPI alone, with crossover to 177Lu-PSMA-617 permitted upon centrally confirmed radiographic progression

Baseline characteristics were well balanced. Half had de novo metastatic disease and more than two-thirds had high-volume disease by conventional imaging criteria. Abiraterone was the most commonly selected ARPI, followed by Apalutamide and Enzalutamide. In the experimental arm, treatment adherence was high, with 86% completing all six cycles.

This report reflects the second interim analysis for radiographic Progression-Free Survival (rPFS; data maturity 74%) and the first interim analysis for Overall Survival (OS; data maturity 47%) after a median follow-up of 23.6 months.

Efficacy Outcomes

Radiographic Progression-Free Survival: Primary Endpoint Achieved

The addition of 177Lu-PSMA-617 significantly prolonged rPFS compared with ADT + ARPI alone (HR 0.72; P=0.002). Median rPFS has not been reached in either arm. Importantly, benefit was observed across all predefined subgroups, including high- vs low-volume disease, de novo vs recurrent mHSPC, as well as varying ARPI backbones. These findings confirmed that PSMA-targeted radioligand therapy can improve disease control even in the presence of potent systemic hormonal intensification.

Early Overall Survival Trends

Although OS data are immature, there is a favorable trend for early 177Lu-PSMA-617 (HR 0.84). As nearly 60% of progressing control-arm patients crossed over to 177Lu-PSMA-617, subsequent analyses may be confounded, potentially attenuating the ability to detect an OS difference with further follow-up.

Secondary Efficacy Measures

Across all Secondary endpoints, outcomes favored the 177Lu-PSMA-617 arm:

  • ORR: 85% vs 81%
    • Complete responses: 57% vs 42%
  • PSA endpoints:
    • PSA <0.2 ng/mL rates at multiple prespecified time points were higher in the experimental arm
    • PSA progression significantly delayed (HR 0.42)
  • Time to mCRPC: HR 0.70
  • Investigator-assessed PFS: HR 0.64
  • Time to symptomatic skeletal events: Comparable between arms, but favored 177Lu-PSMA-617 numerically

Collectively, these findings indicate deeper and more durable disease responses with early radioligand therapy.

Safety and Tolerability

Overall toxicity was higher with the addition of 177Lu-PSMA-617 but consistent with the known safety profile of radioligand therapy. Common all-grade adverse events (experimental arm) included dry mouth (46%), fatigue (35%), nausea (34%), Hot flashes (29%) and anemia (27%). Grade ≥3 cytopenias occurred more often with 177Lu-PSMA-617 (14% vs 5%), though most were low grade and manageable. Importantly, no treatment-related deaths were reported. Despite higher toxicity rates, Quality-of-Life measures including FACT-P and EQ-5D were not adversely impacted, and time to worsening pain was similar between arms.

Clinical Implications

PSMAddition provides the first Phase III evidence supporting integration of PSMA-targeted radioligand therapy into initial systemic treatment for PSMA-positive mHSPC. While rPFS and multiple disease-control endpoints clearly favor the triplet approach, questions remain regarding long-term survival benefit, patient selection, and optimal treatment duration. Additional biomarker-driven analyses and longer follow-up will be critical in defining how broadly early LuPSMA-617 should be adopted in routine practice.

Phase 3 trial of [177Lu]Lu-PSMA-617 combined with ADT + ARPI in patients with PSMA-positive metastatic hormone-sensitive prostate cancer (PSMAddition). Tagawa ST, Sartor O, Piulats JM, et al. Presented at: European Society for Medical Oncology (ESMO) Congress. October 17-21, 2025. Berlin, Germany. Abstract LBA6

Precision Medicine in Practice: Timely Use of Tumor NGS Remains Suboptimal in Common Cancers

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SUMMARY: Next-generation sequencing (NGS) has revolutionized the management of advanced cancers by enabling identification of tumor-specific genomic alterations for which targeted therapies are now available. National guidelines recommend early and routine NGS testing for patients with advanced or metastatic solid tumors to inform treatment decisions. In the United States, the five most prevalent advanced or metastatic solid tumors include advanced Non-Small Cell Lung Cancer (aNSCLC), metastatic Breast Cancer (mBC), metastatic Prostate Cancer (mPC), advanced Colorectal Cancer (aCRC), and metastatic Pancreatic Cancer (mPanC). For these malignancies, the integration of NGS has become increasingly critical in guiding targeted therapy selection and improving survival outcomes. Despite the approval of multiple targeted therapies for these malignancies, real-world utilization of NGS remains inconsistent.

In this study presented at the 2025 ASCO Annual Meeting, Chehade and colleagues,  evaluated patterns in NGS testing and its timing, relative to patient mortality.

Study Overview: This retrospective analysis leveraged the Flatiron Health EHR-derived de-identified database across 280 cancer clinics, spanning data from 2011 onward. The study included patients with a diagnosis of aNSCLC, mBC, mPC, aCRC, or mPanC, all of whom had records of NGS testing and a documented date of death. The researchers identified 86,536 patients with advanced non-small cell lung cancer, 36,000 with metastatic breast cancer, 35,702 with advanced colorectal cancer, 24,105 with metastatic prostate cancer and 14,964 with metastatic pancreatic cancer. About a third of patients from each cancer group received NGS testing (NSCLC, 36.3%; breast cancer, 32.1%; colorectal cancer, 41%; prostate cancer, 30.9%; and pancreatic cancer, 35.4%).

Patients were categorized based on the interval between receipt of NGS results and death:

  • More than 3 months before death
  • Within 3 months of death
  • After death

Key Findings Across cancer types, only 30% to 40% of patients received NGS testing. Among those who were tested and had a recorded date of death, the timing of NGS was as follows:

Timing of First NGS aNSCLC (N=19,958) mBC (N=5,689) mPC (N=3,397) aCRC (N=8,553) mPanC (N=3,957)
>3 mo before death          72.3%        81.6%        85.4%        85.0%         71.1%
Within 3 mo of death          25.6%        16.9%        13.5%        13.7%         26.5%
After death          2.1%        1.5%        1.1%        1.3%         2.4%

Notably, up to one in four patients with NSCLC or pancreatic cancer received their first NGS results within 3 months of death, a timeframe often too late for actionable therapeutic intervention.

Interpretation and Implications Despite advances in molecularly targeted therapies and growing guideline support for comprehensive genomic profiling, real-world testing patterns remain suboptimal:

  • Low uptake: Only about a third of eligible patients undergo NGS testing.
  • Late testing: A substantial proportion of tested patients receive results within 3 months of death.
  • Missed opportunities: Many patients are never tested—or are tested too late to benefit from life-extending therapies.

These findings highlight ongoing gaps in precision oncology implementation, especially in community-based settings.

Next Steps & Recommendations To improve the utility of NGS in oncology, efforts should focus on:

  • Earlier testing: At diagnosis or at first progression of advanced disease.
  • Workflow integration: Embedding NGS into routine clinical pathways.
  • Education: Raising awareness among clinicians and patients about the benefits of timely testing.
  • Health system support: Addressing barriers such as reimbursement, turnaround times, and tissue availability.

Conclusion: Real-World Data from this large retrospective analysis reveal late-stage testing and underutilization of life-prolonging genomic profiling. This study underscores an urgent need to optimize the timing and uptake of NGS testing in patients with advanced solid tumors. Earlier and broader testing is essential to ensure patients have access to the most effective, personalized treatment strategies, and to avoid the missed potential of life-extending therapies.

Utilization and timing of first tumor next-generation sequencing testing (NGS) in patients (pts) with five most common cancers in the USA. Chehade CH, Jo Y, Ozay ZI, et al. Doi: 10.1200/JCO.2025.43.16_suppl.11014. Abstract # 11014. Presented at: ASCO Annual Meeting; May 30-June 3, 2025; Chicago.

Durvalumab + FLOT Establishes New Benchmark in Curative-Intent Therapy for Gastric and GEJ Cancers

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SUMMARY: The American Cancer Society estimates that in the US about 30,300 new gastric cancer cases will be diagnosed in 2025 and about 10,780 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 gastric cancer. Additionally, one of the strongest risk factors for gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium.

Despite the intent of cure in resectable gastric and GastroEsophageal Junction (GEJ) cancers, long-term survival remains suboptimal, with fewer than half of patients alive at five years. Current perioperative chemotherapy strategies, such as the FLOT regimen (5-FU, Leucovorin, Oxaliplatin, and Docetaxel), are widely accepted as the standard of care, particularly in Western countries. However, recurrence remains a frequent challenge, underscoring the need for enhanced systemic control.

The global, randomized, double-blind Phase 3 MATTERHORN trial evaluated whether adding the immune checkpoint inhibitor Durvalumab to FLOT could improve clinical outcomes in patients with resectable, locally advanced gastric or GEJ adenocarcinoma. This approach leverages prior success of immunotherapy in metastatic settings, where checkpoint inhibitors are already approved in combination with chemotherapy, but expands the strategy into the curative-intent, perioperative context.

Durvalumab (IMFINZI&reg;) is a human immunoglobulin G1 monoclonal antibody that binds to the PD-L1 protein and blocks the interaction of PD-L1 with the PD-1 and CD80 proteins, countering the tumor’s immune-evading tactics, and unleashes the T cells.

Trial Design and Treatment Protocol
In this study, a total of 948 treatment-naïve patients with Stage II to IVa resectable gastric or GEJ adenocarcinoma were randomized 1:1 to receive either Durvalumab plus FLOT (N=474) or placebo plus FLOT (N=474).  Treatment consisted of Durvalumab 1500 mg or Placebo every 4 weeks (Q4W) on Day 1 + FLOT (5-Fluorouracil, Leucovorin, Oxaliplatin and Docetaxel) on Days 1 and 15 for 4 cycles (2 cycles each neoadjuvant/adjuvant), followed by Durvalumab 1500 mg or Placebo on Day 1 Q4W for 10 cycles. Participants were enrolled across Asia, Europe, North America, and South America, reflecting the global burden of disease. Key stratification factors included geographic region (Asia vs non-Asia), nodal status, and PD-L1 expression. The median age was approximately 62 years, and around 70% of patients had gastric tumors, with the remainder involving the GEJ. Most patients (70%) had node-positive disease at baseline. Treatment groups were well balanced. Treatment was administered perioperatively, consisting of two neoadjuvant and two adjuvant cycles. Durvalumab or placebo was continued post-chemotherapy as monotherapy for 10 additional cycles. The Primary endpoint was Event-Free Survival (EFS), with Secondary endpoints including Overall Survival (OS), pathologic Complete Response (pCR), and Safety.

Efficacy Findings
At a median follow-up of 31.5 months, the addition of Durvalumab to FLOT significantly improved EFS compared to placebo. The median EFS had not yet been reached in the Durvalumab arm, whereas it was 32.8 months in the placebo group (Hazard Ratio [HR] 0.71; 95% CI, 0.58–0.86; P<0.001), translating to a roughly 30% reduction in the risk of progression, recurrence, or death. Importantly, Durvalumab did not delay surgery or adjuvant therapy initiation. Notably, 24-month EFS rates were higher with Durvalumab (67.4%) compared to placebo (58.5%), indicating a durable benefit. Subgroup analyses consistently favored the Durvalumab combination across clinical and demographic variables, including PD-L1 expression status, nodal involvement, and geographic region, although some subgroups lacked sufficient power for statistical significance.

An early OS analysis, though not yet mature, suggested a favorable trend for the Durvalumab arm (HR 0.78; 95% CI, 0.62–0.97), with median OS not reached in that group compared to 47.2 months in the placebo group.

In addition to EFS, the Durvalumab-containing regimen improved pathologic Complete Response rates as well as Major Pathological Response, suggesting more effective eradication of micrometastatic disease with immunotherapy-enhanced perioperative treatment.

The final Overall Survival results from the MATTERHORN trial were presented at the ESMO Congress 2025. In this definitive analysis, perioperative Durvalumab added to FLOT chemotherapy delivered a statistically significant and clinically meaningful survival advantage over placebo plus FLOT (HR=0.78; 95% CI, 0.63–0.96; P=0.021). Notably, the OS benefit was observed across PD-L1 expression levels, with comparable hazard ratios in both the TAP <1% and TAP ≥1% subgroups, suggesting that the activity of Durvalumab in the perioperative setting is not restricted to PD-L1–positive disease.

Durvalumab also enhanced pathological response metrics. Patients treated with Durvalumab achieved substantially higher nodal negativity rates (ypN0, 58.2% vs 44.8%), indicating deeper locoregional tumor clearance and supporting the biologic premise that checkpoint inhibition can potentiate chemotherapy-mediated cytoreduction. Improvements in Event-Free Survival were consistent across the spectrum of pathological response categories including partial, major, and complete responders, highlighting that meaningful clinical benefit extends beyond patients achieving ypCR.

Safety and Tolerability
The addition of Durvalumab did not compromise surgical outcomes or delay the initiation of adjuvant therapy. The incidence of grade 3/4 adverse events was similar between arms (72% with Durvalumab vs 71% with placebo), as were rates of serious adverse events (48% vs 44%) and treatment-related deaths (5% vs 4%). These findings reinforce the safety of incorporating immunotherapy into the perioperative setting without increasing toxicity burden or interfering with multimodal management.

Biomarker Insights and Future Directions
Approximately 90% of patients were PD-L1–positive in both groups, and 5% had MicroSatellite Instability–High (MSI-H) tumors (lower than the rates of 7% to 9% commonly seen). Although these biomarker-defined subpopulations are known to respond favorably to immunotherapy, their relatively small representation in the study suggests the observed benefits were driven by broader immunomodulatory effects rather than biomarker enrichment alone.

The optimal duration of adjuvant Durvalumab remains an open question. In MATTERHORN, Durvalumab was continued for 10 cycles post-chemotherapy, but further investigation may determine whether shorter courses or biomarker-guided de-escalation could yield similar benefits while minimizing toxicity and cost.

Clinical Implications

The MATTERHORN findings reinforce that integrating Durvalumab into the perioperative FLOT regimen confers durable improvements in both Overall and Event-Free Survival for patients with resectable gastric or gastroesophageal junction (GEJ) adenocarcinoma. Importantly, the magnitude of benefit remained stable across key clinical and biological subgroups, including PD-L1 status and nodal involvement, underscoring the robustness and generalizability of the treatment effect.

Combined with the earlier JCO publication detailing significant gains in Event-Free Survival, these results strengthen the rationale for incorporating immunotherapy into curative-intent treatment pathways for early-stage upper gastrointestinal cancers. Durvalumab + FLOT is poised to emerge as a new global standard of care, reflecting the broader paradigm shift toward perioperative immune-checkpoint blockade in resectable solid tumors.

Final overall survival (OS) and the association of pathological outcomes with event-free survival (EFS) in MATTERHORN: A randomised, phase III study of durvalumab (D) plus 5-fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT) in resectable gastric / gastroesophageal junction (G / GEJ) adenocarcinoma. Tabernero J, Al-Batran, Wainberg ZA, et al. LBA81- Presented at ESMO Congress 2025, Berlin.

Precision Medicine in Practice: Timely Use of Tumor NGS Remains Suboptimal in Common Cancers

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SUMMARY: Next-generation sequencing (NGS) has revolutionized the management of advanced cancers by enabling identification of tumor-specific genomic alterations for which targeted therapies are now available. National guidelines recommend early and routine NGS testing for patients with advanced or metastatic solid tumors to inform treatment decisions. In the United States, the five most prevalent advanced or metastatic solid tumors include advanced Non-Small Cell Lung Cancer (aNSCLC), metastatic Breast Cancer (mBC), metastatic Prostate Cancer (mPC), advanced Colorectal Cancer (aCRC), and metastatic Pancreatic Cancer (mPanC). For these malignancies, the integration of NGS has become increasingly critical in guiding targeted therapy selection and improving survival outcomes. Despite the approval of multiple targeted therapies for these malignancies, real-world utilization of NGS remains inconsistent.

In this study presented at the 2025 ASCO Annual Meeting, Chehade and colleagues,  evaluated patterns in NGS testing and its timing, relative to patient mortality.

Study Overview: This retrospective analysis leveraged the Flatiron Health EHR-derived de-identified database across 280 cancer clinics, spanning data from 2011 onward. The study included patients with a diagnosis of aNSCLC, mBC, mPC, aCRC, or mPanC, all of whom had records of NGS testing and a documented date of death. The researchers identified 86,536 patients with advanced non-small cell lung cancer, 36,000 with metastatic breast cancer, 35,702 with advanced colorectal cancer, 24,105 with metastatic prostate cancer and 14,964 with metastatic pancreatic cancer. About a third of patients from each cancer group received NGS testing (NSCLC, 36.3%; breast cancer, 32.1%; colorectal cancer, 41%; prostate cancer, 30.9%; and pancreatic cancer, 35.4%).

Patients were categorized based on the interval between receipt of NGS results and death:

  • More than 3 months before death
  • Within 3 months of death
  • After death

Key Findings Across cancer types, only 30% to 40% of patients received NGS testing. Among those who were tested and had a recorded date of death, the timing of NGS was as follows:

Timing of First NGS aNSCLC (N=19,958) mBC (N=5,689) mPC (N=3,397) aCRC (N=8,553) mPanC (N=3,957)
>3 mo before death          72.3%        81.6%        85.4%        85.0%         71.1%
Within 3 mo of death          25.6%        16.9%        13.5%        13.7%         26.5%
After death          2.1%        1.5%        1.1%        1.3%         2.4%

Notably, up to one in four patients with NSCLC or pancreatic cancer received their first NGS results within 3 months of death, a timeframe often too late for actionable therapeutic intervention.

Interpretation and Implications Despite advances in molecularly targeted therapies and growing guideline support for comprehensive genomic profiling, real-world testing patterns remain suboptimal:

  • Low uptake: Only about a third of eligible patients undergo NGS testing.
  • Late testing: A substantial proportion of tested patients receive results within 3 months of death.
  • Missed opportunities: Many patients are never tested—or are tested too late to benefit from life-extending therapies.

These findings highlight ongoing gaps in precision oncology implementation, especially in community-based settings.

Next Steps & Recommendations To improve the utility of NGS in oncology, efforts should focus on:

  • Earlier testing: At diagnosis or at first progression of advanced disease.
  • Workflow integration: Embedding NGS into routine clinical pathways.
  • Education: Raising awareness among clinicians and patients about the benefits of timely testing.
  • Health system support: Addressing barriers such as reimbursement, turnaround times, and tissue availability.

Conclusion: Real-World Data from this large retrospective analysis reveal late-stage testing and underutilization of life-prolonging genomic profiling. This study underscores an urgent need to optimize the timing and uptake of NGS testing in patients with advanced solid tumors. Earlier and broader testing is essential to ensure patients have access to the most effective, personalized treatment strategies, and to avoid the missed potential of life-extending therapies.

Utilization and timing of first tumor next-generation sequencing testing (NGS) in patients (pts) with five most common cancers in the USA. Chehade CH, Jo Y, Ozay ZI, et al. Doi: 10.1200/JCO.2025.43.16_suppl.11014. Abstract # 11014. Presented at: ASCO Annual Meeting; May 30-June 3, 2025; Chicago.

CAN-2409 in Advanced NSCLC: Turning Tumors into Vaccines

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SUMMARY: The American Cancer Society estimates that for 2025, about 226,650 new cases of lung cancer will be diagnosed and 124,730 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers and Adenocarcinoma is now the most frequent histologic subtype of lung cancer.

A New Approach to Overcoming Resistance
For patients with advanced Non-Small Cell Lung Cancer (NSCLC), Immune Checkpoint Inhibitors (ICIs) have changed the treatment landscape. Yet, many patients develop resistance or fail to respond altogether, leaving clinicians with limited options. A novel gene therapy, CAN-2409, is offering a different strategy, one that uses the tumor itself as a source of immune activation.

How It Works: An In Situ Vaccination
CAN-2409 is an engineered, replication-defective adenovirus designed to deliver the Herpes Simplex Virus thymidine kinase (HSV-tk) gene directly into tumor cells. Once inside, the cells express HSV-tk. When patients take the oral prodrug Valacyclovir, the enzyme HSV-tk converts it into a toxic metabolite, selectively killing the tumor cells.

But the therapeutic effect goes far beyond cell death.

  • Immunogenic cell death releases tumor-specific antigens and creates a pro-inflammatory environment.
  • The adenovirus itself adds inflammatory cues.
  • Dendritic cells capture and present these antigens, training cytotoxic T cells to recognize the tumor.

The result is a two-step, multimodal effect: localized destruction followed by a systemic immune response. This “in situ vaccination” primes the immune system not just against the injected lesion, but also against distant metastases, creating the potential for durable control.

Clinical Trial in ICI-Refractory NSCLC
A Phase IIa open-label trial evaluated CAN-2409 plus Valacyclovir in patients with unresectable Stage III/IV NSCLC who had failed to respond adequately to anti-PD-(L)1 therapy. Patients continued on their checkpoint inhibitor therapy and received two intratumoral injections of CAN-2409 (5 × 10^11 vp) five to seven weeks apart via bronchoscopic or percutaneous injection into lung tumor, disease-positive lymph node, or peripheral metastasis, followed by oral prodrug Valacyclovir administered for 15 days. The median age was 67 yrs, 44% were female, 68% were on checkpoint inhibitor therapy alone and 32% were on checkpoint inhibitor therapy plus Pemetrexed regimen. Majority of patients (90%) had Stage IV disease, 46% had PD-L1 TPS < 1%, 91% were former or current smokers.

Participants were enrolled into two cohorts:

  • Cohort 1: Stable disease while on ICI therapy
  • Cohort 2: Progressive disease despite ICI therapy

The goal was to assess Overall Survival (OS), abscopal responses, and immune correlates.

Extended Follow-Up Results
Seventy-six patients were enrolled, of whom 46 patients were considered evaluable

At a median follow-up of 32.4 months, the findings were striking:

  • Median OS (all evaluable patients): 24.5 months
  • Median OS in Cohort 2 (progressive disease): 21.5 months
  • Long-term survival: 37% alive beyond 2 years
  • Histology-specific benefit: Patients with nonsquamous disease had longer OS than those with squamous histology (25.4 vs. 13.3 months).

Notably, patients with nonsquamous tumors showed greater expansion of cytotoxic T cells, B cells, and dendritic cells, suggesting that histology-linked biology may shape immune responsiveness to CAN-2409.

Evidence of Systemic Immune Activation
One of the most compelling signals came from the observation of abscopal responses. Among patients with multiple lesions, 69% experienced shrinkage at uninjected sites, confirming that local therapy could indeed drive a systemic anti-tumor effect.

Safety and Tolerability
Throughout extended follow-up, CAN-2409 maintained a favorable safety profile. The most common Treatment Related Adverse Events (TRAEs) were Grade 1/2, with fatigue, fever, and chills in 18-39% of patients. No dose-limiting toxicities or Grade 4 or more treatment-related AEs were noted. No new safety signals emerged, underscoring its feasibility as a repeat intratumoral intervention alongside checkpoint blockade.

Looking Ahead
These results highlight the promise of CAN-2409 as a next-generation immunotherapy platform for patients with advanced NSCLC resistant to ICIs. With durable survival in a subset of patients, particularly those with nonsquamous histology, the findings support the initiation of a larger, randomized trial to validate efficacy and refine patient selection strategies.

Key Takeaway for Oncology Practice
CAN-2409 represents a novel paradigm in NSCLC, transforming tumors into personalized vaccines that harness both direct cytotoxicity and immune training. For patients progressing on ICIs, this dual mechanism could offer a meaningful new avenue of durable disease control.

MA10.02 CAN-2409 With Continued Immune Checkpoint Inhibitor (ICI) in Patients With Stage III/IV NSCLC With Inadequate Response to ICI. Aggarwal C, Sterman D, Nicholas G, et al. Presented at the 2025 World Conference on Lung Cancer. September 6-9, 2025. Barcelona, Spain.