Author: RR

Emerging Biomarker Insights in Esophageal Squamous Cell Carcinoma: NOTCH1 Mutations as a Predictor of Anti–PD-1 Benefit

RR

SUMMARY: The American Cancer Society estimates that in 2025, about 22,070 new cases of esophageal cancer will be diagnosed in the US and about 16,250 individuals will die of the disease. It is the sixth most common cause of global cancer death. Squamous Cell Carcinoma is the most common type of cancer of the esophagus among African Americans, while Adenocarcinoma is more common in Caucasians. Squamous Cell Carcinoma (SCC) accounts for approximately 85% of cases. Majority of esophageal cancers are unresectable at diagnosis, and most patients treated with curative intent eventually will relapse, and only about 20% of patients will survive at least 5 years following diagnosis. Patients with advanced esophageal cancer have a median survival of less than a year when treated with the standard Fluoropyrimidine plus Platinum based chemotherapy. For those patients progressing on first line chemotherapy, treatment options are limited, with a 5-year relative survival rate of 8% or less.

Recent advancements in the treatment of advanced or metastatic Esophageal Squamous Cell Carcinoma (ESCC) have firmly positioned Immune Checkpoint Inhibitors (ICIs) as a cornerstone of second-line therapy. Numerous agents targeting PD-1 have demonstrated superior clinical outcomes compared to chemotherapy.

Tislelizumab (TEVIMBRA®)  is a humanized immunoglobulin G4 (IgG4) anti-Programmed cell Death protein- 1 (PD-1) monoclonal antibody with high affinity and binding specificity against PD-1. It is uniquely designed to minimize binding to Fc-gamma receptors on macrophages, helping to aid immune cells of the body to detect and fight tumors, while minimizing off-target effects. The FDA in 2024 approved Tislelizumab in combination with platinum-containing chemotherapy for the first-line treatment of adults with unresectable or metastatic ESCC whose tumors express PD-L1 (≥1) and also as a single agent in adults with unresectable or metastatic ESCC after prior systemic chemotherapy that did not include a PD-(L)1 inhibitor.

RATIONALE-302 is a randomized, open-label, multicenter, Phase 3 study in which 512 patients with advanced or metastatic ESCC whose tumor progressed after first-line systemic treatment, were randomly assigned (1:1) to receive Tislelizumab 200 mg IV every 3 weeks or chemotherapy (investigators choice of Paclitaxel, Docetaxel, or Irinotecan). The trial met its Primary endpoint, demonstrating a significant improvement in Overall Survival (OS) with Tislelizumab over chemotherapy.

A comprehensive biomarker analysis stemming from the pivotal RATIONALE-302 trial has shed light on a promising genomic signal that could shape future treatment pathways. Researchers conducted extensive tumor profiling using PD-L1 ImmunoHistoChemistry (N=359), Gene Expression Profiling (N=346), and Mutation analysis (N=209) on tumor samples from patients enrolled in the RATIONALE-302 trial. The aim of this study was to uncover molecular determinants of response to Tislelizumab.

Clinical Findings: NOTCH1 as a Predictive Biomarker
Among the 209 patients with available mutation data, 22% harbored NOTCH1 mutations. This subgroup demonstrated a markedly improved Overall Survival (OS) with Tislelizumab, compared to chemotherapy:

  • Median OS with tislelizumab: 18.4 months
  • Median OS with chemotherapy: 5.3 months
  • Hazard Ratio: 0.35 (95% CI, 0.17–0.71)

In contrast, patients with wild-type NOTCH1 derived minimal OS benefit from tislelizumab (6.0 vs 6.9 months; HR 0.81), underscoring the potential of NOTCH1 status to guide therapeutic decisions.

Mechanistic Insights: An Immunologically Favorable TME
Transcriptomic data linked NOTCH1 mutations to increased expression of Type I interferon (IFN-I) and Toll-Like Receptor (TLR) signatures—hallmarks of an activated Tumor MicroEnvironment (TME). Concurrently, these tumors exhibited reduced infiltration by B cells and neutrophils, which have been associated with resistance to immunotherapy.

Further validation using murine models showed that NOTCH1 deficiency promotes a TME, more permissive to anti–PD-1 activity, supporting a biological rationale for these clinical findings.

Independent of PD-L1 and TMB
Importantly, the survival benefit associated with NOTCH1 mutations was independent of PD-L1 expression levels and Tumor Mutational Burden (TMB). Even among patients with low PD-L1 tumor positivity (<10%), those with NOTCH1 mutations showed a trend toward improved OS with Tislelizumab over chemotherapy.

Broader Genomic Context
In addition to NOTCH1, alterations in genes such as KMT2D also correlated with improved response to Tislelizumab compared to investigator chosen chemotherapy, while EGFR alterations were associated with diminished benefit. The frequently mutated genes in the RATIONALE-302 cohort – TP53, CCND1, FGF3/4/19, CDKN2A, PIK3CA, KMT2D, NFE2L2, and TP63- fall into functional categories including cell cycle regulation, differentiation, PI3K signaling, and chromatin remodeling consistent with previous reports.

Clinical Implications
These findings strongly suggest that NOTCH1 mutation status should be evaluated in patients with advanced ESCC being considered for anti–PD-1 therapy. Routine integration of Next-Generation Sequencing (NGS) may enhance treatment personalization by identifying patients most likely to derive significant benefit from immunotherapy, beyond the current reliance on PD-L1 ImmunoHistoChemistry or TMB alone.

Next Steps
While these results are promising, prospective validation is needed. A clinical trial is currently being planned to assess whether patients with NOTCH1-mutated ESCC may be optimally treated with ICI monotherapy. Additional translational studies are underway to further clarify resistance mechanisms and inform future biomarker-driven strategies.

NOTCH1 Mutation and Survival Analysis of Tislelizumab in Advanced or Metastatic Esophageal Squamous Cell Carcinoma: A Biomarker Analysis From the Randomized, Phase III, RATIONALE-302 Trial. Lu Z, Du W, Jiao X, et al. J Clin Oncol. Published online April 3, 2025. https://doi.org/10.1200/JCO-24-01818

 

Optimizing Long-Term Anticoagulation in Cancer-Associated Thrombosis: Insights from the API-CAT Trial

RR

SUMMARY: The Center for Disease Control and Prevention (CDC) estimates that approximately 1-2 per 1000 individuals develop Deep Vein Thrombosis (DVT)/Pulmonary Embolism (PE) each year in the United States, resulting in 60,000-100,000 deaths. Venous ThromboEmbolism (VTE) is the third leading cause of cardiovascular mortality, after myocardial infarction and stroke. Ambulatory cancer patients initiating chemotherapy are at varying risk for Venous Thromboembolism (VTE), which in turn can have a substantial effect on health care costs, with negative impact on quality of life.

Approximately 20% of cancer patients develop VTE and about 20% of all VTE cases occur in patients with cancer. There is a two-fold increase in the risk of recurrent thrombosis in patients with cancer, compared with those without cancer, and patients with cancer and VTE are at a markedly increased risk for morbidity and mortality. The high risk of recurrent VTE, as well as bleeding in this patient group, makes anticoagulant treatment challenging. Traditionally, a six-month course of either Direct Oral AntiCoagulants (DOACs) or Low-Molecular-Weight Heparin (LMWH) has served as the standard initial treatment duration.

However, cancer is a chronic and often progressive condition, and the thrombotic risk doesn’t dissipate once the initial treatment window concludes. Clinical guidelines generally recommend the continuation of anticoagulation for as long as the malignancy remains active or systemic therapy is ongoing. Yet, this approach necessitates a careful balancing act – prolonged anticoagulation mitigates thrombotic recurrence but heightens the risk of bleeding, a risk that persists over time.

A major challenge in this domain has been the lack of robust evidence from randomized clinical trials to guide extended anticoagulation beyond six months, particularly regarding the optimal dose that maintains efficacy while minimizing harm. While reduced-dose anticoagulation has emerged as a promising strategy in non-cancer populations, its application to cancer-associated thrombosis had not been thoroughly evaluated until recently.

The Apixaban Cancer Associated Thrombosis (API-CAT) trial is a large, randomized, double-blind, noninferiority study aimed to determine whether a reduced dose of Apixaban (2.5 mg twice daily) could effectively prevent recurrent VTE in patients with active cancer, while also offering a safer bleeding profile, compared to the standard full dose (5 mg twice daily). All participants had previously completed a minimum of six months of anticoagulation for either proximal deep-vein thrombosis or pulmonary embolism. The trial enrolled 1,766 patients, randomly assigned to either the reduced-dose (N=866) or full-dose (N=900) Apixaban group. The baseline characteristics of the patients in this trial were similar to those in observational studies and randomized trials. The median age of the patients was 69 years, and 43% were men. Among patients with active cancer, the most frequent sites of the primary cancer were the breast (22.7%), colon or rectum (15.2%), gynecologic system (12.1%), and lung (11.3%). The Primary efficacy outcome was centrally adjudicated fatal or nonfatal recurrent VTE over the 12-month follow-up period and key Secondary outcome was clinically relevant bleeding, which was defined as a composite of adjudicated major or clinically relevant nonmajor bleeding during the 12-month follow-up period.

The results were compelling: the reduced-dose regimen demonstrated noninferiority to the full dose in preventing VTE recurrence. Specifically, recurrent events occurred in 2.1% of patients in the reduced-dose group compared to 2.8% in the full-dose group (adjusted subhazard ratio=0.76; P=0.001 for noninferiority). More importantly, the incidence of clinically relevant bleeding – a composite measure that included both major and non-major events with real-world impact – was significantly lower in the reduced-dose group (12.1% vs. 15.6%; adjusted subhazard ratio=0.75; P=0.03). The incidence of death was similar in the two groups (19.6% in the full-dose group and 17.7% in the reduced-dose group), and most deaths were related to cancer.

Notably, the study defined clinically relevant bleeding more broadly than previous trials—capturing both major and non-major events that impact patient well-being and quality of life. This approach reflects the reality that even so-called “minor” bleeds can significantly affect daily functioning and emotional health, particularly in patients with incurable malignancies.

In conclusion, reduced-dose Apixaban offers a clinically effective and safer alternative for extended anticoagulation in patients with active cancer, successfully preventing recurrent venous thromboembolism while minimizing bleeding risks. With cancer patients living longer due to advances in immunotherapy and targeted treatments, clinicians are increasingly tasked with navigating long-term thrombosis prevention strategies. The API-CAT trial helps address a key evidence gap and marks a significant advancement in the long-term management of cancer-associated thrombosis and reinforces the importance of personalized care in oncology.

Cancer-Associated Venous Thromboembolism- Beyond 6 Months. Mahe I, Carrier M, Mayeur D, et al. for the API-CAT Investigators. N Engl J Med 2025;392:1439-1440

Exploring the emerging HER2-Low and HER2-Ultralow subtypes in breast cancer therapy advancements

RR

Written by: Denise Yardley, MD
Sponsored by: Daiichi-Sankyo

The landscape of breast cancer treatment is advancing with innovative discoveries challenging the traditional HER2 classification. The identification of HER2-low and HER2-ultralow subtypes offers a more nuanced understanding of tumor biology, paving the way for personalized therapies that promise better outcomes for a wider range of patients. This fresh perspective reshapes clinical practice, indicating a new era in the fight against breast cancer where precision medicine leads the charge.

Breast cancer remains an extremely heterogeneous disease, with a number of subtypes characterized by distinct molecular and clinical features. One key classifying marker is the human epidermal growth factor receptor 2 (HER2). The expression of HER2 or lack thereof traditionally serves to categorize tumors as either HER2 positive or HER2 negative, based on the detected level of HER2 protein expression. The emergence of new antibody conjugate drugs challenged the reliance of conventional HER2 targeted therapies on 3+ HER2 expression by immunohistochemistry (IHC) or gene amplification, thereby establishing HER2 low as a novel breast cancer entity that stands to benefit from HER2 targeted therapies. As a result of DESTINY-Breast 04 in 2022, ASCO CAP guidelines for HER2 testing, affirming the importance of accurately identifying with HER2 low to ensure optimal patient selection for HER2 targeted therapies, were revised in 2023 to include advancements in diagnostic techniques that have led to the identification of two additional subtypes: HER2-low and HER2-ultralow breast cancer. Identifying these novel HER2 subtypes have significant implications for treatment and prognosis.

The identification of the HER2 prototype oncogene served as a ripe therapeutic target in breast cancer as well as other cancers. The focus of these therapeutic interventions were on the small 15-20% group of tumors demonstrating HER2 protein overexpression as a function of HER2 gene amplification. The development and subsequent efficacy of the targeted monoclonal anti-HER2 antibody trastuzumab led to its approval for metastatic breast cancer in 1998 followed by the approval of pertuzumab in 2012. Trastuzumab worked by binding the HER2 protein receptor, inhibiting HER2 homodimerization thus preventing HER2-mediated signalling while pertuzumab inhibited HER2 heterodimerization with HER3, a related growth factor receptor. However, a low or moderate expression of the HER2 target without gene amplification failed to benefit from conventional anti-HER2 agents (NSABP B-47).

Extensive pathology training efforts and quality assurance programs followed to reliably achieve high concordance for identifying and characterizing tumors denoted as HER2+ with the intent of identifying tumors most likely to benefit from classical HER2 targeted agents. The HER2 testing algorithm resulted in a binary categorization of tumors that were either HER2 negative or HER2 positive, on the basis on an IHC score of 3+ or IHC 2+ with in situ hybridization (ISH) positive. HER2 negative was a catchall that included tumors that were completely devoid of the HER2 protein (IHC 0) as well as those that had low to moderate expression labelled as IHC 1+ and IHC 2+ but ISH negative. This distinction however was not clinically meaningful, and the two groups were combined and were not eligible for HER2 therapies. It was not at all clear if there was a distinct tumor biology associated with lower level HER2 expression. The monoclonal anti-HER2 antibodies were ineffective in HER2 low tumors because their activity relies mainly on the blockade of aberrant HER2 signaling via dimerization inhibition, HER2 internalization, and/or antibody dependent cellular cytotoxicity (ADCC). Since these therapies bind the extracellular domain of the HER2 receptor, effective efficacy hinged on HER2 receptor overexpression which facilitates ADCC.

Despite the impact of the success of these agents in improving outcomes in HER2+ overexpressing tumors, a subgroup of patients failed to respond or experience disease recurrence, creating a robust pathway for the development of more effective and well tolerated second line therapies. Antibody drug conjugates (ADC), already a mainstay in hematologic malignancies, functioned as tumoral antibody specific antibodies connected via a linker to a potent cytotoxic payload. Trastuzumab emtansine (T-DM1) soon emerged, incorporating the antitumor properties of trastuzumab joined via a noncleavable linker with the cytotoxic activity of the microtubule inhibitory agent DM1. Use of this ADC allowed for targeted receptor binding and transport of cytotoxic chemotherapy, specifically into cancer cells, with subsequent disruption of the intracellular signaling pathways. The results of the EMILIA trial moved trastuzumab emtansine as a new standard in the second line setting of HER2+ MBC, following the demonstration of improved PFS and OS coupled with a more favorable toxicity profile than lapatinib and capecitabine.

Given these advances, refractoriness in classical HER2+ breast cancers developed to trastuzumab emtansine fostering the development of the third generation ADC trastuzumab deruxtecan, with a monoclonal anti-HER2 antibody linked to a topoisomerase payload through a tetrapeptide cleavable linker. This ADC had a higher drug to antibody ratio of 8 and was effective in trastuzumab emtansine insensitive HER2+ breast tumors. A series of trials referred to as DESTINY trials, evaluated this third generation ADC with DESTINY Breast 01, 02, and 03 in HER2+ breast cancer while DESTINY Breast 04 and 06 looked at HER2 low breast cancer, embracing the 80% of breast cancers assessed as HER2 negative and historically not candidates for anti-HER2 therapy. The DAISY trial was deigned to evaluate trastuzumab deruxtecan according to HER2 expression levels showing the greatest response in the HER2 overexpressing tumors defined by IHC 3+ or ISH positive followed by cohort 2 consisting of HER2 low tumors defined as IHC2+/ISH negative or HER2 nonexpressing tumors or IHC 0. This suggested that very low levels of HER2 expression could allow for receptor binding of trastuzumab deruxtecan and furthermore, that the definition of HER2 low needed to be expanded to include HER2 ultralow, cases that show faintly perceptible HER2 staining that is greater than 0% and < 10% (currently considered IHC 0). What emerged was that HER2 expression is now increasingly perceived as a continuum that defies the former classical dichotomous distinction of HER2 positive and HER2 negative cancers that traditionally guided treatment decision making. While monoclonal antibodies were ineffective in HER2 low tumors because their activity relies mainly on binding of the extracellular domain of the HER2 receptor and is more effective if the receptor is overexpressed facilitating ADCC. This is in stark contrast to the ADC trastuzumab deruxtecan, which can overcome some of these monoclonal antibody limitations by also being able to release a cytotoxic payload that can be internalized by surrounding cells that do not express HER2 (bystander effect). With the introduction of the third generation ADC therapies in what was previously collectively classified as HER2 negative tumors, a paradigm shift in the treatment of tumors without conventionally defined HER2 overexpression or HER2 gene amplification has occurred.

The identification of HER2-low and HER2-ultralow breast cancer represents a significant advancement in the field of breast cancer research and treatment. HER2 IHC scoring, nomenclature, testing modalities and current treatment protocols are evolving and the reproducibility of pathologists truly being able to separate IHC HER2 0 and HER2 1+ persists. Alternative assays and/or testing modalities to better discriminate low levels of HER2 protein expression may lead to future algorithms but at present, ongoing research and clinical trials are essential to further understand the biological behavior and clinical significance of HER2-low and HER2-ultralow breast cancer. As an example, the majority of HER2-low and HER2-ultralow breast cancers are hormone receptor-positive (HR+) which has important implications for treatment with the combinations of hormone therapy with HER2-targeted therapy and the potential to further improve outcomes for patients with HR+/HER2-low and HR+/HER2-ultralow breast cancer. Of overriding importance, is the need for additional studies to also evaluate the long-term outcomes of patients with these HER2 subtypes and to identify additional HER2-targeted therapies that may be effective. The DESTINY Breast 04 and 06 trials highlight the need for refining the diagnostic techniques, and to develop standardized testing protocols, to ensure accurate classification of HER2 status. By embracing personalized treatment approaches, clinicians can improve outcomes for patients with HER2-low and HER2-ultralow breast cancer and provide more effective and targeted care. The traditional dichotomy of HER2 status has now been supplanted by the expanding spectrum of HER2 positivity in breast cancer. Comprehensive characterization of the evolving spectrum of HER2 tumors, to further define their clinical and molecular features, is of paramount importance.

Germline and Somatic Genomic Testing for Metastatic Prostate Cancer: ASCO Guideline

RR

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.

The five year survival among patients first diagnosed with metastatic prostate cancer is approximately 30%. Early detection and treatment may improve outcomes. Risk factors for prostate cancer include age, ethnicity, and family history of prostate cancer. In individuals with a family history of prostate cancer in one or more first-degree relatives, the Relative Risk of prostate cancer increases approximately 2-3 fold, and the risk increases with an increasing number of affected relatives, and is inversely related to the age at time of diagnosis among those relatives.

It is estimated that approximately 40% of all diagnosed prostate cancers are inherited and prostate cancer risk also has been implicated in other familial cancer syndromes such as Hereditary Breast and Ovarian Cancer (HBOC) syndrome and Lynch Syndrome (LS). HBOC syndrome typically is found in families with early onset cancer and multiple cancer diagnoses such as, breast, ovarian and pancreatic cancer. Tumor suppressor DNA repair genes BRCA1 and BRCA2, has been implicated in prostate cancer, particularly in HBOC families. Patients with a BRCA1 mutation have a nearly 2-fold Relative Risk of prostate cancer among men less than 65 years, whereas those with BRCA2 mutations have a more than 7 fold Relative Risk. Further, patients with BRCA2 mutations are also associated with clinically aggressive disease, progression, and higher rates of cancer-specific mortality. It is estimated that the frequency of BRCA2 mutations ranges from 1-3%.

Somatic genomic testing in metastatic prostate cancer can offer insights into both prognosis and potential treatment responses, helping guide clinical decisions. Germline genetic testing can also yield similar insights, with the added benefit of revealing inherited cancer risks that may be relevant to patients relatives, including risks for cancers such as breast, pancreatic, colon, and endometrial. As a result, research has focused on determining which germline and somatic genetic tests deliver the most valuable information for individual patient cases.

The present ASCO guideline was developed by a multidisciplinary Expert Panel, following review of evidence on germline and somatic genomic testing for patients with metastatic prostate cancer. A total of 1,713 papers were identified in the literature search, and the recommendations are based on evidence from eight systematic reviews and six trials. This guideline is applicable to a patient who has a life expectancy of more than 6 months, is a candidate for systemic treatment, and for whom appropriate germline and somatic testing, including expertise in interpretation, is readily available.

This guideline addresses the following questions:
1) Why germline and somatic genomic testing should be offered?
2) The criteria for which patients should be offered testing?
3) Which test(s) to use?
4) When in the disease course testing should be considered?
5) Which biospecimens should be used for testing?

RECOMMENDATIONS

Clinical Question: Who should receive germline testing with NGS technologies?

Recommendation: All patients with metastatic prostate cancer should undergo germline genetic testing with next-generation sequencing technologies.

Clinical Question: Who should receive somatic testing with NGS technologies?

Recommendation: Those patients with metastatic prostate cancer (both Castrate Sensitive and Castrate Resistant Prostate Cancer) who are being considered for biomarker-directed systemic treatment should undergo somatic testing with next-generation sequencing technologies. While there are no current FDA-approved biomarker-directed treatments following somatic testing for metastatic Castrate Sensitive Prostate Cancer, somatic testing may be warranted in the presence of high-volume disease, or where there is a high likelihood the patient’s disease will progress to Castrate Resistant Prostate Cancer, where the patient is a candidate for future treatment with a biomarker-directed therapy (PARP inhibitor or checkpoint inhibitor).

Clinical Question: Who should receive sequential somatic testing with NGS technologies?

Recommendation: The panel recommends that sequential somatic testing may be offered when there has been a meaningful change in the patient’s status or treatment plan, especially in cases where prior tests were negative or uninformative (eg, insufficient or low tumor content).

Clinical Question: What are the strengths and weaknesses of primary tumor archival tissue versus fresh metastatic biopsy tissue versus ctDNA testing for somatic testing?

Recommendation: Archival tissue samples are preferred in initial testing. ctDNA is preferred when there is no accessible metastatic site to biopsy or for sequential testing. In the setting of minimal disease burden associated with low ctDNA fraction, metastatic biopsy is preferred.

Clinical Question: What are the key therapeutic impacts of germline or somatic testing for single-gene genetic variants (eg, BRCA1, BRCA2)?

Recommendation: Patients with pathogenic germline variants or somatic alterations in BRCA1 and BRCA2 demonstrate poorer outcomes, but are candidates for treatment with PARP inhibitor monotherapy, PARP inhibitor with Androgen Receptor Pathway Inhibitor combination therapy, and platinum-based agents.

Clinical Question: What are the key prognostic impacts of germline or somatic testing?

Recommendation: Treatment recommendations should not be made based on prognostic only biomarkers. However, they may be considered for directing patients to clinical trials. Germline information may still be important for patient counseling, informing hereditary risk for patients and families.

Pre-Test Genetic Counseling for Germline Testing

Before conducting germline testing, clinicians should ensure patients understand the following essential aspects:

  • Purpose of Testing: Explain the goals and implications of germline genetic testing.
  • Hereditary Nature: Emphasize that the results can reveal inherited cancer risks.
  • Family Impact: Discuss how findings might indicate elevated cancer risks for relatives.
  • Testing Options: Inform patients about the availability of gene panel testing.
  • Possible Outcomes:
    • Pathogenic/Likely Pathogenic Variants (P/LPVs)
    • Variants of Uncertain Significance (VUS)
    • Negative or Inconclusive Results
  • Legal Protections: Outline patient protections under the Genetic Information Nondiscrimination Act (GINA).
  • Cascade Testing: Stress the importance of testing family members when a P/LPV is found.

Germline and Somatic Genomic Testing for Metastatic Prostate Cancer: ASCO Guideline. Yu EY, Rumble RB, Agarwal N, et al. J Clin Oncol. 2025;43:748-758. DOI:10.1200/JCO-24-02608.

ZYNLONTA® in Combination with Rituximab Shows Dramatic Activity in High Risk Follicular Lymphoma

RR

SUMMARY: The American Cancer Society estimates that in 2025, about 80,350 people will be diagnosed with Non Hodgkin Lymphoma (NHL) in the United States and about 19,390 individuals will die of this disease. Indolent Non-Hodgkin Lymphomas are mature B cell lymphoproliferative disorders and include Follicular Lymphoma, Nodal Marginal Zone Lymphoma (NMZL), Extranodal Marginal Zone Lymphoma (ENMZL) of Mucosa-Associated Lymphoid Tissue (MALT), Splenic Marginal Zone Lymphoma (SMZL), LymphoPlasmacytic Lymphoma (LPL) and Small Lymphocytic Lymphoma (SLL).

Follicular Lymphoma is the most indolent form and second most common form of all NHLs, and they are a heterogeneous group of lymphoproliferative malignancies. Approximately 20% of all NHLs are Follicular Lymphomas and the average age of diagnosis is 65 years. Advanced stage indolent NHL is not curable and as such, prolonging Progression Free Survival (PFS) and Overall Survival (OS), while maintaining Quality of Life, have been the goals of treatment intervention. Asymptomatic patients with indolent NHL are generally considered candidates for “watch and wait” approach. Patients with advanced stage symptomatic Follicular Lymphoma are often treated with induction chemoimmunotherapy followed by maintenance RITUXAN® (Rituximab). This can result in a median Progression Free Survival (PFS) of 6-8 yrs and a median Overall Survival (OS) of 12-15 yrs. However, approximately 30% of the patients will relapse in 3 years, with prognosis worsening after each subsequent relapse. Despite advances in treatment for Follicular Lymphoma, there remains an unmet need for additional options that offer treatment-free intervals with durable, complete responses.

Loncastuximab tesirine (ZYNLONTA®) is an Antibody-Drug Conjugate (ADC) and consists of a humanized monoclonal antibody (anti-CD19) linked to a cytotoxic alkylating agent (pyrrolobenzodiazepine dimer, or PBD). Upon binding to CD19 on B-calls, Loncastuximab is internalized into the cells and PBD is released inside the cells, where it crosslinks DNA and induces tumor cell death. Loncastuximab is presently indicated for the treatment of adult patients with relapsed or refractory Large B-Cell Lymphoma after two or more lines of systemic therapy, including Diffuse Large B-Cell Lymphoma (DLBCL) not otherwise specified, DLBCL arising from low-grade lymphoma, and high-grade B-cell lymphoma. Preliminary data suggested promising activity of Loncastuximab in Follicular Lymphoma, with and synergistic activity between Rtuximab-induced cytotoxicity and Loncastuximab.

The researchers in this study evaluated Loncastuximab tesirine combined with Rituximab for second-line and later treatment of Follicular Lymphoma. This single institution, investigator-initiated, Phase 2 trial enrolled 39 patients with Grade 1-3A Relapsed/Refractory Follicular Lymphoma treated with one or more lines of therapy, who presented with progression of disease within 24 months (POD24). Treatment for the initial 21 weeks consisted of Rituximab 375 mg/m2 IV weekly for 4 weeks followed by 1 dose every 8 weeks for a total of 5 doses in combination with Loncastuximab 0.15 mg/kg IV every 3 weeks for 2 doses followed by 0.075 mg/kg IV every 3 weeks for a total of 7 doses. Premedication with Dexamethasone 4 mg twice daily for 3 days was required. Patients achieving Complete Response at Week 21 discontinued Loncastuximab and received two more doses of Rituximab every 8 weeks. Patients with a partial response at week 21 continued both agents for 18 more weeks. No prophylaxis was required per study protocol. The median age of patients was 68 years and majority of patients were men (54%) with advanced-stage (82%), high-disease burden by GELF criteria (92%), and/or POD24 after frontline immunochemotherapy (51%). The median FLIPI score was 3 with most patients assigned to the high-risk group (61.5%). Median lines of prior therapy were 1, and R-CHOP was the most common first-line therapy (56.5%), followed by Bendamustine with Rituximab (25.6%), single-agent Rituximab (15.3%), and Fludarabine, Mitoxantrone, and Dexamethasone (2.6%). The Primary endpoint was Complete Metabolic Response (CMR) rate at week 12, assessed by the Lugano 2014 classification, in patients who had received at least three doses of Loncastuximab. The safety analysis included all patients who received one or more doses of Loncastuximab.

At a median follow-up of 18.2 months, the Objective Response Rate (ORR) at week 12 was 97.1%, with a CMR rate of 68.6% and a Partial Metabolic Response (PMR) rate of 28.6%. The CMR rate improved to 80% at week 21. All patients who achieved a CMR maintained their response. Baseline bone marrow involvement resolved in all patients (N=10) at week 12 reassessment. The response rates were similar in patients with POD24 and those without, each of which made up roughly half the patients in the trial. At 18 months, the Progression Free Survival (PFS) rate was 90.1% and the Overall Survival (OS) rate was 93.3%, and the median PFS and OS was not reached. The main adverse events with this therapy were skin rash that worsened with sun exposure, and fluid retention, which could be treated with diuretics.

In conclusion, a combination of Loncastuximab with Rituximab demonstrated dramatic activity with robust Complete Metabolic Rate and promising survival benefit with manageable toxicities, in patients with high risk Relapsed or Refractory Follicular Lymphoma. The results of this study support this combination as a new treatment option for this patient group, and multicenter expansion cohort is ongoing. Because of the high Complete Response by week 12, the researchers recently reduced the treatment length from 10 to 6 months, with the hope that relatively short course of treatment combined with lower toxicity will allow patients to better tolerate and complete the therapy.

Loncastuximab tesirine with rituximab in patients with relapsed or refractory follicular lymphoma: a single-centre, single-arm, phase 2 trial. Alderuccio JP, Alencar AJ, Schatz JH, et al. The Lancet. 2025;12:E23-E34.

FDA Approves Radioligand Therapy with PLUVICTO® Before Chemotherapy in Castrate Resistant Prostate Cancer

RR

SUMMARY: The FDA on March 28, 2025, expanded the indication for Lutetium Lu 177 vipivotide tetraxetan (PLUVICTO&reg;) to include adults with Prostate-Specific Membrane Antigen (PSMA)-positive metastatic Castration-Resistant Prostate Cancer (mCRPC) who have been treated with Androgen Receptor Pathway Inhibitor (ARPI) therapy and are considered appropriate to delay taxane-based chemotherapy. Patients with previously treated mCRPC should be selected for PLUVICTO&reg; using LOCAMETZ&reg; (active ingredient Gallium Ga 68 gozetotide) or another approved PSMA Positron Emission Tomography (PET) product based on PSMA expression in tumors.

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. The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer, and is the first treatment intervention. Androgen Deprivation Therapies have included bilateral orchiectomy or Gonadotropin Releasing Hormone (GnRH) analogues, with or without first generation Androgen Receptor (AR) inhibitors such as CASODEX® (Bicalutamide), NILANDRON® (Nilutamide) and EULEXIN® (Flutamide) or with second-generation Androgen-Receptor Pathway Inhibitors (ARPI), which include ZYTIGA® (Abiraterone), XTANDI® (Enzalutamide) and ERLEADA® (Apalutamide). Approximately 10-20% of patients with advanced prostate cancer will progress to Castration Resistant Prostate Cancer (CRPC) within five years during ADT, and over 80% of these patients will have metastatic disease at the time of CRPC diagnosis. The estimated mean survival of patients with CRPC is 9-36 months, and there is therefore an unmet need for new effective therapies. Patients who progress on Androgen Deprivation Therapy are often switched to second line hormonal treatments that block testosterone with a different mechanism of action, and upon further progression, offered taxane based chemotherapy.

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.

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 FDA in March 2022, approved PLUVICTO® for the treatment of adult patients with Prostate-Specific Membrane Antigen (PSMA)-positive metastatic Castration-Resistant Prostate Cancer (mCRPC), who had been treated with Androgen-Receptor Pathway Inhibitors (ARPI) such as Enzalutamide or Abiraterone acetate and 1 or 2 taxane based chemotherapy regimens. This approval was based on the VISION Phase III study.

PSMAfore is a Phase III trial conducted to assess the benefit of PLUVICTO® in patients with metastatic Castration-Resistant Prostate Cancer who had progressed on ARPIs, but had NOT received taxane based chemotherapy, with the hope of making this promising therapy available to more patients earlier in the course of their treatment journey. This study enrolled 468 patients (N=468) with taxane-naive metastatic CRPC who had PSMA-positive disease on gallium-68–PSMA-11 PET/CT, and were candidates for an ARPI change after one progression on prior ARPI. Patients were randomized (1:1) to receive PLUVICTO® 7.4 GBq (200 mCi) IV every 6 weeks for 6 doses, or a change in ARPI (Abiraterone or Enzalutamide). The Primary endpoint was radiographic Progression Free Survival (rPFS). Secondary endpoints included Overall Survival (OS), Prostate-Specific Antigen (PSA) declines of 50% or more from baseline – known as a PSA50 response, Quality of Life measures, and Safety profiles.

At the Primary analysis conducted at 7.3 months, patients treated with PLUVICTO® demonstrated a median rPFS of 9.3 months compared to 5.6 months in the ARPI change group, showing a statistically significant and clinically meaningful benefit (HR=0.41; P<0.0001).

In the updated exploratory analysis, performed with a median follow-up of 24 months, PLUVICTO® more than doubled median rPFS versus ARPI change group (11.6 months versus 5.6 months, HR=0.49), with a 51% reduction in the risk of radiographic progression or death with PLUVICTO® versus a change in ARPI. At the preplanned final analysis, Overall Survival (OS) numerically favored PLUVICTO® but was not statistically significant. The median OS was 24.5 months with PLUVICTO® and 23.1 months with a change in ARPI (HR=0.91 (95% CI, 0.72-1.14). High crossover rate may have confounded OS analysis. Approximately 60% of patients randomized to the change in ARPI group subsequently crossed over to receive PLUVICTO® following confirmed radiographic progression. The Objective Response Rate (ORR) in the PLUVICTO® group was 49% versus 14% in the change in ARPI group, with Complete Response Rates of 21% versus 2.8%, respectively. PSA50 response was 51% with PLUVICTO® and 17% with change in ARPI.

The most frequently reported all-grade adverse events for PLUVICTO® included dry mouth, fatigue, nausea, and constipation, and were primarily Grade 1-2. Further, PLUVICTO® did not impair the ability of patients to be treated with subsequent chemotherapy.

It was concluded that in the updated analysis of the PSMAfore trial, PLUVICTO® more than doubled median rPFS versus a change in ARPI, with favorable safety profile and proven tolerability. The findings from the PSMAfore study suggest that PLUVICTO® could provide a viable therapeutic option earlier in the disease course, potentially delaying or obviating the need for more toxic chemotherapy regimens.

https://www.fda.gov/drugs/resources-information-approved-drugs/fda-expands-pluvictos-metastatic-castration-resistant-prostate-cancer-indication

KADCYLA® Improves Overall Survival in Residual HER2-Positive 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.

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. HERCEPTIN® (Trastuzumab) is a humanized monoclonal antibody targeting HER2, and adjuvant and neoadjuvant chemotherapy given along with HERCEPTIN® reduces the risk of disease recurrence and death, among patients with HER2-positive early stage, as well as advanced metastatic breast cancer. Since the approval of HERCEPTIN®, several other HER2-targeted therapies have become available. The duration of adjuvant HERCEPTIN® therapy has been 12 months and this length of treatment was empirically adopted from the pivotal registration trials.

KADCYLA® (Ado-Trastuzumab Emtansine, T-DM1) is an Antibody-Drug Conjugate (ADC) comprised of the antibody HERCEPTIN® and the chemotherapy agent Emtansine, linked together. Upon binding to the HER2 receptor, it not only inhibits the HER2 signaling pathways but also delivers a chemotherapy agent Emtansine, a microtubule inhibitor, directly inside the tumor cells. This agent is internalized by lysosomes and destroys the HER2-positive tumor cells upon intracellular release. In the EMILIA trial, KADCYLA® was associated with significant increase in Overall Survival (OS), when compared with TYKERB® (Lapatinib) plus XELODA® (Capecitabine), in HER2-positive metastatic breast cancer patients, who had previously received HERCEPTIN® and a Taxane.

It is well established that patients with HER2-positive early breast cancer, following HERCEPTIN® based neoadjuvant therapies, have a pathological Complete Response rate of 40-60%. Those without a pathological Complete Response tend to have significantly less favorable outcomes. These patients irrespective of pathological response status complete their standard adjuvant therapy which includes 12 months of HER2-targeted therapy.

KATHERINE trial was conducted to evaluate the benefit of switching from standard HER2-directed therapy to single-agent KADCYLA®, after neoadjuvant chemotherapy along with either single or dual HER2 targeted therapy, in patients with residual invasive cancer at surgery. This study was conducted to address the unmet need of patients who have residual invasive breast cancer after receiving neoadjuvant chemotherapy plus HER2-targeted therapy.

The KATHERINE trial is an open-label, Phase III global study, which compared KADCYLA® with HERCEPTIN®, as an adjuvant treatment for patients with HER2-positive early breast cancer, who had residual invasive disease following neoadjuvant chemotherapy and HERCEPTIN®. This study included 1,486 patients with HER2-positive early stage breast cancer, who were found to have residual invasive disease in the breast or axillary lymph nodes at surgery, following at least six cycles (16 weeks) of neoadjuvant chemotherapy with a Taxane (with or without Anthracycline) and HERCEPTIN®. Within 12 weeks of surgery, patients (N=1486) were randomly assigned in a 1:1 ratio to KADCYLA® 3.6 mg/kg IV every 3 weeks or HERCEPTIN® 6 mg/kg IV every 3 weeks, for 14 cycles (743 patients in each group). Patients also received standard-of-care radiation and endocrine therapy as per institutional guidelines. Both treatment groups were well balanced and Hormone Receptor positive disease was present in 72% of the patients. The majority of the patients (77%) had received an Anthracycline-containing neoadjuvant chemotherapy regimen, and in 19% of the patients, another HER2-targeted agent in addition to HERCEPTIN® (dual HER2 blockade) had been administered as a component of neoadjuvant therapy. The Primary end point was invasive Disease Free Survival-iDFS (defined as freedom from ipsilateral invasive breast tumor recurrence, ipsilateral locoregional invasive breast cancer recurrence, contralateral invasive breast cancer, distant recurrence, or death from any cause). The Primary analysis showed that 3-year invasive DFS was significantly higher in the KADCYLA® group than in the HERCEPTIN® group (88.3% vs. 77.0%; HR=0.50; P<0.001), suggesting that KADCYLA® reduced the risk of developing an invasive breast cancer recurrence or death by 50%.

The researchers in this publication reported the prespecified final analysis of invasive DFS, and the second interim analysis of Overall Survival. With a median follow-up of 8.4 years, KADCYLA® sustained its superiority over HERCEPTIN® in improving invasive DFS and OS. The 7-year invasive DFS rate was 80.8% with KADCYLA® vs. 67.1% with HERCEPTIN® (unstratified HR=0.54, confirming a 46% reduction in risk. The 7-year OS was 89.1% with KADCYLA® vs. 84.4% with HERCEPTIN® (unstratified HR=0.66; P=0.003), demonstrating a 34% reduction in mortality risk.

Further analyses revealed consistent benefits across key subgroups which included patients with low tumor burden minimal residual disease (1 cm or less, node-negative), HER2-negative residual disease on retesting, both ER-positive and ER-negative patients, as well as HER2 expression level, with patients with IHC 3+ HER2 expression experiencing the most significant benefit (HR=0.47), whereas those with IHC 2+ ISH-amplified tumors had a smaller, though still positive, effect (HR=0.84).

The incidence of adverse events of Grade 3 or higher was noted in 26.1% of patients receiving KADCYLA® compared to 15.7% in the HERCEPTIN® group. The frequency of CNS metastases was comparable between the two cohorts, suggesting that while KADCYLA® enhances control of extracranial disease, it does not necessarily reduce CNS metastases.

In conclusion, the KATHERINE trial has established KADCYLA® as the new standard of care for patients with HER2-positive early breast cancer with residual invasive disease following neoadjuvant therapy. Long-term follow-up confirms sustained benefits in invasive DFS and OS, with an acceptable safety profile. While KADCYLA® significantly reduces recurrence and improves survival, certain high-risk subgroups may require additional therapeutic strategies, prompting the need for ongoing research. Future advancements in HER2-targeted therapies, including Tyrosine Kinase Inhibitors, Antibody Drug Conjugates, and immunotherapy combinations, will further refine treatment strategies and improve outcomes for this high-risk patient population.

Survival with Trastuzumab Emtansine in Residual HER2-Positive Breast Cancer. Geyer CE, Untch M, Huang C-S, et al. for the KATHERINE Study Group. N Engl J Med 2025;392:249-257

BIZENGRI® for Non Small Cell Lung Cancer and Pancreatic Adenocarcinoma

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SUMMARY: The FDA granted accelerated approval to Zenocutuzumab-zbco (BIZENGRI®) for adults with advanced, unresectable, or metastatic Non-Small Cell Lung Cancer (NSCLC) harboring a neuregulin 1 (NRG1) gene fusion with disease progression on or after prior systemic therapy, or advanced, unresectable, or metastatic pancreatic adenocarcinoma harboring a NRG1 gene fusion with disease progression on or after prior systemic therapy. This represents the first FDA approval of a systemic therapy for patients with NSCLC or pancreatic adenocarcinoma harboring an NRG1 gene fusion.

Genomic rearrangements involving the neuregulin 1 (NRG1) gene have been implicated in a variety of solid tumors, including lung, breast, pancreas, ovarian, and prostate cancers. NRG1 fusions are rare oncogenic drivers occurring in less than 1% of solid tumors, highly enriched in KRAS-wild-type pancreatic adenocarcinoma and invasive mucinous adenocarcinoma of the lung. NRG1 fusions produce chimeric ligands that activate the ERBB Receptor Tyrosine Kinase (RTK) family, a group of proteins frequently exploited by cancer cells to promote tumor growth. In lung cancer, NRG1 fusions are associated with poor prognosis in patients with lung cancer, with low Response Rates to standard chemotherapy and immunotherapy, and a short Overall Survival.

The ERBB RTK family includes EGFR (ERBB1), HER2 (ERBB2), HER3 (ERBB3), and HER4 (ERBB4). These proteins mediate crucial cell signaling pathways that regulate growth and survival. They can be oncogenically activated by ligand stimulation such as NRG1 fusion proteins binding to HER3 or HER4, mutations and translocations that may confer constitutive enzymatic activity, such as EGFR kinase domain mutations, the EGFRvIII variant (where the extracellular region of EGFR is deleted), EGFR fusions or gene amplification, or protein overexpression resulting in increasing receptor abundance on cell surfaces to amplify signaling.

NRG1 preferentially binds to HER3 and HER4, promoting their heterodimerization with other ERBB family members like HER2 and EGFR. This interaction is critical because HER3, a pseudokinase, lacks intrinsic enzymatic activity and depends on phosphorylation by its heterodimer partners. The activated HER3 forms docking sites for SH2-domain proteins, triggering multiple downstream signal transduction pathways like the PI3K pathway, which drive proliferation and survival.

Zenocutuzumab is a bispecific humanized immunoglobulin G1 (IgG1) containing two different Fab arms targeting the extracellular domains of HER2 and HER3. The HER2-targeting arm binds HER2, concentrating the antibody locally and positioning it (Dock) to block NRG1 binding to HER3 (Dock-and-block mechanism). The HER3-targeting arm prevents HER3 from undergoing the conformational changes necessary for heterodimerization with HER2 and EGFR. This dual targeting halts HER3 phosphorylation, disrupting downstream oncogenic signaling. Moreover, the glycoengineered IgG1 backbone of Zenocutuzumab enhances its affinity for Fc receptors, boosting Antibody-Dependent Cellular Cytotoxicity (ADCC)-a mechanism by which immune cells destroy antibody-coated tumor cells.

eNRGy is a Phase 2 part of an open-label, multicenter, multicohort, registrational, Phase 1–2 clinical study of Zenocutuzumab, in patients with solid tumors with a NRG1 fusion. A total of 204 patients (N=204) with 12 tumor types were enrolled and patients had a median of one prior line of therapy, including platinum chemotherapy (72%) and Afatinib (11%). The median patient age was 62 years and most were female (60%), and 35% were Asian. The most common NRG1 fusion partners were CD74 (35%), SLC3A2 (14%), ATP1B1 (11%), SDC4/7 (7%), and CDH1/2 (3%). The most common fusion partners among patients with NSCLC were CD74 (in 56%) and SLC3A2 (in 23%), and the most common fusion partner among those with pancreatic cancer was ATP1B1 (in 44%). Most NRG1 fusions were identified by RNA sequencing (81%), followed by DNA sequencing (14%). Patients received Zenocutuzumab 750 mg IV every 2 weeks until disease progression. The Primary efficacy outcome measure was confirmed Overall Response Rate (ORR) and Secondary end points included Duration of Response (DOR), Progression Free Survival (PFS) and Safety. 

Among 158 patients who had measurable disease, the ORR among patients with NSCLC was 29% and median DOR was 12.7 months. The ORR among pancreatic adenocarcinoma patients was 42% and the DOR was 7.4 months. Responses were noted across multiple NRG1 fusion partners. In the pooled safety population, the most common adverse reactions were diarrhea, musculoskeletal pain, fatigue, nausea, infusion-related reactions, dyspnea, rash, constipation, vomiting, abdominal pain, and edema. The most common Grade 3 or 4 laboratory abnormalities were increased gamma-glutamyl transferase, anemia, thrombocytopenia and hyponatremia.

It was concluded from this analysis that Zenocutuzumab provided robust and durable efficacy in advanced NRG1 positive NSCLC and pancreatic adenocarcinoma, with a well-tolerated safety profile, and represents a potential first and best-in-class therapy for patients with NRG1 fusion solid tumors.

Efficacy of Zenocutuzumab in NRG1 Fusion–Positive Cancer. Schram AM, Goto K,  Kim D-W, et al. for the eNRGy Investigators. N Engl J Med 2025;392:566-576

Adjuvant KEYTRUDA® Improves Disease Free Survival in Muscle-Invasive Urothelial Carcinoma

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SUMMARY: The American Cancer Society estimates that in the United States for 2024, about 83,190 new cases of bladder cancer were diagnosed and approximately 16,840 patients died of the disease. Bladder cancer is the fourth most common cancer in men, but it is less common in women. Bladder cancer accounts for 90% of urothelial cancers, and urothelial cancer can also be found in the renal pelvis, ureter and urethra.

A third of the patients initially present with locally invasive disease. The standard treatment for Cisplatin-eligible patients with Muscle-Invasive Bladder Cancer (MIBC) is neoadjuvant chemotherapy followed by radical cystectomy. However, the high relapse rate and risk of death despite this treatment has prompted further research into optimizing outcomes. There is presently no clear consensus with regards to the routine use of adjuvant Cisplatin-based chemotherapy. Further, not all patients are eligible for adjuvant or neoadjuvant Cisplatin-based chemotherapy.

Immune checkpoints are cell surface inhibitory proteins/receptors that are expressed on activated T cells. They harness the immune system and prevent uncontrolled immune reactions. By inhibiting checkpoint proteins and their ligands, T cells are unleashed, resulting in T cell proliferation, activation and a therapeutic response. It has been noted that PD-L1 is widely expressed in tumor and immune cells of patients with urothelial carcinoma. This in turn helps cancer cells to evade detection from the immune system by binding to the PD-1 receptor on cytotoxic T lymphocytes.

Pembrolizumab (KEYTRUDA®) is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. By doing so, it unleashes the tumor-specific effector T cells, and is thereby able to undo PD-1 pathway-mediated inhibition of the immune response.

AMBASSADOR trial (Alliance A031501) is a randomized Phase 3 study, conducted to evaluate whether Pembrolizumab could enhance Disease-Free Survival (DFS) and Overall Survival (OS) in patients with high-risk Muscle Invasive Urothelial Carcinoma (MIUC) after radical surgery, compared to observation alone. This study enrolled 702 patients with high-risk MIUC who underwent radical surgery (cystectomy or nephroureterectomy) within 4-16 weeks before registration. Patients were considered to have high-risk MIUC if they were not eligible for or declined neoadjuvant cisplatin-based chemotherapy and had pT3 or higher, or pN+, or microscopic positive surgical margins, or if they have persistent muscle-invasive disease (defined as a pathological stage of ypT2 or higher or ypN+ or microscopic positive surgical margins) despite the receipt of neoadjuvant chemotherapy at the time of radical surgery. Patients were randomized in a 1:1 ratio, to receive Pembrolizumab 200 mg IV every 3 weeks for 1 year (N=354) or to undergo observation (N=348). Both treatment groups were well balanced and stratification factors for randomization included PD-L1 status (positive or negative, with positivity defined as a Combined Positive Score of 10 or more using the PD-L1 IHC 22C3 pharmDx assay), prior receipt of neoadjuvant chemotherapy, and pathological stage. The median age was 69 years and patients with upper tract and urethral urothelial carcinoma were included in this study. The coPrimary endpoints were DFS and OS, and key Secondary endpoints included DFS and OS stratified by PD-L1 expression.

As of July 2024, with a median follow-up of 44.8 months, the median DFS was significantly longer in the Pembrolizumab group (29.6 months) compared to the observation group (14.2 months). The Hazard Ratio (HR) for disease progression or death was 0.73 (P=0.003), demonstrating a clear benefit. The DFS benefit was observed across all subgroups, regardless of age, PD-L1 status, receipt of neoadjuvant chemotherapy, pathological stage, or tumor location. PD-L1 status therefore should not be used to select patients for treatment with adjuvant Pembrolizumab. The Overall Survival data remain immature. The safety profile of Pembrolizumab was consistent with previous studies, though Grade 3 or higher adverse events were more frequent in the Pembrolizumab group (50.6%) compared to the observation group (31.6%).

In conclusion, adjuvant Pembrolizumab significantly improves DFS in patients with high-risk MIUC post-radical surgery, offering a promising treatment option for this population. These results, together with emerging tools such as circulating tumor DNA (ctDNA) may enable more precise patient selection and stratification, optimizing the use of adjuvant therapies. As Overall Survival data mature and biomarker research evolves, the role of Pembrolizumab may become even more defined within the broader context of urothelial carcinoma treatment.

Adjuvant Pembrolizumab versus Observation in Muscle-Invasive Urothelial Carcinoma. Apolo AB, Ballman KV, Sonpavde G, et al. N Engl J Med 2025;392:45-55

Development of PAC-MANN Assay for Early Detection of Pancreatic Ductal Adenocarcinoma

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SUMMARY: The American Cancer Society estimates that in 2025, about 67,440 people will be diagnosed with pancreatic cancer and 51,980 people will die of the disease. Detecting cancer at early stages can significantly increase survival rates and outcomes. Pancreatic Ductal AdenoCarcinoma (PDAC) is one of the most lethal malignancies, ranking among the leading causes of cancer-related mortality globally. A significant challenge in improving PDAC outcomes is its frequent diagnosis at an advanced stage, when therapeutic options are limited and prognosis is poor. Early detection is critical to expanding treatment possibilities and enhancing survival rates. Currently, CA 19-9 is the only FDA-approved biomarker for PDAC; however, it is sanctioned solely for monitoring therapeutic response and not for diagnostic purposes.

Protease Activity in Cancer Detection
Protease production is a hallmark of tumor progression. In PDAC, as in many cancers, elevated circulating protease activity is observed. Proteases contribute to cancer metastasis by degrading extracellular matrices, facilitating tumor invasion. This biological activity presents a diagnostic opportunity: measuring protease activity in peripheral blood could provide a noninvasive means of detecting malignancy.

Assay Development: PAC-MANN
Montoya Mira, Fischer, and colleagues developed a novel, noninvasive diagnostic assay named PAC-MANN (Protease Activity Characterization via Magnetic Nanosensor), aimed at detecting PDAC via serum protease activity. The method utilizes a magnetic nanosensor coupled to a fluorescently labeled, protease-sensitive peptide probe. When exposed to a blood sample, if PDAC-associated proteases are active, they cleave the peptide substrate, releasing a fluorescent signal. The intensity of fluorescence correlates with protease activity, allowing for rapid and quantifiable detection.

Key Features of PAC-MANN Assay:

  • Sample Volume: Requires only 8 µL of blood.
  • Turnaround Time: Results available within 45 minutes.
  • Cost Efficiency: Material cost estimated at less than one cent per test.
  • Throughput: Capable of analyzing 300–500 samples per day with minimal personnel and equipment.

Clinical Performance

Validation Studies:

  • Sample Cohort: 110 pre-treatment PDAC samples (mean age 65.6 years; 57% male) and 246 noncancerous controls (mean age 63.2 years; 59% male), including cases of pancreatitis and pancreatic neoplasia.
  • Assay Accuracy:
    • Standalone PAC-MANN assay demonstrated 98% specificity and 73% sensitivity across all PDAC stages.
    • PAC-MANN combined with CA 19-9 achieved 85% sensitivity and 96% specificity for detecting stage I PDAC.
    • The assay accurately differentiated PDAC from noncancerous pancreatic conditions with 100% specificity.

Surgical Cohort Findings:
In patients undergoing tumor resection, post-surgical evaluation showed a 16 ± 24% reduction in probe cleavage signal, indicating potential utility in monitoring treatment efficacy.

Future Directions and Clinical Implications

Researchers emphasize that PAC-MANN is an initial step toward improved cancer diagnostics. Planned next steps include:

  • Prospective Clinical Trials: Targeting high-risk patient populations.
  • Global Sample Analysis: Expanding validation to diverse healthcare settings.
  • Technological Refinement: Enhancing assay sensitivity via engineering modifications (e.g., nanoparticle composition, probe architecture).
  • Multiplexing Potential: Early data suggest improved performance when multiple probes are used concurrently.
  • Broader Application: Initial results indicate potential use in detecting other gastrointestinal and possibly non-GI cancers through the measurement of protease activity.

Limitations and Considerations

While promising, the assay is not intended to replace imaging modalities. A positive test would necessitate further localization via advanced imaging techniques. As part of a multi-modal diagnostic strategy, PAC-MANN may significantly improve early PDAC detection and patient outcomes.

Conclusion

The PAC-MANN assay offers a rapid, low-cost, and highly specific method for detecting PDAC at early stages, especially when used in combination with CA 19-9. Its minimal sample requirement and ease of use make it a viable candidate for widespread clinical implementation. Further research and trials will ascertain its role in routine screening, particularly among high-risk populations, and its potential extension to other cancer types.

Early detection of pancreatic cancer by a high-throughput protease-activated nanosensor assay. Montoya Mira JL, Quentel A, Patel RK, et al. Science Translational Medicine.12 Feb 2025.Vol 17, Issue 785.