Late Breaking Abstract – ASCO 2025: A New Era for High-Risk Resected Head and Neck Cancer: Nivolumab Adds Disease-Free Survival Benefit in NIVOPOSTOP Trial

SUMMARY: The American Cancer Society estimates that 59,660 new cases of cancer involving the oral cavity and pharynx will be diagnosed in the US in 2025 and 12,770 will die of the disease. The head and neck region includes the oral cavity, oropharynx, hypopharynx and larynx. Squamous Cell Carcinoma (SCC) of the Head and Neck accounts for about 3-5% of all cancers in the United States. Common risk factors include tobacco and alcohol use and Human PapillomaVirus (HPV) infection. Even though tobacco has long been associated with head and neck cancer development, cannabis has similar carcinogens.

The Standard of Care for patients with Stage III–IVA Head and Neck Squamous Cell Carcinoma (HNSCC) has remained largely static for nearly 2 decades: surgery followed by risk-adapted adjuvant radiotherapy, with or without concurrent Cisplatin based chemotherapy. Despite refinements in technique and supportive care, relapse rates remain high, particularly among patients with adverse pathological features such as extranodal extension and positive margins.

The treatment paradigm for Head and Neck cancer has been rapidly evolving with the recognition and better understanding of immune evasion and the role of immune checkpoints or gate keepers in suppressing antitumor immunity. Blocking the immune checkpoints unleashes the T cells, resulting in T cell proliferation, activation, and a therapeutic response. Checkpoint inhibitors administered in a neoadjuvant setting activates both the priming phase of immunity within tumor tissue, and the effector phase within the tumor microenvironment. It has been shown that neoadjuvant immunotherapy expands more T-cell clones than adjuvant treatment. Preclinical models have also demonstrated that both radiation therapy and Cisplatin chemotherapy increase the PD-L1 expression on the tumor, suggesting that combining radiotherapy with anti-PD-1 therapy could improve the outcomes.

Phase 3 NIVOPOSTOP trial (GORTEC 2018-01) provides compelling evidence that integrating immunotherapy into the adjuvant setting may finally shift this long-standing treatment landscape. Nivolumab (OPDIVO®) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2. Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response.

Study Design and Patient Population
NIVOPOSTOP (NCT03576417) was an international, randomized, open-label Phase 3 study that enrolled 680 patients with completely resected LA-SCCHN (Locally Advanced Squamous Cell Carcinoma of the Head and Neck), which included the oral cavity, oropharynx, hypopharynx, and larynx. Eligible patients were less than 75 years old, with ECOG performance status 0-1, and exhibited high-risk features for recurrence, including extracapsular nodal extension, positive surgical margins, involvement of 4 or more lymph nodes, or extensive perineural invasion. PD-L1 expression was not required for study eligibility. Majority of patients had disease of the oral cavity (58%), about 50% were current smokers, most patients had Stage IVA or IVB disease (83%), and slightly more than one-half of patients (56%) had a PD-L1 Combined Positive Score less than 20. Patients were first stratified by HPV status and enrolling center before being randomly assigned to receive standard CRT or standard CRT plus nivolumab.

Patients were randomized 1:1 to receive:

  • Control Arm (SOC CRT): 66 Gy radiotherapy with three cycles of Cisplatin 100 mg/m² Q3W (N=334).
  • Experimental Arm (NIVO + CRT): One lead-in dose of Nivolumab 240 mg, followed by CRT plus Nivolumab 360 mg Q3W for three cycles, followed by six cycles of Nivolumab 480 mg Q4W for maintenance (N=332).

Both treatment groups were well balanced. The Primary endpoint was Disease Free Survival (DFS). Key Secondary endpoints include Overall Survival (OS) and Safety.

Primary Endpoint Met: Significant Improvement in Disease-Free Survival
At a median follow-up of 30.3 months, the trial met its Primary endpoint. Among the 666 patients included in the Disease-Free Survival (DFS) analysis (ITT population), the addition of adjuvant Nivolumab significantly reduced the risk of disease recurrence or death compared with CRT alone (HR 0.76; 95% CI, 0.60–0.98; P = 0.034).

Three-year DFS rates were 63.1% with NIVO + CRT (95% CI, 57.0–68.7) and 52.5% with CRT alone (95% CI, 46.2–58.4). This represents a 24% relative reduction in recurrence risk with Nivolumab. Importantly, this benefit was observed across all PD-L1 expression levels, supporting the use of this strategy in an unselected population.

Safety Profile: Manageable Toxicity with Increased Grade 3–4 Events
While the addition of Nivolumab was associated with an increase in grade 3-4 adverse events, particularly within the first 100 days post-CRT (13.1% vs. 5.6%), no increase in treatment-related mortality was seen (0.6% vs. 0.7%). Late grade ≥3 toxicities occurring beyond 9 months were rare in both groups and did not exceed grade 3. The overall safety profile was considered acceptable and consistent with known immune-related toxicities.

Locoregional Control Improved with Nivolumab
One of the most noteworthy findings was a significant reduction in locoregional recurrences. At 3 years, locoregional failure occurred in 13% of patients in the NIVO + CRT arm versus 20% in the CRT-only arm (HR 0.63; 95% CI, 0.42–0.94). Interestingly, unlike perioperative immunotherapy regimens such as KEYNOTE-689 that predominantly reduced distant failures, NIVOPOSTOP’s benefit was concentrated in locoregional disease control, suggesting a synergistic effect between radiotherapy and immune checkpoint inhibition.

Survival Data Pending but Trending Favorably
Although Overall Survival (OS) data remain immature, early trends favor the Nivolumab arm. At the time of reporting, 74% of patients receiving NIVO + CRT remained alive at 3 years, compared to 68% in the CRT-alone group. The final OS analysis is planned upon reaching 283 events (currently at 158).

Clinical Context and Expert Perspectives
The NIVOPOSTOP findings stand in sharp contrast to prior trials like KEYNOTE-412 and JAVELIN Head and Neck 100, which failed to show benefit from concurrent immune checkpoint inhibitor with CRT in unselected populations. Notably, the timing and sequencing of immunotherapy in NIVOPOSTOP, administered in the postoperative setting and continued as maintenance may have circumvented the immunosuppressive milieu of CRT and allowed more robust immune priming. The researchers emphasized the clinical need among the ~40–45% of LA-SCCHN patients who relapse after surgery and CRT.

Conclusion
NIVOPOSTOP represents the first successful Phase 3 trial to demonstrate a Disease-Free Survival advantage with the addition of immunotherapy to adjuvant CRT in high-risk, resected LA-SCCHN. With a favorable balance of efficacy and manageable toxicity, this regimen is poised to reshape clinical practice, marking a long-overdue advancement in the postoperative management of head and neck cancer.

NIVOPOSTOP (GORTEC 2018-01): A phase III randomized trial of adjuvant nivolumab added to radio-chemotherapy in patients with resected head and neck squamous cell carcinoma at high risk of relapse. Bourhis J, Auperin A, Borel C, et al. J Clin Oncol 43, 2025 (suppl 17; abstr LBA2).

FDA Approves ZYNYZ® for Squamous Cell Carcinoma of the Anal Canal

SUMMARY: The FDA on May 15, approved Retifanlimab-dlwr (ZYNYZ®), a PD-1–blocking monoclonal antibody, with Carboplatin and Paclitaxel for the first-line treatment of adults with inoperable locally recurrent or metastatic Squamous Cell carcinoma of the Anal Canal (SCAC). The FDA also approved Retifanlimab as a single agent for adults with locally recurrent or metastatic SCAC with disease progression on or intolerance to platinum-based chemotherapy.

The American Cancer Society estimates that 10,930 new cases of Anus, anal canal, and anorectum cancers will be diagnosed in 2025, and 2030 individuals will die of the disease. Squamous Cell carcinoma of the Anal Canal (SCAC) is a rare but increasingly prevalent malignancy, closely associated with persistent infection by high-risk Human PapillomaVirus (HPV), particularly HPV-16 and HPV-18. HPV-driven oncogenesis plays a pivotal role in SCAC development by disrupting tumor suppressor proteins such as p53 and Rb via viral oncoproteins E6 and E7. These oncoproteins also generate a highly immunogenic Tumor MicroEnvironment (TME), recruiting Tumor-Infiltrating Lymphocytes (TILs) and expressing immune checkpoints like PD-L1, providing a compelling rationale for the use of Immune Checkpoint Inhibitors (ICIs) in this disease.

While early-stage SCAC is often curable with chemoradiation, outcomes in advanced or metastatic cases remain poor, with 5-year survival dropping to 30% in Stage IV disease. Platinum-based chemotherapy, particularly the combination of Carboplatin and Paclitaxel as established by the InterAAct trial, has been the frontline standard. However, outcomes have remained suboptimal, fueling efforts to explore combination regimens that leverage the immunogenicity of HPV-driven SCAC.

Rationale for Immunotherapy in SCAC

HPV-positive tumors are characterized by an “inflamed” TME, enriched with TILs and immune regulatory molecules such as PD-1 and PD-L1. This immune signature is associated with both favorable prognosis and responsiveness to immunotherapy. ICIs like Pembrolizumab and Nivolumab have demonstrated modest activity as monotherapy in pretreated SCAC, with Overall Response Rates (ORR) ranging from 13% to 30% and median Progression-Free Survival (PFS) of approximately 2-4 months. However, these agents alone have not transformed outcomes, prompting exploration of synergistic strategies.

Preclinical studies indicate that chemotherapy can enhance immunogenic cell death, promote antigen presentation, and reduce immunosuppressive myeloid populations, thus priming the TME for immune-based therapies. These insights provided the foundation for evaluating the anti–PD-1 antibody Retifanlimab in combination with Carboplatin and Paclitaxel.

Retifanlimab (ZYNYZ®) is a humanized monoclonal antibody targeting PD-1, thereby restoring T-cell activity against tumor cells.

POD1UM-303 (InterAACT 2; NCT04472429) was a randomized, double-blind, multicenter Phase 3 trial that enrolled 308 patients across 81 centers with inoperable, locally recurrent, or metastatic SCAC who were chemotherapy-naive in the advanced setting. Participants received standard Carboplatin (AUC 5, IV day 1) and Paclitaxel (80 mg/m² IV, days 1, 8, and 15) for six cycles, and were randomized 1:1 to receive either:

  • Retifanlimab 500 mg IV every 4 weeks, or
  • Placebo IV every 4 weeks
    Treatment was continued for up to one year or until disease progression or unacceptable toxicity. Cross-over to single-agent Retifanlimab was allowed for patients in the placebo arm upon disease progression.

The Primary endpoint was Progression-Free Survival (PFS) per RECIST v1.1 by Blinded Independent Central Review. Key Secondary endpoints included Overall Survival (OS), Overall Response Rate (ORR), and Duration of Response (DoR).

Clinical Outcomes

  • Progression-Free Survival:
    • Retifanlimab arm: 9.3 months (95% CI, 7.5–11.3)
    • Placebo arm: 7.4 months (95% CI, 7.1–7.7)
    • Hazard ratio: 0.63 (95% CI, 0.47–0.84; P=0.0006)
  • Overall Survival (Interim Analysis):
    • Retifanlimab arm: 29.2 months (95% CI, 24.2–NE)
    • Placebo arm: 23.0 months (95% CI, 15.1–27.9)
    • HR: 0.70 (95% CI, 0.49–1.01), not yet statistically significant
  • Overall Response Rate:
    • Retifanlimab arm: 56% (95% CI, 48%–64%)
    • Placebo arm: 44% (95% CI, 36%–52%)
  • Disease Control Rate: 87% vs 80%, respectively
  • Crossover Allowed: 45% of patients in the placebo arm received Retifanlimab upon progression.

Safety and Tolerability

The combination of Retifanlimab and chemotherapy was generally well tolerated. Immune-related Adverse Events (AEs) increased, as expected with PD-1 blockade, but were manageable and did not significantly impact chemotherapy delivery or dose intensity.

Monotherapy Insights: POD1UM-202

Retifanlimab was also studied as a single agent in POD1UM-202 (NCT03597295), a Phase 2 trial of 94 patients with previously treated, platinum-refractory SCAC:

  • ORR: 14% (95% CI, 8%–23%)
  • Median DOR: 9.5 months
  • Notable Findings: Better responses observed in p16-positive and PD-L1–positive tumors; tumor inflammation signature scores correlated with improved survival.

Conclusion and Clinical Implications

The POD1UM-303 trial marks a major advancement in the treatment of advanced SCAC. Retifanlimab in combination with Carboplatin and Paclitaxel not only met its Primary endpoint but also demonstrated consistent improvements in response rates, survival outcomes, and disease control, without compromising safety.

As the first positive Phase 3 study in this setting, POD1UM-303 establishes a new standard of care for patients with advanced SCAC and solidifies the role of immunotherapy in HPV-associated malignancies. Continued exploration of predictive biomarkers and deeper understanding of the TME will be critical to refining treatment strategies in this rare but challenging cancer.

POD1UM-303/InterAACT 2: Phase 3 study of retifanlimab with carboplatin-paclitaxel (C-P) in patients (Pts) with inoperable locally recurrent or metastatic squamous cell carcinoma of the anal canal (SCAC) not previously treated with systemic chemotherapy (Chemo). Rao S, et al. ESMO Congress 2024, LBA2

Perioperative KEYTRUDA® Reshapes the Treatment Landscape for Resectable Locally Advanced HNSCC

SUMMARY: The American Cancer Society estimates that 59,660 new cases of cancer involving the oral cavity and pharynx will be diagnosed in the US in 2025 and 12,770 will die of the disease. The head and neck region includes the oral cavity, oropharynx, hypopharynx and larynx. Squamous Cell Carcinoma (SCC) of the Head and Neck accounts for about 3-5% of all cancers in the United States. Common risk factors include tobacco and alcohol use and Human PapillomaVirus (HPV) infection. Even though tobacco has long been associated with head and neck cancer development, cannabis has similar carcinogens.

The Standard of Care for patients with Stage III–IVA Head and Neck Squamous Cell Carcinoma (HNSCC) has remained largely static for nearly 2 decades: surgery followed by risk-adapted adjuvant radiotherapy, with or without concurrent chemotherapy. Despite refinements in technique and supportive care, relapse rates remain high, particularly among patients with adverse pathological features such as extranodal extension and positive margins.

The treatment paradigm for Head and Neck cancer has been rapidly evolving with the recognition and better understanding of immune evasion and the role of immune checkpoints or gate keepers in suppressing antitumor immunity. Blocking the immune checkpoints unleashes the T cells, resulting in T cell proliferation, activation, and a therapeutic response. Checkpoint inhibitors administered in a neoadjuvant setting activates both the priming phase of immunity within tumor tissue, and the effector phase within the tumor microenvironment. It has been shown that neoadjuvant immunotherapy expands more T-cell clones than adjuvant treatment. Preclinical models have also demonstrated that both radiation therapy and Cisplatin chemotherapy increase the PD-L1 expression on the tumor, suggesting that combining radiotherapy with anti-PD-1 therapy could improve the outcomes.

Pembrolizumab (KEYTRUDA®) is a fully humanized, Immunoglobulin G4, monoclonal antibody and checkpoint inhibitor, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the tumor-specific effector T cells. Pembrolizumab has been shown to improve Overall Survival in patients with Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma

KEYNOTE-689, a landmark Phase 3 trial, has provided the most compelling evidence to date that perioperative immunotherapy, specifically Pembrolizumab, can significantly improve clinical outcomes for patients with resectable, locally advanced Head and Neck Squamous Cell Carcinoma (HNSCC). This international, randomized, placebo-controlled study enrolled 714 patients (N=714) with newly diagnosed, resectable, Stage III–IVA HNSCC of the oral cavity, oropharynx, larynx, or hypopharynx.

Patients were randomized 1:1 to receive:

  • Investigational arm (N=356):
    • 2 cycles of neoadjuvant Pembrolizumab (200 mg IV Q3W) starting about 3 weeks before surgery.
    • Standard-of-care surgery.
    • Up to 3 doses of Pembrolizumab administered concurrently with adjuvant chemoradiotherapy (depending on pathologic risk).
    • 12 additional adjuvant doses of Pembrolizumab Q3W (total treatment duration: about 1 year).
  • Control arm (N=358):
    • Identical treatment structure, substituting placebo for Pembrolizumab.

PD-L1 expression was assessed via Combined Positive Score (CPS), and stratification included CPS ≥1 and CPS ≥10 subgroups, recognizing the prognostic and potentially predictive value of PD-L1 expression. The Primary endpoint was Event-Free Survival (EFS), defined as time from randomization to disease progression, local/regional recurrence, distant metastasis, or death from any cause. Secondary endpoints included Overall Survival (OS) and Major Pathological Response.

The trial met its Primary endpoint of EFS. At median follow-up of 38.3 months, patients in the investigational arm had significantly improved EFS compared with the Standard of Care arm (median 51.8 months vs. 30.4 months; HR=0.73; P=0.0041). Patients who received Pembrolizumab who had a CPS score ≥10 derived the greatest benefit (median 59.7 months vs. 26.9 months; HR = 0.66; P=0.002) whereas the median EFS in the CPS ≥1 subgroup was 59.7 vs. 29.6 months (HR, 0.70; P = .0014).

Major pathological response defined as 90% or more tumor regression was also notably improved. Among all patients, the major pathological response rate was 9.4% with Pembrolizumab vs. 0% with Standard of Care (P < 0.00001). In the CPS ≥10 subgroup, the major pathological response rate reached 13.7%.

While the interim analysis did not demonstrate a statistically significant OS benefit, trends were favorable, particularly in the CPS ≥10 group (HR, 0.72; P =0.02). Further OS follow-up is ongoing.

Adverse events were consistent with known profiles of checkpoint inhibitors. Grade 3 or more  Treatment-Related Adverse Events (TRAEs) occurred in 44.6% of the Pembrolizumab group and 42.9% in the Standard of Care group. Immune-mediated adverse events were observed in 43.2% of the Pembrolizumab arm, with hypothyroidism being the most common (24.7%). Mortality attributable to treatment was slightly higher with Pembrolizumab (1.1% vs. 0.3%).

The researchers concluded that perioperative Pembrolizumab is now emerging as a new standard of care in the treatment of resectable locally advanced HNSCC. The findings from this study underscore the importance of harnessing the immune system both before and after surgery. Neoadjuvant administration may prime the immune response when tumor antigen burden is highest, while adjuvant therapy may help eliminate residual microscopic disease.

Neoadjuvant and adjuvant pembrolizumab plus standard of care in resectable locally advanced head and neck squamous cell carcinoma: phase 3 KEYNOTE-689 study. Uppaluri R, et al. Abstract CT001. Presented at: American Association for Cancer Research Annual Meeting; April 25-30, 2025; Chicago.

 

FDA Approves OPDIVO® Plus YERVOY® for Unresectable or Metastatic MSI-H/MMR Deficient Colorectal Cancer

SUMMARY: The FDA on April 8, 2025, approved Nivolumab (OPDIVO®) with Ipilimumab (YERVOY®) for adult and pediatric patients 12 years of age and older with unresectable or metastatic MicroSatellite Instability-High (MSI-H) or MisMatch Repair deficient (dMMR) colorectal cancer (CRC). The FDA also converted the accelerated approval to regular approval for single agent Nivolumab for adult and pediatric patients 12 years of age and older with MSI-H or dMMR metastatic CRC, that has progressed following Fluoropyrimidine, Oxaliplatin, and Irinotecan.

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23. The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. MSI is therefore a hallmark of defective/deficient DNA MisMatchRepair (dMMR) system and occurs in 15% of all colorectal cancers. Defective MMR can be a sporadic or heritable event. Approximately 65% of the MSI high colon tumors are sporadic and when sporadic, the DNA MMR gene is MLH1. Defective MMR can manifest as a germline mutation occurring in MMR genes including MLH1, MSH2, MSH6 and PMS2. This produces Lynch Syndrome often called Hereditary Nonpolyposis Colorectal Carcinoma – HNPCC, an Autosomal Dominant disorder that is often associated with a high risk for Colorectal and Endometrial carcinoma, as well as several other malignancies including Ovary, Stomach, Small bowel, Hepatobiliary tract, Brain and Skin. MSI is a hallmark of Lynch Syndrome-associated cancers. MSI high tumors tend to have better outcomes and this has been attributed to the abundance of tumor infiltrating lymphocytes in these tumors from increase immunogenicity. These tumors therefore are susceptible to blockade with immune checkpoint inhibitors.

MSI testing is performed using a PCR or NGS based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors. Tumors considered MSI-H have deficiency of one or more of the DNA MMR genes. MMR gene deficiency can be detected by ImmunoHistoChemistry (IHC). NCCN Guidelines recommend MMR or MSI testing for all patients with a history of Colon or Rectal cancer. Unlike Colorectal and Endometrial cancer, where MSI-H/dMMR testing is routinely undertaken, the characterization of Lynch Syndrome across heterogeneous MSI-H/dMMR tumors is unknown.

Nivolumab is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, whereas Ipilimumab is a fully human immunoglobulin G1 monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4, also known as CD152). Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response.

The present FDA approval is based on CheckMate 8HW, which is an ongoing Phase III, multinational, open-label, randomized trial evaluating Nivolumab plus Ipilimumab as compared with Nivolumab alone or chemotherapy, in patients with MSI-H or dMMR metastatic CRC. In this study, patients with unresectable or mCRC and MSI-H/dMMR status by local testing who had received 0-1 prior line of therapy were randomly assigned in a 2:2:1 ratio to receive either Nivolumab monotherapy (N=353), Nivolumab plus Ipilimumab combination therapy (N=354), or the investigator’s choice of chemotherapy (mFOLFOX6 or FOLFIRI with or without Bevacizumab or Cetuximab (N=132). Patients who had previously received two or more prior lines of therapy for unresectable or metastatic disease were randomly assigned, in a 1:1 ratio, to receive Nivolumab plus Ipilimumab or Nivolumab alone. In the Nivolumab monotherapy arm, patients received Nivolumab 240 mg IV once every two weeks for six doses, followed by 480 mg IV every four weeks. In the Nivolumab plus Ipilimumab arm, patients were given Nivolumab 240 mg IV plus Ipilimumab 1mg/kg IV every three weeks for four doses, followed by Nivolumab 480 mg IV every four weeks. The median patient age was 64 years and tumor location was in the right colon in two thirds of the patients. Treatments continued until disease progression or unacceptable toxicity in all treatment groups or a maximum of 2 years. The dual Primary end points were Progression-Free Survival (PFS) as determined by Blinded Independent Central Review (BICR) comparing Nivolumab plus Ipilimumab to chemotherapy in the first-line therapy setting, and PFS comparing Nivolumab monotherapy to Nivolumab plus Ipilimumab across all lines of therapy, in patients with centrally confirmed MSI-H/dMMR metastatic CRC. At a median follow-up of 31.5 months the results from the prespecified interim analysis (the primary analysis) showed that the PFS outcomes were significantly better with Nivolumab plus Ipilimumab than with chemotherapy (HR=0.21; P<0.001).

The researchers herein reported the first results from the other dual Primary endpoint of PFS for Nivolumab plus Ipilimumab versus Nivolumab monotherapy across all lines of therapy in patients with centrally confirmed MSI-H/dMMR metastatic CRC. Of all the randomized patients 296 in the Nivolumab plus Ipilimumab group and 286 in the Nivolumab monotherapy group had centrally confirmed MSI-H/dMMR status. With a median follow-up of 47.0 months, Nivolumab plus Ipilimumab demonstrated clinically meaningful and statistically significant improvement in PFS by BICR versus Nivolumab monotherapy, with a median PFS Not Reached (NR) in the Nivolumab plus Ipilimumab group, compared to 39.3 months for those on Nivolumab monotherapy (HR=0.62; P= 0.0003). The PFS rates at 12, 24, and 36 months were higher in the Nivolumab plus Ipilimumab group at 76%, 71%, 68% versus 63%, 56%, 51% for Nivolumab monotherapy. The Objective Response Rate (ORR) was significantly higher with Nivolumab plus Ipilimumab at 71%, compared to 58% with Nivolumab alone (P=0.0011). No new safety concerns were identified.

It was concluded that the CheckMate 8HW study met its dual Primary endpoints, with Nivolumab plus Ipilimumab demonstrating a statistically significant and clinically meaningful improvement in PFS compared to Nivolumab monotherapy across all lines of therapy in MSI-H/dMMR metastatic CRC. Moreover, Nivolumab plus Ipilimumab was associated with higher ORR, confirming its potential as a new standard of care for patients with MSI-H/dMMR metastatic CRC. The CheckMate 8HW study is a pivotal contribution to the treatment landscape of MSI-H/dMMR metastatic Colorectal cancer, providing compelling evidence for the use of Nivolumab plus Ipilimumab in the first-line and beyond.

Nivolumab plus ipilimumab versus nivolumab in microsatellite instability-high metastatic colorectal cancer (CheckMate 8HW): a randomised, open-label, phase 3 trial. Andre T, Elez E, Lenz H-J, et al. The Lancet. 2025; 405:383-395

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

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&reg;)  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

 

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

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

Ongoing Benefit with Enfortumab Vedotin Plus Pembrolizumab in Metastatic Urothelial Carcinoma

SUMMARY: The American Cancer Society estimates that in the United States for 2025, about 84,870 new cases of bladder cancer will be diagnosed and approximately 17,420 patients will die 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. Approximately 12% of urothelial cancer cases at diagnosis are locally advanced or metastatic.

Patients with urothelial carcinoma are currently treated in the first line setting with a Platinum based chemotherapy regimen, and a checkpoint Inhibitor (PD-1 or PD-L1 inhibitor) in the second line setting. However, approximately 50% of patients with advanced urothelial carcinoma are ineligible for Cisplatin-based chemotherapy due to toxicities, and responses are rarely durable. There is therefore a critical need for effective and tolerable first line treatment options in locally advanced or metastatic urothelial carcinoma.

Enfortumab vedotin-ejfv (PADCEV®) is a first-in-class Antibody-Drug Conjugate (ADC) that targets Nectin-4, a cell adhesion molecule highly expressed in urothelial cancers and other solid tumors. Nectin-4 has been implicated in tumor cell growth and proliferation. Following binding to Nectin-4 on the cell surface, Enfortumab vedotin becomes internalized and is processed by lysosomes, with the liberation of its cytotoxic payload, MonoMethyl Auristatin E (MMAE), which in turn disrupts microtubule assembly, leading to cell cycle arrest and apoptosis. Enfortumab vedotin resulted in significantly longer Overall Survival, Progression Free Survival, and a higher Overall Response Rate, than standard chemotherapy, in patients with locally advanced or metastatic urothelial carcinoma, who had previously received Platinum-based treatment and a PD-1 or PD-L1 inhibitor. Preclinical studies with Enfortumab vedotin have shown hallmarks of immune cell death potentially augmented by PD-1/PD-L1 inhibitors, and the rationale for this clinical trial was based on results from a previous cohort study.

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. Pembrolizumab is the first agent to improve Overall Survival over chemotherapy, in the second line setting, for patients with recurrent, advanced urothelial carcinoma, and a significant proportion of patients who respond, have very durable responses.

EV-302 is a landmark Phase III, global, open-label, randomized trial comparing the efficacy and safety of Enfortumab vedotin and Pembrolizumab with the efficacy and safety of platinum-based chemotherapy, in patients with previously untreated locally advanced or metastatic urothelial carcinoma. A total of 886 eligible patients were randomly assigned in a 1:1 ratio to receive 3-week cycles of Enfortumab vedotin 1.25 mg/kg IV on days 1 and 8 and Pembrolizumab 200 mg IV on day 1 of every 3-week cycle (N=442) or chemotherapy consisting of Gemcitabine and either Cisplatin or Carboplatin (N=444), determined on the basis of eligibility to receive Cisplatin, for a maximum of 6 cycles. The maximum number of Pembrolizumab cycles allowed was 35 and there was no maximum number of cycles set for Enfortumab vedotin. The treatment groups were well balanced. The median age was 69 yrs and randomization was stratified according to eligibility to receive Cisplatin (eligible or ineligible), PD-L1 expression status (High-CPS 10 or more versus Low-CPS less than 10), and liver metastases (present or absent). The co-Primary end points were Progression Free Survival (PFS) and Overall Survival (OS) as assessed by Blinded Independent Central Review (BICR). Secondary end points included Overall Response Rate (ORR) as assessed by BICR, Duration of Response, and Safety.

In the primary analysis of EV-302 (KEYNOTE-A39) study, the combination of Enfortumab vedotin plus Pembrolizumab group nearly doubled median PFS (12.5 months versus 6.3 months) and OS (31.5 months versus to 16.1 months), when compared to platinum-based chemotherapy, in patients with previously untreated locally advanced or metastatic urothelial carcinoma.

In this report, the researchers reported the outcomes of EV-302 study after 1 year of additional follow-up (about 2.5 years of median follow-up), and an exploratory analysis of patients with confirmed Complete Response.

The PFS benefit with Enfortumab vedotin plus Pembrolizumab was maintained with an additional year of follow-up (12.5 versus 6.3 months; HR=0.48; P<0.00001). The OS benefit was also maintained with Enfortumab vedotin plus Pembrolizumab with a 49% reduction in the risk of death, when compared to platinum-based chemotherapy (33.8 versus 15.9 months; HR=0.51; P<0.00001). The PFS and OS benefit was observed across prespecified subgroups, including the Cisplatin-eligible and ineligible patients.

The ORR in the Enfortumab vedotin plus Pembrolizumab group was 67.5% versus 44.2% in the chemotherapy group (P<0.0.001) and the median Duration of Response was 23.3 months versus 7.0 months, respectively. A Complete Response was observed in 30.4% of patients treated with Enfortumab vedotin plus Pembrolizumab versus 14.5% among patients treated with chemotherapy. The median duration of Complete Response was not reached for Enfortumab vedotin plus Pembrolizumab and 15.2 months for chemotherapy. The probability of maintaining a Complete Response at 2 years with Enfortumab vedotin plus Pembrolizumab was 74%. For patients with a confirmed Complete Response, the 2-year PFS and OS rates were 78% and 95% in the Enfortumab vedotin plus Pembrolizumab group, respectively, versus 54% and 86% in the chemotherapy group, respectively.

It was concluded that, these data with longer follow up suggests that treatment with Enfortumab vedotin plus Pembrolizumab resulted in significantly superior outcomes, compared to chemotherapy, in patients with untreated locally advanced or metastatic urothelial carcinoma, emerging as a potential new standard of care, irrespective of Cisplatin eligibility. The results from this study mark a significant paradigm shift in the management of locally advanced or metastatic urothelial carcinoma, offering new hope for patients and clinicians alike.

EV-302: Updated analysis from the phase 3 global study of enfortumab vedotin in combination with pembrolizumab (EV+P) vs chemotherapy (chemo) in previously untreated locally advanced or metastatic urothelial carcinoma (la/mUC). Powles T, Van Der Heijden M, Loriot Y, et al. 2025 ASCO Genitourinary Cancers Symposium. Abstract 664. Journal of Clinical Oncology. Volume 43, Number 5_suppl February 2025.

Late Breaking Abstract – 2025 ASCO GI Symposium: Personalized Neoantigen Vaccine in Metastatic Colorectal Cancer

SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. MSI is therefore a hallmark of defective/deficient DNA MisMatchRepair (dMMR) system and occurs in 15% of all colorectal cancers. MSI testing is performed using a PCR or NGS based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors.

Checkpoint inhibitors have revolutionized cancer treatment. They are however not as effective in patients with “cold tumors” (MSS), as these tumors effectively hide themselves from the immune system and do not trigger an immune response following treatment with checkpoint inhibitors.

GRANITE is a personalized neoantigen immunotherapy designed to trigger a strong T-cell immune response against a patient’s tumor. A biopsy of the tumor is performed to identify unique mutations (neoantigens) present in the tumor of patients. An AI platform, EDGE, developed and designed by Gritstone Bio is able to identify critical T-cell vaccine targets, and predict which neoantigens are most likely to be recognized by the immune system of patients. The system has an 80% accuracy rate in selecting the top 20 most immunogenic neoantigens, most likely to generate an immune response in a given patient. The selected neoantigens are incorporated into a chimpanzee adenovirus-based primer vaccine and a Self-Amplifying mRNA (SAM) booster vaccine to train the immune system that leads to an induction of both cytotoxic T-lymphocyte and memory T-cell dependent immune responses, that specifically target and destroy the patients cancer cells that express these neoantigens. This vaccine (GRANITE) is administered via intramuscular injection alongside immune checkpoint inhibitors. Thus GRANITE primes the immune system to recognize and attack these tumors. This vaccine is customized for each patient based on the unique mutations of their tumor. In essence, GRANITE helps make the “cold tumors” visible to the immune system, potentially improving patient outcomes.

GRANITE immunotherapy regimen was evaluated in combination with Nivolumab and Ipilimumab, and compared to the combination of Nivolumab and Ipilimumab alone in a Phase1/2 involving patients with advanced metastatic solid tumors. This study demonstrated robust T-cell activation against targeted neoantigens with no dose-limiting toxicities, and over 50% of patients had a reduction in their circulating tumor DNA (ctDNA) and improved Overall Survival (Palmer CD, et al. Nature 2022).

GRANITE immunotherapy regimen is now being studied as first line metastatic treatment in a randomized Phase 2 trial, among patients with Microsatellite-Stable (MSS) Colorectal cancer patients. GO-010 is an ongoing Phase 2/3, randomized, open-label, multi-center study evaluating the efficacy and safety of GRANITE immunotherapy regimen in combination with Checkpoint Inhibitors (CPIs) as an add-on to Fluoropyrimidine/Bevacizumab as maintenance treatment, following first line therapy with FOLFOX/Bevacizumab, in patients with mCRC. In this study, 104 patients were randomized in a 1:1 ratio, and 67 patients were included in this treated analysis with 39 patients assigned to the GRANITE arm and 28 patients to the control arm. (36 patients withdrew from the study primarily due to early progressive disease or withdrawal of consent, and one patient has yet to begin study treatment). The vaccine manufacturing success rate was 100%. Both treatment groups were well balanced with regards to demographics, clinical characteristics stage, sidedness and presence of liver metastases. Approximately 75% of patients had liver metastases. For the Phase 2 portion of this study, the Primary end point being assessed is molecular response defined as 30% or more decrease from baseline in ctDNA. For the Phase 3 portion of this trial, the Primary end point is Progression Free Survival (PFS). Secondary end points for both Phase 2 and 3 include Adverse Events, Overall Survival (OS), Overall Response Rate (ORR), Duration of Response (DoR) and Clinical Benefit Rate.

Preliminary data from the Phase 2 portion of a Phase 2/3 study showed a positive early trend in PFS for GRANITE immunotherapy patients with a Hazard Ratio (HR) of 0.82 in all patients, HR of 0.52 in high-risk patients1 (more than 90% with liver metastases). The median PFS was 12 months with GRANITE immunotherapy versus 7 months for the control group. Long-term ctDNA responses aligned with positive PFS trend favoring GRANITE immunotherapy patients versus control patients.

In the high-risk group, between first blood draw (time of randomization) and last blood draw (most recent study visit), the ctDNA shifted from high (more than 2% VAF-Variant Allele Frequency) to low (2% or less VAF) in 56% of patients treated with GRANITE immunotherapy versus 22% of control patients. Progressive disease was observed in 44% versus 78% respectively, within this group.

In the low-risk group of patients whose ctDNA was negative after induction chemotherapy, sustained ctDNA negativity was observed in 67% of GRANITE immunotherapy recipients versus 38% in the control patients. Progressive disease was observed in 11% and 38% of these patients, respectively. GRANITE immunotherapy was well tolerated and vast majority of adverse events were Grade1/2 and no patients discontinued study treatment due to an adverse event.

In conclusion, this preliminary Phase 2 results are highly encouraging and suggested that GRANITE immunotherapy demonstrated positive early PFS and long-term ctDNA responses, compared with Fluoropyrimidine/Bevacizumab alone, in front-line metastatic MSS-Colorectal cancer, providing the rationale for a confirmatory Phase 3 trial.

A randomized phase 2 study of an individualized neoantigen-targeting immunotherapy in patients with newly diagnosed metastatic microsatellite stable colorectal cancer (MSS-CRC). Hecht JR, Spira AI, Nguyen AV, et al. J Clin Oncol 43, 2025 (suppl 4; abstr LBA13). DOI 10.1200/JCO.2025.43.4_suppl.LBA13

Survival Benefits with Perioperative IMFINZI® Combined with Neoadjuvant Chemotherapy in Muscle Invasive Bladder Cancer

SUMMARY: The American Cancer Society estimates that in the United States for 2025, about 84,870 new cases of bladder cancer will be diagnosed and approximately 17,420 patients will die 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. Approximately 12% of urothelial cancer cases at diagnosis are locally advanced or metastatic.

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. Perioperative immunotherapy, particularly with immune checkpoint inhibitors, has shown promise in improving these outcomes. 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.

Durvalumab (IMFINZI®) is a selective, high-affinity human IgG1 monoclonal antibody directed against PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80. A preceding single-group, Phase 2 trial indicated that perioperative Durvalumab, combined with neoadjuvant Gemcitabine plus Cisplatin chemotherapy followed by radical surgery, was both safe and effective. Building on these findings, the Phase 3 NIAGARA trial aimed to evaluate the efficacy and safety of perioperative Durvalumab combined with neoadjuvant chemotherapy (Gemcitabine plus Cisplatin), followed by radical cystectomy, compared with neoadjuvant chemotherapy alone followed by radical cystectomy, in Cisplatin-eligible MIBC patients.

The NIAGARA trial was an open-label, randomized, multicenter, Phase 3 study, enrolling 1,063 (N=1063) Cisplatin-eligible patients with Muscle Invasive Bladder Cancer (clinical stage cT2–T4aN0/1M0). Patients were randomized in a 1:1 ratio to receive one of two treatment regimens. The experimental arm (Durvalumab group) included neoadjuvant Durvalumab 1500 mg IV alongside Gemcitabine plus Cisplatin every 3 weeks for 4 cycles, followed by radical cystectomy and adjuvant Durvalumab monotherapy 1500 mg IV every 4 weeks for up to 8 cycles (N=533). The comparison arm consisted of neoadjuvant Gemcitabine plus Cisplatin followed by radical cystectomy alone, without the addition of Durvalumab (N=530). Patients were stratified by clinical tumor stage (cT2N0 vs more than cT2N0), renal function (CrCl 60 mL/min or more vs 40 or more to less than 60 mL/min), and PD-L1 status (high vs low/negative). The dual Primary endpoints of the trial were Event-Free Survival (EFS) and pathological Complete Response (pCR), with Overall Survival (OS) as a key Secondary endpoint, as well as Metastasis Free Survival and Disease-Specific Survival. Event-Free Survival was defined as the time from randomization until progression that precluded surgery, failure to undergo surgery, recurrence after cystectomy, or death from any cause.

In the pre-planned interim analysis, the results demonstrated a significant improvement in both EFS and OS in the Durvalumab group compared to the chemotherapy-alone group. At 24 months, the estimated EFS was 67.8% in the Durvalumab group, compared to 59.8% in the comparison group (HR=0.68; P<0.001). Furthermore, the estimated OS at 24 months was 82.2% in the Durvalumab group versus 75.2% in the comparison group (HR for death=0.75; P=0.01). A pathological Complete Response (pCR) as assessed by central pathology review was noted in 37.3% of the patients in the Durvalumab group and in 27.5% of those in the comparison group. Notably, the percentage of patients who underwent radical cystectomy was similar between the two groups, with 88% in the Durvalumab group and 83% in the comparison group, indicating that the addition of Durvalumab did not reduce surgical completion rates.

An exploratory post hoc analysis of EFS and OS in patients with pCR versus those without pCR was also performed in the intent-to-treat population. The researchers herein reported additional outcomes and exploratory analysis results from NIAGARA study.

Patients in the Durvalumab group had a 33% reduction in risk of developing distant metastases or death (HR=0.67; P<0.001), and 31% reduction in risk of death from bladder cancer (HR=0.69; P=0.008) versus patients in the comparator group. More patients in the Durvalumab group achieved a pCR at the time of surgery versus the comparator (37% versus 28%) and patients who achieved a pCR had better EFS and OS, compared to those who did not. Patients in the Durvalumab group derived greater EFS and OS benefit versus the comparator group in both pCR group (EFS HR=0.58; OS HR=0.72), reducing the risk of disease progression or death by 42% and the risk of death by 28%, as well as non-pCR group (EFS HR=0.77; OS HR=0.84), reducing the risk of disease progression or death by 23% and risk of death by 16%. The most common immune-related adverse events included hypothyroidism in 10% of patients treated with Durvalumab compared to 1% in the comparator group, and hyperthyroidism in 3% versus 0.8% respectively. All immune mediated adverse events resolved in 41% of affected patients in the Durvalumab group and 44% in the comparator group.

It was concluded that the addition of perioperative Durvalumab to neoadjuvant chemotherapy significantly improved EFS and OS in both pCR and non-pCR groups, compared to chemotherapy alone, without compromising the ability to perform radical cystectomy. Further, perioperative Durvalumab combined with neoadjuvant chemotherapy reduced the risk of developing metastases and death from bladder cancer. These results are practice-changing, marking a major advancement in the treatment of MIBC. The findings support the hypothesis that perioperative immune checkpoint inhibitors, by priming the immune system before surgery and targeting residual micrometastatic disease post-surgery, improve long-term clinical outcomes. Biomarkers like circulating tumor DNA (ctDNA) could be pivotal in guiding treatment decisions, as emerging data suggests that negative ctDNA status post-neoadjuvant therapy correlates with reduced relapse risk.

Additional efficacy and safety outcomes and an exploratory analysis of the impact of pathological complete response (pCR) on long-term outcomes from NIAGARA. Galsky M, Van Der Heijden M, Catto J, et al. J Clin Oncol 43, 2025 (suppl 5; abstr 659). DOI 10.1200/JCO.2025.43.5_suppl.659

AI Tool SCORPIO Predicts Overall Survival in Patients Receiving Therapy with Immune Checkpoint Inhibitors

SUMMARY: Immune checkpoint inhibitors (ICIs) have dramatically transformed the management and prognosis of various malignancies. By enhancing the ability of the immune system to identify and destroy cancer cells, ICIs have provided significant improvements in treatment outcomes across a range of tumor types.

Currently, Tumor Mutational Burden (TMB) and PD-L1 expression are the primary biomarkers approved by the FDA for predicting ICI efficacy. While these biomarkers have shown promise, they exhibit limited accuracy and face significant practical limitations, such as the need for sufficient tumor tissue for TMB analysis and the lack of standardized protocols for PD-L1 ImmunoHistoChemistry (IHC). These challenges underscore the need for a predictive model that is more accessible, cost-effective, and applicable across diverse healthcare settings.

Machine learning is a a branch of artificial intelligence that enables algorithms to learn from data, and identify key patterns and make predictions based on available clinical and biological data. SCORPIO is an AI-based model that was developed to address this clinical need, and provides an accurate and scalable tool for predicting patient responses to ICIs.

Study Design: The present study employed a machine learning approach to predict the efficacy of ICIs across a range of cancer types. By using routine blood tests as well as clinical characteristics, and utilizing data from diverse populations and cancer types, SCORPIO aimed to provide a broadly applicable predictive tool that could be used in real-world clinical settings to guide treatment decisions, with the goal of improving precision medicine. SCORPIO was developed and validated using retrospective data from multiple cohorts, including internal data from two major cancer centers (Memorial Sloan Kettering Cancer Center and Mount Sinai Health System, as well as data from 10 global Phase 3 clinical trials.

Participants: This study encompassed a total of 9,745 patients treated with ICIs across 21 different cancer types. The participants came from diverse backgrounds, including varying ethnicities, socioeconomic statuses, comorbidities, and health literacy levels, which added to the robustness of this model and real-world applicability. The study included data from patients at Memorial Sloan Kettering Cancer Center (2,000 patients), Mount Sinai Health System (1,159 patients), and global clinical trials (4,447 patients), representing the largest dataset in cancer immunotherapy to date.

Data Collection Methods: The SCORPIO model was trained using routine blood test results and basic clinical variables such as age, gender, cancer type, and prior treatments. The model was validated across multiple datasets to ensure that it could accurately predict both overall survival (OS) and Clinical Benefits (Response Rate and stable disease) for patients treated with ICIs. This study utilized machine learning algorithms to identify patterns in this data and make predictions about patient outcomes.

Analysis Techniques: Time-dependent Area Under the receiver operating characteristic Curve (AUC) was used to evaluate the predictive accuracy of SCORPIO for OS across different time points (6, 12, 18, 24, and 30 months). The performance of this model was compared to existing FDA-approved biomarkers, including TMB and PD-L1 immunostaining, to assess its superiority in predicting patient outcomes.

Results: The SCORPIO model demonstrated strong predictive performance in multiple cohorts. In internal testing, SCORPIO achieved median time-dependent AUC values of 0.763 and 0.759 for predicting OS at various time points, significantly outperforming TMB, which achieved AUC values of 0.503 and 0.543. SCORPIO also outperformed TMB for predicting clinical benefit, with AUCs of 0.714 and 0.641, compared to TMB’s 0.546 and 0.573. Additionally, SCORPIO was able to predict clinical outcomes more accurately than PD-L1 IHC. 
External validation using data from 10 global phase 3 clinical trials and a real-world cohort from Mount Sinai Health System further supported the predictive power of SCORPIO. Despite the heterogeneity in the Mount Sinai Health System cohort, performance of SCORPIO remained consistent, demonstrating its potential for broad applicability in different patient populations and healthcare settings. While SCORPIO performed consistently well for Overall Survival prediction, its ability to predict Clinical Benefit varied across cancer types and cohorts, indicating that while the model is reliable for survival prognosis, there may still be challenges in accurately predicting Response Rate or stable disease in some contexts.

Conclusion: The SCORPIO model represents a significant advancement in the field of cancer immunotherapy. By leveraging routine blood tests and basic clinical data, SCORPIO provides a highly accurate and accessible method for predicting patient response to ICIs, surpassing the performance of existing FDA-approved biomarkers like TMB and PD-L1 IHC. Its consistent performance across diverse patient populations and cancer types makes it a promising tool for precision oncology.

This model could revolutionize the way physicians identify patients who are most likely to benefit from ICIs, offering a cost-effective, scalable alternative to current biomarkers that rely on complex genomic and immunologic assays. The widespread use of SCORPIO in clinical practice could improve patient outcomes by guiding more personalized treatment decisions, especially in settings where resources for advanced biomarker testing are limited. Future studies will focus on further refining the model to enhance its ability to predict clinical benefit across all cancer types and patient cohorts.

Prediction of checkpoint inhibitor immunotherapy efficacy for cancer using routine blood tests and clinical data. Yoo, S-K, Fitzgerald CW, Cho BA, et al. Nat Med (2025). https://doi.org/10.1038/s41591-024-03398-5