Avelumab delivers clinically meaningful outcomes in older, routine-care patients with Merkel cell carcinoma despite frequent adverse events, according to findings presented on October 2 at the European Academy of Dermatology and Venereology 2026 Congress in Vienna. The retrospective study demonstrates the immunotherapy’s real-world efficacy in a vulnerable demographic.
Real-World Cohort Demonstrates Efficacy in Older Patients
In a real-world cohort of older patients in Austria, avelumab, marketed as Bavencio, proved effective for treating Merkel cell carcinoma (MCC). Magdalena Forstinger, MD, a physician-researcher with Sigmund Freud Privatuniversität and Klinik Hietzing in Vienna, presented these findings at the EADV 2026 Congress. In 2017, avelumab, a programmed death ligand-1 (PD-L1)-blocking antibody, became the first treatment approved by the FDA for MCC. However, clinical evidence regarding its safety and efficacy in routine care settings remained sparse, particularly for older populations who frequently present with comorbidities and compromised immune systems and are typically underrepresented in formal clinical trials.
The nationwide, multicenter, retrospective chart review examined patients with inoperable locally advanced or metastatic MCC who received at least one cycle of avelumab. The analysis included 49 patients with a median age of 81 years, ranging from 62 to 96 years old. Cardiovascular, metabolic, oncologic, and pulmonary conditions represented the most common baseline comorbidities among the cohort.
Clinical Takeaways from the Vienna Evaluation
- Nearly half of evaluable patients responded to avelumab treatment in this routine care environment.
- Median real-world progression-free survival reached 10.1 months, while median real-world overall survival stood at 22.9 months.
- Adverse events occurred in 71.4% of patients, requiring careful clinical monitoring and management.
Survival Outcomes and Response Rates in Routine Practice
At the initiation of treatment, 42.9% of study participants presented with stage IIIB MCC, while 57.1% presented with stage IV disease. Furthermore, 16.3% of the cohort were immunocompromised or immunosuppressed, and 77.6% maintained an ECOG performance status ≤ 1. Avelumab served as the first-line monotherapy in 77.6% of cases, with 22.4% receiving concurrent modalities such as radiotherapy. The median follow-up period extended to 8.9 months, with a range spanning from 0 to 73.1 months.
Nearly half of the 48 evaluable patients demonstrated a measurable response to the therapy. The primary endpoint of median real-world progression-free survival was recorded at 10.1 months with a 95% confidence interval ranging from 1.8 to 18.4 months. The real-world objective response rate reached 47.9%, and the median real-world overall survival hit 22.9 months. Additionally, median time to response measured 3.9 months, and the median duration of response among active responders registered at 19.2 months.
| Clinical Endpoint | Real-World Study Metric |
|---|---|
| Median Age of Cohort | 81 Years (Range: 62-96) |
| Real-World Progression-Free Survival | 10.1 Months |
| Real-World Overall Survival | 22.9 Months |
| Real-World Objective Response Rate | 47.9% |
| Patients Experiencing Adverse Events | 71.4% |
Forstinger noted that real-world progression-free survival and overall survival aligned closely with outcomes published in the 2021 phase 2 JAVELIN Merkel 200 trial evaluating first-line avelumab for metastatic MCC. However, the real-world objective response rate was lower. JAVELIN did not include immunocompromised patients, she added.
Managing Immune-Related Adverse Events in Vulnerable Populations
Safety evaluations revealed that 71.4% of patients experienced an adverse event during treatment. Specifically, 53.1% encountered an immune- and/or treatment-related adverse event, with 24.5% experiencing a grade ≥ 3 adverse event. These complications prompted treatment interruptions or discontinuations in 28.6% of participants, including permanent discontinuation for 12.2% of the cohort.
Previously documented adverse events associated with avelumab in MCC treatment include fatigue, musculoskeletal pain, infusion-related reactions, rash, nausea, constipation, cough, and diarrhea. Potentially serious immune-mediated adverse reactions involve pneumonitis, colitis, hepatitis, endocrinopathies, nephritis with renal dysfunction, and dermatologic reactions.
A post-hoc analysis indicated that scores of ≤ 1 on the ECOG performance status scale associated with lower hazard ratios for real-world progression-free survival and overall survival. Forstinger emphasized that these specific survival correlations warrant interpretation strictly as hypothesis-generating data.
Consulting a Doctor
Forstinger reported no relevant financial relationships.
References
- European Academy of Dermatology and Venereology (EADV) 2026 Congress, Vienna.
- JAVELIN Merkel 200 Phase 2 Clinical Trial Data.
