First-line avelumab treatment in patients with metastatic Merkel cell carcinoma: 4-year follow-up from part B of the JAVELIN Merkel 200 study

May 18, 2024



Publication Date

May 18, 2024


D' Angelo SP, Lebbe C, Mortier L, Brohl AS, Fazio N, Grob JJ, Prinzi N, Hanna GJ, Hassel JC, Kiecker F, Heydebreck A, Guzel G, Nghiem P Summary

Immunotherapy is a type of drug that helps fight cancer by boosting the immune system and has become the standard treatment for Merkel cell carcinoma (MCC) that has spread distantly in the body (metastatic MCC) or cannot be treated with surgery/radiation. This study summarizes the 4-year results from a clinical trial that included 116 metastatic MCC patients on the immunotherapy avelumab, and that led to the approval of avelumab for MCC. The results showed that patients receiving avelumab survived longer on average than patients receiving chemotherapy (20 vs 10-14 months). 4 years after the trial started, most patients (94%) had stopped avelumab and 38% of the patients were still alive. This clinical trial is the largest one done in patients with MCC and supports that avelumab is effective in the long-term for patients with metastatic MCC, especially when compared to chemotherapy.



Results from the JAVELIN Merkel 200 study led to the approval of avelumab [an anti–programmed death-ligand 1 (PD-L1) antibody] for the treatment of metastatic Merkel cell carcinoma (mMCC) in multiple countries and its inclusion in the treatment guidelines as a preferred or recommended therapy in this setting. Here, we report 4-year follow-up results from the cohort of patients with mMCC who received avelumab as first-line treatment.

Patients and methods

In part B of JAVELIN Merkel 200, a single-arm, open-label, phase II study, patients with mMCC who had not received prior systemic therapy for metastatic disease received avelumab 10 mg/kg via intravenous infusion every 2 weeks until confirmed disease progression, unacceptable toxicity, or withdrawal. In this analysis, long-term overall survival (OS), patient disposition, and subsequent treatment were analyzed.


In total, 116 patients received first-line avelumab. At the data cutoff (2 February 2022), the median follow-up was 54.3 months (range 48.0-69.7 months). Seven patients (6.0%) remained on treatment and an additional 21 patients remained in follow-up (18.1%); 72 patients (62.1%) had died. The median OS was 20.3 months [95% confidence interval (CI) 12.4-42.0 months], with a 4-year OS rate of 38% (95% CI 29% to 47%). In patients with PD-L1+ or PD-L1− tumors, the 4-year OS rate was 48% (95% CI 26% to 67%) and 35% (95% CI 25% to 45%), respectively. In total, 48 patients (41.4%) received poststudy anticancer drug therapy, most commonly etoposide (20.7%), carboplatin (19.0%), and avelumab (12.1%).


Avelumab first-line monotherapy in patients with mMCC resulted in meaningful long-term OS, which compared favorably with historical studies of first-line chemotherapy. These results further support the role of avelumab as a standard of care for patients with mMCC.

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