Real-world safety and effectiveness of avelumab in immune-compromised (IC) and non-IC patients with Merkel cell carcinoma (MCC): Results from a prospective German registry (MCC-TRIM)

Merkelcell.org Summary

Merkel cell carcinoma (MCC) is a rare but fast-growing skin cancer that can spread to other parts of the body. One common treatment is immunotherapy, a drug that helps the immune system fight cancer. However, some people with MCC have weak immune systems (immunosuppressed) because of conditions like HIV, organ transplants, or blood cancers such as leukemia. These immunocompromised patients are usually left out of clinical trials, so doctors don’t know much about how well immunotherapy works for them.
A clinical trial in Germany from 2019–2023 looked at 54 immunocompromised and 189 healthy MCC patients who were treated with the immunotherapy drug Avelumab. About 29% of the immunocompromised patients responded to the drug, compared to 35% of the healthy ones. On average, immunocompromised patients lived 9.9 months after starting immunotherapy, while healthy patients lived 38.2 months. Both groups had similar side effects.
This study shows that immunotherapy is safe for immunocompromised MCC patients and can still help fight their MCC. Even though healthy patients had longer responses, immunocompromised patients still saw benefits. For now, immunotherapy remains the best treatment option for MCC patients with cancer that has spread, whether they are immunocompromised or not.

This study was sponsored by Merck Health Care/MerckSerono.

Abstract

Background: MCC is a rare and aggressive form of skin cancer. Avelumab was the first immunotherapy approved for patients with metastatic MCC in Europe. Immunosuppression is an established risk factor for developing MCC, but IC patients have typically been excluded from clinical trials of immunotherapies. We report an analysis of clinical characteristics, survival outcomes, and safety in IC and non-IC patients with MCC treated with avelumab in routine clinical practice in Germany. Methods: This prospective, noninterventional, multicenter, dynamic cohort study (MCC-TRIM; EUPAS25338) enrolled patients with MCC in Germany between April 2019 and September 2023. Primary data from a study-specific electronic case report form and secondary data from the German national skin cancer registry were combined. For this analysis, avelumab-treated patients were grouped as IC or non-IC based on prespecified comorbid conditions and concomitant medications. Survival outcomes with first-line avelumab treatment were assessed using the Kaplan-Meier method. Results: Among 875 patients with MCC (various disease stages) enrolled in the study, 243 were treated with avelumab, of whom 189 (77.8%) were considered non-IC and 54 (22.2%) were considered IC. Patient characteristics are summarized in the Table. At data cutoff (March 2024), median follow-up (IQR) was 14.3 months (6.4-29.4) in the non-IC subgroup and 8.9 (4.2-22.8) in the IC subgroup. In non-IC and IC subgroups, median (95% CI) overall survival from start of first-line avelumab was 38.2 (15.7-not estimable) and 9.9 (4.8-29.8) months, and median progression-free survival was 7.9 (4.0-11.6) and 4.3 (1.0-7.8) months, respectively. The incidence rate of ADRs related to avelumab was 1.01 (95% CI, 0.75-1.34) events per person-year in the non-IC subgroup and 0.71 (95% CI, 0.32-1.45) events per person-year in the IC subgroup. Conclusions: Results from this German nationwide registry showed the safe and effective use of avelumab in routine clinical practice for IC and non-IC patients with MCC.