1147P - First-line treatment (tx) patterns and overall survival (OS) of patients (pts) with advanced Merkel cell carcinoma (aMCC) in England from 2013-2022: Results of a nationwide observational cohort study

Background

MCC is a rare, aggressive cutaneous neoplasm. In September 2017, the European Commission approved avelumab (Ave) for the tx of metastatic MCC based on demonstrated meaningful survival benefit. This study sought to investigate tx patterns and OS of pts with aMCC (stage III/IV) in the National Cancer Registration Dataset (NCRD) in England.

Methods

This cohort included pts ≥18 years and newly diagnosed with stage III/IV MCC (ICD-O: C44, 8247 morphology) between January 2013 and December 2020 in the NCRD in England and followed up until May 2022. Summary and descriptive statistics were calculated for categorical and continuous variables. The Kaplan-Meier method was used to estimate median OS from diagnosis date (overall) and OS from initiation of 1L tx stratified by regimens received and by stage at baseline.

Results

A total of 667 pts with aMCC were included. Mean age (SD) was 77.4 years (10.3), most pts were male (61.0%), and 14.1% were immunocompromised. At diagnosis, 66.3% and 33.7% had stage III and IV disease, respectively. The mean (SD) baseline modified Deyo-Charlson Comorbidity Index was 4.0 (1.8). Overall, 478 pts (71.7%) died during follow-up; median OS from diagnosis was 18.4 months (95% CI, 15.6-20.9). In total, 199 pts (29.8%) received 1L tx (39.2% Ave, 60.8% non-Ave). When stratified by stage, 26.9% of stage III pts received systemic tx (39.5% Ave, 60.5% non-Ave); the corresponding numbers for stage IV pts were 35.6% (38.7% Ave, 61.3% non-Ave). OS from 1L initiation is presented in the table. Table: 1147P

NE, not estimable.*Non-Ave includes 95.5% chemotherapy and 4.5% other treatment.

Conclusions

This nationwide real-world study of pts with aMCC demonstrates the effectiveness of Ave with considerably prolonged survival in pts with both stage III and stage IV disease. The study findings validate results from the JAVELIN Merkel 200 clinical trial and other observational studies.

Clinical trial identification

Editorial acknowledgement

Editorial support was provided by Eleanor Bishop on behalf of Clinical Thinking and was funded by Merck and Pfizer.

Legal entity responsible for the study

The authors.

Funding

This study was sponsored by Merck (CrossRef Funder ID: 10.13039/100009945), as part of an alliance between Merck and Pfizer.

Disclosure

C. Knott: Financial Interests, Personal, Full or part-time Employment: Health Data Insight CIC; NHS England. S. Mahmoudpour, M. Kearney: Financial Interests, Personal, Full or part-time Employment: Merck. E. Boutmy: Financial Interests, Personal, Full or part-time Employment: Merck; Financial Interests, Personal, Stocks/Shares: Merck. P. Verpillat: Financial Interests, Personal, Full or part-time Employment, at the time of the study: Merck.