Background: The rarity of Merkel Cell Carcinoma (MCC) has meant a paucity of prospective trials from which to establish ‘best practice’ in the treatment of MCC. Significant heterogeneity exists between centres in the loco-regional management of stage I-III MCC. There are biological differences between the Australian MCC population, which is predominantly UV-driven with a high tumour mutational burden, and the northern hemisphere’s MCC population, which is majority viral-driven with a low tumour mutational burden.
Methods: The I-MAT trial is a phase II, prospective, randomised, placebo-controlled, multi-institutional trial for patients with stage I-III MCC. Treatment will be avelumab vs placebo for 6 months duration. The primary aim of the I-MAT trial is to develop an effective, well-tolerated adjuvant immunotherapy regimen. The primary endpoint is recurrence-free survival (RFS) assessed at 24 months. Biological differences for MCPyV-positive versus MCPyV-negative patients in the adjuvant setting will be explored.
Results: Recruitment of 132 participants will occur from 15 multinational sites over a three year period commencing in the final quarter of 2019. The last patient last visit is anticipated to be October 2024.
Conclusion: Due to the 2018 Medical Research Futures Fund (Rare Cancers, Rare Diseases, Unmet Needs) grant success and support by Merck Serono, the I-MAT trial is on track to open in Australia in the fourth quarter of 2019 with international sites to follow. Extensive consultation with all disciplines and international collaborators will ensure the success of the trial.