The Study: You remember avelumab, right? It’s a new PD-L1 inhibitor with promising results in RCC. Turns out that market is pretty well tapped, so EMD Serono (read: a subsidiary of Merck) is looking for more creative ventures. Good news for the market / bad news for patients is that MCC is sorely lacking in safe and durably effective systemic treatment options. Interim results were reported last week of their phase 2 trial JAVELIN Merkel 200 that enrolled 39 patients with untreated metastatic MCC. All patients received avelumab 10 mg/kg q2 weeks until progression or intolerable toxicity with a primary endpoint of “durable” response (i.e., objective response lasting at least 6 months). At this early interim analysis, 29 patients had at least 3 months follow-up with 18 (62%) achieving objective responses. It’s “estimated” that 83% of responses will last 6 months, but obviously that’s a bit immature. Nevertheless, toxicity rates weren’t too bad with only 1 in 5 having a grade 3 toxicity and none to date having a grade 4-5 toxicity.
Bottom Line: It’s still early, but PD-1 axis inhibition is building speed as the standard for metastatic MCC, with avelumab soaring highest. | D’Angelo, JAMA Oncol 2018