Use of Avelumab in Merkel Cell Carcinoma: Linking Early Response With Overall Survival
Posted: Wednesday, July 17, 2019
For patients with chemotherapy-refractory metastatic Merkel cell carcinoma treated with the monoclonal antibody avelumab, early objective response may provide a “clinically relevant predictor” of overall survival, according to findings from the JAVELIN Merkel 200 trial published in Cancer Immunology, Immunotherapy. The use of objective response as a clinical predictor may allow physicians to make more accurate survival predictions for patients diagnosed with metastatic Merkel cell carcinoma, concluded Sandra P. D’Angelo, MD, of the Memorial Sloan Kettering Cancer Center, New York, and colleagues.
“This is in contrast with chemotherapy, whereby responses can be very high; however, they are not durable, without association with survival,” the authors observed. “On the basis of these findings, physicians may be able to reassure patients whose disease demonstrates early response to avelumab that they may have an improved prognosis in terms of expected duration of survival.”
In this single-arm, open-label, multicenter phase II study, the authors enrolled 88 patients diagnosed with metastatic Merkel cell carcinoma. Patients were treated with 10 mg/kg of avelumab every 2 weeks until confirmed disease progression, unacceptable toxicity, or study withdrawal.
A total of 29 patients reported objective responses, with 20 achieving an objective response by week 7 of treatment and 7 more patients reaching an objective response between weeks 7 and 13 of treatment. After 18 months of avelumab treatment, the survival probabilities for patients who reached an objective response after week 7 was 90%. Patients who did not achieve an objective response but were still alive after 7 weeks of treatment had a survival probability of 26.2%.
A median overall survival was not reached among patients with an objective response, whereas patients who did achieve an objective response had a median overall survival of 8.8 months. The adjusted Cox model found that objective response coincided with a 95% risk reduction of death compared with patients who did not display such a response.
Disclosure: The study authors’ disclosure information may be found atlink.springer.com.