ESMO Commentary: A new promise for a rare skin cancer

The ‘immunotherapy revolution’ has started to bring new promises also for the treatment of some rare cancers. Results from a late-braking study¹ presented at the European Cancer Congress (ECC2015), in Vienna, showed for the first time that Merkel cell carcinoma, a rare and often aggressive skin malignancy, is responsive to checkpoint inhibitors.

Advanced Merkel cell carcinoma (MCC) is an important medical need. Patients’ response to chemotherapy, which is currently the only treatment option, are good but not durable. Nearly half of the patients with Merkel cell carcinoma as a primary tumour tipically relapse, and in those with locally advanced disease or metastatic disease the median survival is around 9.6 months.

As Merkel polyomavirus-specific T cells and the expression of PD-L1 were found in the tumour cells, there was a good rationale to believe that Merkel cell carcinoma might be responsive to PD-1 pathway blockade.

The small phase II, single arm study presented in Vienna enrolled 24 patients with advanced and unresectable Merkel cell carcinoma. Only ten of the patients who were treated with pembrolizumab were available for response. Despite of the some of these patients have been treated only for few weeks and a follow-up is needed, experts are optimistic of these preliminary results, as Celeste Lebbe of Hôpital St. Louis in Paris, France, commented. 

¹22LBA: Activity of PD-1 blockade with pembrolizumab as first systemic therapy in patients with advanced merkel cell carcinoma

P. Nghiem⁽¹⁾, S. Bhatia⁽²⁾, A. Daud⁽³⁾, P. Friedlander⁽⁴⁾, H. Kluger⁽⁵⁾, H. Kohrt⁽⁶⁾, R. Kudchadkar⁽⁷⁾, E. Lipson⁽⁸⁾, L. Lundgren⁽⁹⁾, K. Margolin⁽⁶⁾, S. Reddy⁽⁶⁾, E. Shantha⁽¹⁰⁾, W. Sharfman⁽⁸⁾, E. Sharon⁽¹¹⁾, J. Thompson⁽¹²⁾, S. Topalian⁽¹³⁾, M. Cheever⁽¹⁴⁾