Toxicity Associated With Concomitant Ruxolitinib and Avelumab in Merkel Cell Carcinoma
Posted: Monday, February 1, 2021
According to research published in Frontiers in Oncology, a combination treatment of the selective JAK1 and JAK2 inhibitor ruxolitinib and the anti–PDL-1 inhibitor avelumab may result in severe toxicity for patients with Merkel cell carcinoma. Patients with immunosuppressive conditions such as myeloproliferative syndrome frequently experience the emergence of Merkel cell carcinoma, which is routinely treated with avelumab. Ruxolitinib is a standard treatment of myeloproliferative syndrome.
“Modifying the schedule, reducing the dose of both drugs or only one, is a necessary to study in order to be able to treat both pathologies,” concluded Giuseppe Di Lorenzo, MD, PhD, of the University of Molise, Italy, and colleagues.
The small study included six patients who had been diagnosed with Merkel cell carcinoma between June 2019 and April 2020, at Tortora Hospital or Santa Maria la Pietà Hospital in Italy. Among them, two patients had been treated with the combination of ruxolitinib and avelumab. Both patients were initially treated with ruxolitinib following a diagnosis of myeloproliferative syndrome.
Neither patient experienced hematologic side effects while receiving ruxolitinib monotherapy over several months. Once avelumab was introduced, one patient experienced grade 4 thrombocytopenia, grade 2 anemia, and grade 2 leukopenia after cycle 1 of treatment. The second patient experienced grade 3 thrombocytopenia, grade 2 neutropenia, and grade 1 anemia following cycle 4 of treatment.
Due to these toxicities, both patients had their treatment regimens suspended. Within 1 month of treatment discontinuation, both saw normal hematologic values return and began receiving avelumab monotherapy. One patient’s progression of Merkel cell carcinoma led to the suspension of avelumab and the reinstatement of a ruxolitinib regimen, whereas the other patient continued receiving avelumab treatment alone.
Disclosure: The study authors reported no conflicts of interest.
