FDA Takes Closer Look at Use of Pembrolizumab in Multiple Myeloma
Posted: Tuesday, July 3, 2018
According to a U.S. Food and Drug Administration (FDA) analysis of immune-related adverse events and response to pembrolizumab in patients with multiple myeloma, the utility of immunotherapy in patients unable to mount an immune response deserves further study. The findings, which are based on data from KEYNOTE-183 in the relapsed or refractory setting and KEYNOTE-185 in the newly diagnosed setting, were presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 8008).
“While recognizing that there are some clinical contexts where randomization is impossible, where possible, randomized trials, even early on in the phase II stage, can really give us exponentially more critical safety information and allow us to move forward in this space,” shared lead author Aviva C. Krauss, MD, of the FDA, with The ASCO Post.
KEYNOTE-183 evaluated the use of pomalidomide and dexamethasone with or without pembrolizumab in 249 patients with relapsed or refractory multiple myeloma. KEYNOTE-185 evaluated the use of lenalidomide and dexamethasone with or without pembrolizumab in 301 patients with newly diagnosed multiple myeloma ineligible for autologous stem cell transplant.
In KEYNOTE-183, 29 deaths in the pembrolizumab arm and 21 deaths in the control arm occurred, for an overall survival hazard ratio of 1.61. The overall response rate was 34% in the pembrolizumab arm and 40% in the control arm. In KEYNOTE-185, 19 patients in the pembrolizumab group and 9 patients in the control died, for an overall survival hazard ratio of 2.06.
A closer look at the data showed that previous cytotoxic treatment may impact the outcomes of patients treated with immunotherapy. For instance, in those with resistant disease, the objective response rate was similar in those who developed an immune-related adverse event and in those who did not. However, in those with newly developed disease, there seemed to be a trend toward improved response in those who had an immune-related adverse event versus those who did not.