Merck & Co. said it has stopped enrollment in two Phase III trials assessing its cancer immunotherapy Keytruda® (pembrolizumab) in combination with other therapies to treat multiple myeloma, following reports of patient deaths
The pharma giant said in a statement yesterday that it “paused” enrollment in KEYNOTE-183 and KEYNOTE-185 at the recommendation of its data monitoring committee “to allow for additional information to be collected to better understand more reports of death in the Keytruda groups.”
Merck did not disclose the number of deaths or furnish other details on the deaths in its statement.
Patients currently enrolled in the two studies will continue to receive treatment, Merck said, adding that its other clinical studies of Keytruda will continue unchanged.
KEYNOTE-183 is a Phase III study designed to compare the combination of pomalidomide and low-dose dexamethasone plus Keytruda to pomalidomide and low-dose dexamethasone alone in patients with refractory or relapsed and refractory multiple myeloma (rrMM) who have undergone at least two lines of prior treatment.
KEYNOTE-183 has an estimated enrollment of 300 patients, an estimated primary completion date of August 31, 2018, and an estimated study completion date of October 31, 2019.
The other Phase III study, KEYNOTE-185, is designed to compare the combination of lenalidomide and low-dose dexamethasone plus Keytruda to lenalidomide and low-dose dexamethasone alone in patients with newly diagnosed and treatment-naïve multiple myeloma who are ineligible for autologous stem cell transplant (autoSCT).
KEYNOTE-183 has an estimated enrollment of 640 patients, an estimated primary completion date of August 31, 2019, and an estimated study completion date of July 31, 2021.
Both KEYNOTE studies were initiated in October 2015.
Keytruda is a humanized monoclonal antibody that works by blocking interaction between the programmed cell death protein 1 (PD-1) and its receptor ligands, PD-L1 and PD-L2, thus increasing the immune system’s ability to fight cancer. Keytruda is a blockbuster drug, having generated $1.402 billion in revenue last year (148% above 2015) and $584 million in the first quarter alone (up 134% from Q1 2016).
The FDA approved Keytruda in 2014 as the first PD-1 inhibitor indicated to treat unresectable or metastatic melanoma following treatment with ipilimumab. Since then, Keytruda has won approval for additional indications in non-small-cell lung cancer, head and neck squamous cell cancer, classical Hodgkin's lymphoma, urothelial carcinoma—and as of last month, pediatric and adult patients with unresectable or metastatic microsatellite instability-high or mismatch repair solid tumors, for which Merck won accelerated FDA approval.