Merck & Co. said it has stopped enrollment within two Phase III trials assessing its cancer immunotherapy Keytruda ® (pembrolizumab) in combination with some other therapies to treat multiple myeloma, following reports of individual deaths

The pharma giant said within a statement yesterday that it “ paused” enrollment in KEYNOTE-183 and KEYNOTE-185 at the recommendation of its data monitoring panel “ to allow for additional information to be collected to better understand a lot more reports of death in the Keytruda groups. ”

Merck did not disclose the number of deaths or provide other details on the deaths in its statement.

Patients currently enrolled in the two studies will continue to get treatment, Merck said, adding that its other medical studies of Keytruda will continue unchanged.

KEYNOTE-183 is a Phase III study designed to compare the particular combination of pomalidomide and low-dose dexamethasone plus Keytruda in order to pomalidomide and low-dose dexamethasone alone in patients along with refractory or relapsed and refractory multiple myeloma (rrMM) who have undergone at least two lines of prior therapy.

KEYNOTE-183 has an estimated enrollment of three hundred patients, an estimated primary completion date of August thirty-one, 2018, and an estimated study completion date of Oct 31, 2019.

The other Phase III research, 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-naï ve multiple myeloma who are ineligible for autologous come cell transplant (autoSCT).

KEYNOTE-183 has an approximated enrollment of 640 patients, an estimated primary completion time of August 31, 2019, and an estimated study finalization date of July 31, 2021.

Each KEYNOTE studies were initiated in October 2015.

Keytruda is a humanized monoclonal antibody that works simply by blocking interaction between the programmed cell death protein one (PD-1) and its receptor ligands, PD-L1 and PD-L2, hence increasing the immune system’ s ability to fight malignancy. Keytruda is a blockbuster drug, having generated $1. 402 billion in revenue last year (148% above 2015) plus $584 million in the first quarter alone (up 134% from Q1 2016).

The FDA accepted Keytruda in 2014 as the first PD-1 inhibitor pointed out to treat unresectable or metastatic melanoma following treatment along with ipilimumab. Since then, Keytruda has won approval for additional signals in non-small-cell lung cancer, head and neck squamous cell malignancy, classical Hodgkin’s lymphoma, urothelial carcinoma— and as of final month, pediatric and adult patients with unresectable or even metastatic microsatellite instability-high or mismatch repair solid cancers, for which Merck won accelerated FDA approval.