The FDA has placed a partial clinical hold on three trials related to Bristol-Myers Squibb's immunotherapy Opdivo after issues with trials for a rival drug.

The decision affects the CA209602 (CheckMate-602), CA209039 (CheckMate-039) and CA204142 trials investigating Opdivo (nivolumab)-based combinations in patients with relapsed or refractory multiple myeloma.

The FDA's decision follows the halting of three myeloma trials for Merck & Co's own PD-1 inhibitor Keyruda in July, following reports that more patients died in the Keyrdua arms of the studies than the control arms.

“The FDA determined data currently available from non-Opdivo studies indicate the risks of PD-1/PD-L1 treatment plus pomalidomide or lenalidomide and possibly PD-1/PD-L1 treatments alone or with other combinations outweigh potential benefit for patients with multiple myeloma,” Bristol-Myers said on its website.

“BMS remains steadfast in our commitment to improve outcomes for patients with multiple myeloma, and will work closely with the FDA to address concerns."