CMV is a common and potentially serious viral infection in allogeneic HSCT recipients.
Kenilworth, NJ – The Food and Drug Administration (FDA) approved Merck & Co.'s Prevymis (letermovir) for prevention of cytomegalovirus (CMV) infection in adults who are CMV-seropositive recipients of an allogeneic hematopoietic stem cell transplant (HSCT).
CMB is a common and serious infection in stem cell transplant patients, and CMV-seropositive patients receiving the transplant are at high risk for CMV reactivation.
The approval was based on a Phase III clinical trial that showed significantly fewer patients in the Prevymis group compared to the placebo group developed clinically significant CMV infection.
Per OncLive, “In the pivotal study that led to the approval, 37.5 percent of patients treated with letermomvir developed CMV by week 24 post-HSCT compared with 60.6 percent of those in the placebo arm (P<.0001). Moreover, letermovir was associated with lower all-cause mortality versus placebo at 24 weeks (12 percent vs 17 percent). The median time to engraftment and bone marrow suppression rates were similar in each group.”
“Our findings demonstrate that letermovir is a significant and welcomed advance in the prevention of clinically significant CMV infection and lowers mortality in this highly vulnerable patient population,” said Francisco Marty, associate professor of medicine at Harvard Medical School and attending physician in transplant and oncology infectious diseases at Dana-Farber Cancer Institute and Brigham and Women’s Hospital in Boston, in a statement.
Merck picked up the drug in a deal exceeding $500 million about five years ago with AiCuris GmbH & Co KG. This approval will trigger a $122 million milestone payment for the Germany company, which will also be eligible for royalties.
It is expected to go on sale in December. Analysts are projecting sales in 2022 at about $200 million. The oral version, before discounts, will run about $195 per day, and the injection formulation will be about $270. John Carroll, writing for Endpoints News,points out, “That’s a modest score for Merck, which has been devoting much of its time and attention these days to its checkpoint drug Keytruda.”
Recommended dosing for the drug is once daily for 100 days after the stem cell transplant. That makes the effective list price $19,500 for the pills and $27,000 for injections. List price is not always a reflection of what the patient pays, because of variations in out-of-pocket costs, duration of treatment, and individual healthcare plans.
“Prevymis is the first new medicine for CMV infection approved in the U.S. in 15 years,” said Roy Baynes, Merck Research Laboratories’ senior vice president, head of clinical development, and chief medical officer, in a statement. “Prevymis continues Merck’s longstanding tradition of bringing forward important new therapies to address serious infectious diseases. We are proud to add this breakthrough medicine to our existing offerings for physicians and patients.”
Prevymis is part of a new class of non-nucleoside CMV inhibitors known as 3,4 dihydro-quinazolines. It inhibits viral replication by targeting the viral terminase complex. Merck doesn’t believe that cross-resistance with drugs outside of this class is likely.
There are drugs available to treat CMV, but Prevymis is the first preventive therapy.
