Merck is stopping development of two drugs as potential treatments for hospitalized Covid-19 patients, and one of those medicines will move forward in clinical testing only as a potential outpatient therapy.
The drug that will be completely dropped, MK-7110, is a fusion protein that Merck added to its pipeline via its $425 million acquisition of OncoImmune last November. That Maryland-based biotech had advanced its drug to Phase 3 testing, reporting preliminary results showing that a single dose of the infused therapy gave patients a 60% higher probability of improvement compared to those given a placebo. In addition, the risk of death or respiratory in treated patients was reduced by more than half.
Last December, Kenilworth, New Jersey-based Merck reached an agreement with the U.S. government, which committed up to $356 million to manufacture and supply 60,000 to 100,000 doses of the drug to address pandemic response goals. But after that deal was struck, Merck disclosed in its annual report that the FDA required additional clinical data to support emergency use authorization of the drug.
Merck said Thursday that based on the need for new clinical trials and the research needed to manufacture the drug at scale, MK-7110 likely would not become available until the first half of next year. Given the uncertainty of clinical and regulatory development combined with the growing number of available Covid-19 therapies, Merck said it decided to stop work on MK-7110 for Covid-19.
The pharma giant has also come up short with molnupiravir, an antiviral in development under a partnership with Ridgeback Biotherapeutics. Merck said Thursday that after a planned interim analysis of a Phase 2 study testing molnupiravir, the data indicate that the drug is unlikely to demonstrate clinical benefit in hospitalized patients. The company said it has decided not to advance the drug to Phase 3 testing in this setting. But the company is proceeding with a Phase 3 test of the drug in patients who are not hospitalized; an 800 mg dose has been selected for the late-stage study.
A Deep-dive Into Specialty Pharma
A specialty drug is a class of prescription medications used to treat complex, chronic or rare medical conditions. Although this classification was originally intended to define the treatment of rare, also termed “orphan” diseases, affecting fewer than 200,000 people in the US, more recently, specialty drugs have emerged as the cornerstone of treatment for chronic and complex diseases such as cancer, autoimmune conditions, diabetes, hepatitis C, and HIV/AIDS.
Merck said that the data monitoring committee for the molnupiravir study suggested amending the trial to focus on patients early in the course of the disease as well as those considered high risk for poor outcomes, such as the elderly, obese patients, and those who have diabetes. The company plans to start enrolling patients for the Phase 3 study by late April or early may. Final data are expected to become available in September or October.
The drug announcements are the latest in a string of disappointments for Merck’s Covid-19 R&D efforts. In January, the company exited Covid-19 vaccine development after early-stage clinical trial results for candidates fell short of matching immune responses produced by other Covid vaccines.
Merck said Thursday that in addition to pressing ahead with developing molnupiravir for outpatient use, it would also focus on its partnership with Johnson & Johnson on the manufacturing of that company’s Covid vaccine. But the future of that vaccine is uncertain after the FDA and the Centers for Disease Control and Prevention recommended that dosing of the J&J shot be paused while authorities analyze reports of a rare blood clot side effect.
Photo: Christopher Occhicone/Bloomberg, via Getty Images
