Merck reveals HIV combo trial is back in the running after FDA partial hold lifted

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The middle of Merck & Co.’s clinical batting order took center stage on the company’s first-quarter earnings call, including a phase 2 HIV combo therapy that once again returned to the lineup.

The Big Pharma has resumed a phase 2 study of MK-8591D, an oral regimen of islatravir and Gilead’s Sunlenca, executives said on a call with analysts Thursday. Gilead’s drug was approved in December as a twice-yearly treatment for patients with multi-drug resistant HIV.

The two companies decided to slam the brakes on the trial back in November 2021 after dosing was stopped in a related study testing a combo of islatravir and another drug called MK-8507. At the time, Merck disclosed that the islatravir-MK-8507 combo spurred a reduction in patients’ lymphocyte and CD4+ T-cell levels.

But now islatravir is being revived, with an FDA hold on the trial having been lifted after an amended protocol using a lower dose of islatravir was agreed to, according to a Merck spokesperson. In addition, the company is launching multiple new phase 3 studies testing the med with its FDA-approved HIV drug Pifeltro.

“We are committed to advancing the science to offer new treatment options for the treatment of HIV,” Dean Li, M.D., Ph.D., president of Merck Research Labs, said on the call.

But elsewhere the company is reevaluating priorities. A spokesperson confirmed to Fierce Biotech that MK-7075, a treatment for overgrowth syndrome that did not appear in the company’s earnings presentation, is “not currently active.” The med is still in development but is being deprioritized, the spokesperson explained.

The mid-stage pipeline updates come as Merck’s executives touted internal and external victories meant to assure investors that its post-Keytruda plans were materializing. Less than two weeks ago, the company announced it was buying Prometheus Biosciences for $10.8 billion, an immunology company with a promising lead asset developed to treat ulcerative colitis and Crone’s disease that recently posted a phase 2 victory. That med, PRA023, is set to do battle with a competitor from Roivant that’s so far performed similarly.

The deal echoes Merck’s $11.5 billion acquisition of Acceleron Pharma in September 2021, which handed the New Jersey pharma keys to cardiovascular med sotatercept, now a potential crown jewel. After diving deeper into the med’s phase 3 victory, Merck executives said today that they plan to file for U.S. approval in the third quarter for patients with pulmonary arterial hypertension. Chief Medical Officer Eliav Barr, M.D., previously told Fierce Biotech that he expects the drug to launch in early 2024.

The sum of the Big Pharma’s recent deals and internal development had CEO Rob Davis sounding confident that Merck is well-situated to thrive beyond Keytruda’s expected loss of exclusivity in 2028.

“I am no longer focusing on 2028,” he said on the call. “I am looking at ‘how do we have sustainable growth well into the next decade.'”

By Max Bayer


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