Dive Brief:

• GlaxoSmithKline will stop enrolling cancer patients into two mid-stage studies testing a closely watched cancer immunotherapy alongside Merck & Co.’s Keytruda, marking another setback for the British drugmaker’s ambitions in oncology research.

• The decision followed a recommendation from an independent monitoring committee that oversees one of the trials. In a Wednesday statement, GSK said it will evaluate the “totality of the data” to determine the impact on its broader development plans for the drug, called feladilimab.

• Feladilimab is a top drug prospect for GSK, one of a class of experimental cancer medicines known as ICOS receptor agonists. But their potential may now be in question after GSK’s decision and the failure of a study testing a similar drug from Jounce Therapeutics last fall.

Dive Insight:

Three months ago, Hal Barron, GSK’s head of research and development, gave an upbeat presentation to investors at J.P. Morgan’s virtual healthcare conference.

Barron gave feladilimab top billing, listing it as one of GSK’s billion-dollar drug prospects and detailing its progress in the two studies that the company has now stopped.

In one, called INDUCE-3, GSK was testing feladilimab together with Keytruda in patients with locally advanced or metastatic cancer of the head and neck, focusing specifically on people whose tumors expressed a protein associated with response to immunotherapies.

GSK had hoped data from the trial’s first interim analysis would support progression into the next phase of study. Instead, after a recommendation from a data monitoring committee, GSK will stop enrolling patients and halt dosing of the drug.

At the same time, GSK is also suspending enrollment into a second study called INDUCE-4 that’s evaluating feladilimab against a placebo when added to a regimen of Keytruda and chemotherapy. Data were expected in 2024, so Wednesday’s decision marks an early end for the trial.

Other studies of the drug continue, including one in lung cancer and another in solid tumors. Tests of similar drugs from Bristol Myers Squibb and Xencor are also underway.

Steve Scala, an analyst at Cowen, wrote in a note to clients that, while the exact reasons for the trial stop remain unclear, they may have to due with there being increased side effects from GSK’s drug, or little benefit adding it to Keytruda.

“The loss of feladilimab also means GSK’s already limited oncology pipeline appears to have lost one of its late-stage assets,” Scala added.

The setback for feladilimab follows disappointments for two other treatments GSK has touted. In late January, Merck KGaA announced it was discontinuing a study testing a GSK-partnered drug called bintrafusp alfa in non-small cell lung cancer. The drug targets a cytokine known as TGF-ß that’s received extensive attention as a possible immunotherapy target.

That same day, news broke that the Food and Drug Administration delayed a decision on dostarlimab, a checkpoint inhibitor from GSK that works similarly to Keytruda. The delay was due to coronavirus-related restrictions on required manufacturing inspections.

Both drugs are marked as potential blockbusters by GSK, which aims to launch each this year or next.

GSK did win approval last August for the first multiple myeloma drug that works by targeting a protein called BCMA. But that drug, Blenrep, now faces competition from a new CAR-T treatment from Bristol Myers Squibb and Bluebird bio, as well as a pipeline of fast-advancing rivals.

The British drugmaker, like many other pharmas, has bet heavily on oncology research in recent years, choosing to re-enter the field after a poorly timed exit under former CEO Andrew Witty.