GSK will pull a blood cancer drug from the U.S. market after the treatment failed in a confirmatory clinical trial, the British drugmaker announced Tuesday.

Following a request from the Food and Drug Administration, GSK has begun the process of withdrawing its approved multiple myeloma therapy Blenrep. Patients who are already in a risk mitigation program to receive Blenrep can enroll in a compassionate use program to access treatment, the company said.

Blenrep was conditionally approved by the FDA in August 2020 after early data showed nearly a third of treated patients responded to the therapy, which targets a protein commonly found on malignant B cells.

But results from a larger study designed to confirm Blenrep’s benefit, released earlier this month, indicated the drug did not extend progression-free survival by any longer than a standard treatment regimen in patients with relapsed or refractory multiple myeloma. Progression-free survival is a common measurement in cancer drug studies and reflects the length of time trial participants go without dying or their cancer growing.

While GSK has other late-stage studies testing Blenrep in earlier lines of multiple myeloma treatment, the FDA appears to have indicated its accelerated approval requirements were not met.

“We respect the Agency’s approach to the accelerated approval regulations and associated process,” said GSK Chief Medical Officer Sabine Luik, in the company’s statement. “We will continue the DREAMM clinical trial program and work with the US FDA on a path forward for this important treatment option for patients with multiple myeloma.”

Two studies, dubbed DREAMM-7 and DREAMM-8, are expected to deliver results in the first half of next year. The first is testing Blenrep in combination with two multiple myeloma drugs against a commonly used treatment called Darzalex, also in combination with those other drugs. The second is assessing Blenrep together with the myeloma treatment Pomalyst against another triple combination regimen.

Data from those trials, once available, will be shared with health agencies and “inform future regulatory pathways,” GSK said.

With its 2020 approval, Blenrep became the first drug approved to target the BCMA protein. But sales since then have been slow, reflecting restrictions on the drug’s use related to its safety risks, such as a type of eye toxicity. Over the first nine months of 2022, GSK recorded sales of 55 million pounds, or about $65 million, in the U.S. Globally, sales eclipsed $108 million.

Competing drugs have also reached market, giving new options for doctors looking to prescribe a BCMA-targeting treatment. Two CAR-T cell therapies from Bristol Myers Squibb and Johnson & Johnson were approved by the FDA in March 2021 and February, respectively. Last month, J&J also won an FDA OK for an antibody drug that targets BCMA as well as a protein found on immune cells.

The FDA has been applying more scrutiny to cancer drugs approved on an accelerated basis, holding several advisory committee meetings and putting pressure on drugmakers to act quickly to withdraw medicines that fail confirmatory tests. Other companies like Regeneron and Incyte have also pulled cancer drugs or cancer drug indications this year.