US FDA Approves GSK’s Blood Cancer Drug Blenrep for Market Return

The United States Food and Drug Administration (FDA) has approved the return of British drugmaker GSK’s medicine Blenrep, a treatment for blood cancer, to the U.S. market. This decision marks a major comeback for the company nearly three years after the drug was removed due to weak results in earlier tests.

What the Drug Does

Blenrep is made for patients suffering from multiple myeloma, a type of blood cancer that affects bone marrow. The FDA has now approved the drug to be used with two other medicines — bortezomib and dexamethasone — for patients whose cancer has returned or stopped responding to earlier treatments.

The approval gives new hope to patients who have already tried at least one therapy and need new treatment options.

A Split Decision

The FDA’s green light came after reviewing data from two large studies. One study showed that the new combination helped patients live three times longer without the disease getting worse, and reduced the risk of death by 51% compared to treatment with Darzalex, a drug made by Johnson & Johnson.

However, the FDA did not approve another combination of Blenrep with pomalidomide and dexamethasone, which was tested in a separate trial.

This approval also goes against the advice of an expert panel that, in July, voted against both combinations. Despite this, the FDA decided that the benefits of the approved treatment outweighed the risks.

Why Blenrep Was Withdrawn Before

GSK had withdrawn Blenrep from the U.S. market in 2022 after it failed to show better results than another treatment in a required trial. That failure raised doubts about its long-term potential.

Now, new study data has helped rebuild trust in the drug’s effectiveness and safety. GSK says the FDA approval will help bring the medicine back to doctors and patients who need it.

Safety Monitoring and Vision Risks

GSK said the medicine will be offered under a simplified safety monitoring plan to help doctors manage side effects. One of the main risks with Blenrep involves vision problems, so the program will make sure doctors can identify and treat any eye-related issues early.

Market Reaction and Future Outlook

Following the news, GSK’s shares in the U.S. dropped by about 4% in after-hours trading. Some investors said the market reaction was cautious because the approval was limited to one combination only.

Still, the company believes this decision will strengthen its business in the coming years. GSK expects Blenrep could reach peak sales of over £3 billion ($4 billion). The company says it does not expect big sales immediately, as the product is still in the early rollout stage.

Tony Wood, GSK’s Chief Scientific Officer, said the drug will be an important part of the company’s future growth. “With more than 180,000 new cases of multiple myeloma each year, this approval gives us confidence that Blenrep can help many patients worldwide,” he said.

Global Availability

Blenrep is already approved for use in several countries, including the United Kingdom, Japan, Canada, and Switzerland. The same combinations were approved in the European Union in July 2025, making the U.S. approval another key step in the medicine’s global rollout.

The Growing Cancer Treatment Market

Experts say the multiple myeloma treatment market is expected to grow rapidly, reaching $45 billion by 2032. With this approval, GSK hopes to play a major role in that expansion.

The FDA’s decision not only marks a comeback for Blenrep but also signals growing confidence in new, combination-based cancer treatments that give patients more choices for better care.