GSK’s anti-BCMA Therapy Notches FDA Approval for Refractory Multiple Myeloma

On August 6th, the company announced that the USFDA has granted accelerated approval to BLENREP as a monotherapy treatment for adult patients with relapsed or refractory multiple myeloma, making it the first approved anti-BCMA therapy till date.

By Ruchi Jhonsa, Ph.D.

Multiple myeloma is the second most common blood cancer in the US. The American Cancer Society estimates that in 2020 alone, approximately 32000 people will be diagnosed, and 12000 will succumb to the disease. Currently, available treatments for multiple myeloma are effective in reducing cancer growth. However, it is only a matter of time when myeloma becomes refractory to available therapies and grows out of existing cancer cells. Hence, biopharma companies are investing millions to identify a potential treatment for the disease that relapses.

In 2015, GlaxoSmithKline started working on a multiple myeloma med, BLENREP, that targeted BCMA, a cell surface protein essential for myeloma cell growth. The antibody-drug conjugate combines BCMA directed humanized monoclonal antibody and a cytotoxic agent auristatin F linked via a non-cleavable linker. Since BCMA is specifically expressed in cancer cells, a BCMA directed therapy specifically targets cancer cells while sparing healthy cells. In 2018, GSK started testing the drug’s effectiveness in slashing cancer growth in the DREAMM-2 trial, which enrolled patients who had failed to respond to at least four prior therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.

Although the trial is ongoing, an urgent need for a drug to treat refractory or relapsed multiple myeloma has prompted accelerated approval for this drug. However, continued approval will rest upon verification of clinical benefits in confirmatory trials.

Dr. Hal Barron, Chief Scientific Officer, and President R&D, GSK, said, “As the second most common form of blood cancer in the US, multiple myeloma is an incurable and devastating disease. BLENREP is the first approved anti-BCMA therapy and has the potential to transform the treatment of patients with relapsed or refractory myeloma who have limited treatment options today.’’

DREAMM-2 Trial

BLENREP has received accelerated approval from the USFDA based on six months of primary data from the DREAMM-2 trial. In the study, patients were treated with 2.5mg/Kg dose of BLENREP once every three weeks. The interim data showed that 31% of patients who had undergone seven lines of treatment before this trial had a reduction in tumor growth following drug treatment. The duration of response (DoR), which determines how long the tumor reacted to the drug, was not reached at the six-month analysis, but 73% of responders had a DoR equal to greater than six months.

But the efficacy of the med is shadowed by the risk of adverse events. Nearly three-quarters of patients in GSK’s phase 2 trial suffered eye-related reactions or keratopathy- a condition that can result in dry eyes, blurry vision, and even severe vision loss, and two patients died. Despite this, only 2.1% of patients affected by keratopathy discontinued the treatment.

What is in the Future for BLENREP?

Eye related adverse events are grave and are being taken very seriously by the company. For that matter, Glaxo is taking upon itself to educate physicians regarding these adverse events and ways to manage them if they occur. Alongside this, the company is planning to broaden BLENREP’s treatable patient population by moving the treatment into earlier lines of therapy.

Dr. Sagar Lonial, MD, Chief Medical Officer, Winship Cancer Institute of Emory University in Atlanta, Georgia, Chair of Emory Department of Hematology and Medical Oncology and Principal Investigator for DREAMM-2, said: “While treatable, refractory multiple myeloma is a significant clinical challenge with poor outcomes for patients whose disease has become resistant to the current standard of care. Due to the limited options currently available, these patients are often retreated with drugs from the same classes after they relapse, which is why the approval of BLENREP, the first anti-BCMA therapy, is significant for both patients and physicians alike.”

Related Article: BMS, bluebird bio’s Investigational BCMA CAR-T Therapy Faces Regulatory Setback

References

1. https://www.gsk.com/en-gb/media/press-releases/fda-approves-gsk-s-blenrep-belantamab-mafodotin-blmf-for-the-treatment-of-patients-with-relapsed-or-refractory-multiple-myeloma/

Author

Ruchi Jhonsa