Abecma and cilta cel are part of an emerging class of multiple myeloma treatments that target a protein called BCMA, which is found on cancer cells. GlaxoSmithKline was first to get a BCMA drug on the market with Blenrep, a drug combining a synthetic antibody with a tumor-destroying chemical. But Blenrep’s effectiveness is limited and side effects can include a form of vision loss.
Therapies like Abecma and cilta cel, by comparison, produced deeper and more durable remissions in patients enrolled in clinical testing. Abecma eliminated or reduced signs of disease in 72% of patients in the main study supporting its approval, while cilta cel did so in 97% of participants in its chief trial.
While effective, these treatments involve a complex manufacturing process that requires removing white blood cells from patients, re-engineering them in a laboratory and then re-infusing them into patients weeks later. This process appears to have factored into the delay to cilta cel. In a statement to BioPharma Dive, Legend said J&J has developed a new way to measure the therapy’s potency, requiring a review that will take extra time.
Abecma itself was delayed for months after the FDA rejected Bristol Myers Squibb and Bluebird’s initial application over their documentation of manufacturing procedures.
Legend’s shares fell 6% in morning trading Tuesday following the announcement of the delay after the market’s close on Monday.
The cilta cel setback could present Bristol Myers with an opportunity to expand its market share and win the confidence of physicians who will be administering its treatment. Since Abecma’s launch in March, Bristol Myers has recorded $95 million in sales, matching Blenrep’s nine-month performance of 67 million British pounds, or $91 million.
The delay could prove even more consequential, given that additional rivals may be arriving soon. So-called bispecific antibody treatments from Regeneron, AbbVie and J&J are in development. Unlike Abecma and cilta cel, these drugs would not require as complicated manufacturing — though they would need to be dosed periodically, whereas the cell therapies are meant to be a one-time infusion.