BioMarins One-Year Data on Its Hemophilia Gene-Therapy Looked Good. Can It Win FDA Approval? – Barron’s

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BioMarin Pharmaceutical has been running the worlds largest clinical trial of a gene therapy in hopes of sparing hemophilia patients from frequent bleeding and chronic drug infusions. But the company suffered a rebuke last August, when U.S. regulators demanded a lengthier study before approval would be considered.

On Sunday, BioMarin (ticker: BMRN) released data on the first year of the continuing study of its Roctavian therapy. The data looked good. In 112 participants, the product was safe and a single treatment with the gene therapy reduced annual bleeding rates by 84%. That is better than the performance of todays standard therapy, which periodically infuses a patient with artificial versions of the clotting factor that their defective genes cant make. Like other gene-augmentation therapies, Roctavian adds working versions of the gene to a patients cells, to supply the correct instructions for production of the clotting protein.

But Sundays data from BioMarin didnt clear an issue that has worried the U.S. Food and Drug Administration and that led the agency to rebuff last years approval request and demand a longer follow-up. The levels of clotting factor produced in Roctavian recipients decline over time. While remaining above levels needed to prevent bleeding, the worry is that a continued decline might end the treatments usefulness after a number of years. Gene therapies were originally hailed as potential cures.

In early trading Monday, BioMarin stock was off 8%, to $83, while the Nasdaq Composite index was off 1%.

The new data will continue to fuel the debate, concluded RBC Capital Managements Kennen MacKay in a Monday note. He called the new information positive, though likely controversial.

MacKay observed that the data in BioMarins press release showed wide variability in how patients responded to the gene therapy. The treated patients median blood levels of clotting factor tapered from 39 units-per-deciliter at six months after treatment, to 24 units at one year. A subset of 17 patients treated earlier showed continued declines to 16 units at 18 months, then 15 units at two years.

BioMarin has said that it plans to talk with the FDA in hopes of persuading the agency to consider approval based on one-year datainstead of requiring two years of follow-up on trial participants. European regulators have shown a willingness to consider approval based on one year of data.

Eun Yang, at Jefferies, described the new data as positive, but remained doubtful that the FDA would relax its demand for longer follow-up of the gene therapy patients.

A majority of analysts surveyed by FactSet, including Jefferies Yang, rate BioMarin a Buy with price targets for the stock that average $111. Even after recent setbacks, the stock isnt cheap by standards that prevail outside of the biotech bubble. The consensus forecast at Sentieo.com sees BioMarin breaking even in 2021, then earning about $1.35 in 2022, $3.00 in 2023, and $5.00 in 2024.

RBCs Mackay has a Hold and a $90 price target. He worries that delays in launching the companys gene therapies will leave revenue gaps as BioMarins existing drugs lose their exclusivity.

We anticipate continued debate, despite this clinical de-risking, MacKay says, of the latest gene therapy data.

Write to Bill Alpert at william.alpert@barrons.com

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BioMarins One-Year Data on Its Hemophilia Gene-Therapy Looked Good. Can It Win FDA Approval? - Barron's