Sarepta bags drug to fully unlock DMD gene therapy opportunity

Sarepta Therapeutics has secured a license to a drug that could enable more patients to receive its gene therapies. The deal grants Sarepta the exclusive right to use Hansa Biopharma’s imlifidase to eliminate neutralizing antibodies in Duchenne muscular dystrophy (DMD) and limb-girdle muscular dystrophy (LGMD) patients.

Many gene therapies, including those in development in DMD and LGMD at Sarepta, use a type of adeno-associated virus (AAV) to get the genetic material into cells. Some patients have preexisting antibodies against AAV, rendering them ineligible for treatment with gene therapies that rely on the vector. One study found 17% of patients have antibodies against Sarepta’s AAVrh74 vector.

The Hansa deal gives Sarepta a shot at making the significant minority of patients with anti-AAVrh74 antibodies eligible for treatment with its DMD and LGMD gene therapies. The agreement centers on the antibody-cleaving enzyme imlifidase.

By cleaving IgG antibodies at the hinge region with high specificity, Hansa and Sarepta think imlifidase may be able to eliminate the immune defenses that make some patients ineligible for gene therapy. Sarepta would use imlifidase as a pre-treatment prior to gene therapy in such patients.

The potential for imlifidase to expand the addressable market for DMD and LGMD gene therapies has persuaded Sarepta to pay $10 million for an exclusive license to use the enzyme in the indications. Sarepta is also on the hook for close to $400 million in milestones and is responsible for developing the drug and bringing it to market.

Hansa is on the cusp of winning approval for imlifidase in Europe, having received a positive opinion from the Committee for Medicinal Products for Human Use late last month. The approval will cover the use of imlifidase in highly sensitized adult kidney transplant patients.

Striking the deal with Sarepta could open the door to the use of imlifidase in other populations. With Sarepta handling development, but only securing a license in two indications, the arrangement could enable Hansa to gather evidence that supports additional gene therapy deals without using internal resources to validate the concept. Shares in Hansa rose 17% in response to the news.

For Sarepta, the deal provides it with another potential way to address neutralizing antibodies. Last month, Sarepta secured an option to license Selecta Biosciences’ immune tolerance platform for use against neutralizing antibodies in DMD and LGMD patients.