Hemgenix Perseveres in Hemophilia B Gene Therapy Market Despite Challenges

In the wake of Pfizer's recent exit from the hemophilia B gene therapy space, CSL Behring remains committed to Hemgenix, the first FDA-approved hemophilia gene therapy. Despite facing similar hurdles that led to Pfizer's discontinuation of Beqvez, CSL sees potential for growth and is working to overcome obstacles in patient adoption and healthcare system integration.

Slow Uptake and Limited Patient Pool

Hemgenix, approved by the FDA in November 2022, has treated only 12 patients during its first year on the market. The therapy targets a small subset of the hemophilia population, with CSL estimating that about 1,000 U.S. patients could benefit from the treatment.

Dr. Guy Young, director of the hemostasis and thrombosis center at Children's Hospital Los Angeles, explained that not all hemophilia B patients are eligible for Hemgenix. The therapy is restricted to adults with severe or moderately severe disease, and patients must meet specific health criteria, including having relatively healthy livers and low levels of pre-existing antibodies against the adeno-associated virus (AAV) vector used in the treatment.

Patient Hesitancy and Healthcare System Barriers

Bob Lojewski, general manager of North America at CSL Behring, expressed frustration at the lack of enthusiasm within the patient community. Many eligible patients are taking a wait-and-see approach, with some hesitant to be among the first to receive the commercial treatment.

The U.S. healthcare system presents significant infrastructural challenges for Hemgenix adoption. Dr. Young described a lengthy process to gain internal clearance for administering the therapy, involving multiple committees and extensive logistical preparations. The high cost of Hemgenix, listed at $3.5 million per treatment, also creates financial complexities for healthcare providers.

CSL's Commitment and Signs of Progress

Despite these challenges, CSL remains optimistic about Hemgenix's future. The company has seen positive developments, with about 200 patients undergoing neutralizing antibody tests for potential treatment. CSL CEO Paul McKenzie noted that hospital systems are beginning to recognize the importance of offering this transformational therapy to patients.

Dr. Young recently received his first out-of-state referral for Hemgenix treatment, suggesting growing patient demand. He anticipates that as institutions gain experience with the therapy, the process will become smoother and faster.

CSL's Lojewski stated that the company aims to reach "about half of all prophylactic-treated patients" with Hemgenix. While confident in achieving this goal, he acknowledged uncertainty regarding the timeline for widespread adoption.