B-cell therapy BE-101 granted FDA’s orphan drug status for hemophilia B

The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to BE-101, Be Biopharma’s B-cell treatment candidate for hemophilia B.

This designation is given to therapies that are meant to treat rare diseases, defined as conditions affecting fewer than 200,000 people in the U.S. It offers several incentives, including seven years of marketing exclusivity for the therapy if it’s approved, exemption from user fees, and eligibility for tax credits on qualified clinical trials.

“BE-101 has the potential to be the first and only Factor IX replacement therapy that is extremely durable, re-dosable and [dose adjustable], representing an opportunity to dramatically improve the treatment paradigm in hemophilia B,” Joanne Smith-Farrell, PhD, Be Bio’s CEO, said in a company press release. “The Orphan Drug Designation reinforces the potential of this therapy and underscores the need for improved therapeutic options for these patients.”

Hemophilia B is caused by mutations in the F9 gene that impair the production or activity of factor IX (FIX), a protein that’s needed for blood clotting. As in other types of hemophilia, patients with hemophilia B are highly susceptible to episodes of prolonged and excessive bleeding.

Factor replacement therapy, which involves the administration of a version of the missing or defective clotting factor to patients, is considered the mainstay treatment for hemophilia. However, these treatments require patients to receive infusions regularly to maintain clotting factor levels high enough to prevent bleeding episodes.

B-cells used in BE-101 are first collected from the patient

BE-101 is an autologous B-cell treatment. This means the B-cells that are used as part of BE-101 are collected from the patient who will receive treatment. A functional version of the F9 gene is then inserted into the genome — the entire set of genes found within a cell — of the collected B-cells, which will then be expanded and differentiated into plasma cells.

Plasma cells are specialized B-cells that are capable of producing high amounts of antibodies within a short period of time. When infused back into the patient, they are expected to migrate to the bone marrow where they will produce and release FIX at constant levels.

In preclinical studies, a single BE-101 dose was able to induce sustained therapeutic FIX activity. The data, obtained using immunodeficient mice, showed that FIX-producing cells were in the bone marrow, where they survived and expanded. No safety issues or abnormal clinical observations were seen in mice receiving treatment.

The FDA recently cleared BE-101 to start being tested in clinical trials involving hemophilia B patients. A Phase 1/2 trial called BeCoMe-9 is the first-in-human study to test the treatment’s safety and preliminary efficacy in adults with moderately severe to severe hemophilia B, and is due to start in the second half of the year.