FDA Designates CT103A, CAR T-cell Therapy, an Orphan Drug
The U.S. Food and Drug Administration (FDA) has granted orphan drug status to CT103A, an experimental CAR T-cell therapy that IASO Biotherapeutics and Innovent Biologics are developing to treat relapsed or refractory multiple myeloma.
Orphan drug designation is given to therapies with a potential to substantially improve care for rare diseases, defined as conditions affecting 200,000 or fewer people in the U.S. It confers certain incentives to the therapy’s developers; in particular, orphan drugs are eligible for seven years of market exclusivity if they are approved by the FDA.
This status “is of great significance to patients with multiple myeloma and represents the FDA’s recognition of CT103A and the clinical data provided by IASO Bio,” Wen Wang, MD, PhD, CEO and chief medical officer of IASO, said in a press release.
Immune cells called T-cells have the capacity to kill cancerous cells, but tumor cells often find ways to avoid immune-mediated destruction.
CT103A, also called IBI326, is a CAR T-cell therapy. Put simply, this type of therapy involves equipping T-cells with a specially designed protein receptor, called a chimeric antigen receptor or CAR, that helps them to more effectively identify and target cancer cells.
Specifically, CT103A involves equipping T-cells to target a protein called B-cell maturation antigen (BCMA), commonly expressed on the surface of myeloma cells.
IASO reports that BCMA-targeting CAR-T cells can induce remission in multiple myeloma patients. But they are known to have a high degree of immunogenicity — the development of immune responses against the treatment that prevents repeat dosing — and to wane in effectiveness over time so that relapses are likely. The specific receptor given to the T-cells in CT103A is designed to address these issues.
Ascending doses of CT103A were investigated in an open-label Phase 1 clinical trial (ChiCTR1800018137) that involved 18 relapsed or refractory multiple myeloma patients who had a median of four prior therapy lines. After a median of 394 days (a little over one year), all had responded to the treatment, with 72.2% achieving complete responses or better.
All patients with available data were also negative for minimal residual disease, or the small number of cancer cells that sometimes remain after treatment and may cause disease relapse.
“Theoretically, fully human CAR might offer the advantage of reduced immunogenicity [immune responses] and therefore facilitate a better persistence of CAR T cells,” the trial’s researchers reported, noting that “short persistence of CAR T cells in vivo [in a living body] may be one of the most important reasons for BCMA-positive relapse.”
This CT103A trial “used a second-generation anti-BCMA CAR [therapy] with a fully human component,” they added.
Orphan drug status recognizes “our effort to develop a novel anti-BCMA CAR with better efficacy and persistence. It underscores the importance of bringing this therapeutic option to patients with multiple myeloma, and strongly motivates us to expedite the clinical development of IBI326,” said Hui Zhou, PhD, senior vice president of Innovent.
“We are looking forward to the launch of CT103A both in China and US as soon as possible,” Wang added.