The FDA’s orphan drug designation provides incentives for rare-disease therapies such as seven-year market exclusivity, tax credits for clinical testing, and exemption from application fees. Fast-track designation provides additional regulatory support for investigational treatments and makes tenalisib eligible for accelerated approval and priority review.
“We are pleased to receive U.S. FDA orphan-drug designations for the active moiety of tenalisib for the treatment of peripheral and cutaneous T-cell lymphoma, and we look forward to advancing the drug into further development for treatment of T-cell lymphoma,” Swaroop Vakkalanka, PhD, founder and president of Rhizen Pharmaceuticals, said in a press release.
Tenalisib is a highly selective, oral inhibitor of PI3K delta/gamma. Preclinical studies have shown the treatment has a dual method of action in that it both inhibits cancer cell growth and modulates immune cells within the tumor microenvironment, changing their immunosuppressive properties into anti-cancer ones.
The trial enrolled 58 patients with cutaneous or peripheral T-cell lymphoma and randomized them to ascending doses of tenalisib (200 mg, 400 mg, or 800 mg) twice daily.
Among the first 20 patients who completed at least two treatment cycles, 45% responded to tenalisib, including two patients who had no detectable cancer cells (complete responses) and seven who experienced a reduction in tumor burden (partial responses).
Updated results from the trial were recently presented at the 10th Annual T-Cell Lymphoma Forum in La Jolla, California.
In an oral presentation, titled “RP6530, a dual PI3K d/g inhibitor: Interim results of a Phase I/Ib Study in Patients with Relapsed/Refractory Peripheral T-cell Lymphoma,” Bradley Haverkos, MD, from the University of Colorado School of Medicine, showed that half of the patients with peripheral T-cell lymphoma responded to tenalisib in the study.
A poster, “Results of Ongoing Phase 1/1b study of RP6530, a dual PI3K d/g inhibitor in Patients with Relapsed/Refractory Cutaneous T-cell Lymphoma,” presented by Auris Huen, MD, University of Texas MD Anderson Cancer Center, showed that 44% of patients with cutaneous T-cell lymphoma responded to the treatment.
While the number of patients included in the analysis has not been disclosed, both presentations showed an acceptable safety profile for tenalisib.