Pacira BioSciences, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation to PCRX-201 (enekinragene inzadenovec), the company?s novel, intra-articular helper-dependent adenovirus (HDAd) gene therapy product candidate that codes for interleukin-1 receptor antagonist (IL-1Ra), for the treatment of osteoarthritis of the knee. The company?s RMAT application was supported by the preliminary safety and efficacy findings from a Phase 1 open-label, proof-of-concept, single ascending dose trial that enrolled 72 patients in two three-dose cohorts: a co-administered intra-articular steroid cohort and a cohort that did not receive a steroid. PCRX-201 was well tolerated, with efficacy observed through at least 52 weeks at all doses and cohorts.

The highest level of efficacy was achieved in the co-administered steroid group, which showed a greater percentage of patients with at least a 50% improvement in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and stiffness scores, as well as a meaningful improvement in (Knee Injury and Osteoarthritis Outcomes Score) KOOS functional assessment. Preliminary 36-week data were presented at the Osteoarthritis Research Society International (OARSI) 2023 World Congress, the premier annual international forum in osteoarthritis research and treatment. The 52-week data have been accepted for presentation at OARSI 2024 taking place in Vienna, Austria in April 2024 and the company expects to present 104-week efficacy and safety data later this year.

Established under the 21st Century Cures Act, RMAT designation is a dedicated program designed to expedite the development and review processes for promising therapies, including genetic therapies, that are intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition, and for which preliminary clinical evidence indicates that the drug or therapy has the potential to address an unmet medical need. RMAT designation provides the benefits of intensive FDA guidance on efficient drug development, including the ability for early interactions with FDA to discuss surrogate or intermediate endpoints, potential ways to support accelerated approval and satisfy post-approval requirements, potential priority review of the Biologics License Application (BLA), and other opportunities to expedite development and review. PCRX-201 was also granted Advanced Therapy Medicinal Products (ATMP) designation by the European Medicines Agency in May 2023.

PCRX-201 was acquired from GQ Bio Therapeutics GmbH, a privately held biopharmaceutical company headquartered in Hamburg, Germany. GQ Bio?s product candidates are next-generation gene transfer vehicles. These gene therapy vectors are highly efficient in entering joint cells to confer multi-year clinical benefit.

In PCRX-201, the high-capacity adenoviral gene therapy vector codes for the expression of IL-1Ra, a cytokine inhibitor that plays a central role in blocking inflammation and catabolic processes that are associated with pain and disease progression in osteoarthritis. Its unique design includes an inducible promoter so that, only in the presence of inflammation signaling, the vector turns joint cells into factories to produce sustained therapeutic levels of IL-1Ra to manage pain and mitigate osteoarthritis-related joint damage while remaining localized to the joint space.