Pacira BioSciences announces first patient dosed in phase II study evaluating safety and efficacy of PCRX 201 (enekinragene inzadenovec) for the treatment of osteoarthritis of the knee

Pacira BioSciences Inc.  announced the first patient has been dosed in the Phase II ASCEND study of PCRX 201 (enekinragene inzadenovec) for the treatment of osteoarthritis, or OA, of the knee. PCRX 201 features an innovative design based on the company’s proprietary high-capacity adenovirus, or HCAd, gene therapy vector platform. It is injected locally into the knee joint to boost cellular production of interleukin-1 receptor antagonist (IL-1Ra)  and block interleukin-1 pathway activation to improve chronic inflammation, pain and function. 

ASCEND will evaluate two doses of PCRX 201, Dose A is 1.4 x 10¹⁰ genome copies (GC) and Dose B is 1.4 x 10¹¹ GC. Patients will be randomized 1:1:1 to Dose A, Dose B or saline. All cohorts will receive concurrent pretreatment with an intraarticular corticosteroid (methylprednisolone 40 mg), a technique common in gene therapy dosing to improve tolerability and gene transfer. Part A of the study will randomize approximately 45 patients and Part B will randomize approximately 90 patients. The drug product used in Part B of the study will be manufactured using the company’s newly developed, suspension-based batch manufacturing process intended for commercial scale-up. Pacira expects to report topline results from Part A of the study before the end of 2026.

For both Parts A and B of the study, the primary endpoint is the number and percent of treatment-emergent adverse events, adverse events of special interest and serious adverse events for  PCRX 201  plus steroid pretreatment versus saline plus steroid pretreatment from Week 1 to Week 52. The study’s secondary and exploratory endpoints include efficacy assessments such as changes in pain and physical function from baseline at Weeks 38 and 52. Efficacy will be measured using the Numerical Rating Scale (NRS); the Western Ontario and McMaster Universities Index (WOMAC), and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Biomarkers, including structural endpoints, as well as immunogenicity and biodistribution will also be evaluated and all subjects will be followed for 5 years.

“We are excited to advance PCRX 201 into Phase II clinical development as it marks an important milestone on our 5x30 path to growth and value creation, as well as our transition into an innovative biopharmaceutical organization,” said Frank D. Lee, chief executive officer of Pacira. “There is a significant need for innovation in the treatment of OA of the knee, as current therapies are based on decades-old mechanisms and only provide up to three to six months of relief. In our large Phase 1 study, a single intra-articular injection of PCRX 201 was well tolerated and demonstrated unprecedented pain relief and durability across all levels of OA severity for at least two years. PCRX 201 has the potential to address the underlying chronic inflammatory processes that contribute to OA joint degeneration over time, with local administration that is contained in the joint – delivering medicine where it matters.”