Pacira Releases 104-Week Safety and Efficacy Data for Local PCRX-201 Use in Knee Osteoarthritis

Pacira BioSciences, Inc., recognized for its pioneering non-opioid pain treatments, has unveiled new findings about its gene therapy candidate, PCRX-201 (enekinragene inzadenovec), for osteoarthritis of the knee. This data will be showcased at the upcoming American College of Rheumatology’s annual ACR Convergence meeting. The results highlight that PCRX-201 provides prolonged improvements in knee pain, stiffness, and function for up to 104 weeks post-administration, with a favorable safety profile.

The findings are from an open-label, phase 1 study assessing the safety and efficacy of PCRX-201 administered via ultrasound-guided intraarticular injections in 72 patients with moderate to severe osteoarthritis of the knee, classified by the Kellgren-Lawrence scale. Participants were divided into two groups. One group received different doses of PCRX-201, while the other received a pre-treatment with an intraarticular corticosteroid to enhance tolerability and gene transfer.

Remarkably, sustained benefits in pain and function were noted across all doses and both cohorts throughout the 104-week period. Particularly, the pre-treated group experienced greater pain reductions and fewer adverse events. Specific results from this cohort included 48%-65% improvement in pain and 53%-72% improvement in stiffness, as measured by the WOMAC Index. Additionally, notable enhancements in daily living activities were observed. By 16 weeks, over 70% of the participants reported more than a 50% reduction in baseline pain.

No severe treatment-related adverse events emerged, regardless of steroid pre-treatment or dosage. Joint effusions were the most common side effect, occurring in 36% of the pre-treated patients versus 61% in the non-pre-treated group. These effusions were typically mild to moderate and resolved within a median of 33 days in the pre-treated group.

Dr. Stanley Cohen, a leading rheumatologist and primary investigator of the trial, emphasized the significance of these findings. He noted that PCRX-201 offers prolonged pain relief, addressing the root cause of osteoarthritis knee pain—inflammation—unlike traditional treatments that only temporarily alleviate symptoms.

Pacira BioSciences plans to further this clinical investigation with a Phase 2, double-blind, active-controlled study set for 2025. Frank D. Lee, the CEO of Pacira BioSciences, expressed optimism about PCRX-201's potential to offer long-term pain management for millions of osteoarthritis patients. He highlighted that PCRX-201, being a locally administered therapy, delivers relief directly to the knee joint capsule, marking a significant advancement in gene therapy applications.

PCRX-201 is engineered to produce interleukin-1 receptor antagonist (IL-1Ra), an anti-inflammatory protein that reduces interleukin-1 signaling, a critical factor in osteoarthritis progression. Unlike systemic gene therapies, PCRX-201 targets the disease site, potentially reducing pain and disability while slowing structural degeneration.

In notable regulatory developments, PCRX-201 became the first gene therapy for osteoarthritis to receive the Regenerative Medicine Advanced Therapy (RMAT) designation from the FDA in March 2024. This designation facilitates accelerated drug development and review by providing intensive FDA guidance and early interaction opportunities. Additionally, PCRX-201 received Advanced Therapy Medicinal Products (ATMP) designation from the European Medicines Agency in May 2023.

Pacira BioSciences remains at the forefront of developing non-opioid pain therapies, with a commitment to transforming patient lives through innovative treatments like PCRX-201.