If you or someone you know lives with knee osteoarthritis, you know how frustrating it is: the pain, the stiffness, the limited mobility… and the constant cycle of short-term fixes.
Well, buckle up, because Pacira BioSciences just dropped some exciting news that could rewrite the osteoarthritis playbook, and it all centers around a single, long-lasting gene therapy injection.
One Shot, Two Years of Relief
On April 28, 2025, Pacira BioSciences (NASDAQ: PCRX) announced groundbreaking data on PCRX-201, its gene therapy candidate for knee osteoarthritis.
And here’s the thing: just one injection delivered meaningful pain relief, reduced stiffness, and improved function for up to two years, even in patients with advanced osteoarthritis.
Yep. One shot. Two years of relief. That’s unheard of in this space.
The findings were presented at the 2025 OARSI World Congress in South Korea, one of the top global gatherings for osteoarthritis research.
PCRX-201 is Not Your Average Pain Reliever
It’s a locally administered gene therapy built on Pacira’s proprietary HCAd (high-capacity adenovirus) vector platform.
That’s a fancy way of saying it delivers instructions to your knee cells, telling them to produce more IL-1Ra, a natural protein that blocks inflammation at the source.
Even cooler? PCRX-201 is designed to “turn on” only when inflammation is present. When things calm down, it powers off. Think of it as your knee’s smart anti-inflammatory switch.
What Did the Study Show?
The Phase 1 study included 72 patients aged 30 to 80, all diagnosed with knee osteoarthritis ranging from mild to severe. Patients were split into two groups:
One group received just the gene therapy, while the other received a corticosteroid pre-treatment (methylprednisolone) before the gene therapy to boost its effectiveness.
Across both groups, here’s what they saw over two years:
Pain was reduced by 41%–65%, and stiffness by 33%–72%.
Improvements were consistent across all severity levels, but people with milder osteoarthritis (Kellgren-Lawrence grade 2) saw the biggest gains.
No serious adverse events were linked to the treatment.
The most common side effect was joint effusion (swelling). But even that was more manageable in the pre-treated group and usually cleared up in about a month.
This is a Big Deal
Most current treatments for osteoarthritis offer relief for maybe 3 to 6 months, and many just mask the pain without addressing the root cause. PCRX-201 flips that script.
According to Prof. Ali Mobasheri, lead investigator of the study:
“This gene therapy doesn’t just manage symptoms, it tackles the root inflammatory causes of osteoarthritis at the cellular level.”
That’s a big deal. It signals a shift from reactive care to proactive, disease-modifying treatment, a long-standing goal in the arthritis research community.
FDA and EMA are Already Paying Attention
Back in March 2024, the U.S. FDA granted RMAT (Regenerative Medicine Advanced Therapy) designation to PCRX-201, making it the first gene therapy for osteoarthritis to earn this title.
The European Medicines Agency also tagged it as an Advanced Therapy Medicinal Product (ATMP) in 2023.
This means faster regulatory guidance, potential for accelerated approval, and a lot of optimism for patients who’ve been stuck with outdated solutions.
Pacira BioSciences’ (NASDAQ: PCRX) progress with PCRX-201 positions the company at the forefront of a potential multibillion-dollar market opportunity.
Knee osteoarthritis currently affects over 14 million Americans, with global prevalence rapidly rising due to aging populations.
Existing treatments offer only short-term relief, leaving a wide open space for innovation. With an RMAT designation from the FDA and ATMP classification from the EMA, PCRX-201 is on a streamlined regulatory path that could significantly accelerate its time to market.
