Korean Biotechs Race to Develop Disease-Modifying Osteoarthritis Therapies

Competition among South Korean biotech companies to develop disease-modifying osteoarthritis drugs (DMOADs)—therapies designed to slow or reverse structural damage in knee osteoarthritis—is intensifying.

According to global market research firms, the osteoarthritis market across seven major countries—the United States, France, Germany, Italy, Spain, the United Kingdom, and Japan—was valued at approximately $2.6 billion in 2024 and is projected to grow at a compound annual rate of 5.3%, reaching $3.8 billion by 2031.

Industry sources say several Korean companies, including Medipost, Nature Cell, Kolon TissueGene, and Ensol Biosciences, are conducting or preparing Phase 3 clinical trials—the final stage of clinical developmentAA&D—for proprietary knee osteoarthritis therapies.

Unlike conventional treatments focused on pain relief or joint lubrication, DMOADs aim to slow disease progression or restore damaged cartilage. To date, however, no DMOAD has been approved by global regulators such as the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA). As a result, current treatment options remain largely symptomatic or surgical, including joint replacement.

Medipost is pursuing U.S. and Japanese regulatory approval for Cartistem, the first cell therapy for knee osteoarthritis approved in South Korea.

Cartistem received approval from the Ministry of Food and Drug Safety (MFDS) in 2012 as an allogeneic mesenchymal stem cell therapy derived from umbilical cord blood. The treatment has been administered to an estimated 35,000 patients through 2024, with real-world data continuing to be collected.

Long-term follow-up results published in a global academic journal in 2021 showed that, among 73 patients followed from a South Korean Phase 3 trial, 97.7% of those treated with Cartistem demonstrated at least a one-grade improvement on the ICRS scale at Week 48, compared with 71.7% in the microfracture surgery group. Histological assessments also showed statistically significant improvement in the Cartistem group.

While short-term functional measures—including VAS, IKDC, and WOMAC scores—did not show statistically significant differences at Week 48, significant improvements were observed in the Cartistem group during long-term follow-up at three to five years.

Based on these findings, Medipost received approval from Japan’s Pharmaceuticals and Medical Devices Agency (PMDA) in 2021 to initiate a Phase 3 trial. Patient dosing was completed in 2024, and long-term follow-up is ongoing.

In December 2025, Medipost signed an exclusive licensing agreement with Teikoku Pharma for commercialization in Japan, securing an upfront payment of $8.06 million and regulatory milestones totaling $10.1 million, with additional sales-based milestones.

The company is currently finalizing the clinical study report and plans to announce Phase 3 results in the second quarter of this year. Regulatory filings are targeted for the second half of the year, with approval expected by 2027.

On February 4, the FDA approved the Phase 3 protocol for Cartistem in the U.S. Medipost plans to initiate patient enrollment in the first quarter of 2026.

“Alongside the U.S. trial, we are actively pursuing global partnerships with multinational pharmaceutical and biotech companies,” said Seung-jin Lee, Head of Global Business Development and CEO of Medipost’s U.S. subsidiary. “Leveraging Phase 3 progress in Japan and North America, we aim to expand global commercialization opportunities.”

Nature Cell is preparing to pursue accelerated approval and initiate Phase 3 trials in the U.S. for JointStem, following an End-of-Phase 2 meeting with the FDA held on November 18 last year.

JointStem is an autologous adipose-derived mesenchymal stem cell therapy for knee osteoarthritis. After two unsuccessful attempts to secure approval in South Korea in 2023 and 2025, the company shifted its development focus to the U.S. market.

According to Nature Cell, the FDA raised no objections to using key components of the Korean Phase 3 trial to support U.S. approval, requesting only limited changes to certain chemistry, manufacturing, and controls (CMC) testing methods.

While two Phase 3 trials are typically required for U.S. approval, discussions with the FDA indicated that only one additional U.S. Phase 3 study would be necessary, potentially reducing development costs by more than $68.3 million.

Nature Cell plans to submit its Phase 3 application later this month and expects feedback following the standard 90-day IND review period.

The company also disclosed five-year follow-up data from its Korean Phase 3 trial, showing sustained reductions in WOMAC pain and VAS scores, along with improved joint function. During follow-up, 94.23% of patients did not undergo total knee replacement surgery, and no treatment-related serious adverse events were reported.

Kolon TissueGene resumed its U.S. Phase 3 trial in 2020 under the name TG-C, following the revocation of Invossa’s approval in South Korea in 2019. The study is enrolling approximately 1,000 patients with severe knee osteoarthritis and is scheduled to conclude in March, with topline results expected in July.

Earlier this year, the company participated in the J.P. Morgan Healthcare Conference, holding commercialization-focused meetings with global pharmaceutical companies, investors, and manufacturing partners.

“As the Phase 3 results approach, interest from pharmaceutical companies across multiple regions is increasing,” said CEO Seung-ho Jeon. “We aim to deliver an innovative treatment option to osteoarthritis patients worldwide.”

Kolon TissueGene plans to submit a biologics license application to the FDA in the first quarter of 2027.

Previously presented Phase 2 and Phase 3 data showed that only 7.0% of TG-C–treated patients ultimately required knee replacement surgery, with an average delay of 5.7 years from disease onset.

Ensol Biosciences is developing Engedi-1000 (E1K), a synthetic peptide-based osteoarthritis therapy, and received MFDS approval in January to initiate a Phase 3 clinical trial.

The study will enroll 363 patients with knee osteoarthritis and evaluate repeated intra-articular dosing over one year, comparing E1K with LG Chem’s Synovian injection.

E1K is designed to modulate the transforming growth factor beta-1 (TGF-β1) signaling pathway, selectively inhibiting Smad1/5/9 signaling associated with cartilage degradation while restoring Smad2/3 activity that supports cartilage regeneration.

In addition to pain relief and functional improvement, the company aims for long-term modification of joint structure, positioning E1K as a DMOAD candidate.

Ensol Biosciences is also preparing for U.S. Phase 3 trials and has been holding pre-IND meetings with the FDA since December. The company plans to conclude discussions within the first quarter and is in licensing talks with multiple global pharmaceutical partners.

If development proceeds as planned, the company expects U.S. market entry within one to two years following launch in South Korea.