Medipost (078160.KQ) on Thursday unveiled positive Phase 3 clinical trial results for Cartistem, its knee osteoarthritis treatment, ahead of its launch into the Japanese market. The company aims to file for product approval in Japan within this year, obtain authorization in 2027, and begin full-scale supply around 2028. Developed with domestic technology, the allogeneic umbilical cord blood-derived mesenchymal stem cell therapy is set to face its global commercialization test 14 years after its Korean launch.
"Cartistem's Japan Phase 3 clinical trial achieved clear statistical significance consistently across both primary and secondary efficacy endpoints," Lee Seung-jin, head of the global business division and concurrent CEO of Medipost's Japan and U.S. subsidiaries, said at a press conference held at the Four Seasons Hotel in Seoul on Thursday. "Having reconfirmed Cartistem's cartilage regeneration effect that was proven through the Korean Phase 3 trial, this will serve as a solid foundation for Cartistem to enter the global market as a disease-modifying osteoarthritis drug (DMOAD) that induces structural recovery of damaged cartilage."
Cartistem is the world's first allogeneic umbilical cord blood-derived stem cell therapy, having received approval from Korea's Ministry of Food and Drug Safety in 2012. Autologous cartilage restoration using Cartistem performed on knee joint cartilage is known to restore cartilage function and preserve the joint, delaying the need for artificial joint replacement surgery. Recognized for achieving approximately 40,000 sales cases over the past 14 years in Korea, the drug received approval from Japan's Pharmaceuticals and Medical Devices Agency (PMDA) to skip Phase 1 and 2 trials and proceed directly to Phase 3, significantly reducing time and cost.
The trial was conducted at 13 medical institutions in Japan on 130 knee osteoarthritis patients with K&L grade 2-3, which indicates the severity of osteoarthritis. Patients were randomly assigned to the Cartistem group (59 patients) and the sodium hyaluronate injection group (61 patients), with safety and efficacy tracked over 52 weeks after administration. The primary efficacy endpoints that determine the trial's success were set as two measures: the patient-reported Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for knee pain and function, and the International Cartilage Repair Society (ICRS) grade assessed through arthroscopic examination. This contrasts with typical osteoarthritis Phase 3 trials that set only subjective measures such as pain relief or functional improvement as primary endpoints. As a result, both WOMAC score changes and the rate of ICRS grade improvement by one level or more showed statistically significant superiority compared to the control group. Secondary endpoints including the Visual Analogue Scale (VAS) score for pain levels and the International Knee Documentation Committee (IKDC) score for knee functionality all showed significant improvement. The company assesses that the secondary endpoints of this Japan Phase 3 trial being identical to the primary endpoints of the U.S. Phase 3 trial could signal positively for entry into the U.S. market. No causal relationship with the drug was confirmed for any serious adverse events during the trial.
Medipost established a foundation for local commercialization in December last year by signing an exclusive distribution licensing agreement for Cartistem in Japan with Teikoku Pharma. At that time, the company received an upfront payment of 11.8 billion won and will receive milestone payments worth approximately 14.8 billion won (based on December 2025 exchange rates) upon obtaining Japanese product approval. Based on these trial results, the company expects to comfortably achieve product approval in Japan. Once Cartistem is fully launched through its Japanese partner in about two years, the company can expect revenue from active pharmaceutical ingredient and finished drug supply, as well as milestone payments based on sales performance. "We plan to disclose within this year the Real World Evidence obtained from treatment data of over 550 patients who received autologous cartilage restoration using Cartistem in Korea more than three years ago," Lee said. "The conversion rate to artificial joint surgery among patients who have had between three and 12 years of follow-up was found to be less than 1%, which we believe can be used as useful evidence when Japan's Ministry of Health, Labor and Welfare sets insurance drug prices."
Japan has one of the world's highest proportions of elderly population aged 65 and over, making it strategically important in the global degenerative arthritis treatment market. Medipost plans to accelerate its entry into the world's largest U.S. market based on its performance in Japan. The company obtained Investigational New Drug (IND) approval for Cartistem's Phase 3 clinical trial from the U.S. Food and Drug Administration (FDA) in March and is driving clinical development with a target of FDA approval in 2031.
However, whether a Korean stem cell therapy can achieve commercial success in Japan's conservative medical market remains uncertain. "Japan differs greatly from Korea, where insurance only covers artificial joint surgery, and there is a strong tendency among patients to avoid surgery itself," Lee said. "Since satisfaction with stem cell therapies that work by promoting autologous cartilage regeneration is expected to be high, we plan to focus on communicating Cartistem's long-term efficacy and safety until market launch."
