Medipost has voluntarily withdrawn its phase 2 clinical trial of Cartistem in Japan. The company said it did so to focus on a separate phase 3 monotherapy study.

In a public disclosure Friday, Medipost said it has received approval from the Japanese Pharmaceuticals and Medical Devices Agency (PMDA) for the end-of-phase 2 report of Cartistem. This comes more than four years after the PMDA approved the phase 2 clinical trial in December 2019.

Cartistem is an allogeneic cord blood-derived mesenchymal stem cell therapy for knee osteoarthritis by the Ministry of Food and Drug Safety (MFDS) in 2012. Medipost has been conducting clinical trials of Cartistem in the U.S. and Japan to expand into global markets.

In particular, Medipost has signed a technology transfer agreement with EVASTEM, a joint venture established with VICX Therapeutics in Japan, to conduct clinical trials of Cartistem (EVA-001 in Japanese code name) in Japan.

Initially, Medipost planned to evaluate the efficacy and safety of the combination of Cartistem and High Tibial Osteotomy (HTO) in patients with knee osteoarthritis with K&L grades 2-4 in the phase 2 trial by dividing patients into two groups -- Cartistem plus HTO and HTO alone.

Explaining reasons for the voluntary withdrawal, Medipost said that the early approval of the monotherapy phase 3 study reduced the significance of proceeding with the phase 2 study for combination therapy. The company added that it intends to strengthen its business competitiveness by focusing its clinical research and development capabilities and funds in Japan on the phase 3 monotherapy of Cartistem.

Medipost received approval from the PMDA in March 2021 for a phase 3 trial of Cartistem monotherapy, which is currently underway. The company explained that the progress of the combination therapy has been slow due to Covid-19, and it was able to enter the phase 3 monotherapy trial in Japan based on clinical results in Korea.

"The practical significance of the combination therapy phase 2 has been significantly reduced," a Medipost official said. “We have decided to focus on the monotherapy phase 3, which will allow us to enter the Japanese market more broadly and quickly, after reviewing our strategy during the full-scale clinical progress after the end of Covid-19."

The official went on to say, “Last year, we completed more than 50 percent of phase 3 patient enrollment by launching additional sites and holding a symposium to accelerate the clinical trial. Now that we have decided to select and focus on phase 3, we will complete patient enrollment and dosing by the end of this year."

Last December, Medipost applied to the MFDS to amend its domestic marketing authorization to add an indication for Cartistem for treating talar cartilage and osteochondral defects in the ankle joint.

Medipost conducted a phase 3 study in six hospitals in Korea from March 4, 2020, to June 13, for patients with talar cartilage and osteochondral defects of the ankle joint. The study aimed to evaluate the efficacy and safety of adding Cartistem to the micropuncture treatment.

As a result of the trial, the Cartistem group showed a significant improvement compared to the control group (micropuncture) at 48 weeks postoperatively. There was no statistically significant difference in the safety evaluation, demonstrating the safety and efficacy of the treatment.

Medipost plans to introduce the product to the domestic market after obtaining the product license under the exclusive domestic distribution rights agreement with Hyundai Bioland.