[Edaily Reporter NA EUN-KYUNG ] “This is significant because regeneration of the meniscus was observed following the injection. The results strongly suggest the possibility of structural improvement beyond mere pain relief.”

Lee Seong-gu, President of ANTEROGEN CO., LTD. ( ANTEROGEN CO., LTD.(065660) ), made these remarks during a meeting with E-Daily on the morning of the 19th at the company’s Central Research Institute in Gangseo-gu, Seoul, regarding the clinical results of “ANT-301,” a candidate drug for the treatment of knee osteoarthritis. He explained that an additional analysis of magnetic resonance imaging (MRI) scans from participants in the domestic Phase 1 clinical trial revealed changes suggesting meniscus regeneration and the resolution of bone cysts following a single injection.

ANTEROGEN CO., LTD.(065660)Based on these results, the company will proceed with follow-up clinical trials for ANT-301. It has also begun exporting “Allostem Sheet,” a treatment for epidermolysis bullosa that received approval in Japan this year. The company expects next year to be a turning point, as revenue from sales in Japan aligns with clinical progress on its flagship candidate.

ANT-301: Potential for Structural Improvement Observed with Injection

ANT-301 is an injectable therapy consisting of mesenchymal stem cells derived from donor fat and cultured within a hydrogel. The hydrogel, approximately 1 mm in size, serves as a scaffold for the cells. Unlike methods that detach cells from culture dishes and administer them as a suspension, this treatment is designed to be injected directly into the joint cavity while preserving the cells’ original growth environment.

CEO Kim Mi-hyung explained, “Our development goal was to deliver the cells in a healthy state with minimal damage and to create an environment where they could remain in the joint for an extended period,” adding, “We developed a long-acting formulation to ensure the stem cells continuously secrete regenerative substances.” According to the company, genetic material from the administered cells was detected for up to about one month in animal trials.

Six patients with Kelgren–Lawrence (KL) Grade 3–4 osteoarthritis—indicating severe disease—participated in the domestic Phase 1 trial conducted at Seoul National University Hospital. KL Grade 3 represents a moderate stage characterized by a marked narrowing of the joint space, while KL Grade 4 is a severe stage involving significant cartilage damage and bone deformation, where joint replacement surgery is typically considered. While major competing drugs—such as Roer-Sivibint and MEDIPOST CO., LTD.(078160)’s injectable osteoarthritis drug candidates—are primarily developed for patients with KL grades 2–3, ANT-301 included patients with more advanced osteoarthritis. After a single administration of either a low or high dose, safety, pain levels, joint function, and imaging changes were monitored for 12 months.

However, in the upcoming Phase 2 trial, the company plans to focus on patients with KL Grade 3, excluding those with KL Grade 4. CEO Kim explained, “The patients who showed the smallest improvement in pain were those with KL Grade 4, who had the most advanced osteoarthritis,” adding, “We considered including both Grades 3 and 4 in the Phase 2 trial, but we determined that securing positive results in KL Grade 3 patients alone would be highly significant.”

The MRI findings presented by the company this time are the result of an additional analysis of images from one participant. The company explained that regeneration of the meniscus—which absorbs shock in the knee—and the resolution of a bone cyst, which forms as a sac-like structure within the bone, were observed. These findings are scheduled to be published in a scientific paper.

President Lee emphasized, “Unlike methods that involve transplanting cells through surgery, it is rare to observe such cartilage regeneration findings with an injectable treatment.” However, since this was a Phase 1 trial without a control group involving only a small number of patients, the regenerative effects and clinical significance must be verified in subsequent trials.

ANTEROGEN CO., LTD. plans to submit an Investigational New Drug (IND) application for a Phase 2 clinical trial to the Ministry of Food and Drug Safety later this month. Unlike the single-dose Phase 1 trial, the company is pursuing a design that involves two doses administered one month apart and evaluates efficacy over one year in patients with Grade 3 KL scores. The strategy is to increase the number of doses and focus on the patient group that showed a relatively good response in Phase 1 to enhance the durability of the effect and the extent of improvement.

In the U.S., the company will first take steps to resolve the clinical hold placed on its existing trial. According to the company, the FDA had requested additional data to confirm whether a hydrogel approximately 1 mm in size could be administered using a standard syringe; the trial was placed on hold because the company was unable to submit sufficient data at the time. Subsequently, the Phase 1 clinical trial conducted in Korea demonstrated safety when administered via a standard syringe. CEO Kim stated, “We plan to submit data to the U.S. Food and Drug Administration (FDA) this week showing that there were no safety issues when using a standard syringe in the Phase 1 trial in Korea,” adding, “Once the hold is lifted, we will discuss a plan to proceed to Phase 2 in the U.S. based on the domestic results.”

Allostem Expands Growth Pillars Through Sales in Japan and U.S. Clinical Trials

Allostem Sheet is a therapeutic product consisting of a sheet containing adipose-derived stem cells that is applied to skin wounds. It received manufacturing and marketing approval in Japan last April, and exports began recently. Next year is expected to be a period for confirming the commercial success of Allostem Sheet as sales performance in Japan accumulates.

In the U.S., the company is revising the trial protocol for the Phase 2 study of AloStem Sheet for dystrophic epidermolysis bullosa (DEB). While the original design required wounds to heal completely to demonstrate therapeutic efficacy, the revised Investigational New Drug (IND) application aims to lower the threshold for the primary endpoint by recognizing efficacy even if the wound area is reduced by a certain percentage or more.

In this process, the company referenced the development case of “ZEVASKYN” by U.S.-based Aveo Therapeutics, which received FDA approval last year. President Lee stated, “With the approval of ZEVASKYN, a precedent has been set where efficacy is recognized if a large wound recovers to a certain level, even if it does not close completely,” adding, “We have also adjusted the development strategy for the Allostem Sheet based on clinical results obtained in South Korea and Japan.”

ANTEROGEN CO., LTD. submitted an amendment to its U.S. clinical trial protocol on the 17th of last month and submitted responses to the FDA’s additional inquiries on the 15th. Barring any further issues, the company plans to proceed with the Phase 2 clinical trial after completing the Institutional Review Board (IRB) amendment process at the clinical trial sites. CEO Kim explained, “We will proceed with preparations at each institution while confirming whether the FDA has any further inquiries.”

The company is prioritizing increasing the value of both ANT-301 and Allostem Sheet through follow-up clinical trials rather than early technology exports. It also cited the ability to supply domestically manufactured products to overseas clinical trials as a competitive advantage that reduces development costs and time.

CEO Kim stated, “Our plan is to complete at least the domestic Phase 2 trial before deciding on the next steps,” adding, “We will continue clinical development by leveraging our strength in supplying domestically produced products to overseas markets.”