[Edaily Reporter NA EUN-KYUNG ] Ahead of the inclusion of “Alostemcit,” a treatment for epidermolysis bullosa, in Japan’s national health insurance reimbursement list, ANTEROGEN CO., LTD.(065660)has estimated the number of potential patients in Japan who meet the approved indications at approximately 1,000. ANTEROGEN CO., LTD. expects the market to expand as the number of prescribing hospitals and diagnosed patients increases.

“Estimated Market Size in Japan: 1,000 Patients… The Drug Will Create the Market”

Kim Mi-hyung, CEO of ANTEROGEN CO., LTD., met with Pharm Daily at the company’s headquarters in Gangseo-gu, Seoul, on the 13th. “Before there were treatments for epidermolysis bullosa, patients were concentrated at a few university hospitals and specialists,” she said. “But once the drug is launched, the number of hospitals capable of diagnosing and prescribing it will increase.” She added, “For pulmonary arterial hypertension treatments as well, the actual number of diagnosed patients increased significantly beyond initial projections upon launch. In a sense, the drug creates the market.”

ANTEROGEN CO., LTD. estimates that there are approximately 600 patients with dystrophic epidermolysis bullosa (DEB) in Japan. She explained that when patients with junctional epidermolysis bullosa (JEB) and severe simple epidermolysis bullosa (EB) are included, the number of potential patients falling under the approved indications rises to about 1,000.

Allostem Sheet is an allogeneic cell therapy that incorporates mesenchymal stem cells, isolated from the adipose tissue of healthy individuals, into a hydrogel sheet. It is applied to the lesions of patients with dystrophic epidermolysis bullosa (DEB)—a rare genetic disorder characterized by easy skin peeling and recurrent wounds—to induce skin regeneration. In Japan, the insurance-covered price was set at 182,096 yen (approximately 1.67 million won) per 5 cm × 5 cm sheet, and the drug was officially listed on the national formulary on the 15th.

Depending on the size of the lesion, multiple Allostem Sheets can be applied simultaneously, and there are no separate caps on the treatment duration or total usage. In Japanese clinical trials, ANTEROGEN CO., LTD. applied an average of 15 to 20 sheets per patient once a week for up to 12 weeks. If treatment is completed early, the usage can be reduced; if wounds remain, treatment can be extended at the discretion of a specialist.

Expanding Indications and Removing Usage Restrictions… Differentiating from Vizuvec

Vizuvec, a gene therapy developed by Crystal Biotech and a competing treatment, is the world’s first gene therapy for epidermolysis bullosa (EB) that delivers the normal COL7A1 gene to skin cells to induce the production of type VII collagen. It has been rapidly expanding its market share since its launch in the U.S. in 2023. Last year, it recorded global sales of $389.1 million (approximately 540 billion won), marking a 34% increase from the previous year. However, limitations include the fact that its indication is restricted to DEB, there is an upper limit on the weekly dosage, and repeated administration is required.

In contrast, AllostemCite leverages the tissue-regenerative properties of stem cells rather than compensating for a specific genetic defect. As a therapy that utilizes the tissue-regenerative capabilities of stem cells, its indications were expanded during the approval process following a proactive proposal by Japan’s Ministry of Health, Labor and Welfare. Unlike Vizuvec, which received approval in Japan only for DEB associated with the COL7A1 gene mutation, AllostemCite has a broader treatment scope.

Furthermore, the company explains that since there are no separate restrictions on the total number of treatment sessions, it can target patients who are difficult to treat with Vizuvec or those who have not seen sufficient efficacy.

CEO Kim stated, “Currently, patients in Japan with junctional epidermolysis bullosa (JEB) or severe simple epidermolysis bullosa (EB)—conditions for which Vizubec is not approved—can only use Allostemcit,” adding, “It may also be possible to sequentially administer Allostemcit to patients who did not achieve sufficient efficacy after Vizubec treatment.”

Following commercialization in Japan, ANTEROGEN CO., LTD. plans to resume clinical trials in the United States. The company received approval for its Phase 2 clinical trial plan from the U.S. Food and Drug Administration (FDA) in 2021 and has now completed the process of obtaining orphan drug designation, selecting clinical sites, and securing Institutional Review Board (IRB) approval. The company aims to enroll the first patient in September or October, with the clinical trial expected to last approximately one year.

CEO Kim said, “We will discuss the scale of subsequent clinical trials with the FDA based on the results of the U.S. Phase 2 trial, Japanese approval data, and real-world usage data,” adding “Given that the Phase 3 clinical trial for Bizubec also involved 30 participants, and considering the nature of ultra-rare diseases, it appears that a Phase 3 trial could also be conducted with around 30 participants,” he added. “Since the expected trial size is not large, we are considering not only technology transfer but also conducting the clinical trial ourselves from start to finish.”

Meanwhile, ANTEROGEN CO., LTD. had its marketing authorization for “QuinCell,” an autologous adipose-derived cell therapy, revoked last month after failing to complete the renewal process. The company explained at the time that the renewal application was not submitted due to a procedural error. CEO Kim said, “(The revocation of the QuinCell marketing authorization) was a simple administrative error in which the employee in charge missed the deadline for the renewal application,” adding, “Since it was not due to safety or quality issues, we resubmitted the same data to apply for a new marketing authorization, and it is currently in the final review stage at the Ministry of Food and Drug Safety.”