[Edaily Reporter NA EUN-KYUNG ] Aston Science’s cancer vaccine AST-301 (HER2-ICD vaccine) is set to receive its first Phase 2 clinical trial results for stomach cancer this coming October. The company has completed patient recruitment and dosing, and has also locked the database. Following the announcement of the results, the company plans to begin full-scale technology transfer negotiations, apply for a technology evaluation by the end of the year, and pursue a listing on the KOSDAQ market in the second half of next year.

The number of joint research agreements utilizing the “Th-Vac” antigen-determinant discovery platform has also increased, and related revenue began to materialize in the first half of this year. The achievements secured in both clinical development and commercialization are expected to serve as key grounds for the company’s initial public offering (IPO) efforts.

Patient Dosing Completed… Initial Results to Be Released in October

Aston Science conducted a Phase 2 clinical trial of AST-301 involving 24 patients with HER2-positive gastric cancer. The study compared safety, immune responses, and recurrence patterns in patients who had completed surgery and standard adjuvant chemotherapy and received three or six doses of AST-301 at three-week intervals. All dosing has been completed, and an independent external analysis agency is currently analyzing the data.

Kim Won-il, Chief Scientific Officer (CSO) of Aston Science, met with Edaily at the company’s headquarters in Hanam, Gyeonggi Province, on the 2nd. “We have completed dosing for the last patient in the AST-301 Phase 2 clinical trial, and database locking for the analysis of most primary endpoints—excluding variables requiring long-term follow-up—has also been completed,” he said, adding, “We expect to receive the analysis results this coming October.”

He added, “AST-301 has received Orphan Drug Designation (ODD) for gastric cancer from the U.S. Food and Drug Administration (FDA), and we are currently reviewing eligibility for accelerated review for the gastric cancer indication. Based on the upcoming Phase 2 clinical trial results, we plan to pursue accelerated review and designation as a breakthrough therapy.”

In the Phase 2 clinical trial, which involved patients under close observation without additional treatment following completion of standard therapy, the company compared the results of a group that received three doses of AST-301 with a group that received six doses to determine the optimal dosing schedule for subsequent clinical trials. The trial was conducted as an open-label study, and the difference in efficacy compared to patients under observation without additional treatment will be indirectly compared with the results of previously published large-scale confirmatory clinical trials.

The entire study will be finalized next March, upon completion of the one-year follow-up for the last patient. In October, the company will release results on safety, as well as key biomarkers monitoring recurrence, disease-free survival (DFS), and immune responses following administration in both treatment groups.

Leading existing treatments targeting HER2 include the monoclonal antibody “Herceptin” and the blockbuster antibody-drug conjugate (ADC) “Enhertu,” which currently dominates the market. These drugs attack cancer cells by directly binding to HER2 or blocking its signaling pathways and are used to treat HER2-positive gastric cancer. However, resistance can develop during treatment as HER2 expression decreases, the target site changes, or other growth signals become activated. Since each drug carries its own side effects—such as cardiotoxicity or interstitial lung disease—the patient’s condition and potential overlapping toxicities must be carefully considered when administering combination therapy.

Unlike these therapies, which act directly on HER2, AST-301 attacks cancer cells through the immune system. When the vaccine activates T cells that recognize HER2, these cells circulate throughout the body, seeking out and eliminating cancer cells that express HER2.

Director Kim “Since AST-301 is not a drug that acts directly on cancer cells, it is easy to combine with other anticancer drugs, and I believe it can relatively reduce the burden of resistance seen with HER2-targeted therapies,” he explained. “Furthermore, because it targets the intracellular region of HER2 and the immune response can expand to other cancer antigens during the process of destroying cancer cells, there is a possibility that anticancer immunity will be maintained even if HER2 expression decreases.”

Moderna Takes a Personalized Approach, Aston Takes a Universal Approach

Recently, market expectations for therapeutic cancer vaccines have grown after Moderna and MSD’s personalized messenger RNA (mRNA) cancer vaccine, “Intismeran Autogen,” met its primary endpoints in a Phase 3 clinical trial for melanoma when used in combination with Keytruda. While there have been many cases where cancer vaccines induced an immune response without actually improving recurrence rates or survival, Moderna’s demonstration of the potential to suppress recurrence in late-stage clinical trials is seen as a turning point that paves the way for cancer vaccines to be recognized as a legitimate treatment modality.

Director Kim stated, “Moderna’s results go beyond the success of a specific mRNA candidate; they have laid the groundwork for therapeutic cancer vaccines to be utilized as new treatments in actual clinical practice,” adding, “This will serve as a turning point that sparks growing interest in cancer vaccines as a whole.”

The Moderna vaccine and AST-301 are similar in that they deliver cancer antigen information to the body to activate T cells that recognize and attack the corresponding cancer cells. However, while Moderna’s vaccine is a personalized mRNA vaccine that selects multiple neoantigens by analyzing tumor mutations in each patient, AST-301 is a plasmid DNA (pDNA) vaccine containing an intracellular region of HER2 that is common to many stomach cancer patients. It can be produced in advance and administered to patients who meet the criteria.

Director Kim emphasized, “AST-301 can be mass-produced in advance and stored long-term, and it can be easily administered on an outpatient basis, offering strengths in terms of price and patient accessibility,” adding, “Upon commercialization, it will likely fall well within the current price range typical of cancer treatment antibodies.”

Adding Platform Revenue Streams to Prepare for IPO

Aston Science is also expanding the commercialization of Th-Vac, its antigen determinant discovery platform. An antigen determinant is a specific fragment of an antigen that the immune system—such as T cells—actually recognizes as a target. Even within the same cancer antigen, there is a mix of regions that elicit strong immune responses and those that do not; therefore, the selection of the antigen determinant determines the performance of the cancer vaccine.

Th-Vac uses the advanced in silico program “ASEP” to predict candidate epitopes and then validates the actual T-cell response in human immune cells and animal models. The company explained that this process reduces the trial-and-error associated with traditional screening methods, which required testing countless protein fragments one by one. The process is expected to take approximately six months from candidate screening to the identification of initial lead compounds, and a total of 1 year and 6 months to 2 years to prepare for clinical trials following additional optimization and preclinical studies.

The business model follows an “option-to-license” approach, in which partner companies cover research costs, review initial data, and then decide whether to license the technology. Aston Science receives an upfront payment, milestone payments at each development stage, and sales royalties through this process.

Following the signing of its first platform technology export agreement with China’s Abogen in 2023, the company has entered into research and development agreements for mRNA-based therapeutics with Spain’s Sertest Biotech, U.S. companies, and domestic pharmaceutical firms. Revenue from these agreements began to materialize in the first half of this year, and the company expects some of these to lead to formal technology transfers as early as the end of this year or early next year.

This represents the most significant change compared to the time of the previous technology evaluation. At that time, AST-301 was in the early patient recruitment phase of its Phase 2 clinical trial, and there was only one platform agreement; however, AST-301 has now completed all dosing and is awaiting the announcement of key results, and the company has secured multiple platform agreements and related revenue. Based on this, the company aims to list on the KOSDAQ market in the second half of next year.

Jeong In-hyuk, Chief Financial Officer (Vice President) of Aston Science, stated, “Compared to the previous technology evaluation, both the clinical stage of our flagship pipeline and the commercialization results of our platform business have advanced,” adding, “Based on the AST-301 data and multiple platform agreements, we plan to proceed with the technology evaluation by the end of this year and pursue a listing next year.”

Aston Science recently secured a Series D investment of 39.6 billion won—exceeding its initial target—despite the current freeze in venture capital (VC) investment in the biotech sector. New investors include the Korea Development Bank, Korea Investment Partners, Soliderus Investment, Yuanta Investment, CKD Venture Investment, and Daily Partners.