[E-Daily Reporter Kim Jinsoo ] Aptabio Therapeutics Inc.(293780)is exploring opportunities to export its platform technology, led by the aptamer-based drug delivery platform “Apta-DC.” Apta-DC is a technology designed to overcome drug resistance by altering the pathway through which existing anticancer drugs are delivered to cancer cells. In particular, its value is expected to be significant, as it is a platform technology capable of non-exclusive technology exports, going beyond the value of a simple Apta-DC pipeline.

Aptabio Therapeutics Inc. plans to validate the clinical efficacy of the technology through “Apta-16,” which incorporates Apta-DC. If Apta-16 demonstrates its ability to overcome drug resistance and prove its safety in actual patients, it is expected to not only lead to the development of follow-up new drugs but also increase global attention on Apta-DC.

'ApDC' to Overcome the Limitations of ADCs

Although antibody-drug conjugates (ADCs) have recently established themselves as a core modality in the global anticancer drug market, intensifying competition, drug resistance, toxicity, and manufacturing complexity remain challenges to be addressed. Consequently, efforts are underway to overcome the limitations of existing ADCs by utilizing peptides, aptamers, and small-molecule compounds.

An aptamer is a short nucleic acid designed to bind selectively to a specific protein. Apta-DC is an aptamer-drug conjugate (ApDC) technology that utilizes aptamers as anticancer drug delivery vehicles, distinguishing it from antibody-based ADCs. Aptamers have the advantage of being smaller in molecular size than antibodies, allowing for greater flexibility in delivery vehicle design.

Aptamer-drug conjugates also offer structural advantages over ADCs. Unlike antibodies, they can be chemically synthesized, which facilitates mass production and reduces manufacturing costs. By incorporating the drug directly into the aptamer sequence, the use of separate linkers is minimized, which is expected to reduce the complexity of the production process and minimize quality variations between batches.

Aptabio Therapeutics Inc. uses a method that delivers drugs into cells by binding aptamers to “nucleolin,” which is expressed on the surface of various cancer cells. Binding aptamers to nucleolin is intended to alter the cellular uptake pathway of existing anticancer drugs and thereby counteract drug resistance.

Cytarabine, used to treat acute myeloid leukemia (AML), enters cells via the transporter ENT1 and is activated by the enzyme DCK. If abnormalities occur in this process, drug efficacy may decrease; however, Aptabio Therapeutics Inc. applied cytarabine to Apta-16 to reduce dependence on the existing transporter, thereby preventing a decline in efficacy.

Furthermore, the company addressed the issue of drug efficacy loss before reaching the target site—a common problem with aptamers—by utilizing a “G-quadruplex” structure. Aptamers, which are nucleic acid-based molecules, are typically degraded within minutes by DNA and RNA-degrading enzymes in the blood; however, AptaBio enhanced their stability by incorporating a G-quadruplex—a stable quadruple-helix structure formed when four guanine bases cluster in a square configuration at specific sites on the DNA.

An Aptabio Therapeutics Inc. representative explained, “Since a short half-life is a common challenge that must be addressed in the field of gene therapy as well, the G-quadruplex is a core competitive advantage of the Apta-DC platform.”

Aptabio Therapeutics Inc. is incorporating cytarabine into Apta-16 and gemcitabine into Apta-12, a pancreatic cancer treatment candidate. A key advantage of this approach is that by loading different anticancer drugs onto Apta-DC-based technology, the platform can be expanded into multiple development programs.

This is particularly significant because it opens the door to technology licensing for the platform itself. While a technology licensing agreement for a single candidate typically involves the transfer of rights to a specific pipeline, a platform agreement can include the rights to discover and develop multiple candidates under a single contract. Consequently, the scale of such an agreement is likely to be much larger than that of a single-pipeline technology licensing deal. Furthermore, platform technology licensing is typically “non-exclusive,” allowing the technology to be licensed to multiple companies.

An Aptabio Therapeutics Inc. official stated, “The turning point for the technology export of the Apta-DC platform will be the proof-of-concept in humans for Apta-16,” adding, “We plan to begin Phase 1 clinical trials for Apta-16 this year and will accelerate R&D to demonstrate the validity of the platform technology.”

Big Pharma Shows Strong Interest in Aptamers

The fact that aptamer-related agreements are being signed one after another in the global market further bolsters Aptabio Therapeutics Inc.’s prospects for technology exports.

In 2019, AstraZeneca signed a joint research agreement with the UK-based Aptamer Group for kidney-targeted drug delivery and extended it in 2021. In 2024, the two companies began collaborating to evaluate aptamer-based technology for delivering small interfering RNA (siRNA) to fibrotic liver cells. Since then, Aptamer Group has continued its research, announcing that it observed the suppression of target genes in fibrotic liver cells by conjugating siRNA provided by AeroSpace Technology of Korea, Inc. to its own delivery vehicle.

Subsequently, in April of this year, Merck & Co. (MSD) signed a collaboration and drug supply agreement with Chulip & Science Inc. (formerly Aptamer Sciences Inc.) for clinical trials of the anticancer candidate “AST-201” in combination with Keytruda. Under this agreement, MSD will supply Keytruda and provide scientific collaboration.

There are also examples of mergers and acquisitions (M&A). In 2023, Astellas acquired U.S.-based Iveric Bio for approximately $5.9 billion. “Izerbay,” Iveric Bio’s core asset, is an ophthalmic treatment in which an RNA aptamer directly inhibits complement protein C5—which is involved in inflammatory responses—and has even received approval from the U.S. Food and Drug Administration (FDA). Although its mechanism of action differs from that of aptamer-drug conjugates—which are used as anticancer drug delivery systems—this has effectively demonstrated the potential of aptamers.

An Aptabio Therapeutics Inc. official explained, “Among the approximately 30 business meetings we held recently at global events such as Bio USA, there were a great many inquiries regarding Apta-DC,” adding, “The fact that it can simultaneously address the issue of resistance to existing anticancer drugs and offer the potential for expansion into follow-on candidate compounds is what is drawing global attention.”

He continued, “If we can demonstrate the efficacy of Apta-DC, it will open the door to deals based on the platform rather than individual assets, and as a result, we expect the scale of technology exports to be significantly larger than before.”