Akeso's EGFR/TROP2 Bispecific ADC AK158D1 Granted NMPA Phase I Clearance for Advanced Solid Tumors, Marking Its Fourth Clinical-Stage ADC Candidate

HONG KONG, Sept. 17, 2026 /PRNewswire/ -- Akeso, Inc. (9926.HK) ("Akeso" or the "Company") announced that AK158D1, its investigational next-generation bispecific antibody-drug conjugate (ADC) targeting EGFR and TROP2, has secured Phase I clinical trial clearance from the Center for Drug Evaluation (CDE) under China's National Medical Products Administration (NMPA). The trial will assess the candidate in patients with advanced malignant solid tumors.

AK158D1 is Akeso's fourth ADC to enter clinical development and joins the Company's growing clinical-stage ADC portfolio, which includes AK146D1 (TROP2/Nectin-4), AK138D1 (HER3), and AK157D1 (B7-H3). It is also Akeso's second bispecific ADC to reach the clinic, further advancing the Company's global strategy of combining next-generation immuno-oncology (IO2.0) approaches with next-generation ADC platforms (ADC2.0).

EGFR (epidermal growth factor receptor) and TROP2 (trophoblast cell surface antigen 2) constitute a highly promising target pair for bispecific ADC therapeutic development, with broad co-expression across a spectrum of solid tumor types. Each target has well-validated anti-tumor mechanisms of action, and their dual targeting holds significant synergistic anti-tumor potential.

To date, single-target ADCs directed against either EGFR or TROP2 have been constrained by three key clinical limitations: narrow tumor coverage, off-target toxicity, and multidrug resistance. As a next-generation dual-targeting ADC, AK158D1 integrates the precise tumor recognition enabled by bispecific antibodies, a highly potent cytotoxic payload, and an enhanced safety profile to create a potential breakthrough ADC to address the shortcomings of conventional single-target ADC modalities.

Preclinical data for AK158D1 have demonstrated potent anti-tumor activity with a favorable safety profile, supporting its potential as a novel therapeutic option for a wide range of patients, including those who are refractory to, intolerant, or ineligible for existing standard of care regimens.

Akeso is advancing its IO2.0 + ADC2.0 strategy, built on proprietary bispecific and multi-specific antibody technology and centered on cornerstone IO2.0 assets including ivonescimab and cadonilimab. Through this approach, the Company is elevating treatment standards for major diseases worldwide and building a broad oncology portfolio to create next-generation standard of care.

Leveraging its technological leadership in bispecific and multi-specific antibodies, Akeso is systematically building a comprehensive global IO2.0 + ADC2.0 therapeutic matrix for major diseases worldwide.

In the immuno-oncology field, Akeso has two approved bispecific antibodies for cancer treatment. The Company is actively evaluating ivonescimab and cadonilimab in combination with its proprietary next-generation ADC candidates. Increasingly, global partners recognize both ivonescimab and cadonilimab as preferred agents for combination regimens and breakthrough therapy explorations across a wide spectrum of tumor types. In the ADC space, Akeso has built a pipeline of highly differentiated next-generation candidates, including AK146D1, AK138D1, AK157D1 and AK158D1, which are already in clinical development. These agents are designed to address the narrow therapeutic window and safety limitations commonly associated with first-generation ADCs.

About AK158D1

AK158D1 is a bispecific ADC developed by Akeso, featuring a humanized antibody that dually targets EGFR and TROP2. Preclinical pharmacodynamic studies have shown strong antigen-binding affinity and robust in vitro and in vivo pharmacological activity.

About Akeso
Akeso (HKEX: 9926.HK) is a leading biopharmaceutical company committed to the research, development, manufacturing and commercialization of the world's first or best-in-class innovative biological medicines. Founded in 2012, Akeso has built a comprehensive R&D innovation ecosystem anchored by its proprietary Tetrabody antibody technology platform, AI-powered drug R&D platform, Dual-Shield ADC technology platform, Dual-Lock T-cell engager (TCE) technology platform, Tissue-Smart siRNA/mRNA technology platform, and cell therapy technology platforms.

Backed by world-class GMP manufacturing facilities and a highly efficient, integrated commercialization system, Akeso has developed into a globally competitive biopharmaceutical enterprise. Leveraging its fully integrated, multi-functional platform, the Company maintains a robust pipeline of more than 50 innovative assets targeting cancer, autoimmune diseases, inflammation, metabolic disorders, and other major therapeutic areas. Of these, nearly 30 candidates have advanced into clinical trials, including 15 bispecific or multi-specific antibodies and bispecific ADCs. Eight innovative drugs are commercially available, and two additional drugs with three indications are currently under regulatory review for marketing approval.

Akeso is committed to becoming a global leader in biopharmaceuticals through efficient and breakthrough innovation in R&D, developing novel therapies that are first-in-class or best-in-class, and providing better disease solutions for patients around the world.

Forward-Looking Statements
This announcement by Akeso, Inc. (9926.HK, "Akeso") contains "forward-looking statements". These statements reflect the current beliefs and expectations of Akeso's management and are subject to significant risks and uncertainties. These statements are not intended to form the basis of any investment decision or any decision to purchase securities of Akeso. There can be no assurance that the drug candidate(s) indicated in this announcement or Akeso's other pipeline candidates will obtain the required regulatory approvals or achieve commercial success. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the P.R. China, the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; Akeso's ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of Akeso's patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

Akeso does not undertake any obligation to publicly revise these forward-looking statements to reflect events or circumstances after the date hereof, except as required by law.

SOURCE Akeso, Inc.