Akeso Unveils Promising Preclinical Data for IL-1RAP Targeting Antibody (AK135) at SITC 2025

HONG KONG, Nov. 7, 2025 /PRNewswire/ -- Akeso, Inc. (HKEX: 9926.HK) published the preclinical research data for its novel antagonistic monoclonal antibody targeting IL-1RAP, AK135, at the 40th Annual Meeting of the Society for Immunotherapy of Cancer (SITC) held in National Harbor, Maryland.

The results demonstrated that AK135 effectively targets IL-1RAP and blocks three key pro-inflammatory signaling pathways—IL-1, IL-33, and IL-36 at their source, thereby halting the transmission of inflammatory signals. In preclinical models, AK135 provided significant pain relief in neuropathy, exhibiting dose-dependent efficacy, while also showing good tolerability and safety profiles.

In vitro Results:

• ELISA, Fortebio molecular interaction technology, and flow cytometry (FACS) results demonstrated that AK135 has high affinity for IL-1RAP, with binding activity comparable to or superior to that of the control antibody CAN04.
• Reporter gene assays further confirmed that AK135 effectively inhibits the activation of IL-1, IL-33, and IL-36 signaling pathways, showing excellent half-maximal inhibitory concentration (IC50) values in each of the pathways.
• In tumor cell models, AK135 significantly reduced the secretion of pro-inflammatory cytokines (such as IL-6 and IL-8) induced by IL-1, IL-33, and IL-36.

In vivo Results:

• The in vitro experiments confirmed the high affinity and potent neutralizing activity of AK135. To further evaluate its in vivo efficacy, the research team established a Chemotherapy-induced peripheral neuropathy (CIPN) mouse model and assessed the pharmacological effects of AK135 through intermittent low-dose paclitaxel administration.
• Following AK135 treatment, the paw withdrawal threshold (PWT) in the CIPN model was significantly increased, indicating that AK135 effectively alleviated mechanical allodynia, with a dose-dependent efficacy.
• Throughout the treatment period, mice in all dose groups maintained stable body weight, with no significant signs of toxicity, demonstrating good tolerance.

CIPN is a prevalent and dose-limiting side effect of chemotherapy, affecting 50-90% of treated patients, of which 30-40% progressing to chronic neuropathic pain. Despite its clinical significance, effective treatment options remain limited, and the underlying mechanisms are not fully understood. Emerging evidence suggests that pro-inflammatory cytokines released by the damaged neurons play a key role in CIPN pathogenesis. IL-1 receptor accessory protein (IL-1RAP/IL-1RAcP) is a critical mediator of inflammatory signaling, amplifying responses through the interleukin-1 (IL-1), interleukin-33 (IL-33), and interleukin-36 (IL-36) pathways. Akeso developed AK135, a novel antagonistic monoclonal antibody targeting IL-1RAP, to alleviate the peripheral neuralgia by inhibiting these proinflammatory signaling pathways.

About AK135 (IL-1RAP Targeting Antibody)
AK135 is a novel antagonistic antibody targeting IL-1RAP, internally developed by Akeso, aimed at treating chemotherapy-induced peripheral neuropathy (CIPN). By precisely blocking IL-1RAP, this product simultaneously inhibits the three core inflammatory signaling pathways—IL-1, IL-33, and IL-36, providing relief from neuroinflammatory responses at their source. Preclinical studies have shown that AK135 significantly alleviates neuropathic pain in a dose-dependent manner, while also demonstrating good tolerance. Currently, AK135 is in Phase I clinical trials for the treatment of CIPN.

Forward-Looking Statement of Akeso, Inc.
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 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 the 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.

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, the company has created a unique integrated R&D innovation system with the comprehensive end-to-end drug development platform (ACE Platform) and bi-specific antibody drug development technology (Tetrabody) as the core, a GMP-compliant manufacturing system and a commercialization system with an advanced operation mode, and has gradually developed into a globally competitive biopharmaceutical company focused on innovative solutions. With fully integrated multi-functional platform, Akeso is internally working on a robust pipeline of over 50 innovative assets in the fields of cancer, autoimmune disease, inflammation, metabolic disease and other major diseases. Among them, 24 candidates have entered clinical trials (including 15 bispecific/multispecific antibodies and bispecific ADCs. Additionally, 7 new drugs are commercially available. Through efficient and breakthrough R&D innovation, Akeso always integrates superior global resources, develops the first-in-class and best-in-class new drugs, provides affordable therapeutic antibodies for patients worldwide, and continuously creates more commercial and social values to become a global leading biopharmaceutical enterprise.

For more information, please visit https://www.akesobio.com/en/about-us/corporate-profile/ and follow us on Linkedin.

SOURCE Akeso, Inc.