Akeso's 'IO2.0 + ADC2.0' Strategy: A High-Stakes Bet on Reshaping Oncology

HONG KONG – June 15, 2026 – Akeso, Inc. (HKEX: 9926) has initiated a pivotal Phase Ib/II clinical trial for its advanced breast cancer therapy, a move that signals a significant escalation in its ambitious strategy to redefine the oncology landscape. While the enrollment of the first patient may seem like a routine clinical update, for institutional investors and market analysts, it represents a critical validation point for the company's proprietary "IO2.0 + ADC2.0" platform—a high-stakes bet on combining next-generation immunotherapies with precision-guided "smart bomb" cancer drugs.

The trial evaluates AK138D1, a next-generation HER3-targeted antibody-drug conjugate (ADC), both as a standalone treatment and in combination with ivonescimab, Akeso's already-approved blockbuster bispecific antibody. The study targets two of the most challenging and prevalent forms of breast cancer: hormone receptor-positive, HER2-negative (HR+/HER2-) disease and triple-negative breast cancer (TNBC). This milestone is not just about advancing a single drug candidate; it's about proving the viability of a synergistic therapeutic architecture that could generate a portfolio of high-value assets and solidify Akeso's position as a leader in biopharmaceutical innovation.

Redefining the ADC Playbook

Antibody-drug conjugates, which pair a targeting antibody with a potent cytotoxic payload, have become one of the hottest areas in oncology investment. However, the first generation of these therapies has often been plagued by a trade-off between efficacy and toxicity, limiting their widespread use. Akeso aims to solve this with its "ADC 2.0" approach, exemplified by AK138D1.

The drug's innovative design is engineered to minimize uptake in healthy tissues, a feature intended to significantly widen the therapeutic window and reduce the severe side effects, such as interstitial lung disease (ILD) and hematologic toxicity, that have hampered competitors. Early data has already shown a promising safety profile with no observed ILD. Furthermore, AK138D1 is designed to overcome the "binding site barrier"—a phenomenon where ADC molecules cluster on the outer surface of a tumor, failing to penetrate deeper into the cancerous tissue. By ensuring more uniform distribution, Akeso believes its candidate can deliver a more powerful and complete anti-tumor effect.

This technological differentiation is crucial in an increasingly crowded HER3 ADC field. With major players like Daiichi Sankyo/Merck and Bristol Myers Squibb (through its acquisition of SystImmune's candidate) also advancing their assets, Akeso's ability to demonstrate a superior safety and efficacy profile will be paramount to capturing market share. For investors, AK138D1 represents a de-risked asset built on a validated mechanism (a DXd payload) but with proprietary engineering that offers a clear competitive edge.

The Power of the Platform: Ivonescimab as the Cornerstone

The true strategic brilliance of Akeso's plan lies not just in its next-gen ADC, but in its combination with ivonescimab, the cornerstone of its "IO 2.0" platform. Ivonescimab is a first-in-class bispecific antibody that simultaneously targets PD-1 and VEGF, two critical pathways involved in tumor growth and immune evasion. This dual-action mechanism has already proven its mettle.

In May 2024, ivonescimab was approved in China for non-small cell lung cancer (NSCLC), and it has since demonstrated superiority over an active PD-1 inhibitor in a head-to-head Phase 3 trial, a landmark achievement in immuno-oncology. With over 60,000 patients treated commercially in China and a Biologics License Application (BLA) under review by the U.S. FDA, ivonescimab is a proven commercial asset and a powerful engine for Akeso's growth. Its partnership with Summit Therapeutics for development in ex-China markets further underscores its global potential.

By combining AK138D1 with a validated, powerful immunotherapy like ivonescimab, Akeso is creating a potent one-two punch. The scientific rationale is compelling: ivonescimab's ability to reactivate the immune system and normalize the tumor's blood supply is expected to create an ideal microenvironment for the ADC to penetrate the tumor and deliver its cytotoxic payload more effectively. This synergy aims to produce a therapeutic effect far greater than the sum of its parts, potentially establishing a new standard of care.

Targeting High-Value, High-Need Markets

Akeso's clinical and commercial acumen is further demonstrated by its choice of targets. The AK138D1-202 study focuses on HR+/HER2- breast cancer, which accounts for roughly 65% of all cases, and the notoriously aggressive TNBC, which makes up another 10-20%. These segments represent enormous markets with significant unmet needs.

In the HR+/HER2- space, many patients eventually develop resistance to standard-of-care endocrine therapies and CDK4/6 inhibitors, leaving them with limited options. In TNBC, the lack of targeted therapies and high rates of recurrence create a desperate need for novel treatments. By positioning its "IO2.0 + ADC2.0" combination for these populations, from newly diagnosed to heavily pretreated patients, Akeso is strategically targeting multi-billion dollar market opportunities where a demonstrable improvement in outcomes could lead to rapid adoption and peak commercial success.

This focus is a clear signal to the market that Akeso is not just pursuing scientific novelty but is building a pipeline with a clear path to commercial viability. The company’s integrated structure—from its proprietary AI-powered R&D platforms and world-class manufacturing to its proven commercialization system—provides the foundation needed to execute this complex strategy. With a portfolio of over 50 assets and eight innovative drugs already on the market, Akeso has demonstrated it has the infrastructure and expertise to transform pipeline potential into revenue. This latest trial is the next critical step in proving that its most ambitious vision yet is ready to deliver for both patients and investors.