BOSTON, May 04, 2026
Aktis Oncology has announced the initiation of a Phase 1b clinical trial evaluating AKY-2519, a next-generation B7-H3–targeted miniprotein radioconjugate, in patients with metastatic castration-resistant prostate cancer (mCRPC). This milestone marks a significant step in advancing targeted radiopharmaceutical therapies designed to address critical gaps in oncology, particularly for patients with limited treatment options. The trial is part of a broader strategy to expand AKY-2519 across multiple B7-H3 expressing solid tumors, positioning Aktis as a strong contender in precision cancer therapeutics with data expected to emerge in 2027.
Dual-Trial Strategy Expands Clinical Reach
Aktis is executing a two-trial clinical development strategy to maximize the therapeutic potential of AKY-2519 across diverse patient populations. The first Phase 1b open-label trial focuses specifically on mCRPC patients, including both PLUVICTO-naïve and PLUVICTO-experienced cohorts, addressing a key unmet need where existing PSMA-targeted therapies fall short.
The study will evaluate three dose levels, followed by dose expansion to generate robust safety and efficacy data. In parallel, Aktis plans to launch a second Phase 1b basket trial in the second half of 2026 targeting lung, colorectal, and other high B7-H3 expressing tumors, enabling broader clinical validation. This dual approach is strategically designed to accelerate indication-specific insights while improving the probability of success in later-stage trials.
Targeting B7-H3: A High-Value Oncology Opportunity
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The focus on B7-H3, a protein widely expressed across multiple aggressive tumor types, reflects a growing industry shift toward novel tumor-specific targets beyond traditional pathways. Many mCRPC patients are either ineligible for existing therapies or experience suboptimal responses, highlighting the urgent need for alternative mechanisms.
AKY-2519 leverages a miniprotein radioconjugate platform that delivers tumor-targeted radiation with high precision, aiming to improve tumor penetration, retention, and anti-cancer activity while minimizing exposure to healthy tissues. This approach not only enhances therapeutic efficacy but also supports companion imaging capabilities, allowing clinicians to confirm target engagement before treatment—an important step toward personalized oncology.
Platform Innovation Drives Next-Gen Radiopharma
At the core of Aktis’ innovation is its proprietary miniprotein radioconjugate platform, which is isotope-agnostic and engineered for optimal delivery of radioactive payloads directly to cancer cells. Unlike traditional antibody-based approaches, miniproteins offer faster tissue penetration and clearance, improving both safety and effectiveness.
The platform also enables real-time imaging validation, reducing treatment uncertainty and supporting data-driven clinical decisions. Aktis’ pipeline further includes AKY-1189, targeting Nectin-4 expressing tumors, currently in Phase 1b trials with anticipated data in early 2027. Together, these programs demonstrate a scalable strategy to address a broad spectrum of solid tumors, including breast, lung, colorectal, and urothelial cancers.
Addressing Unmet Needs in Advanced Prostate Cancer
Despite advancements in oncology, mCRPC remains a challenging disease with limited durable treatment options. Existing therapies often fail due to low target expression or resistance, leaving a significant portion of patients underserved. By targeting B7-H3, AKY-2519 introduces a new therapeutic pathway that could benefit patients who do not respond to current standards of care. The inclusion of both treatment-naïve and experienced patients strengthens the clinical relevance of the trial and increases the likelihood of identifying real-world clinical value. If successful, AKY-2519 could play a transformative role in redefining radiopharmaceutical-based cancer treatment paradigms.
Aktis Oncology’s Phase 1b program represents a critical inflection point where innovative science meets clinical execution. While challenges remain—including regulatory complexity and clinical variability—the company’s structured trial design, differentiated technology, and focus on high-value targets position it well in the competitive oncology landscape. The upcoming clinical data will be essential in validating whether B7-H3–targeted radioconjugates can deliver on their promise as a next-generation cancer therapy.
Source: Aktis Oncology press release
