From April 17 to 22, 2026 local time, the 117th Annual Meeting of the American Association for Cancer Research (AACR) was held at the San Diego Convention Center in the United States. Keyisheng Pharma, a controlled subsidiary of 3D Medicines Inc. (Stock Code: 1244.HK) focusing on innovative radiopharmaceutical R&D, unveiled for the first time the preclinical and preliminary clinical data of its independently developed PSMA-targeted radiopharmaceutical drug conjugate (RDC), ¹⁷⁷Lu-PSMA-3D1015 (hereinafter referred to as “3D1015”).

The research findings were presented in poster format at AACR 2026 (Abstract ID: 1254). As an innovative in-house RDC candidate, 3D1015 consists of a small-molecule ligand conjugated with the beta-emitting radionuclide Lutetium-177 (¹⁷⁷Lu), targeting prostate-specific membrane antigen (PSMA), with the intended indication of metastatic castration-resistant prostate cancer (mCRPC). As a core radiopharmaceutical pipeline asset developed by Keyisheng Pharma leveraging 3D Medicines’ innovative molecular design platform, its small-molecule ligand is derived from the parent company’s proprietary oncology drug portfolio.

In preclinical studies, 3D1015 demonstrated high binding affinity to the target protein and specific enricshment in tumor lesions. Tissue distribution studies in tumor-bearing mice revealed high tumor uptake and prolonged retention of the agent. 3D1015 exhibited potent tumor growth inhibition; significant anti-tumor activity was observed even at low dosing levels in the LNCaP xenograft mouse model. In head-to-head comparative studies, its tumor suppressive efficacy was markedly superior to benchmark molecules in the industry. Initial toxicological assessments in animal models showed transient mild decreases in white blood cells and lymphocytes, which nearly fully recovered by the end of the study. No abnormalities in liver and renal function, tissue pathology or bone marrow smears were detected, demonstrating favorable safety and tolerability of 3D1015 in preclinical animal models.

The first-in-human clinical trial of 3D1015 (NCT07537010) is designed to evaluate the safety, radiation dosimetry and preliminary efficacy in patients with metastatic castration-resistant prostate cancer (mCRPC). The preliminary clinical data disclosed at the conference validated that 3D1015 injection delivers precise targeting properties, a favorable safety profile and encouraging early efficacy signals in humans.

3D1015 exhibited specific high tumor uptake and a differentiated excretion profile. SPECT/CT imaging confirmed that 3D1015 specifically and avidly accumulates in PSMA-positive primary lesions, lymph node metastases and bone metastases, with sustained drug retention in tumor tissues observed up to 216 hours post-administration. Notably, unlike the renal-dominant excretion seen in preclinical models, 3D1015 is primarily eliminated via the hepatobiliary-intestinal pathway in humans. This differentiated clearance mechanism provides a critical foundation for reducing common renal toxicities in clinical practice.

3D1015 demonstrated well-managed safety and tolerability. During the study, patients showed overall good tolerance, with no dose-limiting toxicities (DLTs) or serious adverse events (SAEs) reported. Only reversible hematological toxicities such as transient anemia were noted. The cumulative absorbed radiation doses to critical organs, including the kidneys, red bone marrow and salivary glands, remained far below established safety thresholds.

Treatment with 3D1015 delivered multi-dimensional clinical benefits. The conference highlighted the clinical course of one mCRPC patient with prior failure of standard therapies, who received individualized dynamic dose escalation from 10 mCi to 100 mCi. In terms of symptomatic improvement, intractable hematuria that had persisted for months completely resolved after the second cycle of treatment (approximately 25 mCi), leading to substantial improvements in clinical quality of life. In terms of biochemical response, at the assessment following the fourth cycle (approximately 100 mCi, cumulative activity of ~200 mCi), total prostate-specific antigen (TPSA) achieved a deep response with a maximum reduction of 71% from peak levels. Radiological evaluation showed marked shrinkage of target lesions with no new metastatic lesions. PSMA PET/CT further confirmed significant reduction or even complete clearance of radiotracer uptake in the majority of lesions. The patient remains on ongoing treatment and continues to derive clinical benefits.

Sustainable Productivity of the Radiopharmaceutical Platform

The clinical data of 3D1015 marks the successful first-in-human validation of KeyiSheng Pharma’s in-house RDC R&D platform, and further demonstrates the Company’s systematic layout and continuous innovation capabilities in the RDC field.

As a radiopharmaceutical subsidiary incubated by 3D Medicines, Keyisheng Pharma inherits the parent company’s technical expertise in innovative small-molecule drug design. Backed by globally proprietary integrated platforms covering ligand molecular design, candidate screening and drug evaluation (including cold and hot molecule assessment), the Company has established a closed-loop R&D system spanning RDC molecular design, screening and preclinical evaluation. Moving forward, KeyiSheng will continue to explore and develop multiple radionuclides, including various beta-emitting and alpha-emitting isotopes, as well as novel therapeutic targets.

Increased Investment to Accelerate Platforsm Value Realization

Building on the progress of 3D1s015, Keyisheng Pharma will scale up R&D investment in its radiopharmaceutical platform. While advancing the IND application and commercialization planning for 3D1015, the Company will accelerate the development of next-generation RDC candidates represented by alpha-emitting radiopharmaceuticals, and explore the clinical potential of combination regimens pairing radiopharmaceuticals with immunotherapies. In addition, Keyisheng plans to further expand the platform’s applications across novel targets and a broad range of solid tumors, and continuously deliver differentiated, globally competitive innovative radiopharmaceutical products.

Established in December 2025, Keyisheng Pharma (Shenzhen) Co., Ltd. is a controlled ssubsidiary of listesd company 3D Medicines Inc. (01244.HK). The Company focuses on the R&D, industrialization and commercialization of radiopharmaceuticals represented by RDCs, and is committed to building a world-class innovative radiopharmaceutical platform. Its lead candidate 3D1015 is a PSMA-targeted RDC drug armed with the cytotoxic radionuclide ¹⁷⁷Lu, developed for the treatment of metastatic castration-resistant prostate cancer (mCRPC), with robust potential to become a best-in-class therapy in this disease area.

Poster Abstract Link:https://aacrjournals.org/cancerres/article/86/7_Supplement/7182/782181/Abstract-7182-Development-and-evaluation-of-a