Suzhou SmartNuclide Biopharmaceutical Co., Ltd.

A first-in-human trial of SNA028, a two-step pretargeted radioimmunotherapy targeting the GPA33 antigen, has been registered at Tianjin Medical University Cancer Institute and Hospital in China, in a trial sponsored by China-based firm SmartNuclide Biopharma. The move marks the clinical debut of a radiopharmaceutical approach to GPA33-positive advanced colorectal cancer. The SNA028 clinical trial (NCT07590856) is listed as not yet recruiting, with a planned start date of May 2026 and primary completion expected by December 2027. The Phase I study is single-center, open-label, and non-randomized, enrolling up to 20 adults aged 18 to 75 with histopathologically confirmed colorectal cancer who have progressed on standard therapy and carry GPA33-positive tumors with at least one measurable lesion per RECIST 1.1. The sequential seven-arm design reflects the three optimization questions the trial is structured to answer: the appropriate dose of GPA33-CC, the interval between GPA33-CC and 177Lu-SmartD2 administration, and the mass dose of the radiolabeled effector. GPA33-CC is tested at 0.3, 1, and 3 mg/kg; intervals between the two components are set at 3, 5, or 7 days; and SmartD2 mass doses range from 60 to 200 nmol, according to the trial record. Primary endpoints cover safety and tolerability, pharmacokinetics of GPA33-CC, and radiation dosimetry of 177Lu-SmartD2, with secondary endpoints assessing biodistribution via standardized uptake values and immunogenicity of the targeting component. GPA33 targeting in colorectal cancer GPA33, or Glycoprotein A33, is a cell-surface antigen expressed broadly and selectively across primary and metastatic colorectal cancer, including in putative cancer stem cell populations, making it a durable target for antibody-based approaches in this disease. The pretargeted radioimmunotherapy architecture of SNA028 is designed to decouple tumor localization from radionuclide delivery: GPA33-CC is administered first to accumulate at GPA33-positive tumor tissue, and after a defined clearance interval, 177Lu-SmartD2 is infused to bind the pre-localized targeting agent and deliver beta-particle irradiation selectively to the tumor site. Lutetium-177 is a beta-emitting radionuclide whose relatively short path length is suited to irradiating small tumor deposits while limiting exposure to surrounding normal tissue, a property that has driven its adoption across published preclinical GPA33-targeted PRIT systems. The most directly comparable clinical-stage program is GPA33-SADA, developed by Y-mAbs Therapeutics using self-assembling and disassembling (SADA) pretargeting technology licensed from Memorial Sloan Kettering Cancer Center and MIT. That system pairs an anti-GPA33 bispecific SADA construct with a radiolabeled DOTA-hapten effector and has been evaluated in early clinical work in colorectal cancer. SNA028 uses different proprietary component designations and cannot be assumed to share the same pretargeting chemistry or molecular format as the Y-mAbs program; the trial record does not specify whether SNA028 employs bioorthogonal click chemistry, a hapten-based capture system, or another architecture. No other GPA33-directed radiopharmaceutical programs with active clinical trials were identified in the course of this analysis. Trial identifier: NCT07590856. The sponsor of this trial is not named in the registry record. Tianjin Medical University Cancer Institute and Hospital is listed as the collaborating site. No press release or corporate announcement associated with SNA028 was identified. This article was generated with AI assistance and reviewed and edited by the AllSci editorial team Explore more at AllSci News: https://allsci.com/news/ Leave a Reply Cancel reply Your email address will not be published. Required fields are marked * Comment * Name * Email * Website Privacy Terms About Us Copyright © 2026. AllSci Corp. All rights reserved.