SLX-1411

SLX-1411 is a first-in-class antibody-drug conjugate (ADC) targeting G protein-coupled receptor 151 (GPR151), an orphan GPCR that is highly and selectively expressed in certain malignancies, such as small cell lung cancer (SCLC) and other neuroendocrine tumors, while remaining largely absent in healthy tissues. Developed by Solve Therapeutics, SLX-1411 consists of a humanized monoclonal antibody conjugated to a topoisomerase I inhibitor payload via a cleavable linker. The drug is designed to selectively deliver the cytotoxic agent to GPR151-expressing malignant cells, minimizing off-target toxicity due to the restricted expression of the target in normal tissues. SLX-1411 is being developed in conjunction with SLR-108, an 89Zr-labeled antibody-radionuclide conjugate (ARC) that serves as a companion diagnostic for PET imaging to identify patients with sufficient target expression for treatment. As of early 2024, SLR-108 is in Phase 1 clinical testing, while SLX-1411 is in late-stage preclinical development or early clinical transition.