ATRC-101 is a monoclonal antibody derived from a human antibody identified using Atreca’s discovery platform. The target of ATRC-101 is a tumor-specific ribonucleoprotein (RNP) complex consisting of polyadenylate-binding protein 1 (PABP1) bound to RNA, shown to be present on a majority of human ovarian, non-small cell lung, colorectal, breast cancers and acral melanoma samples across patients. ATRC-101 is believed to function through Driver Antigen Engagement, a novel mechanism of action in oncology. This mechanism involves systemic delivery of an antibody that, in preclinical models, engages the innate immune system to cause remodeling of the tumor microenvironment and drive T cell-mediated destruction of tumor cells. ATRC-101 has demonstrated robust anti-tumor activity as a single agent in multiple preclinical syngeneic tumor models, including a model in which PD-1 checkpoint inhibitors typically display limited activity.

Clinical Trials

Atreca is currently enrolling participants in a Phase 1b first-in-human study of ATRC-101 in select solid tumors. The trial includes a combination arm evaluating ATRC-101 with pembrolizumab. More information on the trial is available at

Expanded Access Policy

Expanded Access refers to the use of an investigational therapy outside of a clinical trial for potential treatment of a serious or life-threatening condition. Consistent with our purpose to discover novel therapeutics that bring clinically meaningful benefit to patients with cancer, Atreca is focused on conducting the clinical trials necessary to evaluate the safety and efficacy of our potential treatments and to gain the regulatory approvals required to make our therapies widely available to patients as quickly as possible. Consistent with this philosophy, Atreca does not provide access to investigational therapies on an Expanded Access basis. Atreca may reevaluate Expanded Access once preliminary safety and efficacy information has been obtained in clinical trials, such as following Phase 2 or Phase 3 trials. We encourage patients to speak with their physicians and to participate in clinical trials.