June 17, 2025

Calibr-Skaggs doses first patient with switchable CAR-T cell therapy in a phase 1 trial for metastatic breast cancer CLBR001 ABBV-461 is a novel, investigational, two-part, switchable chimeric antigen T cell (sCAR-T) immunotherapy designed to treat solid tumors.

June 17, 2025

LA JOLLA, CA The Calibr-Skaggs Institute for Innovative Medicines, the drug development division of Scripps Research, today announced a milestone in cancer treatment with the dosing of the first patient in a phase 1 trial (NCT06878248) evaluating CLBR001 ABBV-461, a modular, switchable chimeric antigen receptor T cell (sCAR-T) therapy in patients with advanced or metastatic breast cancer who have no suitable treatment options. This is the first study of the sCAR-T platform in solid tumors.

CAR-T therapy has been transformative for patients with hematological malignancies who failed numerous prior treatments. However, conventional CAR-T therapies have not yet been as successful at treating patients with solid tumors. This challenge is what Calibr-Skaggs' switchable CAR-T cell therapy platform was designed to address.

The sCAR-T platform developed by Calibr-Skaggs is designed to enhance the precision and safety of CAR-T therapies, and has demonstrated promising preliminary results in a phase 1 clinical trial for hematological malignancies. Additionally, initial results have demonstrated CLBR001 sCAR-T cells can expand in the body in significantly greater numbers than conventional CAR-T cells, affording a better chance of penetrating the hostile solid tumor microenvironment. And the switch offers an added advantage by allowing the cells to rest, potentially avoiding CAR-T exhaustion.

There's a critical need to develop gene and cell therapy approaches that are able to recreate the success observed in blood cancers for patients with solid tumors like breast cancer, said Travis Young, PhD, vice president of biology at Calibr-Skaggs. By integrating an antibody-based switch,' there's the potential to enhance the precision of targeting solid tumor cells, while also mitigating potential safety risks.

The clinical trial testing CLBR001 ABBV-461 is now underway in the US. CLBR001 ABBV-461 is being developed in collaboration with AbbVie.

About the Phase 1 Clinical Trial

NCT06878248 is a Phase 1, Open-Label, Dose-Escalation Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Combination of CLBR001, an Engineered Autologous T Cell Product, and ABBV-461, an Antibody-Based Biologic, in Subjects with Locally Advanced or Metastatic Breast Cancer. The goals are to establish the safety and efficacy of the two-part therapy while establishing optimal biologic switch doses. Patients will be administered a single infusion of CLBR001 cells post lymphodepletion followed by cycles of ABBV-461 switch with regular assessments of safety and disease response to treatment.

About Calibr-Skaggs' sCAR-T Platform

This platform uses a unique two-component system: an engineered T cell product (CLBR001) and an antibody-based drug the switch.' The switch binds to both the target antigen on tumor cells and the CLBR001 cells, effectively switching on the CLBR001 cells to eliminate the cancerous cells, which is like a remote control for physicians. This design feature provides potential efficacy advantages and also safety optionality, as the physician can pause dosing of the switch in the case of an adverse event.

About Scripps Research

Scripps Research is an independent, nonprofit biomedical research institute ranked one of the most influential in the world for its impact on innovation by Nature Index. We are advancing human health through profound discoveries that address pressing medical concerns around the globe. Our drug discovery and development division, Calibr-Skaggs, works hand-in-hand with scientists across disciplines to bring new medicines to patients as quickly and efficiently as possible, while teams at Scripps Research Translational Institute harness genomics, digital medicine and cutting-edge informatics to understand individual health and render more effective healthcare. Scripps Research also trains the next generation of leading scientists at our Skaggs Graduate School, consistently named among the top 10 US programs for chemistry and biological sciences. Learn more at www.scripps.edu.

About the Calibr-Skaggs Institute for Innovative Medicines

The Calibr-Skaggs Institute for Innovative Medicines was founded on the principle that the creation of new medicines can be accelerated by pairing world-class biomedical research with state-of-the-art drug discovery and development capabilities. Leveraging the unique scientific framework of Scripps Research, Calibr-Skaggs has created a portfolio of drug candidates based on Scripps Research technologies and is shaping a new paradigm for advancing nonprofit biomedical research to impact patients. Learn more at calibr.scripps.edu.

*For inquiries, please contact Alex Brooks, abrooks@scripps.edu.

Cancer Calibr-Skaggs

LINK:	https://www.scripps.edu/news-and-events/press-room/2025/20250617-calib...
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