Calibr, a division of Scripps Research focused on the “bench to bedside” development of transformative medicines, today announced encouraging preliminary data from the first nine subjects in a first-in-human Phase 1 clinical trial studying the first switchable CAR-T cell product (CLBR001 + SWI019) for patients with B cell malignancies.

The ongoing dose escalation trial investigating the safety, tolerability, and optimal dosing for Calibr’s next-generation “switchable” chimeric antigen receptor T-cell (sCAR-T) therapy platform is the first step towards a universal, more versatile, and safer approach to cell therapy.  

The results, presented at CAR-TCR Summit 2022 on September 21, showed that CLBR001 + SWI019 achieved an overall response rate (ORR) of 78% (7 of the first 9 evaluable patients) and a complete response (CR) of 67% (6 of 9 patients).

All subjects participating in the study were heavily pretreated with a median of 5 prior therapies, including a subject who previously received NK cell therapy.

Most responses were achieved with just a single dose of CLBR001 cells and one cycle of SWI019—with further cycles of SWI019 showing evidence of deepening responses over time. 

Administration of CLBR001 + SWI019 to date has been generally well tolerated.

No safety signals related to the cell product CLBR001 alone were reported, and clinical activity of the CLBR001 cells was, as designed, only observed following administration of the switch molecule SWI019.

Patients who experienced CRS or ICANS had significantly shorter duration of these events compared with those in pivotal trials for commercial CAR-T cell products (2–3 days vs 5–17 days, respectively).

This improvement in resolution of adverse events is attributable to the ability to hold or reduce the dose of SWI019 following CRS or ICANS, and effectively turn “off” the CLBR001 cells.

The ability for the switch to control cell activity is foundational to the platform and supports the safety of the system. 

These promising early results were achieved in the lowest dosing cohorts in the trial: 140e6–420e6 CAR+ CLBR001 cells and just 10–60 μg/kg of SWI019.

At these doses, CLBR001 cells reached higher levels in peripheral blood over the first 90 days than commercial CAR-T cell products.  

Current cohorts are testing higher doses of both CLBR001 and SWI019.

The strong responses, robust engraftment, and shorter duration of adverse events differentiates the switchable platform from previous approaches.   

“These results underscore the potential of Calibr’s switchable CAR-T cell platform to act like a ‘software’ and ‘hardware’ approach, where the biological response of the CLBR001 cell ‘hardware’ can be programmed using the switch dose as the ‘software’,” said Travis Young, PhD, vice president of biologics at Calibr.

“This is our first step towards demonstrating that the platform is truly universal in its programmability towards any target, including those for solid tumours.”    

The Phase 1 trial investigating CLBR001 + SWI019 is ongoing in dose escalation. No DLTs have been observed as of the data cutoff. 

The sCAR-T platform technology was developed by Calibr, and a partnership with AbbVie has enabled this first-in-human trial.

Expansion of the platform into solid tumours is currently underway. AbbVie holds certain rights to commercialisation. 

About the CLBR001 + SWI019 trial 

Calibr at Scripps Research is currently enrolling patients with B cell malignancies including lymphomas and chronic lymphocytic leukaemia in an open-label Phase I clinical study to test the safety and tolerability of CLBR001 + SWI019 (NCT04450069).

Up to 30 patients may be enrolled in this multi-center, dose-escalation trial to determine the optimal dose of CLBR001 and SWI019. 

About the sCAR-T platform 

Calibr’s novel platform approach consists of a combination of sCAR-T cells (CLBR001) and a tumour-specific antibody switch (SWI019).

Similar to CAR-T therapies currently on the market and in development, Calibr’s novel approach harnesses a patient’s own T cells by genetically altering them in a laboratory and then returning them to the patient’s bloodstream to selectively abolish tumour cells.

Unlike other CAR-T therapies, however, Calibr’s sCAR-T cells are initially inactive and activate only when dosed with the tumour-specific antibody “switch” (the anti-CD19 SWI019 switch in this first trial).

In contrast to conventional CAR-T therapies which are always active once administered, precise control over the timing and strength of activity afforded by sCAR-T is designed to provide a safer, more effective option against cancer.  

About Calibr 

Calibr 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 has created a portfolio of drug candidates based on Scripps technologies and is shaping a new paradigm for advancing nonprofit biomedical research to impact patients. 

Source: Scripps Research Institute