KEY TAKEAWAYS
- The ongoing BASECAMP-1 observational study aims to identify HLA LOH patients eligible for Tmod CAR T-cell therapy trials EVEREST-1 and EVEREST-2.
- 664 patients are enrolled, and the trial is still ongoing. So far, feasibility has been found in using routine diagnostics to identify rare patients for tailored clinical studies.
For this observational BASECAMP-1 screening study, researchers aimed to pinpoint individuals with tumor-associated HLA LOH who qualify for Tmod CAR T-cell therapy and are undergoing leukapheresis. This prepares them for participation in the autologous CAR T-cell therapy trials EVEREST-1 (A2B530 targets carcinoembryonic antigen; NCT05736731) and EVEREST-2 (A2B694 targets mesothelin).
BASECAMP-1 has a two-part eligibility process. Patients with metastatic solid tumors or at high risk of relapse undergo screening for germline HLA-A*02. If patients exhibit germline HLA-A*02:01 heterozygosity, their tumor tissue is further tested for somatic tumor HLA-A*02:01 LOH through Tempus next-generation sequencing. Alternatively, patients may also be identified through the Tempus AWARE program, which analyzes tissue obtained during routine clinical workups.
Institutional investigators will receive molecular results and can discuss enrollment options with treating physicians. Patients with tumors showing HLA-A*02 LOH may then qualify for leukapheresis screening, with banked T cells available for the EVEREST-1 and EVEREST-2 studies.
By June 1, 2023, 664 patients across 9 institutions participated in the study. Among 584 patients whose HLA status was determined, 234 showed HLA-A*02:01 heterozygosity (40%). Out of 117 patients whose LOH results were available, 13 tested positive for LOH (11%).
Since January 2022, the AWARE program has been active. It identified 52 patients across multiple sites with study-specific diseases and HLA-A*02:01 LOH. Currently, 13 patients are undergoing screening, 23 were deemed ineligible, and 16 have consented to participate.
These findings highlight the potential of routine diagnostic tools to identify rare, molecularly defined patients for personalized clinical studies.
Source: https://jitc.bmj.com/content/11/Suppl_1/A727
Clinical Trials: https://clinicaltrials.gov/study/NCT04981119
https://clinicaltrials.gov/study/NCT05736731
Simeone DM, Randolph Hecht J, Smith C, et al636 BASECAMP-1: A master prescreening study to identify patients with high-risk or metastatic solid tumors with HLA loss of heterozygosity (LOH) in preparation for Tmod CAR T-cell therapy trialsJournal for ImmunoTherapy of Cancer 2023;11:doi: 10.1136/jitc-2023-SITC2023.0636.
