TCR2 Therapeutics Announces Positive Interim Results
from Ongoing Phase 1/2 Trial of Gavo-cel for Treatment Refractory Mesothelin-Expressing Solid Tumors
- Clinical activity observed in all three mesothelin-expressing tumor types treated
- Gavo-cel disease control rate (DCR) 81% with tumor regression in 15 of 16 evaluable patients
- Overall response rate (ORR) 31% in patients infused with gavo-cel following lymphodepletion
- Meaningful survival benefit at 11.2 months for patients with refractory mesothelioma
- Recommended Phase 2 Dose (RP2D) being refined after identification of the Maximum Tolerated Dose (MTD)
- TCR2 to host a conference call on Friday, September 17 at 9:00a.m. ET
CAMBRIDGE, Mass., Sept. 17, 2021 - TCR2 Therapeutics Inc. (Nasdaq: TCRR), a clinical-stage
cell therapy company with a pipeline of novel T cell therapies for patients suffering from cancer, today announced positive interim results from the ongoing Phase 1 portion of the gavo-cel Phase 1/2 clinical
trial for mesothelin-expressing solid tumors. A dataset will also be featured in an oral presentation at the European Society for Medical Oncology (ESMO) Congress 2021 on September 17 at 14:20 CEST (8:20am EST) (Presentation #959O) and is part
of the official ESMO Press Programme.
As of the June 30, 2021 data cutoff, 17 patients (12 mesothelioma, 4 ovarian cancer and 1 cholangiocarcinoma)
had received a single gavo-cel infusion in the dose escalation portion of the gavo-cel Phase 1 clinical trial. The median number of prior lines of therapy was 5,
including immune checkpoint inhibitors (n=11) and mesothelin-directed therapies (n=5). Gavo-cel was administered up to dose level 5 (DL5) (5x108/m2 following lymphodepletion). Two dose limiting toxicities were reported: one Grade 3 pneumonitis at DL1 that resolved with supportive measures, which permitted the continuation of dose escalation, and
one Grade 5 bronchoalveolar hemorrhage at DL5, which along with the development of severe CRS in all 3 patients treated at this dose level, led the Safety Review Team to declare 5x108/m2 as the MTD. Following identification of the MTD, one patient has received gavo-cel at 3x108/m2 after lymphodepletion using a split dosing approach to refine the RP2D and an additional patient has been treated at DL3 (1x108/m2 following lymphodepletion). In both cases gavo-cel was well tolerated with only Grade 1 non-hematological toxicities
15 of the 16 patients evaluable for efficacy experienced regression of their target lesions, ranging in magnitude from 5% to 75%. Six
patients achieved partial responses (PRs) by target lesion assessment, four of whom (3 with mesothelioma and 1 with ovarian cancer) achieved a PR according to RECIST 1.1 criteria, including one who also achieved a complete metabolic response. One
patient with cholangiocarcinoma was also considered to have achieved a PR by investigator assessment, for an ORR of 31%. By independent review assessment, the ORR was 25% with a DCR Rate of 81%. The median overall survival for patients with
mesothelioma is 11.2 months, whereas the median progression free survival is 5.9 months.
The interim gavo-cel data reported today showed continued
clinical benefit and a manageable safety profile in a population of patients that previously achieved minimal or no improvement due to the advanced and aggressive state of their cancer, said principal investigator David Hong, M.D., deputy
chair of the Department of Investigational Cancer Therapeutics at The University of Texas MD Anderson Cancer Center. Patients with treatment refractory cancer have very limited treatment options and will often need hospice and supportive care.
We are encouraged by the early survival data from gavo-cel in patients previously treated with checkpoint inhibitors and other therapies.