TCR2 Therapeutics Stock Plunges On Safety Signals From Gavo-cel Solid Tumor Trial

TCR2 Therapeutics Inc TCRR stock dropped to a 52-week low after interim results from the ongoing Phase 1 portion of the gavo-cel Phase 1/2 trial for mesothelin-expressing solid tumors.
The data will be at the European Society for Medical Oncology (ESMO21) Congress 2021.
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, which was resolved with supportive measures, and dose escalation continued.
One Grade 5 bronchoalveolar hemorrhage at DL5, along with severe CRS in all three patients treated at this dose level was reported.
The safety review team declared 5x108/m2 as the maximum tolerated dose.
Six patients were evaluable for response. Tumor regression was observed in 15 (94%) patients with a disease control rate (DCR) of 81%.
Six patients achieved partial responses (PRs) by target lesion assessment, four of whom achieved a PR.
The objective response rate (ORR) was 31% by independent review assessment and 38% by investigator assessment.
Price Action: TCRR stock dropped 31.7% at $10.74 during the market session on the last check Friday.
Check out our coverage of the European Society for Medical Oncology Congress (ESMO21).