MAINZ – BioNTech SE (Nasdaq: BNTX, “BioNTech” or “the Company”) presented data from its ongoing first-in-human Phase 1/2 trial evaluating the safety and preliminary efficacy of the Company’s novel CAR-T cell therapy candidate, BNT211, in patients with advanced solid tumors. The preliminary results demonstrated an encouraging safety profile and anti-tumor activity in testicular cancer patients at the first evaluated dose levels of BNT211. The data were presented in the Clinical Trials Plenary Session at the AACR Annual Meeting 2022 by Prof. John Haanen, M.D., Ph.D., Netherlands Cancer Institute (NKI), Amsterdam, Netherlands.
BNT211 is a potential first-in-class therapeutic approach which comprises two drug products, an autologous CAR-T cell therapy targeting the oncofetal antigen Claudin-6 (CLDN6) and a CLDN6-encoding CAR-T cell amplifying RNA vaccine (CARVac), which is based on BioNTech’s mRNA-lipoplex technology to improve persistence and functionality of the adoptively transferred cells.
The presentation included data from 16 patients who received CLDN6 CAR-T cells at dose levels 1 (1×107 CAR-T cells) and 2 (1×108 CAR-T cells) alone or combined with CARVac. Tumor indications included testicular cancer (n=8) ovarian cancer (n=4), endometrial cancer, fallopian tube cancer, sarcoma, and gastric cancer (1 patient each). Treatment with CLDN6 CAR-T alone or in combination with CARVac up to dose level 2 was well tolerated and showed encouraging signs of clinical activity. All 16 patients showed robust CAR-T cell expansion 10-17 days after infusion with cell frequencies close to 109 total counts in dose level 2. Adverse events and dose limiting toxicities were manageable; cytokine release syndromes of grade 1 and 2 and one transient occurrence of neurotoxicity grade 1 were observed.
At the first efficacy assessment 6 weeks post infusion, 6 of 14 evaluable patients showed a partial response, and 5 patients had stable disease with shrinkage of target lesions. One patient showed no change from baseline and two patients were progressing. Responses were seen in testicular (n=4) and ovarian cancer (n=2) patients. At 12 weeks, 4 of the 6 patients with a partial response showed deepening and durability of responses with one patient reaching a complete response 18 weeks after infusion. All 4 testicular cancer patients in the higher dose level had disease control and 3 of these patients showed objective responses. In addition, 1 testicular cancer patient showed partial response after infusion of the lowest CAR-T dose level in combination with CARVac. Antitumor activity tended to be higher at the higher CAR-T dose and when combined with the vaccine, with 4 of 5 patients in the CARVac combination group showing a partial response.
“Seeing first anti-tumor effects even at the lowest CAR-T cell dose in this heavily pre-treated patient population is truly remarkable and points to the potential of our CAR design and our CARVac approach,” said Özlem Türeci, MD, Co-Founder and Chief Medical Officer at BioNTech. “The results support our assumption that Claudin-6 is a well-suited new tumor target. Bringing these innovations together in one regimen may benefit patients with hard-to-treat solid tumors with an otherwise poor prognosis, such as advanced testicular cancer. Our preliminary data indicate that the successes of CAR-T in hematological cancers may indeed be transferred to solid tumors.”