Precision BioSciences Reports Clinical Program Updates for Its Allogeneic CAR T Pipeline
Precision BioSciences, Inc. recently announced program updates across its allogeneic CAR T cell therapy pipeline, including updated data for its Phase 1/2a clinical study of PBCAR0191 with enhanced lymphodepletion (eLD) presented at the 63rd American Society of Hematology (ASH) Annual Meeting.
“Precision’s clinical stage CAR T pipeline continues to generate promising data in lymphoma patients. We have recently observed a potential signal in patients who have relapsed following auto CAR T therapy and responded to treatment with PBCAR0191. This is a growing population of patients with the greatest need for new treatment options, and PBCAR0191 has the potential to be a first-in-class allogeneic CAR T product for this patient population,” said Michael Amoroso, Chief Executive Officer of Precision BioSciences. “In parallel, we are continuing to advance PBCAR19B, our immune evading stealth cell candidate, in a relapsed and/or refractory (R/R) patient population with non-Hodgkin’s lymphoma (NHL), in pursuit of a potential best-in-class CD19 targeting allogeneic product candidate.”
The updated data from the PBCAR0191 Phase 1/2a study included 22 (17 NHL, 5 B-ALL) heavily pre-treated R/R subjects with predominantly advanced or aggressive B-cell malignancies who were evaluable as of November 16, 2021. Evaluable subjects received a median 5 lines of prior treatment, including 27% (6/22) who previously received a CD19-directed autologous CAR T.
For patients that received treatment of PBCAR0191 following eLD as of November 16, 2021:
- PBCAR0191 showed no ≥ Grade 3 cytokine release syndrome (CRS), one Grade 3 immune effector cell-associated neurotoxicity syndrome (ICANS) with resolution to ≤ Grade 2 in 72 hours, no evidence of graft versus host disease and one infectious death at Day 54 deemed possibly related to treatment2
- PBCAR0191 yielded an overall response rate of 73% and a complete response rate of 59% using a 3 x 106 cells/kg cell dose
- Four responders among the 17 evaluable NHL subjects reached Day 180 durability assessment
Most notably, a potential signal for PBCAR0191 was observed among six subjects that previously received an autologous CAR T:
- 100% of these patients responded and 66% experienced a complete response at ≥ Day 28
- More than half of these patients had a longer duration of response on PBCAR0191 than with the prior autologous CAR T treatment
“Today, there are no FDA approved therapeutics for lymphoma patients who have relapsed following auto-CAR T therapy. PBCAR0191 has the potential to be developed as a salvage treatment for this growing population with high unmet need, and we are actively enrolling additional patients in this relapse setting to further validate this observed activity,” said Bijal Shah, MD, Associate Professor, Malignant Hematology Department, H. Lee Moffitt Cancer Center and Research Institute.
The Phase 1 clinical study of PBCAR19B is actively enrolling subjects with R/R NHL. Flat doses of PBCAR19B CAR T cells following standard lymphodepletion (sLD)3 are administered starting at Dose Level 1 (2.7 × 108 CAR T cells). The company has dosed the first three subjects at Dose Level 1.
“In parallel to our development with PBCAR0191, we are continuing to enroll patients in the PBCAR19B clinical trial and expect to share initial results for this program in mid-2022,” said Alan List, MD, Chief Medical Officer of Precision BioSciences. “Unique attributes of ARCUS designed to make complex gene edits in a single step may allow PBCAR19B to achieve a best-in-class allogeneic product profile to potentially displace CD19 directed autologous CAR T.”
PBCAR19B is a novel immune-evading stealth cell candidate employing a single-gene edit to knock-down beta-2 microglobulin designed for evading T cell rejection, while also inserting an HLA-E transgene to further evade rejection from natural killer cells. Precision BioSciences’ CAR T cells are the only allogeneic CAR T cells in human clinical trials made with a single gene editing step designed to specifically avoid the potentially deleterious effects of making multiple edits to T cells.
PBCAR269A is an investigational allogeneic CAR T immunotherapy targeting B-cell maturation antigen for the treatment of R/R multiple myeloma. The following has been observed among 14 patients that have been evaluated for clinical activity and safety across four dose levels of PBCAR269A4 monotherapy following sLD:
- No Grade ≥ 3 CRS or ICANS
- Dose-dependent increase in PBCAR269A peak expansion
Overall, PBCAR269A monotherapy response observed in the Phase 1/2a trial was not comparable with autologous CAR T profiles. Therefore, Precision is continuing to enroll subjects with PBCAR269A in combination with nirogacestat, a gamma secretase inhibitor developed by SpringWorks Therapeutics, in pursuit of a potential therapeutic index comparable with or better than autologous CAR T. Initial clinical data from the combination cohort is expected to be presented in mid-2022.
The company’s balance of cash and cash equivalents was approximately $152 million as of November 30, 2021. The company continues to expect that existing cash and cash equivalents, expected operational receipts, and available credit will be sufficient to fund its operating expenses and capital expenditure requirements into 2023.
Precision BioSciences, Inc. is a clinical stage biotechnology company dedicated to improving life (DTIL) with its novel and proprietary ARCUS genome editing platform. ARCUS is a highly specific and versatile genome editing platform that was designed with therapeutic safety, delivery, and control in mind. Using ARCUS, the Company’s pipeline consists of multiple “off-the-shelf” CAR T immunotherapy clinical candidates and several in vivo gene editing candidates designed to cure genetic and infectious diseases where no adequate treatments exist. For more information, visit www.precisionbiosciences.com.
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