Lyell to acquire ImmPACT Bio, discontinue LYL797 and LYL845 programs

Lyell Immunopharma (LYEL) announced that it has entered into a definitive agreement to acquire ImmPACT Bio, a privately-owned clinical-stage biotechnology company. ImmPACT’s lead program, IMPT-314, is a CD19/20-targeting chimeric antigen receptor, or CAR, T-cell product candidate that Lyell will continue to develop for hematologic malignancies, including large B-cell lymphoma. IMPT-314 was designed to outperform the efficacy of approved CD19 CAR T-cell therapies via a dual-targeting CAR T-cell design and to improve CAR T-cell persistence by enriching for naive and central memory T cells during manufacturing. In connection with the acquisition, Lyell has prioritized its pipeline to focus resources on its most differentiated CAR T-cell clinical programs, including IMPT-314 following the close of the acquisition and LYL119. The enhanced anti-exhaustion technology incorporated into LYL119, including c-Jun overexpression, NR4A3 knockout, Epi-R and Stim R, has the potential to achieve improved efficacy at lower cell doses with an acceptable safety profile. In a validated in vivo preclinical model of non-small cell lung cancer, LYL119 achieved tumor control at a 10-fold lower cell dose than LYL797 with more gradual cell expansion to peak, and a substantial increase in the duration of cell killing demonstrated by a repetitive tumor cell killing assay in vitro. Lyell is discontinuing development of LYL797, its ROR1-targeted CAR T-cell product candidate to focus on the Phase 1 clinical trial of its next-generation ROR1-targeted CAR T-cell product candidate LYL119, which is expected to initiate enrollment of patients with platinum-resistant ovarian cancer or relapsed/refractory endometrial cancer this year or early next year. The LYL845 tumor-infiltrating lymphocyte program is also being discontinued as the clinical data in patients with advanced melanoma did not meet our rigorous pre-determined criteria for continued development. Its next-generation TIL and rejuvenation programs that are in preclinical development will also be discontinued. Following the close of the transaction, Lyell expects its cash balance will fund operations into 2027, through important clinical milestones for each pipeline program, including initiation of a pivotal trial for IMPT-314, which is expected to start in 2025. Upon closing, Lyell will acquire worldwide rights to ImmPACT’s pipeline, including the next- generation bispecific CD19/CD20 autologous CAR T-cell therapy, currently in clinical development for B-cell lymphoma and autoimmune diseases, and an activating TGF-beta Claudin 18.2 CAR T-cell candidate, which is in preclinical development. Lyell will prioritize the development of IMPT-314 for patients with B-cell lymphoma. Deal terms include upfront consideration payable upon closing the potential transaction of $30M in cash, subject to certain adjustments, and 37.5M shares of Lyell common stock. ImmPACT shareholders will also be eligible to receive contingent consideration consisting of 12.5M shares of Lyell common stock that may be earned upon the achievement of a value-enhancing clinical milestone and a low single-digit royalty on future net sales of the dual-targeting CD19/20 CAR T-cell product in the United States. The proposed transaction, which has been unanimously approved by the Boards of Directors of both companies, is expected to close in the fourth quarter of 2024. The closing of the proposed transaction is subject to expiration of the Hart-Scott-Rodino antitrust waiting period and the satisfaction of other customary closing conditions.