• Strengthens Lyell’s clinical pipeline with the addition of IMPT-314, a dual-targeting CD19/CD20 CAR T-cell product candidate
  • Data from ImmPACT’s multi-center Phase 1-2 clinical trial of IMPT-314 in patients with large B-cell lymphoma treated in the 3rd line CAR-naïve setting to be presented at a major medical conference later this year; initiation of a pivotal trial for IMPT-314 expected in 2025
  • Lyell has prioritized its pipeline to focus on next-generation CAR T-cell therapies, including IMPT-314 and LYL119, and is discontinuing development of LYL797, LYL845 and earlier-stage TIL programs
  • Cash runway following the close of the transaction is expected to fund operations into 2027, through important clinical milestones for each pipeline program

SOUTH SAN FRANCISCO, CA, USA I October 24, 2024 I Lyell Immunopharma, Inc. (Nasdaq: LYEL) announced today that it has entered into a definitive agreement to acquire ImmPACT Bio USA Inc. (“ImmPACT”), a privately-owned clinical-stage biotechnology company. ImmPACT’s lead program, IMPT-314, is a CD19/20-targeting chimeric antigen receptor (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 naïve and central memory T cells during manufacturing. The acquisition of ImmPACT is expected to significantly strengthen Lyell’s clinical-stage pipeline of next- generation CAR T-cell therapies and complement its suite of proprietary technologies designed to generate longer-lasting, functional T cells to achieve more durable outcomes for patients with solid tumors and hematologic malignancies.

“Lyell’s vision is to bring meaningful and durable clinical benefit to patients suffering from cancer with our next-generation cell therapies,” stated Lynn Seely, M.D., Lyell’s President and Chief Executive Officer. “The emerging data from ImmPACT’s ongoing Phase 1-2 trial and the Phase 1 clinical data from a published UCLA-sponsored trial suggest the potential of IMPT-314 to have improved complete response rates and duration of response compared to the approved CD19 CAR T-cell therapies in CAR-naïve patients with aggressive B-cell lymphoma. Since licensing this product candidate from UCLA, the team at ImmPACT has made impressive progress in the multi-center IMPT-314 Phase 1-2 clinical program. We look forward to presenting initial data from this program at a major medical conference later this year and initiating a pivotal trial for IMPT-314 in 2025.”

“I am incredibly proud of the ImmPACT team and all of their accomplishments in developing next-generation CAR T-cell therapies,” stated Sumant Ramachandra, M.D., Ph.D., Chief Executive Officer of ImmPACT. “This transaction validates our novel science and enhances the potential for this therapy to make a meaningful impact on patients’ lives. I am confident that in Lyell, we have found a team that shares our passion for advancing novel science to benefit patients.”

Strengthening the Pipeline with IMPT-314

ImmPACT licensed its dual-targeting CD19/CD20 CAR T-cell product candidate from the University of California, Los Angeles (UCLA). Phase 1 data in 13 patients with relapsed/refractory (R/R) aggressive non-Hodgkin lymphoma treated in a UCLA-sponsored clinical trial were presented at the 2024 AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy. CAR T-cell naïve patients with R/R diffuse large B-cell lymphoma or primary mediastinal B-cell lymphoma after at least two lines of therapy or mantle cell lymphoma, follicular lymphoma or chronic lymphocytic leukemia/small lymphocytic lymphoma after at least three lines of therapy were evaluated. Autologous T cells were obtained and enriched for CD14-/CD25-/CD62L+ naïve or memory T cells. Twelve out of 13 patients achieved a complete or partial response (92% objective response rate), with ten achieving a confirmed complete response (CR) (77% CR rate). The median progression-free survival was 50.1 months, and median overall survival was not reached with a median follow up of 32 months (range: 5.7 – not estimable). A favorable safety profile was observed.

The ongoing Phase 1-2 clinical trial initiated by ImmPACT is a multi-center, open-label clinical trial designed to evaluate the tolerability and clinical benefit of IMPT-314 in patients with R/R aggressive B-cell lymphoma and determine a recommended Phase 2 dose. Initial Phase 1-2 clinical data evaluating IMPT-314 primarily in patients who have received at least two prior lines of therapy for large B-cell lymphoma will be presented at a major medical conference this year. IMPT-314 has received Fast Track Designation from the U.S. Food and Drug Administration for the treatment of R/R aggressive B-cell lymphoma.

Lyell expects to initiate a pivotal trial in 2025 for IMPT-314 in patients in the 3rd line setting who have not yet been exposed to CAR T-cell therapy.

Lyell Pipeline Prioritization

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 (TIL) 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.

Details of the Transaction

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 $30 million in cash, subject to certain adjustments, and 37.5 million shares of Lyell common stock. ImmPACT shareholders will also be eligible to receive contingent consideration consisting of 12.5 million 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. Goldman Sachs & Co LLC is acting as sole financial advisor to Lyell in this transaction and Skadden, Arps, Slate, Meagher & Flom LLP is acting as its legal advisor. Cooley LLP is acting as ImmPACT’s legal advisor.

Conference Call Details

Lyell’s management will host an investor conference call and Webcast beginning at 4:30 pm ET today. The Webcast can be accessed here.

A replay of the event and presentation materials will be archived on the Investor page of the Lyell Website following the end of the event.

About Lyell

Lyell is a clinical-stage company advancing a pipeline of next-generation CAR T-cell therapies for patients with solid tumors or hematologic malignancies. Lyell’s product candidates are enhanced with novel technology designed to generate T cells that resist exhaustion and have qualities of durable stemness in order to drive durable tumor cytotoxicity and achieve consistent and long-lasting clinical response. Lyell is based in South San Francisco, California with facilities in Seattle and Bothell, Washington. To learn more, please visit www.lyell.com.

SOURCE: Lyell Immunopharma