MEI Pharma and Infinity Pharmaceuticals Announce Definitive Merger Agreement to Advance Three Promising Clinical Oncology Candidates

Combination will create a company with a diverse product development pipeline led by a planned new global Phase 2 clinical trial evaluating eganelisib in head and neck squamous cell carcinoma (HNSCC)

Projected ~$100M cash balance of combined company expected to fund operations through mid-2025 and to clinical data over the next 12 to 24 months

Companies to host conference call and webcast today at 8:00 a.m. ET

SAN DIEGO, CA & CAMBRIDGE, MA, USA I February 23, 2023 I MEI Pharma, Inc. (Nasdaq: MEIP) (“MEI”), a clinical-stage pharmaceutical company focused on advancing new therapies for cancer, and Infinity Pharmaceuticals, Inc. (Nasdaq: INFI) (“Infinity”), a clinical-stage biotechnology company developing eganelisib, a first-in-class, oral, immuno-oncology macrophage reprogramming drug candidate, announced today that the companies entered into a definitive merger agreement for an all-stock transaction forming a company combining the expertise and resources of MEI and Infinity to advance a robust pipeline of three clinical-stage oncology drug candidates. All three clinical-stage development programs have the potential, in combination with current therapies, to overcome known resistance mechanisms and meaningfully improve patient outcomes.

The combined company’s clinical-stage oncology development pipeline consists of three differentiated programs:

  • Eganelisib, an oral immuno-oncology macrophage reprogramming product candidate, which is planned to be evaluated in combination with the PD-1 targeted checkpoint inhibitor pembrolizumab (KEYTRUDA®) in patients with head and neck squamous cell carcinoma (HNSCC);
  • Voruciclib, an oral CDK9 inhibitor, currently being studied in combination with venetoclax (VENCLEXTA®) in patients with hematologic malignancies; and
  • ME-344, a novel tumor selective mitochondrial inhibitor targeting the OXPHOS pathway, to be evaluated in combination with bevacizumab (AVASTIN®) in patients with relapsed colorectal cancer.

“We are very excited to enter into this agreement with Infinity given the strength of a combined organization that builds on each company’s potential. The combined organization will have three differentiated clinical-stage oncology assets, expected funding into mid-2025 to reach clinical data in all three programs, and a team with extensive oncology clinical development expertise. I believe these ingredients place the merged organization in a strong position to create value for all our stakeholders,” said Daniel Gold, Ph.D., President and Chief Executive Officer of MEI Pharma. “The new company’s lead program, eganelisib, has already been tested in over 350 patients with demonstrated clinical activity in multiple settings, including in combination therapy with immune checkpoint inhibitors. Along with voruciclib and ME 344, this gives us three promising clinical-stage programs that we believe have significant potential to deliver improved therapeutic options for patients.”

“With this planned merger, we are creating a company that is well capitalized to advance a differentiated clinical-stage therapeutic development pipeline leveraging an experienced drug development and leadership team,” said Adelene Perkins, Chief Executive Officer and Chair of Infinity. “With data supporting multiple potential development paths for eganelisib, we have prioritized head and neck cancer based on our ability to leverage encouraging progression free survival data from this patient population in MARIO-1. Unfortunately, head and neck cancer remains an area of high unmet medical need with a relatively short PFS and overall survival in patients treated with checkpoint inhibitor monotherapy. Because of this, we prioritized the initiation of a randomized, controlled Phase 2 clinical study combining eganelisib with pembrolizumab in head and neck cancer patients which is intended to demonstrate improved clinical benefit.”

“I am looking forward to leading the combined company which, beyond the promising clinical-stage pipeline, leverages the capabilities and resources of two organizations sharing a commitment to developing new oncology therapeutics. The combined company is built around extensive small molecule development experience based on solid science and backed by promising data,” said David Urso, J.D., Chief Operating Officer and General Counsel of MEI Pharma, and the Chief Executive Officer of the combined company upon closing of the merger. “At closing, the combined company is projected to have a strong balance sheet of approximately $100 million which is expected to fund planned studies for our clinical candidates through mid-2025 with the potential to deliver near and long-term value for patients and shareholders.”

About the Combined Clinical Pipeline Drug Candidates

The combined company’s pipeline includes three differentiated, clinical-stage, small molecule oncology therapeutic candidates:

  • Eganelisib: A potential first-in-class, oral, once-daily, immuno-oncology development candidate that selectively inhibits phosphoinositide-3-kinase gamma. Eganelisib has demonstrated encouraging clinical results and tolerability across a broad range of solid tumors in over 350 patients, including head and neck squamous cell carcinoma (HNSCC), metastatic triple-negative breast cancer (mTNBC), as well as urothelial, ovarian and melanoma cancers. The combined company plans to initiate in Q3 2023, subject to U.S. Food and Drug Administration review, a global, randomized, controlled Phase 2 clinical trial of eganelisib plus pembrolizumab vs pembrolizumab for the potential treatment of first line relapsed/metastatic head and neck squamous cell carcinoma. The primary endpoint of the Phase 2 study will be overall survival. In the second half of 2024 we plan to have initial data on safety and progression free survival.
  • Voruciclib: An orally administered Cyclin-Dependent Kinase 9 (CDK9) inhibitor being clinically investigated for hematological malignancies. CDK9 has important functions in cell cycle regulation, including the modulation of two therapeutic targets in cancer: myeloid leukemia cell differentiation protein (MCL1) and the MYC proto-oncogene protein, which regulate cell proliferation and growth. Voruciclib is currently being evaluated in a Phase 1b trial exploring dose and schedule in patients with acute myeloid leukemia (AML) and B-cell malignancies as a single-agent and in combination with venetoclax. The ongoing Phase 1b trial is expected to report initial results from the combination regimen around the end of 2023.
  • ME-344: A novel, parenteral, tumor selective mitochondrial inhibitor drug candidate targeting the OXPHOS pathway involved in the production of adenosine. Clinical investigation of ME-344 is focused on use in combination with the VEGF inhibitor bevacizumab (Avastin®). Data reported from an investigator-initiated, multi-center, randomized study of ME-344 in combination with the VEGF inhibitor bevacizumab (Avastin®) demonstrated biologic activity supporting further clinical investigation. Initiation of a Phase 1b trial is planned to evaluate ME-344 plus bevacizumab in patients with relapsed colorectal cancer in the first half of 2023. Data from the Phase 1b trial to support opening enrollment in an expansion cohort are expected to be reported around the end of 2023.

About the Proposed Merger

Under the terms of the merger agreement, Infinity will become a wholly owned subsidiary of MEI Pharma. Pursuant to an exchange ratio set forth in the merger agreement, the pre-merger MEI Pharma shareholders are expected to own approximately 58.0% and pre-merger Infinity shareholders are expected to own approximately 42.0% of the outstanding equity of the combined company immediately following the merger.

Subject to shareholder approval and the subsequent closing of the merger, the combined company is expected to be renamed and trade on the Nasdaq Stock Market. The combined company would be headquartered in San Diego, California and led by a team with extensive industry and oncology drug development expertise, including David Urso, Chief Executive Officer, Robert Ilaria, Jr., M.D., Chief Medical Officer, and Stéphane Peluso, Ph.D., Chief Scientific Officer. Daniel Gold, Ph.D., and Adelene Perkins, the current chief executive officers of MEI and Infinity, respectively, would serve on the Board of Directors of the combined company. The Board of Directors is expected to be composed of eight members, consisting of Mr. Norman C. Selby, currently Infinity’s Lead Independent Director, who will Chair the Board, Mr. Urso, Dr. Gold, Ms. Perkins, two additional members designated by MEI Pharma, one additional member designated by Infinity and one member mutually agreed upon by MEI Pharma and Infinity.

The merger agreement has been approved by the Boards of Directors of both companies. The merger is expected to close in mid-2023, subject to approvals by MEI Pharma and Infinity shareholders, respectively, and other customary closing conditions.

Torreya Capital, LLC is serving as financial advisor to MEI Pharma, and Morgan, Lewis & Bockius LLP is serving as legal counsel to MEI Pharma. Aquilo Partners, L.P. is serving as financial advisor to Infinity, and WilmerHale is serving as legal counsel to Infinity.

Conference Call and Webcast Information

MEI Pharma and Infinity Pharmaceuticals will host a conference call and webcast today at 8:00 a.m. ET to discuss the merger. To access the live call, please dial 1-833-974-2378 (United States) or 1-412-317-5771 (International). Please ask to join the MEI and Infinity merger conference call.

The conference call will also be webcast live here, as well as from the Events Calendar page in the Investors section of MEI Pharma’s website at and the Events & Presentations page in the Investors/Media section of Infinity’s website at All participants are encouraged to join 10 minutes prior to the start time. An archived version of the webcast will be available on each company’s website for 30 days following the event.

About MEI Pharma

MEI Pharma, Inc. (Nasdaq: MEIP) is a pharmaceutical company focused on developing potential new therapies for cancer. MEI Pharma’s portfolio of drug candidates includes clinical stage candidates with differentiated mechanisms of action intended to address unmet medical needs and deliver improved benefit to patients, either as standalone treatments or in combination with other therapeutic options. For more information, please visit Follow us on Twitter @MEI_Pharma and on LinkedIn.

About Infinity Pharmaceuticals

Infinity Pharmaceuticals, Inc. (Nasdaq: INFI) is a clinical-stage biotechnology company developing eganelisib (IPI-549), a potential first-in-class, oral, immuno-oncology macrophage reprogramming therapeutic which is designed to address a fundamental biologic mechanism of immune suppression in cancer in multiple clinical studies. For more information on Infinity, please refer to Infinity’s website at


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