Menlo Park, California, US, and Grand Cayman, Cayman Islands, December 06, 2022 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced a definitive agreement of its partnership with Akeso Inc. (HKEX Code: 9926.HK, “Akeso”), to in-license its breakthrough bispecific antibody, ivonescimab. Akeso is a pioneer and source originator in developing innovative antibodies. The agreement supports Summit’s mission of developing and commercializing groundbreaking oncology pipeline products aimed at improving the quality of life of patients with serious unmet medical needs. For Akeso, the deal represents an opportunity to introduce its highly innovative antibodies to markets, including the United States, Canada, Europe, and Japan – an important step towards Akeso’s strategic intention of becoming a global biopharma organization.

Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the United States, Canada, Europe, and Japan, is a novel, potential first-in-class bispecific antibody combining the power of immunotherapy via a blockade of PD-1 with the anti-angiogenesis benefits of an anti-VEGF into a single molecule. Ivonescimab is believed to be the PD-1 / VEGF bispecific antibody that is most advanced in the clinic: there are no known PD-1-based bispecific antibodies approved by the US Food and Drug Administration (“FDA”) or the European Medicines Agency (“EMA”). Akeso has already demonstrated success by commercializing the only PD-1 bispecific approved in China. Its product 开坦尼 (pronounced “Kaitanni”) (cadonilimab), a PD-1 / CTLA-4 bispecific, was approved by the Chinese National Medical Products Administration (“NMPA”) earlier this year for the treatment of relapsed or metastatic cervical cancer patients who progressed on or after platinum-based chemotherapy.

Ivonescimab was engineered to bring two well established oncology targeted mechanisms together. It is our belief that the novel design has the potential to reduce side effects and safety concerns.

“The partnership between Summit Therapeutics and Akeso is a strategically compelling opportunity,” stated Robert W. Duggan, Chairman and Chief Executive Officer of Summit. “It represents bringing together Akeso’s extraordinary team, which has built an innovation engine capable of creating novel bispecific technologies, and the talented members of Team Summit with their proven track record of success of global clinical development, regulatory approvals, and commercialization, particularly in oncology. We believe the potential exists for enormous creation through this partnership. We are extremely encouraged by ivonescimab and the potential for improving the quality and duration of patients’ lives based on clinical data to support this point. Team Summit is honored and enthusiastic to partner with Akeso. Our shared mission and vision is to create a significant difference for the betterment of patient healthcare outcomes around the world.”

“Ivonescimab has demonstrated the potential to deliver superior clinical benefit for patients and tremendous value for investors,” said Dr. Michelle Xia, Co-founder, Chairwoman, CEO, and President of Akeso. “The Akeso team has been dedicated to the development of ivonescimab for the past 8 years, and proudly advanced the molecule to the clinical Phase III stage. The global value of ivonescimab awaits great work from a great team to realize. We are so pleased to partner with the world-class Summit team, who has the track record of successfully bringing over a dozen indications to market for the first-in-class blockbuster drug IMBRUVICA® (ibrutinib). Following intense and in-depth strategic, scientific, and operational discussion on ivonescimab between the Akeso and Summit teams in recent months, we are more confident than ever on a winning path for ivonescimab’s global development.

With this tremendous momentum, we look forward to the swift execution of the clinical development and commercial plan in a global setting for ivonescimab.”

As presented at ASCO 2022, ivonescimab treatment was associated with an overall response rate (ORR) in a Phase II study in patients with non-small cell lung cancer (NSCLC) who have failed EGFR-TKI’s of 68.4% and a median Progression-Free Survival (mPFS) time period of 8.2 months when combined with combination chemotherapy (pemetrexed and carboplatin) as compared to historical mPFS of 4.3 months in patients treated with combination chemotherapy (pemetrexed and platinum-based chemotherapy) alone, the current standard of care. In a separate cohort, ivonescimab combined with docetaxel in patients who have failed PD-(L)1 and chemotherapies demonstrated a mPFS of 6.6 months as compared to a historical mPFS of 4.5 months with docetaxel alone, a current standard of care regimen for these patients. The study, which similarly had patients receiving ivonescimab plus chemotherapy as their first line therapy for metastatic disease, was considered to have demonstrated a tolerable safety profile and a low discontinuation rate for adverse events.

Ivonescimab has received Breakthrough Therapy Designation status in China from the NMPA for three indications: combination therapy with chemotherapy for NSCLC patients who have failed a previous EGFR-TKI, combination therapy with chemotherapy for NSCLC patients who have failed to respond to a prior PD-(L)1 therapy, and monotherapy as first-line treatment for locally advanced or metastatic NSCLC patients with positive PD-L1 expression. Ivonescimab is currently being developed in China and Australia in multiple solid tumors, including a Phase III clinical trial in patients with NSCLC that is positive for an epidermal growth factor receptor (EGFR) mutation whose disease has progressed after treatment with an EGFR tyrosine-kinase inhibitor (TKI).

Summit is initiating development activities for SMT112 and will do so first in NSCLC indications. Summit plans to start treating patients in clinical studies by the second quarter of 2023.

The definitive partnership calls for Summit to receive the rights to develop and commercialize ivonescimab (SMT112) in the United States, Canada, Europe, and Japan. Akeso will retain development and commercialization rights for the rest of the regions including China. In exchange for these rights, Summit will make an upfront payment of $500 million. The total potential deal value is $5.0 billion, as Akeso will be eligible to receive regulatory and commercial milestones of up to $4.5 billion. In addition, Akeso will be eligible to receive low double-digit royalties on net sales. In conjunction with the closing of the deal, Dr. Michelle Xia will be appointed to the board of directors of Summit. The deal is subject to customary closing practices, including applicable waiting periods under the Hart- Scott-Rodino (HSR) Act.

“After reviewing a substantial number of opportunities, much of which was focused on potential treatments for solid tumors, we have found the ideal partnership with the potential to change the paradigm for treating patients facing difficult odds with devastating diagnoses,” added Dr. Maky Zanganeh, Co-Chief Executive Officer, President, and a member of Summit’s Board of Directors. “Ten years ago, metastatic lung cancer patients rarely survived for more than ten to twelve months from diagnosis. Today, survival can be measured in years. Our goal is to improve the quality of life of a patient facing immeasurable odds while extending the duration of that patient’s life. Our focus is always on how we can improve the lives of patients. We sought patient-friendly medicinal therapies through our search to expand our pipeline portfolio, and we are proud to take this meaningful step towards accomplishing this goal. We have significant work to do, but we are steadfastly committed to bringing ivonescimab into the hands of patients who need it most. We are thrilled to reach this agreement with Michelle and the team at Akeso, and we are excited to make this vision a reality. I am proud of Team Summit who have diligently worked these past few months to establish a strong bond with the team at Akeso, and I would like to thank the talented people of Team Akeso for spending so much quality time creating this meaningful partnership.”