Centessa Pharmaceuticals Announces Poster Presentation of First Preclinical Data for LockBody® Program at 2022 ASCO Annual Meeting

Preclinical data showed that single-agent LB101, PD-L1xCD47 LockBody, delivered systemically led to meaningful tumor regressions and was well toleratedBOSTON and LONDON, June 05, 2022 (GLOBE NEWSWIRE) — Centessa Pharmaceuticals plc (Nasdaq: CNTA), a clinical-stage pharmaceutical company with a Research & Development (“R&D”) innovation engine that aims to discover, develop and ultimately deliver impactful medicines to patients, today announced presentation of the first preclinical data for LB101, PD-L1xCD47 LockBody, in a poster presentation at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting which is taking place virtually and in person from June 3-7, 2022 in Chicago, IL. The poster presentation will be featured in the Developmental Therapeutics – Immunotherapy session today, June 5, 2022, at 8-11 AM CT. “We are excited to release the first preclinical data for LB101 from our LockBody platform which we believe has the potential to fundamentally redefine immuno-oncology treatment for patients with cancer. These results demonstrated that LB101 as a single-agent and delivered systemically, led to meaningful and durable responses in a difficult-to-treat mouse model with no apparent observed toxicity,” said Saurabh Saha, MD, PhD, Chief Executive Officer of Centessa. The poster includes in vivo data in a MC38 hPD-L1+ syngeneic mouse model, which demonstrated significantly improved efficacy with durable responses for single-agent LB101 (26 of 32 tumors eradicated across two doses) compared to isotype control IgG (0 of 16) and atezolizumab (4 of 32 across two doses). In rechallenge experiments, none of the mice from groups with prior LB101-induced regressions exhibited tumor growth compared to all naïve mice which rapidly established tumors. At equimolar doses to atezolizumab, LB101 exhibited no anemia, weight-loss or overt toxicity. The poster also includes in vitro data, which demonstrated PD-L1 binding in the locked form and CD47 binding with strongly enhanced antibody-dependent cellular phagocytosis (ADCP) in the unlocked form. “The innovative design of our LockBody molecules takes advantage of human IgG-derived hinges to enable tunable, tumor-specific activation of the conditional effector Fab in the tumor micro-environment after selectively enriching in the tumor with the constitutive Fab of our construct. We plan to advance this exciting LockBody program into the clinic late this year and to continue building this potential platform with multiple novel constructs,” added Antoine Yver, MD, MSc, Chairman of Development at Centessa. Details of the poster presentation: Title: LB101, a conditionally tetravalent PD-L1xCD47 bispecific monoclonal antibody (mAb), combines tumor microenvironment (TME) targeted delivery (PD-L1) and a single biological high potency effector (CD47).Poster session: Developmental Therapeutics – ImmunotherapyDate, time and location: June 5, 2022, 8-11 AM Central Time, Chicago, IL.Abstract and poster numbers: Abstract 2562; poster 217 The poster is now live on the ASCO Annual Meeting website at https://conferences.asco.org/am/attend. About Centessa Pharmaceuticals Centessa is a clinical-stage pharmaceutical company with an R&D innovation engine that aims to discover, develop and ultimately deliver impactful medicines to patients. Our programs span discovery-stage to late-stage development and cover a range of high-value indications in rare diseases and immuno-oncology. We are led by a management team with extensive R&D experience, providing direct guidance to our program teams to rapidly advance our candidates from research through all stages of development. For more information, visit www.centessa.com, which does not form part of this release. Forward Looking Statements This press release contains forward-looking statements. These statements may be identified by words such as “may,” “might,” “will,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “objective,” “aim,” “aspire,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue,” “ongoing,” “aim,” “seek,” and variations of these words or similar expressions that are intended to identify forward-looking statements. 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