• Abstracts highlight pipeline programmes in precision oncology, including novel LSD1 inhibitor 
• Further detail on A_2A programme, including novel biomarker for patient selection to be presented 

Exscientia plc (Nasdaq: EXAI) today announced that four abstracts have been accepted for poster presentation at the upcoming American Association for Cancer Research (AACR) Annual Meeting 2023, being held April 14-19, 2023, at the Orange County Convention Center in Orlando, FL. These abstracts highlight the components of Exscientia's approach to precision discovery, design and personalised medicine as well as planned innovation in the clinic.

“The clinical and preclinical data showcased at AACR further validate Exscientia's functional precision medicine platform and translational research capabilities,” said Andrew Hopkins, D.Phil, founder and Chief Executive Officer of Exscientia. “These new data demonstrate the potential of integrating outstanding science with cutting-edge AI, to efficiently identify novel targets with the potential for increased probability of clinical success. We also believe that our platform can be used to predict outcomes that help identify cancer patients with high unmet need who may benefit most from treatment. We look forward to advancing these programmes and expanding our pipeline with the goal of developing precision-designed, truly personalised medicines for patients around the world.”

Abstracts Accepted for Poster Presentation:

Title: Identification of transcript adenosine fingerprint to enrich for A_2AR and PD-1 inhibition responders
Session Title: Biomarkers of Therapeutic Benefit 2
Abstract Number: #2151
Date/Time: Monday, April 17 / 9:00 AM - 12:30 PM EDT

Next generation precision cancer medicine mandates a deep understanding of the disease milieu and drug function to create complex patient selection biomarkers, more than single mutations. To enrich for patients who will most likely respond to EXS21546 (‘546), Exscientia's clinical stage A_2AR-selective antagonist targeting the adenosine pathway, Exscientia researchers leveraged a combination of single cell functional and transcriptomics from complex primary patient samples to identify an adenosine-induced immunosuppression biomarker signature (adenosine burden score or ABS). The ABS correlates with checkpoint inhibitor (CI) response prediction to potentially predict patients likely to benefit from combined A_2AR antagonism and CI. Here, researchers show that the adenosine burden, as monitored by ABS, is reduced following antagonism of A_2AR with ‘546, which in turn restores CI response potential. The ABS is being confirmed retrospectively in the ongoing IGNITE Phase 1/2 clinical study of ‘546 in combination with a PD-1 inhibitor in relapsed/refractory renal cell carcinoma (RCC) and non-small cell lung cancer (NSCLC).

Title: Characterizing antitumor responses to EXS74539, a novel, reversible LSD1 inhibitor with potential in small-cell lung cancer
Session Title: Epigenetics
Abstract Number: #6290
Date/Time: Wednesday, April 19 / 9:00 AM - 12:30 PM EDT

LSD1 is an epigenetic target with critical roles in oncology, notably demethylating histones and other proteins, thereby suppressing the expression of genes required for cellular differentiation. Historically, LSD1 inhibitors in development have been unable to achieve the combination of appropriate pharmacokinetics, good brain penetrance and a reversible mechanism of action. By leveraging generative design algorithms and active learning, Exscientia designed a highly differentiated LSD1 inhibitor, EXS74539 (‘539). ‘539 is a potent, selective and reversible brain-penetrant molecule, combining the potential to treat tumours and metastases in the brain with potential clinical safety benefits through reversible inhibition of LSD1. ‘539 is currently in IND-enabling studies as a potential treatment across oncology and haematology. Preclinical data has shown that ‘539 has potent anti-proliferative activity in in vitro models of small cell lung cancer (SCLC), with anti-tumour activity observed in selected SCLC xenograft tumour-bearing mice.

Title: Discovering novel targetable pathways by combining functional and multi-omic data from primary ovarian cancer samples
Session Title: Novel Targets and Pathways
Abstract Number: #4956
Date/Time: Tuesday, April 18 / 1:30 PM - 5:00 PM EDT

Mapping and interpreting single cell functional and multi-omics data at baseline and after perturbation of complex primary model systems reveals a previously unexplored convergent putative target landscape that Exscientia is further validating as potential next-generation anticancer nodes. The high unmet medical need in indications such as high grade serous ovarian cancer (HGSOC) drives a requirement for innovation to uncover novel targets. Standard target discovery processes that often heavily rely upfront on outgrown cell line models with well-averaged readouts have hindered approval rates for drugs entering trials. This study highlights ongoing work using Exscientia's precision medicine platform in combination with proprietary methodology for multi-omics and multi-modal dataset mapping which could have the potential to improve patient outcomes by uncovering clinical relevance at the target discovery stage. Here, researchers report a novel way of uncovering several high confidence convergent putative targets, seemingly overlooked in cell line studies. By mechanistically characterising one such functional sensitivity node, ALK/FAK1/IGF1R, the study reveals tumour necrosis factor (TNF) via the nuclear factor kappa B (NFкB) pathway as a promising focus area for HGSOC via the evaluation of malignant pleural effusion and ascites from patients with late stage ovarian cancer.

Title: Data from first-in-human study of EXS21546, an A_2A receptor antagonist, now progressing into Phase 1 in RCC/NSCLC
Session Title: Phase I Clinical Trials in Progress
Abstract Number: #CT114
Date/Time: Monday, April 17 / 1:30 PM - 5:00 PM EDT

Pharmacokinetics, pharmacodynamics, safety and tolerability of EXS21546 were confirmed in a healthy volunteer study, allowing selection of a starting dose for the ongoing IGNITE Phase 1/2 study ​​in combination with a PD-1 inhibitor in relapsed/refractory RCC and NSCLC. The IGNITE trial design was based on extensive simulations to enable the most efficient continuous reassessment method settings, and will allow further verification of the patient enrichment biomarker strategy (adenosine burden score or ABS).

About Exscientia

Exscientia is an AI-driven pharmatech company committed to discovering, designing and developing the best possible drugs in the fastest and most effective manner. Exscientia developed the first-ever functional precision oncology platform to successfully guide treatment selection and improve patient outcomes in a prospective interventional clinical study, as well as to progress AI-designed small molecules into the clinical setting. Our internal pipeline is focused on leveraging our precision medicine platform in oncology, while our partnered pipeline broadens our approach to other therapeutic areas. By pioneering a new approach to medicine creation, we believe the best ideas of science can rapidly become the best medicines for patients.

Visit us at https://www.exscientia.ai or follow us on Twitter @exscientiaAI.

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This press release contains forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995, including with respect to Exscientia’s plans to present at AACR, the progress of discovery and development of candidate molecules, and the timing and progress of, and data reported from, pre-clinical studies and clinical trials of Exscientia’s product candidates. Any statement describing Exscientia’s goals, plans, expectations, financial or other projections, intentions or beliefs is a forward-looking statement and should be considered an at-risk statement. Such statements are subject to a number of risks, uncertainties and assumptions, including those related to: initiation, scope and progress of Exscientia’s and its partners’ planned and ongoing pre-clinical studies and clinical trials and ramifications for the cost thereof; clinical, scientific, regulatory and technical developments; the process of discovering, developing and commercialising product candidates that are safe and effective for use as human therapeutics; and other factors. In light of these risks and uncertainties, and other risks and uncertainties that are described in the Risk Factors section and other sections of Exscientia’s Annual Report on Form 20-F, filed with the Securities and Exchange Commission (SEC) on March 23, 2022 (File No. 001-40850), and other filings that Exscientia makes with the SEC from time to time (which are available at https://www.sec.gov/), the events and circumstances discussed in such forward-looking statements may not occur, and Exscientia’s actual results could differ materially and adversely from those anticipated or implied thereby. Although Exscientia’s forward-looking statements reflect the good faith judgement of its management, these statements are based only on facts and factors currently known by the Company at the time of this press release. As a result, you are cautioned not to rely on these forward-looking statements.