- Patient data from higher dose cNeT as monotherapy and cNeT in combination with checkpoint inhibitor expected in 2H 2022 -

- Strong cash position of $266 million supports clinical development and manufacturing expansion into 2H 2024 -

Achilles Therapeutics plc (NASDAQ: ACHL), a clinical-stage biopharmaceutical company developing precision T cell therapies to treat solid tumors, today announced its financial results for the fourth quarter and year-ended December 31, 2021, and recent business highlights.

“In 2021, we generated clinical data demonstrating the unique ability of our T cell platform to detect, quantify and track our clonal neoantigen-reactive T cells, or cNeT, in vivo, giving us the analytical platform to elucidate the mechanism of action of our cNeT product. cNeT dose is now being used in our clinical trials as a release parameter, highlighting our differentiated potential to develop potency assays that we believe are essential for the successful development and regulatory approval of TIL-based therapies,” said Dr Iraj Ali, Chief Executive Officer of Achilles Therapeutics. “In the year ahead, we will build on the important learnings from our first cohort of patients by evaluating higher doses of our tumor-targeting cNeT therapies alone and in combination with a checkpoint inhibitor. We look forward to clinical readouts in our CHIRON and THETIS trials for non-small cell lung cancer and melanoma, respectively, including 6-week clinical activity and engraftment data in the second half of 2022.

Our unique ability to prospectively target and track clonal neoantigens is possible through PELEUS™, our proprietary bioinformatics platform. PELEUS was built on an advanced statistical framework to differentiate clonal from subclonal mutations and is further enhanced using Artificial Intelligence in a range of applications, including neoantigen prioritization. PELEUS is validated through our exclusive access to the landmark TRACERx clinical study of tumor evolution, which provides the extensive longitudinal sequencing data of over 3,200 tumor samples that have been collected over five years from over 795 patients. The detailed genomic analysis from PELEUS allows us to identify the unique clonal neoantigens of each patient. These clonal neoantigens are protein markers that are present on all of an individual’s cancer cells but are absent from healthy tissue, making them ideal cancer targets. With this information, our VELOS manufacturing process uses the natural biology of dendritic cell antigen presentation to select and expand the T cells that are able to recognize the clonal neoantigen targets present in a patient’s tumor. With these powerful, proprietary tools and our forthcoming clinical data, we are well-positioned to advance our precision T cell therapy.

We expect to continue to expand our global footprint with increased manufacturing capacity in the U.K., continued addition of clinical sites, and establishment of our U.S. headquarters in Philadelphia which will house our first U.S. R&D facility. With the capital raised in our successful IPO in April 2021, we have $266 million in cash and cash equivalents to support the clinical development of our cNeT therapy in melanoma, non-small cell lung cancer, head and neck cancer, and other indications into the second half of 2024.”

2021 Business Highlights and Recent Updates

• Established a U.S. headquarters in Philadelphia, PA which will include an R&D facility
• Strengthened the Scientific Advisory Board and Board of Directors with appointments of Alena Gros, Ph.D. and Ben Creelan, M.D. (Press Release, February 2022) and Julie O’Neill and Markwin Velders, Ph.D. (Press Release, May 2021)
• Added to the NASDAQ Biotechnology Index (Press Release, December 2021) and the ICE Biotechnology Index
• Presented data at the ESMO I-O Congress on VELOS Process 2 manufacturing (Press Release, December 2021) highlighting a median dose of 200m cNeT in pre-clinical GMP runs, more than a 10-fold increase over the median dose manufactured with Process 1
• Presented data at AACR (Press Release, April 2021) and SITC Annual Meetings (Press Release, November 2021) showing the detection, quantification and tracking of patient-specific cNeT
• Received regulatory approval for the use of VELOS Process 2 manufacturing in the UK, France, Germany, and Spain in November 2021
• Presented details of the Material Acquisition Platform (MAP)​ at the 2021 ESGCT Congress, supporting the potential use of cNeT in a broad range of solid tumor indications (Press Release, October 2021)
• Expanded the Company’s intellectual property estate, including the grant of US and European patents supporting the approach of targeting clonal neoantigens that are identified with the proprietary PELEUS^TM bioinformatics platform (Press Release, August 2021)
• Raised gross proceeds of $175.5 million in an initial public offering (Press Release, April 2021)

Financial Highlights

• Cash and cash equivalents: Cash and cash equivalents were $266.3 million as of December 31, 2021, as compared to $177.8 million as of December 31, 2020. The Company anticipates that its cash and cash equivalents are sufficient to fund its planned operations into the second half of 2024, including full funding of the ongoing Phase I/IIa CHIRON and THETIS clinical trials
• Research and development (R&D) expenses: R&D expenses were $11.8 million for the fourth quarter ended December 31, 2021, an increase of $2.8 million compared to $9.0 million for the fourth quarter ended December 30, 2020. R&D expenses were $42.2 million for the year ended December 31, 2021, an increase of $19.6 million compared to $22.6 million for the year ended December 31, 2020. The increase was primarily driven by increased activity related to our ongoing clinical trials and overall R&D
• General and administrative (G&A) expenses: G&A expenses were $6.7 million for the fourth quarter ended December 31, 2021, an increase of $2.7 million compared to $4.0 million for December 31, 2020. G&A expenses were $22.0 million for the year ended December 31, 2021, an increase of $10.9 million compared to the $11.1 million for the year ended December 31, 2020. The increase was primarily driven by fees associated with the Company’s public company obligations, and an increase in headcount and related personnel costs
• Net loss: Net loss for the fourth quarter ended December 31, 2021 was $18.2 million or $0.45 per share compared to $12.9 million or $9.32 per share for the fourth quarter ended December 31, 2020. Net loss for the year ended December 31, 2021 was $61.1 million or $2.13 per share compared to $33.2 million or $31.14 per share for the year ended December 31, 2020. The decrease in loss per share is due in part to the increased number of shares following the conversion and issuance of shares from the IPO

2022 Milestones and Upcoming Events

• Patient Dosing: Dose first patients with higher dose (Process 2) cNeT monotherapy and cNeT in combination with a PD-1 inhibitor in 2Q 2022
• Higher-dose Monotherapy: Report additional patient data from higher-dose cohort (Process 2) of cNeT monotherapy for the treatment of NSCLC and melanoma in 2H 2022
• cNeT Combination: Report initial patient data from cNeT in combination with a PD-1 inhibitor for the treatment of melanoma in 2H 2022
• Manufacturing Expansion: Increase manufacturing capacity in the United Kingdom with GMP licensure of the Cell & Gene Therapy Catapult facility in 2Q 2022
• Tumor Archiving Program: Initiate program in 1H 2022

Achilles will present at the upcoming conferences. Additional details will be available in the Events & Presentations section of the Company’s website:

• BioCapital Europe, Organized by LSP: March 10, 2022
• Oppenheimer 32^nd Annual Healthcare Conference: March 15 – 16, 2022
• Immuno-Oncology 360°: March 16 – 18, 2022