Tachyon Announces Presentation at the 2021 ESMO Annual Meeting

Tachyon Therapeutics, Inc. ("Tachyon" or "the Company"), a research and development biotechnology company, announces an abstract presentation of the Company's lead product candidate, TACH101, at the European Society of Medical Oncology ("ESMO") Annual Meeting. ESMO is being held virtually from September 16-21, 2021.

"Triple negative breast cancer represents nearly 20% of all breast cancers and is a highly aggressive subtype that continues to have poor prognosis due to lack of effective treatments," stated Frank Perabo, MD, PhD, CEO of Tachyon Therapeutics. "Large-scale genomic analysis projects show that KDM4 is amplified in about 25% of triple negative breast cancer cases, making KDM4 an attractive epigenetic target for this cancer type. We are anticipating to study TACH101 in the near future in clinical trials."

Highlights from the ESMO abstract are summarized below:

Abstract #210P

• TACH101 was potent in killing a Triple Negative Breast Cancer (TNBC) cell line (MDA-MB-231) with an IC50 of 0.0035 µM.
• TACH101 treatment of MDA-MB-231 TNBC cells caused cell-cycle arrest and induction of apoptosis with an EC50 of 0.132 µM.
• In vivo, TACH101 inhibited tumor growth in the COH70 TNBC xenograft model with tumor growth inhibition > 85%.
• Gene expression analysis of TACH101-treated tumors show that Protein Phosphatase 1 Regulatory subunit 10 (PPP1R10 or PNUTS), a key regulator of the retinoblastoma protein (Rb) and p53, was a direct target of KDM4 and was significant downregulated after 24 hours of treatment.

The poster presentation of Abstract #210P is available for viewing on the ESMO Annual Meeting website at https://oncologypro.esmo.org/meeting-resources/esmo-congress-2021/tach101-a-first-in-class-kdm4-inhibitor-for-treatment-of-triple-negative-breast-cancer.

About Tachyon Therapeutics Inc.

Tachyon Therapeutics, Inc. is an R&D focused biotechnology company advancing novel, first-in-class therapeutics for the treatment of advanced cancers. Tachyon operates with a dedicated internal core development team and a virtual external network of expertise to achieve one goal ? advance our program with speed and innovation, without compromising the quality or integrity of our science. For more information, please visit www.tachyontx.com.

Further Information

For further information about the Company or Investor information please contact:

Frank Perabo, Chief Executive Officer, 832-952-0829, [email protected]