Biotheryx to Present Preclinical Data for Its Dual Protein Degrader BTX-1188 at the 2022 American Society of Clinical Oncology Annual Meeting

BTX-1188 Showed Deep and Durable Dual Degradation of GSPT1 and IKZF1/3 In Vitro Along with Beneficial Immunomodulatory Properties

Data Support Ongoing Phase 1 Development for the Treatment of Hematologic and Solid Tumor Malignancies

SAN DIEGO, CA. May 26, 2022 — Biotheryx, Inc., a clinical stage company discovering and developing a portfolio of innovative small molecule targeted protein degraders (TPDs) in areas of high unmet medical need, today announced that its abstract highlighting supportive preclinical data for its lead asset BTX-1188, a potentially first-in-class, dual protein degrader of GSPT1 and IKZF1/3, will be presented in a poster at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting taking place June 3-7, 2022, in Chicago, Illinois and virtually.

“Our distinctive PRODEGY platform is designed to enable the discovery and development of a broad range of targeted protein degrader molecules and BTX-1188 is the first of our pipeline to enter the clinic,” said Leah Fung, Ph.D., Chief Scientific Officer of Biotheryx. “BTX-1188 is a molecular glue that was rationally designed to degrade  GSPT1 and IKZF1/3. The data being presented at ASCO 2022 support the ongoing Phase 1 clinical trial evaluating BTX-1188 in patients with hematologic and solid tumor cancers and demonstrate what we believe to be our ability to design first-in-class molecular glues with the potential to improve clinical outcomes for patients with cancer and other serious diseases.”

“We are leveraging our deep expertise with the modulation of Cereblon, the only clinically and commercially validated E3 ligase, to design innovative targeted protein degraders with the potential to address significant unmet medical need,” said Philippe Drouet, President and Chief Executive Officer of Biotheryx. “We look forward to presenting these pre-clinical data from our lead program, BTX-1188, at ASCO 2022.”

Key Highlights from BTX-1188 Preclinical Results

  • BTX-1188 has shown deep and durable degradation of GSPT1 and IKZF1/3 and inhibition of MYC in several types of hematologic and solid tumor cell lines, including lymphoma, diffuse large B-cell lymphoma, non-small cell lung cancer and glioma.
  • BTX-1188 has shown inhibition of pro-inflammatory cytokines and enhancement of immune stimulatory cytokines, owing to IKZF1/3 degradation, which may prevent the known systemic inflammatory dose-limiting toxicities associated with pure GSPT1 degradation (Uy 2019)1.
  • BTX-1188 potently inhibits tumor cell proliferation and tumor growth in ex vivo and in vivo models of acute myeloid leukemia (AML) and in in vitro and in vivo models of lung, breast and ovarian cancer.
  • These preclinical results support the ongoing Phase 1 clinical evaluation of BTX-1188 in patients with AML and certain solid tumors, especially in MYC-dependent cancers.

Details for the BTX-1188 ASCO 2022 poster presentation are as follows:

Title: BTX-1188, a first-in-class dual degrader of GSPT1 and IKZF1/3, for treatment of acute myeloid leukemia (AML) and solid tumors
Presenter: Aparajita Hoskote Chourasia, Ph.D.
Abstract Number: 7025
Poster Number: 256
Session: Hematologic Malignancies—Leukemia, Myelodysplastic Syndromes, and Allotransplant
Date and Time: Saturday, June 4, 2022 at 9:00 a.m. CT (10:00 a.m. ET)

This poster presentation will be available on the ASCO Meeting website.  Following the presentation at the meeting, a PDF copy of the poster will be available in the “Publications and Presentations” section of Biotheryx’s website.

About BTX-1188

Biotheryx’s lead molecular glue drug candidate BTX-1188 is a dual protein degrader which was designed to degrade GSPT1, a promising cancer target, and IKZF1/3 (also known as Ikaros/Aiolos), both clinically validated anti-inflammatory and immunomodulatory targets. Prior literature has demonstrated that degradation of GSPT1 can result in antitumor activity in difficult-to-treat tumors such as acute myeloid leukemia (AML) and in solid tumors, including those that overexpress oncogenic transcription factors, such as MYC, however, prior clinical research by others has shown that administration of a GSPT1-only degrader was associated with dose-limiting toxicities related to the release of pro-inflammatory cytokines. BTX-1188 was specifically designed as a potent degrader of GSPT1 that can also directly block inflammation by degrading IKZF1/3. In preclinical studies conducted by Biotheryx, administration of BTX-1188 led to complete eradication of tumors and extended survival in xenograft models of AML. BTX-1188 also led to potent cell killing in a number of cell lines derived from solid tumors. BTX-1188 is currently being evaluated in a Phase 1 dose-escalation trial in patients with hematologic and solid tumor malignancies.

About Biotheryx, Inc.

Biotheryx is a clinical stage biopharmaceutical company discovering and developing a portfolio of innovative small molecule targeted protein degraders (TPDs) in areas of high unmet medical need, with an initial focus on cancer. Members of our founding and scientific teams previously developed the first U.S. Food and Drug Administration (FDA) approved modulators of Cereblon, the most widely validated E3 ligase involved in protein degradation, and have applied their expertise in Cereblon binding to build our proprietary PRODEGY platform. Our lead product candidate, BTX-1188, is a rationally designed dual-targeting molecular glue degrader of GSPT1 and IKZF1/3, which we are currently developing in a Phase 1/2 clinical trial in acute myeloid leukemia and solid tumor patients. Our broad and growing pipeline includes degraders of SOS1 for KRAS mutant cancers and CDK2/4/6 for solid tumors, with a goal of submitting three additional investigational new drug (IND) applications to the FDA over the next three years. For more information, please visit and engage with us on LinkedIn.


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1 Uy, G.L., et al. Blood 134 (Supplement_1): 232 (2019)