Scorpion Therapeutics to Present Preclinical Data for Potential Best-in-Class Mutant-Selective PI3Kα Inhibitor at San Antonio Breast Cancer Symposium

Preclinical data demonstrates potential for STX-478 to improve outcomes in patients harboring tumors with either PI3Kα kinase or helical domain mutations; more than 166,000 people in the United States present with PI3Kα-mutant tumors each year¹

Preclinical data indicate the combination of STX-478 and effective standard-of-care agents delivers synergistic benefit in prevalent cancers

Investigational new drug (“IND”) application submission for STX-478 on track for Q1 2023

Scorpion Therapeutics, Inc. (“Scorpion”), a pioneering oncology company redefining the frontier of precision medicine through its Precision Oncology 2.0 strategy, today announced that it will present preclinical data on STX-478, its potential best-in-class mutant-selective PI3Kα inhibitor, in a poster session at San Antonio Breast Cancer Symposium (“SABCS”) in San Antonio, Texas, taking place December 6 – 10, 2022.

STX-478 is a highly selective, allosteric and CNS-penetrant inhibitor of mutant PI3Kα, designed to improve outcomes in patients harboring tumors with prevalent PI3Kα kinase or helical domain mutations. Scorpion has completed IND-enabling studies for STX-478 and expects to submit an IND application to the U.S. Food and Drug Administration (“FDA”) in the first quarter of 2023.

“We are excited to present preclinical data that further support STX-478’s potential as a best-in-class PI3Kα inhibitor and advances its development as a novel therapeutic for the treatment of many solid tumors that are underserved by existing options,” said Axel Hoos, M.D., Ph.D., Chief Executive Officer of Scorpion Therapeutics. “Despite PI3Kα being one of the most highly-mutated targets in cancer, currently available therapies suffer from serious limitations, including a lack of wild-type selectivity, which induces metabolic dysfunction and causes dose-limiting toxicities, and an inability to penetrate the central nervous system (CNS), which leaves brain metastases – a common occurrence in solid tumor patients – unaddressed. We are confident that STX-478 can address these challenges through superior monotherapy activity, as well as in combination with relevant co-treatments, without sacrificing tolerability.”

Details of the poster presentation are as follows:

Presentation Title: STX-478, a mutant-selective PI3Kα H1047X inhibitor clinical candidate with a best-in-class profile: Pharmacology and therapeutic activity as monotherapy and in combination in breast cancer xenograft models

Session Title: Treatment: Other

Poster Board Number: P4-07-04

Date & Time: Thursday, December 8, 2022, at 7:00 a.m. – 8:15 a.m. CT (8:00 a.m. – 9:15 a.m. ET)

Location: Henry B. Gonzalez Convention Center, Exhibition Hall 1, Poster Session 4

The abstract is now available online on the SABCS conference at https://www.sabcs.org/.

About Scorpion Therapeutics

Scorpion is a pioneering oncology company redefining the frontier of precision medicine to deliver optimized and transformational therapies for larger populations of patients with cancer, a strategy Scorpion refers to as Precision Oncology 2.0. Scorpion has built a proprietary and fully integrated platform of the most advanced technologies across cancer biology, medicinal chemistry, and data sciences, with the goal of consistently and rapidly creating exquisitely selective small molecule compounds against an unprecedented spectrum of targets. Scorpion aims to leverage its platform to advance a broad pipeline of wholly owned, optimized compounds across three target categories: best-in-class molecules targeting validated oncogene targets; first-in-class molecules for previously undruggable targets; and first-in-class molecules for novel cancer targets. For more information, visit www.scorpiontx.com.

¹ American Cancer Society, The Cancer Genome Atlas

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