SOTIO Demonstrates Strong Potential of SOT102 (ADC Targeting Claudin 18.2) for Treatment of Solid Tumors in Preclinical Studies

• Results from preclinical, proof-of-concept studies were presented at the 2021 AACR Annual Meeting
• Results demonstrate strong potential of SOT102 to eliminate tumor cells in a target-specific manner
• First-in-human study in gastric and pancreatic cancer patients with expected launch in early 2022

PRAGUE, Czech Republic, April 12, 2021, a clinical stage immuno-oncology company owned by PPF Group,announced new preclinical data of its antibody-drug conjugate (ADC), SOT102 (formerly SO-N102), for the treatment of solid tumors in a virtual poster presentation at the 2021 American Association of Cancer Research (AACR) Annual Meeting. The data, which demonstrate that SOT102 has strong potential to eliminateCLDN18.2-expressing tumor cells in a target-specific manner, provide proof of concept for SOT102 as well as SOTIO's proprietary ADC platform.

Data highlights from the poster entitled, "SOT102, a novel CLDN18.2-targeting antibody-drug conjugate with strong therapeutic potential in solid tumors expressing low target levels" include:

• SOT102 showed high specificity and binding affinity for CLDN18.2, as well as efficient tumor cell killing in vivo
• Complete responses were observed in all 10 patient-derived mouse xenograft models, including those for gastric, pancreatic, liver, colon and lung adenocarcinomas, independent of CLDN18.2 expression levels
• SOT102 demonstrated favorable tolerability and pharmacokinetic properties, with the latter substantiated by observed half-lives in the range of eight days and 13 days in cynomolgus monkey and rat, respectively
• Stability of SOT102 without significant loss of payload was demonstrated in vitro and in vivo.

"Antibody-drug conjugate therapies have exhibited great promise for the future of cancer treatments, however, successes have been limited by small therapeutic windows, pharmacokinetic limitations and severe safety concerns," said Radek Špíšek, M.D., Ph.D., chief executive officer of SOTIO. "The results from our preclinical proof-of-concept study of SOT102 not only demonstrate excellent signs of safety, tolerability and efficacy in vivo, but also molecular stability and a greatly expanded therapeutic window. These findings provide SOTIO strong rationale for proceeding with in-human studies, which we look forward to initiating in early 2022."

SOT102 is a CLDN18.2 targeting antibody-drug conjugate based on a proprietary, highly specific monoclonal antibody conjugated to a potent cytotoxic drug molecule and is being developed in collaboration with NBE-Therapeutics. IND-enabling studies of SOT102 are currently ongoing with an IND filing planned for the fourth quarter of 2021, followed by a first-in-human clinical study in patients with gastric and pancreatic cancer planned for the first half of 2022.

A copy of the presentation materials can be accessed on the SOTIO website.

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About SOTIO
SOTIO is shaping the future of cancer immunotherapies by translating compelling science into patient benefit. SOTIO's robust clinical pipeline includes a differentiated superagonist of the attractive immuno-oncology target IL-15, a platform to streamline personalized active immune cell therapies, CAR T platform and a new generation of potent and stable antibody-drug conjugates.

SOTIO is a registered trademark of SOTIO a.s. in selected countries.