Shasqi Advances SQ3370 to Phase 2 in Solid Tumors

• Shasqi's lead asset, SQ3370 is designed to activate doxorubicin at the tumor site and established click chemistry in humans
• Phase 1 data presented at ESMO Congress 2022 show SQ3370 is well-tolerated among patients receiving up to approximately 12 times the standard dose of doxorubicin (Dox); dose escalation continues
• The unprecedented therapeutic index of SQ3370, the first agent that allows the administration of over 5 times conventional Dox, unlocks the opportunity to exploit the full potential of the target
• High dose levels of SQ3370 show novel immune-regulatory effects that could treat both local and metastatic lesions

SAN FRANCISCO, Sept. 12, 2022 /PRNewswire/ -- Shasqi, a clinical-stage biotechnology company developing oncology therapeutics with its proprietary Click Activated Protodrugs Against Cancer (CAPAC ®) platform announced today it has opened the Phase 2 of their Phase 1/2a clinical study to further assess SQ3370 in anthracycline- naïve patients. The Phase 2 study follows the company's presentation at the European Society for Medical Oncology (ESMO) Congress, held September 9-13, 2022, evaluating the safety, tolerability, maximum tolerated dose, and recommended Phase 2 dose for SQ3370 in patients with locally advanced and/or metastatic solid tumors (NCT04106492).

"We are encouraged by the promising results from our Phase 1 study and preclinical data which indicate that click chemistry in humans has the potential to revolutionize cancer care by expanding the therapeutic index of anti-cancer therapies such as doxorubicin," said José M. Mejía Oneto, M.D., Ph.D., Founder and CEO of Shasqi. "We look forward to further exploring the safety and efficacy of our lead candidate SQ3370 at unprecedented dose levels in the Phase 2 study."

The Phase 1 clinical data were presented as a poster during the congress:

• Abstract Title: Phase 1 Clinical & Immunologic Data of SQ3370 in Advanced Solid Tumors
• Presentation Number: 1499P
• Poster Session Title: Phase 1 Clinical & Immunologic Data of SQ3370 in Advanced Solid Tumors
• Link to full poster details here.

Key Phase 1 study findings include:

• SQ3370 was well tolerated among 27 DLT evaluable patients receiving up to 12x (1x equals 75mg/m²/cycle of Dox molar equivalents); maximum tolerated dose has not been reached
• Among patients treated with a least one cycle of SQ3370, no protocol defined dose-limiting toxicities, including anthracycline myelosuppression and gastrointestinal (GI) toxicity, were observed and no treatment emergent adverse events (TEAEs) that led to death were considered related to SQ3370; the most frequent Grade ≥3 TEAE was anemia
• The highest doses tested of SQ3370 led to immune activation in soft tissue sarcomas which are considered immunologically cold tumors, validating preclinical findings of SQ3370 previously published:
• Increased cytotoxic T-cell activity observed at higher dose levels of SQ3370 indicate immune activation and a trend toward increase in tumor cell death in heavily pretreated patients
• Immune activation has the potential to improve systemic activity of intra-tumoral administration of SQ3370 which will be explored in Phase 2

"Early data has shown that click chemistry allows for the release of doxorubicin at the tumor site to generate anti-tumor responses. Phase 1 results showing that SQ3370 is well-tolerated among a heavily pretreated patient population further validate this clinical approach and the importance of investigating SQ3370 as a potential treatment option in patients with anthracycline-sensitive- and other solid tumors," said Sant P. Chawla, M.D., FRACP, Principal Investigator, and Head, Sarcoma Oncology Center in Santa Monica, California."

Shasqi is excited to open the Phase 2 study of SQ3370 in anthracycline-naïve patients with advanced soft tissue sarcomas, relapsed or recurrent squamous-cell head and neck cancer, platinum refractory ovarian cancer recurrent and/or metastatic uterine carcinoma, or uterine sarcoma. For more information, visit www.shasqi.com

Shasqi is a privately held, clinical-stage biotechnology company whose mission is to enable patients to beat cancer with tumor-localized therapies by pioneering the use of click chemistry in humans. Click chemistry is a term that describes chemical reactions in which 2 compounds rapidly react with each other; ignoring everything else around them.
Shasqi's proprietary CAPAC platform enables precise oncology therapeutics to reach unprecedented doses at the tumor site with a strong safety profile in two steps. First, the CAPAC platform localizes a click chemistry reagent (activator) to the tumor. Then protodrugs (attenuated drugs activated by click chemistry) are infused systemically. When the protodrug reaches the activator, the payload is released at the tumor site.
The lead asset, SQ3370 has established click chemistry in humans and uses a powerful chemotherapeutic, doxorubicin, as the payload. Shasqi's CAPAC Platform, when applied to a broad range of existing and experimental cancer drugs, is designed to reach unprecedented doses and unlock novel beneficial biological effects.

SOURCE Shasqi, Inc.