Pyrotech Therapeutics Doses First Subject in Phase 1 Study of PTT-121, the World's First Selective GSDMD Inhibitor to Enter Clinical Development

Clinical milestone validates the company's platform for drugging "undruggable" targets

BEIJING, Sept. 1, 2026 /PRNewswire/ -- Pyrotech Therapeutics ("Pyrotech" or the "Company"), a clinical-stage biopharmaceutical company pioneering innate immune modulation and pyroptosis-targeted therapies, announced that the first healthy volunteer has been dosed in the Phase 1 clinical study of PTT-121, its novel gasdermin D (GSDMD) inhibitor. This marks a pivotal milestone for PTT-121 as the world's first selective GSDMD inhibitor to advance into human clinical testing, breaking the previous characterization of GSDMD as an "undruggable" target.

PTT-121 is being developed initially for the treatment of septic shock, a life-threatening condition driven by dysregulated inflammatory responses and widespread pyroptotic cell death. The compound was granted clinical trial approval by China's National Medical Products Administration (NMPA) on August 4, 2026, and is now being evaluated in a first-in-human study at Peking University Third Hospital.

Dr. Feng Shao, co-founder of Pyrotech Therapeutics, said, "The first-in-human dosing of PTT-121 represents the culmination of years of relentless scientific pursuit by our team to translate groundbreaking basic research into a transformative therapy for patients. GSDMD has long been regarded as the holy grail of pyroptosis drug development — a target of extraordinary therapeutic potential that defied conventional medicinal chemistry approaches. By achieving this milestone, we are not only validating our proprietary drug discovery platform but also opening an entirely new therapeutic paradigm for septic shock and a broad spectrum of inflammatory diseases."

The Phase 1 study is a single-center, randomized, double-blind, placebo-controlled study designed to evaluate the safety, tolerability and pharmacokinetics of intravenously administered PTT-121 following single and multiple ascending doses (SAD/MAD) in healthy Chinese adults. The study plans to enroll approximately 84 healthy volunteers aged 18 to 55 years. The primary endpoint is the incidence of treatment-emergent adverse events (TEAEs); secondary endpoints include comprehensive pharmacokinetic and biomarker assessments.

Dr. Tianjing Deng, Chief Executive Officer and co-founder of Pyrotech Therapeutics, said, "Septic shock remains one of the most devastating and poorly managed conditions in modern medicine, claiming millions of lives worldwide each year despite decades of research. The current standard of care offers only supportive management, with no approved therapy that directly targets the underlying inflammatory cascade. PTT-121's unique mechanism — directly inhibiting GSDMD pore formation, blocking the release of pro-inflammatory cytokines and subsequent pyroptotic cell death — represents a fundamentally different approach. We are eager to generate the first human data and build on the compelling preclinical evidence that has positioned PTT-121 as a potential best-in-class therapeutic."

About GSDMD and Pyroptosis

Pyroptosis is a highly pro-inflammatory form of programmed cell death mediated by the gasdermin family of proteins. GSDMD serves as the central executioner of both the canonical and non-canonical inflammasome/pyroptosis pathway: upon activation by inflammatory caspases, GSDMD is cleaved to release its N-terminal domain, which oligomerizes and forms pores in cell membranes. These pores can produce cellular energy failure, the release of inflammatory cytokines such as IL-1β and IL-18, and inflammatory cell death. Excessive and uncontrolled GSDMD-mediated pyroptosis is a key driver of tissue damage, organ failure and mortality in septic shock, as well as a growing list of autoimmune, neurodegenerative and inflammatory disorders.

Despite its well-validated role in many diseases, GSDMD has been considered "undruggable" due to the challenges of selectively targeting its pore-forming activity without disrupting essential cellular functions. PTT-121 overcomes this barrier through a novel mechanism of action, demonstrating high selectivity and potency against GSDMD in preclinical studies. In addition to PTT-121, Pyrotech has developed an orally bioavailable GSDMD inhibitor with potential application to many chronic inflammatory diseases that result from excessive secretion of IL-1β/IL-18, such as gout and hidradenitis suppurativa. These GSDMD inhibitors work downstream of NLRP3 and other inflammasomes, so may have widespread clinical utility.

About PTT-121

PTT-121 is a first-in-class, intravenously administered inhibitor of GSDMD, discovered and developed internally by Pyrotech Therapeutics. It is the first selective GSDMD inhibitor to receive regulatory approval for clinical evaluation. Repurposed compounds (e.g., disulfiram) that may inhibit GSDMD are poorly selective and have different molecular targets. PTT-121's initial clinical indication is septic shock, with potential expansion into a broad range of inflammatory and autoimmune conditions.

About Pyrotech Therapeutics

Pyrotech Therapeutics is a clinical-stage biopharmaceutical company dedicated to developing revolutionary therapies for inflammation and cancer by precisely modulating innate immunity and the pyroptosis pathway. Founded in 2020 based on breakthrough scientific discoveries from Dr. Shao's lab, Pyrotech has built a technology platform that enables the selective modulation of key proteins in the innate immune and pyroptosis pathways.

The Company's pipeline comprises more than ten first-in-class programs targeting novel mechanisms; these span autoimmune diseases, oncology, neurodegenerative disorders and septic shock. Six programs have advanced into clinical development, with several drug candidates soon entering Phase 2 studies.

For more information, please visit www.pyrotech.com. 

Forward-Looking Statements

This press release contains forward-looking statements regarding Pyrotech Therapeutics' business, including statements regarding the clinical development and therapeutic potential of PTT-121, the expected timeline and outcomes of clinical trials, and the Company's strategic plans. These statements are based on current expectations and assumptions and are subject to risks and uncertainties that could cause actual results to differ materially. Factors that could cause actual results to differ include, but are not limited to, risks associated with the clinical development process, including the possibility that clinical trials may not demonstrate safety or efficacy, delays in regulatory approvals, the availability of financing, and competition from other therapeutic approaches. Pyrotech undertakes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law.

SOURCE Pyrotech Therapeutics