Surf Therapeutics, a clinical-stage company developing non-invasive ultrasound neuromodulation therapies to treat immune-mediated diseases, today reported positive first-in-human study results and announced the close of an extension seed financing round, bringing the company’s total funding to approximately $6 million.

The funding follows the successful completion of a multi-center, single-blind, sham-controlled, cross-over study in 14 participants, including adults with inflammatory arthritis. The study demonstrated statistically significant reductions in key pro-inflammatory cytokines, including TNF-α and IL-6 - two key drivers of inflammation in autoimmune disease - compared with sham following repeated ultrasound stimulation, with no device-related adverse events reported. The company plans to publish data from the study later this year and present its findings at EULAR 2026.

“Closing this financing on the back of positive first-in-human data is a milestone we’re proud of – it reflects both the strength of the science and our team’s ability to execute,” said Nishant Doctor, CEO and co-founder of Surf Therapeutics. “Since founding the company in late 2022 and completing both preclinical and first-in-human studies, our team has worked with urgency to translate this technology into a clinical-stage platform. This additional funding strengthens our ability to continue advancing clinical evidence and preparing for a future pivotal trial with a device designed for commercial scalability."

This financing builds on their previous seed round including participation from SOSV, VVP Ignite, TMC Venture Fund, General Inception, Elderberry Ventures, Evoce Capital and others, along with other angel investors like Mir Imran (Rani Therapeutics).

“One of the things that stood out to us about Surf was the team’s ability to move from concept to clinical study with remarkable capital efficiency,” said Joe Kiani, Limited Partner and Advisor to Elderberry Ventures, Executive Chairman of Willow and Like Minded Labs, and founder of Masimo. “They’ve demonstrated that disciplined execution can advance a very promising non-pharmaceutical treatment to help people suffering from Rheumatoid Arthritis into human studies without the massive capital typically required. That combination makes Surf a very exciting company to support.”

This funding announcement follows the recent initiation of Surf’s SUSTAIN early feasibility study, which evaluates the company’s investigational non-invasive ultrasound neuromodulation therapy for rheumatoid arthritis. The trial has begun enrolling patients across three clinical sites in the Dallas–Fort Worth area. For more information about Surf Therapeutics’ upcoming clinical trial, please visit https://clinicaltrials.gov/study/NCT07293871.

About Surf Therapeutics

Surf Therapeutics, Inc. is a clinical-stage company pioneering the development of non-invasive ultrasound neuromodulation technologies to modulate immune-related pathways. Its SUSTAIN™ platform is designed to engage the body’s natural anti-inflammatory pathway without surgery or implanted hardware, enabling safe, at-home use and scalable access to therapy. Surf Therapeutics is headquartered in Austin, Texas. For more information, visit www.surftherapeutics.com.

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“One of the things that stood out to us about Surf was the team’s ability to move from concept to clinical study with remarkable capital efficiency.”