A Japanese biotech startup emerging from the Okinawa Institute of Science and Technology (OIST) is developing a peptide-based strategy designed to make opioid pain treatment safer. Surzen Biotherapeutics, founded around research conducted at OIST, aims to reduce some of the serious limitations associated with conventional opioids, including tolerance, respiratory depression, addiction and overdose. Rather than replacing opioid medicines outright, the company’s approach is intended to modify how opioid receptors communicate when traditional analgesics are present. The technology remains in the preclinical stage, but its developers believe it could eventually support more effective pain relief with a lower burden of adverse effects.
Opioids remain among the most powerful medicines available for severe acute and chronic pain, particularly in cancer care, surgery and advanced disease. Their therapeutic effects arise largely through activation of opioid receptors, membrane proteins that influence neuronal signaling and suppress the transmission of pain-related information. However, the same receptor systems are connected to unwanted effects, and prolonged exposure can produce tolerance, meaning that progressively higher doses may be needed to achieve the same level of analgesia. Dependence and respiratory depression further complicate treatment, while excessive exposure can be fatal. In the United States, more than 300,000 deaths were attributed to prescription opioid overdoses between 1999 and 2023, according to the U.S. Centers for Disease Control and Prevention.
Surzen’s technology is based on a detailed view of opioid receptor biology. Traditional drug development has often treated receptors as individual units, or monomers, that bind medicines and initiate intracellular signals. Research in cell biology and pharmacology, however, indicates that some receptors can associate in pairs known as dimers. Dimerization can alter receptor structure, mobility, signaling strength and the way cells respond to drugs. These receptor-receptor interactions may therefore help determine both the desired analgesic response and the development of tolerance or other side effects. By focusing on the physical organization of receptors at the cell membrane, Surzen’s scientists are attempting to intervene in opioid signaling at a level that conventional drugs generally do not directly address.
The company’s peptide candidates were identified through research led by Dr Peng Zhou in the Membrane Cooperativity Unit at OIST, headed by Professor Akihiro Kusumi. Zhou used single-molecule tracking methods to examine how opioid receptors move, interact and form dimers within cell membranes. Single-molecule imaging can follow the behavior of individual proteins rather than averaging signals across millions of molecules, allowing researchers to observe transient receptor encounters and changes in membrane organization. The work led to the identification of peptides capable of interfering with opioid receptor dimerization. When administered alongside conventional opioids, these peptides are intended to reshape receptor signaling, potentially improving analgesic activity while reducing tolerance and severe unwanted effects.
The scientific motivation behind the startup is also personal for Zhou. After completing a PhD in biochemistry at Wuhan University, he joined Kusumi’s laboratory at Kyoto University, which later moved to OIST. During that period, Zhou’s father was diagnosed with late-stage cancer. Zhou returned home for six months to help care for him and witnessed many patients struggling with severe pain during repeated hospital visits. The experience ultimately influenced his decision to pursue safer pain treatments, particularly for people with terminal illness who may have limited therapeutic options. The name Surzen reflects the Chinese pronunciation of his father’s name, Shu Sheng, linking the company’s identity to the personal origin of its research mission.
Transforming a laboratory discovery into a drug candidate requires more than identifying a promising molecular mechanism. With support from OIST Innovation, the university’s technology development and commercialization hub, Zhou worked to protect the intellectual property associated with the peptide platform and continued testing its potential through preclinical studies in animal models. He also received an OIST Technology Pioneer Fellowship through the university’s Proof of Concept program. The fellowship provided funding, laboratory access, entrepreneurship training and business development support, allowing the research to advance beyond the academic setting and toward commercial development.
The company’s formation accelerated through OIST Innovation’s international network, which connected Zhou with James Feliciano, a venture partner at Saisei Ventures and a veteran of the pharmaceutical industry. Feliciano became Surzen’s chief executive officer, complementing Zhou’s expertise in receptor biology and peptide discovery with experience in drug development and commercialization. Saisei Ventures supplied seed funding, helping the startup assemble a team with scientific, operational and financial capabilities. The company’s leadership also includes Peng Zhou as chief technology officer and Shuhei Tomimoto as senior director of operations. Surzen has established its base in Okinawa, where it can remain close to OIST’s researchers, facilities and biotechnology ecosystem.
The startup is developing its program with international markets in mind, especially the United States and Canada, where opioid exposure and opioid-related health risks remain major public health concerns. If the peptide candidates continue to demonstrate safety and efficacy in preclinical testing, the company will need to complete extensive toxicology studies, optimize manufacturing and establish how the compounds should be administered with existing opioid medicines. It will then have to meet regulatory requirements before beginning human clinical trials. A mechanism that works in cellular systems or animal models does not guarantee a successful medicine, and questions about pharmacokinetics, immune reactions, dosing, long-term safety and clinical benefit will be central to the next stages of development.
Surzen has already received a grant from the Okinawa Prefectural Government through its Okinawa Advanced Medical Technology Infrastructure Development Promotion Program. The funding is intended to support the region’s medical technology ecosystem and represents an early milestone for a company seeking to move an OIST discovery toward therapeutic application. For Angela Ares Pita, manager of OIST’s Proof of Concept program, the startup illustrates how institutional support can help researchers bridge the gap between fundamental science and societal impact. Surzen’s ultimate goal is not simply to create another opioid product, but to develop a biological tool that can make existing pain management more precise and less dangerous. Whether receptor-dimerization-blocking peptides can achieve that promise will depend on the results of rigorous future testing, but the approach offers a distinctive avenue for addressing one of medicine’s most difficult therapeutic challenges.
Subject of Research: Peptide-based modulation of opioid receptor dimerization for safer and more effective pain management.
Article Title: OIST Startup Advances Peptide Strategy for Safer Opioid Pain Relief
Web References: https://www.surzenbio.com/ ; https://www.oist.jp/research/research-units/mcu ; https://www.oist.jp/innovation/technology-development ; https://www.cdc.gov/overdose-prevention/about/prescription-opioids.html
References: U.S. Centers for Disease Control and Prevention, “Prescription Opioids.”
Image Credits: Kanayo Noda
Keywords: Surzen Biotherapeutics, OIST, opioid receptors, receptor dimerization, peptides, pain management, chronic pain, analgesics, drug development, drug discovery, biotechnology, pharmaceuticals, opioid safety, entrepreneurship
