A man has died after participating in a CAR-T cell therapy clinical trial conducted by Shenzhen-based biotech firm Yimufeng Biotechnology Co., Ltd., according to multiple media reports this week. The fatality comes at a critical moment for the company, which is currently attempting to list on the Hong Kong Stock Exchange and has yet to bring any product to market.

The incident has thrust Yimufeng into the media spotlight, but the company's handling of inquiries has added fuel to the fire. When approached by reporters for comment, board director Li Jiaxin reportedly responded dismissively, saying "Get lost, don't bother me."

Participant dies after receiving experimental drug, wife questions informed consent document

On September 4, a woman surnamed Cheng told reporters that her husband, a 49-year-old identified as Zhan, was diagnosed with gastroesophageal junction adenocarcinoma in March 2025. He subsequently underwent a total gastrectomy and six rounds of chemotherapy at Shanghai Changhai Hospital, and his condition remained stable during follow-up treatment.

In early 2026, on the recommendation of his attending physician, Zhan enrolled in a CAR-T cell therapy clinical trial conducted by Yimufeng under the drug code IMC002. Just hours after receiving the investigational drug infusion, Zhan suddenly developed bilateral subdural hematoma and brain herniation, requiring emergency craniotomy. He remained in a coma following the surgery and died on April 26, 2026, in the intensive care unit at Shanghai Changhai Hospital.

Cheng provided reporters with the informed consent form that was signed prior to the trial, which stated that approximately 150 participants were expected to volunteer for the study, and that the research team would make every effort to ensure participant safety and rights throughout the trial. According to the document, chimeric antigen receptor T-cell therapy is a novel tumor immunotherapy strategy that selectively targets and specifically kills tumor cells in a major histocompatibility complex-unrestricted manner.

The consent form's "Possible Risks and Discomforts" section warned that IMC002 treatment could cause cytokine release syndrome, noting that in previous clinical studies, CRS cases were all grade 1-2 and could be effectively controlled with medication, with timely intervention and management available should adverse reactions occur. It also listed other potential side effects including gastritis, acute gastric mucosal injury, gastrointestinal bleeding, hypoalbuminemia, hypokalemia, respiratory failure, peripheral edema, coronary atherosclerosis, immune effector cell-associated hematotoxicity, immune effector cell-associated neurotoxicity syndrome, tumor lysis syndrome, immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, CAR-T-related coagulopathy, hypogammaglobulinemia, infection, allergic reactions, and abnormal CAR-T cell proliferation.

The consent form further stated that the above risks would be closely monitored during treatment, and with appropriate laboratory testing and professional medical judgment, most could be effectively controlled or alleviated through timely and professional symptomatic treatment.

According to Cheng, Yimufeng maintains that the general term "CAR-T-related coagulopathy" encompasses all potential consequences arising from coagulation disorders. However, Cheng argues that the informed consent form failed to explicitly disclose the possibility of intracranial hemorrhage, brain herniation, or other severe outcomes. "The main risk the doctor warned about was cytokine storm, and they said it was manageable. The consent form never mentioned bilateral subdural hemorrhage, subarachnoid hemorrhage, or brain herniation," she said. "If I had known about these risks, who would have agreed to participate in such a trial?"

In response to media inquiries, Yimufeng stated: "Regarding the incident, our company has cooperated with the hospital ethics committee to carry out relevant assessments in accordance with laws and regulations. We fully understand the family's desire to clarify the cause of the incident and respect their right to seek the truth. We will actively cooperate with medical institutions to provide necessary information support to the family and maintain open communication channels. As for the determination of responsibility, the relevant facts should be fairly clarified under legal procedures. We will fully cooperate with all investigations and assessments conducted by all parties in accordance with the law, respect the official conclusions of independent investigations and assessments, and will not make premature judgments."

According to media reports, when a reporter contacted the ethics committee of Shanghai Changhai Hospital on September 3 and identified themselves, a staff member responded dismissively, hanging up after saying "We don't know anything."

Notably, just recently, Yimufeng's chairman Sun Minmin had signed a "Self-Discipline Commitment to Uphold Scientific Research Ethics." On July 26, an industry initiative titled "Proposal on Regulating Scientific Research Behavior and Upholding Scientific Research Ethics" was launched by the China Food and Drug Safety Promotion Association's vice chairman and the Tongxieyi Cellular and Gene Therapy Club. As of 8 PM on July 27, a total of 91 founders and CEOs of CGT companies had signed in support, and Sun Minmin was among the signatories. The first clause of the initiative states that "in any clinical research or trial involving human subjects, the Declaration of Helsinki and relevant ethical standards must be strictly followed, ensuring participants give fully informed and voluntary consent, with their safety as the top priority."

Company has no approved products, pursuing Hong Kong IPO with nearly 300 million yuan in losses over two and a half years

Public information shows that Yimufeng was founded in 2020 as an innovative cell therapy company focused on discovering, developing, manufacturing, and commercializing chimeric antigen receptor T-cell therapies. The company utilizes a "dual engine" approach combining both in vitro and in vivo CAR-T cell therapies to treat solid tumors, hematological malignancies, and autoimmune diseases.

Yimufeng submitted an IPO application to the Hong Kong Stock Exchange main board again on August 18, marking its second attempt after its February filing lapsed. According to the prospectus, founder Sun Minmin, now 40 years old, holds a doctorate in pharmacy from Fudan University. Before founding Yimufeng, she served as chief executive officer assistant and director of drug regulatory affairs and government affairs at Fosun Kite, a subsidiary of Fosun Pharma, and from July 2013 to May 2016 she was a senior manager in the drug supervision department at Shanghai Henlius Biotech Inc., a Hong Kong-listed company.

The director who clashed with reporters, Li Jiaxin, is 39 years old and holds a doctorate in pharmacology from the Shanghai Institute of Materia Medica, Chinese Academy of Sciences. He has served as a board director at Yimufeng since November 2025, providing guidance on the company's business, strategy, and development.

Yimufeng has yet to receive approval for commercial sales of any product. The company posted losses of 71.3 million yuan, 115 million yuan, and 109 million yuan for 2024, 2025, and the first half of 2026 respectively. It is seeking to list under Chapter 18A rules as an unprofitable biotech company.

The IMC002 drug involved in the incident is Yimufeng's core product. According to the prospectus, IMC002 is an autologous CAR-T cell therapy candidate targeting CLDN18.2, a stomach-specific subtype of Claudin-18 that is highly expressed in gastric and pancreatic cancer cells. Expanding research and development investment in IMC002 is a direct contributor to Yimufeng's widening losses. From 2024 to the first half of 2026, the company's R&D spending reached 54.44 million yuan, 77.94 million yuan, and 82.2 million yuan respectively, with R&D costs for IMC002 alone reaching 63.11 million yuan in the first half of 2026.

The prospectus shows that Yimufeng has completed phase I/IIa clinical trials of IMC002 as a third-line treatment for advanced gastric cancer in patients who failed standard therapy, and as a second-line treatment for pancreatic cancer. The company is currently conducting a phase III registrational clinical trial in China for IMC002 in treating advanced gastric cancer/gastroesophageal junction cancer.