Zhejiang University-Originated Startup SaiTu Life Advances Immunosuppressant-Resistant Universal CAR-T Therapy with Potential Price Below $15,000

Multiple CAR-T therapies have been approved for market successively, achieving remarkable achievements in both efficacy and commercialization. However, as current CAR-T therapies predominantly utilize autologous CAR-T cells (derived from the patient’s own blood T cells), manufacturing costs remain prohibitively high. Furthermore, the process from T-cell collection to the successful production of CAR-T cells typically takes 2–3 weeks, potentially causing patients to miss their optimal treatment window. Consequently, the research community has begun to explore allogeneic CAR-T cells, also known as universal CAR-T (UCAR-T) cells. The primary advantage of UCAR-T is that it can be manufactured in advance, with a single batch suitable for multiple patients. This enables immediate availability when needed, significantly reducing both financial and time costs.

Despite the year-on-year increase in the number of clinical trials for universal CAR-T cell therapy, and the RMB 552 million in financing secured in 2023 by 11 domestic companies focused on the development of universal cell therapy drugs, universal CAR-T cells still face significant challenges in terms of immune rejection, cell persistence, and the source of backbone cells.

To address these pain points, a team led by Zeng Xun, a researcher at the First Affiliated Hospital of Zhejiang University School of Medicine, is developing a universal CAR-T therapy for immunosuppressant-resistant systemic lupus erythematosus (SLE). In 2024, Zeng Xun’s team established the startup SaiTu Life to advance this initiative.

Dr. Zeng Xun earned his Ph.D. from the Chinese Center for Disease Control and Prevention. He subsequently served as a postdoctoral fellow and assistant investigator in the Department of Immunology at Stanford University. Currently, he is a researcher at the First Affiliated Hospital, Zhejiang University School of Medicine. His research focuses on cellular immunotherapy. He has published more than 30 papers as first or corresponding author and has presided over multiple projects funded by the National Natural Science Foundation of China.

Recalling his journey, Zeng Xun completed his doctoral degree in China before traveling to Stanford University in the United States for postdoctoral research, focusing on fundamental issues in immunology. During his eleven years in the U.S., although his scientific research progressed smoothly, a conversation with a friend prompted him to reflect: What is the direct application value of basic research? This question led him to continually ponder the significance of scientific inquiry and planted the seed in his mind that research achievements should be translated into practical applications. As he prepared to return to China, Zeng Xun attended a lecture by Professor Carl June of the University of Pennsylvania on how CAR-T cell immunotherapy successfully cured patients. He realized the immense value of directly translating scientific findings into clinical treatments, as well as the immediate feedback and profound impact such translation could bring. Upon returning to China, he resolutely decided to shift his research focus to this field.

Upon conducting an in-depth review of the literature on CAR-T therapy, Zeng Xun recognized its remarkable efficacy in treating hematologic malignancies; however, the prohibitive cost of treatment has become a significant barrier to its widespread adoption. In light of this, he led his team to focus their research on developing more affordable and accessible universal CAR-T therapies, aiming to address the high costs associated with CAR-T treatment and enable this cutting-edge therapy to benefit a broader patient population.

To this end, Zeng Xun’s team established Saitu Life with the vision of “Cell to Life,” aiming to promote its universal CAR-T therapy technology. Regarding CAR-T therapy, Zeng Xun pointed out that while autologous CAR-T and universal CAR-T are similar in their tumor-killing mechanisms, the latter focuses more on addressing key issues in allogeneic T-cell transplantation, namely graft-versus-host disease (GvHD) and host-versus-graft reaction (HvGR). In particular, HvGR has become a major challenge in the development of universal CAR-T therapies due to its involvement in complex immune recognition and rejection mechanisms. Currently, although various strategies such as gene editing to knock out HLA molecules have been attempted, there is yet no mature, simple, and universally applicable method to fully resolve this issue, thereby hindering the commercialization process of universal CAR-T products.

Furthermore, Zeng Xun emphasized the potential cost-effectiveness advantages of universal CAR-T therapy, noting that a single batch of manufactured universal CAR-T product can be administered to multiple patients, thereby significantly reducing treatment costs. However, realizing this advantage heavily depends on technological breakthroughs in mitigating rejection responses to ensure the product’s stability and efficacy in vivo. It can be stated that effectively addressing graft-versus-host disease (GvHD) and host-versus-graft alloreactivity (HvGA) associated with universal CAR-T cells would provide the clinic with a novel immunotherapeutic approach that is highly efficient, safe, controllable, and cost-effective.

Initially, Zeng Xun’s team decided to build a technical platform to address the universality challenges of CAR-T therapy. Theoretically, this platform could cover various hematologic malignancies. However, the team chose systemic lupus erythematosus (SLE) as their primary R&D target, mainly based on two considerations: First, the field of B-cell hematologic malignancy treatment is highly competitive, with multiple CAR-T products targeting CD19 and BCMA already approved both domestically and internationally, making it difficult for new entrants to quickly gain a competitive edge. Second, as an autoimmune disease, SLE is characterized by a chronic course and high survival rates. It affects a large patient population that is sensitive to treatment costs and has high expectations for prognosis. Currently, however, both market and clinical needs remain inadequately met.

Therefore, Saitu Life is dedicated to developing an innovative platform for Immunosuppressant-Resistant Universal (IRU) CAR-T therapy. Its design principle is unique and fundamentally distinct from existing similar therapies both domestically and internationally. The universal CAR-T therapy designed by the team differs significantly in principle from current counterparts at home and abroad; its core innovation lies in conferring resistance to immunosuppressants upon CAR-T cells through genetic mutations. When used in combination with immunosuppressants, these agents inhibit the host’s T cells and NK cells from rejecting the CAR-T cells, while the IRU-CAR-T cells effectively kill target cells. Due to this unique anti-rejection mechanism, the therapy features a more streamlined design process and significantly enhanced anti-rejection efficacy.

This strategy also presents challenges, primarily because immunosuppressants are not a standard treatment modality for all diseases, and their use requires particular caution in the context of hematologic malignancies. Therefore, when selecting indications, the research team placed special emphasis on the suitability of immunosuppressants to ensure the safety and efficacy of the combination therapy. Consequently, the strategy of combining this universal CAR-T therapy with immunosuppressants for the treatment of systemic lupus erythematosus (SLE) fully leverages the clinical advantages of immunosuppressants as a standard-of-care for SLE, further enhancing the safety and efficacy of the therapeutic approach.

Meanwhile, IRU-CAR-T cells enable a “treat-and-discontinue” strategy for CAR-T therapy. Upon completion of treatment, immunosuppressants are withdrawn to restore host-versus-graft activity (HvGA), leading to the rejection of IRU-CAR-T cells. This approach allows physicians to precisely control the persistence of CAR-T cells in patients and flexibly adjust treatment regimens. It effectively suppresses immune rejection during therapy while rapidly restoring the host’s immune system post-treatment, thereby facilitating natural clearance of CAR-T cells and avoiding the risks of tumorigenesis and off-target toxicity associated with long-term persistence.

Currently, the core team at Saitu Life remains stable. Mao Lijun, CEO and Clinical Director, brings over 20 years of experience in new drug R&D. He has led clinical research for multiple drug projects, facilitating their approval and market launch by the FDA and EMA, and participated in the IND application for China’s first novel-target drug while leading its clinical research program. Dr. Zhang Yixi, R&D Director, is the developer of universal IRU-CAR-T technology. Xu Haijun, CFO, previously served as an executive at large multinational corporations and as CFO for several biopharmaceutical companies. He possesses in-depth expertise in group financial control, management system development, financial management, financing, M&A integration, and IPOs.

Regarding the team’s current research progress, Zeng Xun stated that preclinical studies have been completed with favorable results, and the team is planning to advance to the clinical trial phase. In terms of supply chain development, Zeng Xun pointed out that market-ready supplies are already available for all reagents and technologies except T cells. Consequently, the team has adopted an asset-light operational strategy, initially planning to secure financing and outsource CAR-T production to CDMO companies to accelerate clinical trials and accumulate intellectual property (IP) data.

Zeng Xun stated, “CAR-T immunotherapy represents the future direction for treating systemic lupus erythematosus (SLE); however, no CAR-T therapy has currently been approved worldwide for this indication. With adequate funding support, SaiTu Life Sciences would require at least six years from the present to obtain marketing approval, potentially achieving commercialization by 2031 and thereby accelerating the early adoption of universal CAR-T therapies.”

Furthermore, Zeng Xun specifically noted that, as immunosuppressants are a standard treatment for the disease, IRU-CAR-T therapy combined with immunosuppressants is expected to achieve better outcomes than monoclonal antibody therapies in treating SLE, with high safety, low toxicity, and favorable prognosis. More importantly, following successful commercialization, the cost of IRU-CAR-T therapy is projected to be comparable to that of monoclonal antibody treatments, ranging from RMB 50,000 to 100,000 per patient.