• Preclinical data showed enhanced anti-tumor activity and reduced cytokine release compared to conventional single-chain CAR T approaches
• Early clinical case from CELESTIAL-301 trial, the first-in-human KIR-CAR clinical trial in patients with relapsed/refractory B cell non-Hodgkin lymphoma (B-NHL), illustrates an ongoing complete patient response after 6 months
• SynKIR™-310 KIR-CAR is a potential first-of-its-kind multi-chain KIR-CAR living medicine designed with natural 'on-off' switch mechanism, which may limit T cell exhaustion

PHILADELPHIA, April 21, 2026 /PRNewswire/ -- Verismo Therapeutics, a clinical-stage CAR T cell therapy company pioneering a novel multi-chain KIR-CAR platform technology, today announced new preclinical in vivo data for SynKIR™-310 KIR-CAR living medicine, highlighting KIR-CAR's superior anti-tumor activity and improved cytokine profile compared to conventional single-chain CAR T in B cell malignancies. Early clinical data for SynKIR™-310 KIR-CAR were also announced from a multi-site Phase 1 clinical trial, CELESTIAL-301 (NCT06544265) for patients with B cell lymphomas, highlighting a patient's ongoing complete response after 6 months. These data were presented on April 21 at the American Association for Cancer Research (AACR) Annual Meeting 2026 in San Diego, CA (Poster Number: 5193).

"While single-chain CAR T therapies have revolutionized blood cancer treatment, nearly half of blood cancer patients who initially respond relapse as early as six months after treatment,^[1]" said Laura A. Johnson, Ph.D., Chief Scientific Officer and Chief Operating Officer of Verismo Therapeutics. "This urgent patient need is precisely why we designed multi-chain SynKIR™-310 KIR-CAR with a natural 'on-off' switch to potentially address chronic T cell exhaustion and increase durability.

"We are excited to report new preclinical data showing SynKIR™-310 KIR-CAR improved anti-tumor activity with reduced cytokine production compared to a conventional single-chain CAR T approach. We're also encouraged that early clinical observation of one patient in our CELESTIAL-301 trial achieved a complete tumor response that remains ongoing beyond six months. Together, these data support continued clinical evaluation of the KIR-CAR platform and SynKIR™-310, specifically in patients with relapsed or refractory B cell malignancies, including follicular lymphoma."

These preclinical data were shared during poster session "Adoptive Cell Therapy 2" by Megan Blair, Ph.D., In Vivo Lead at Verismo Therapeutics, on April 21, showing multi-chain SynKIR™-310 KIR-CAR had enhanced anti-tumor activity in vivo compared to tisagenlecleucel and axicabtagene ciloleucel analogs, in B-NHL xenograft mouse models, with reduced cytokine production, while maintaining comparable T cell persistence. These findings suggest a potential favorable benefit-risk profile of multi-chain KIR-CAR compared to traditional single-chain CAR T.

Early clinical data from CELESTIAL-301 were also shared, highlighting treatment of a 70-year-old male patient with follicular lymphoma who received SynKIR™-310 KIR-CAR at the lowest dose level (DL1) and achieved complete tumor response 28 days later, which remains ongoing as of their most recent 6-month follow-up appointment.

The CELESTIAL-301 trial is supported in part by the Institute for Follicular Lymphoma Innovation (IFLI), a global non-profit private foundation dedicated to accelerating the development of innovative treatment options for patients with follicular lymphoma, which has committed up to $4.05 million to advance SynKIR™-310 KIR-CAR development in follicular lymphoma (FL) and expand patient enrollment in the trial.

"IFLI invested in SynKIR™-310 because we believe its novel KIR-CAR architecture has the potential to meaningfully change the treatment trajectory for patients with follicular lymphoma who have exhausted standard options, including prior CAR T therapy," said David McCullagh, IFLI Managing Director. "Today's data provide an important early signal supporting the potential of this platform. We look forward to continuing to support Verismo as they advance SynKIR™-310 KIR-CAR toward broader clinical development in FL, along with other B cell malignancies."

About SynKIR™-310 KIR-CAR and the CELESTIAL-301 Clinical Trial

SynKIR™-310 is an investigational autologous engineered cell therapy developed using Verismo's KIR-CAR platform. This approach utilizes a multi-chain, split-signaling architecture derived from natural killer cells, designed to drive long-term anti-tumor T cell function without T cell exhaustion. By keeping antigen recognition separate from T cell activation, the multi-chain architecture is intended to sustain T cell activity to provide a more durable response compared to single-chain CAR T approaches.

CELESTIAL-301 is a Phase 1 first-in-human, multi-center, open-label, basket clinical trial, evaluating SynKIR™-310 KIR-CAR in patients with relapsed/refractory B-NHL, such as FL, and including those who have or have not previously received CD19 CAR T therapies. See clinicaltrials.gov (NCT06544265) for more information.

About Verismo Therapeutics

Verismo Therapeutics, a subsidiary of HLB Innovation, is a pioneer in multi-chain KIR-CAR technology, with assets SynKIR™-110 (NCT05568680) and SynKIR™-310 (NCT06544265) currently in Phase 1 clinical trials. Verismo is the only company developing the KIR-CAR platform, using a modified NK cell-derived receptor and DAP12 pairing, designed to improve T cell functional persistence and reduce exhaustion, resulting in improved efficacy against challenging tumors. The KIR-CAR platform technology was developed specifically to address areas of high unmet medical need, including advanced solid tumors and B cell associated disorders and malignancies. For more information, visit: www.verismotherapeutics.com

About the KIR-CAR Platform

The KIR-CAR platform is a multi-chain T cell therapy that has shown to be a highly effective solid tumor treatment in otherwise CAR-resistant animal models with hard-to-treat tumors. Using NK cell-derived killer immunoglobulin-like receptor (KIR) and DAP12 to split the target binding and T cell activation signals provides a novel paired immune-receptor activation that is independent from CD3 signaling, and works independent of co-stimulation. KIR-CAR enables sustained cell receptor expression in T cells, and induces deeper, more durable tumor treatments. Together, our multi-chain cell signaling platform provides the potential to deliver effective patient treatments by eliminating the constant background signaling and early T cell exhaustion observed in conventional single-chain CAR T therapy, with potential to treat both solid and hematologic tumors.

Forward Looking Statements

This press release contains forward-looking statements, including, but are not limited to, those statements regarding our expectations for the timing, progress, and results of clinical trials; potential regulatory approvals; anticipated benefits, safety, and efficacy of our product candidates; our product development strategies; and other statements that are not historical facts. These forward-looking statements are based on our current expectations and are subject to numerous risks and uncertainties that could cause actual outcomes to differ materially. Important factors that could cause actual results to differ include, among others, risks related to clinical trials, regulatory processes, market acceptance, financial projections, and our ability to successfully develop and commercialize our product candidates. Forward-looking statements in this release represent our beliefs and assumptions only as of the date hereof, and we expressly disclaim any obligation to update these statements as new information becomes available, except as required by law.

¹ Bachy, E., Le Gouill, S., Di Blasi, R., Sesques, P., Manson, G., Cartron, G., Beauvais, D., Roulin, L., Gros, F. X., Rubio, M. T., Bories, P., Bay, J. O., Llorente, C. C., Choquet, S., Casasnovas, R.-O., Mohty, M., Guidez, S., Joris, M., Loschi, M., & Carras, S. (2022). A real-world comparison of tisagenlecleucel and axicabtagene ciloleucel CAR T cells in relapsed or refractory diffuse large B cell lymphoma. Nature Medicine, 1–10. https://doi.org/10.1038/s41591-022-01969-y

Investor Relations:
Pavel Aprelev, Ph.D.
Verismo Therapeutics
Pavel.Aprelev@verismotherapeutics.com

Media Contact:
Peter Collins
TogoRun
p.collins@togorun.com
908-499-1200

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SOURCE Verismo Therapeutics