Candel Therapeutics Reports Extended Survival Tail Observed in Trial of Aglatimagene Besadenovec (CAN-2409) in Advanced Non-Small Cell Lung Cancer Patients with Inadequate Response to Immune Checkpoint Inhibitors

On March 17, 2026 Candel Therapeutics, Inc. (Candel or the Company) (Nasdaq: CADL), a clinical-stage biopharmaceutical company focused on developing multimodal immunotherapies to help patients with cancer, reported an additional 12 months of extended follow-up from its study of aglatimagene plus valacyclovir in combination with continued ICI therapy in patients with advanced NSCLC who had an inadequate response to prior ICI treatment. Among the 46 patients who received two administrations of aglatimagene (per-protocol population), 23 patients (50%) remained alive at 24 months. Additionally, 16 patients (35%) survived beyond 30 months, 12 patients (26%) survived beyond 36 months, 11 patients (24%) survived beyond 40 months, and 6 patients (13%) exceeded 50 months of survival. These outcomes represent an improvement from the prior data cut, in which 39% of the patients in the per-protocol population were alive at 24 months, with 10 patients surviving beyond 30 months, 6 patients each beyond 36 and 40 months, and 2 patients beyond 50 months. The extended follow-up further highlights the durability of anti-tumor immunity observed with aglatimagene-based therapy, and the persistence of a long-term survival tail in this difficult-to-treat population.

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Histologic analysis of available baseline and tumor biopsies demonstrated that among evaluable patients surviving beyond 24 months and with PD-L1 status available, (17/20) 85% had baseline PD-L1 TPS below 50% (a population typically less responsive to ICI). These findings highlight the ability of aglatimagene to convert immunologically "cold," ICI-resistant tumors into immune-active microenvironments.

mOS was 25.4 months among 46 evaluable patients who received two courses of aglatimagene (per-protocol population; cohorts 1 and 2). Among evaluable patients with progressive disease at baseline despite prior ICI therapy (cohort 2, n=41), mOS was 21.5 months, and 25.4 months in patients within cohort 2 with non-squamous histology (n=33). These outcomes compare favorably with historical reference mOS of 9.8–11.8 months reported for patients with progressive disease following ICI treatment receiving standard-of-care docetaxel1,2, representing approximately a two-fold improvement in mOS in this difficult-to-treat population. Aglatimagene maintained its generally favorable tolerability profile throughout the extended follow-up period.

Molecular profiling of paired baseline and post-treatment tumor biopsies revealed that long-term survivors exhibited robust upregulation of genes associated with sustained immune activation and antigen presentation. In particular, enhanced interferon signaling and activation of myeloid and antigen-presenting cell programs were observed, including significant increases in the expression of IFNγ, CSF1, CX3CL1, and IL1β (p = 0.010, 0.026, 0.013, and 0.034, respectively). These findings reflect increased local inflammation and recruitment of immune effector populations within the tumor microenvironment following aglatimagene treatment and may have contributed to the durable anti-tumor immune responses observed in long-term survivors.

"These updated survival data further strengthen our previously reported findings, demonstrating the potential of aglatimagene to meaningfully extend survival for patients with advanced NSCLC who have limited treatment options after failing to respond to, or progressing despite, ICI therapy," said Paul Peter Tak, MD, PhD, FMedSci, President and Chief Executive Officer of Candel Therapeutics. "With its differentiated mechanism of action and favorable safety profile observed to date, aglatimagene represents a novel therapeutic approach for solid tumors, with the potential to improve outcomes beyond current standards of care. These compelling results reinforce our commitment to advancing this program as we continue to develop new treatment options for patients facing this aggressive disease."

"The biomarker data presented here reinforces the multimodal anti-tumor activity of aglatimagene," said Francesca Barone, PhD, Chief Scientific Officer of Candel Therapeutics. "Consistent with its proposed prime-boost mechanism, we observed expansion of T-cell receptor diversity in both tumor tissue and peripheral blood following treatment, reflecting a broadening of the adaptive immune response. Notably, similar TCR repertoire expansion was previously reported in patients with glioblastoma treated with aglatimagene (see link: Neuro Oncol 2025;27:2617-2631), supporting a consistent immunologic signature across tumor types. Together with the observed activation of interferon signaling and antigen-presentation pathways, these findings highlight aglatimagene’s ability to drive both local and systemic anti-tumor immunity."

Based on these findings, together with a strong supporting mechanistic data package, the Company plans to advance this program into a pivotal phase 3 clinical trial in patients with NSCLC with non-squamous histology, with trial initiation expected in the second quarter of 2026. The U.S. Food and Drug Administration (FDA) has previously granted Fast Track designation for aglatimagene plus valacyclovir in combination with ICI therapy for the treatment of patients with stage III/IV NSCLC who are resistant to first-line PD-(L)1 inhibitor therapy and who do not harbor activating molecular driver mutations, or who have progressed on directed molecular therapy.

About aglatimagene besadenovec (CAN-2409)

Aglatimagene, Candel’s most advanced multimodal biological immunotherapy candidate, is an investigational, off-the-shelf, replication-defective adenovirus designed to deliver the herpes simplex virus thymidine kinase (HSV-tk) gene to a patient’s tumor. After intratumoral administration, HSV-tk enzyme activity results in conversion of prodrug (valacyclovir) into deoxyribonucleic acid (DNA)-incorporating nucleotide analogs, leading to immunogenic cell death in cells exhibiting DNA damage and proliferating cells, with subsequent release of a variety of tumor (neo)antigens in the tumor microenvironment. At the same time, the adenoviral serotype 5 capsid proteins promote inflammation through the induction of expression of pro-inflammatory cytokines, chemokines, and adhesion molecules. Together, this regimen is designed to induce an individualized and specific CD8+ T cell-mediated response against the injected tumor and uninjected distant metastases for broad anti-tumor activity, based on in situ immunization against a variety of tumor antigens. Aglatimagene has the potential to treat a broad range of solid tumors. Encouraging monotherapy activity as well as combination activity with standard of care radiotherapy, surgery, chemotherapy, and immune checkpoint inhibitors have previously been shown in several preclinical and clinical settings. More than 1,000 patients have been dosed with aglatimagene in clinical trials with a favorable tolerability profile to date, supporting the potential for combination with standard of care, when indicated.

(Press release, Candel Therapeutics, MAR 17, 2026, View Source [SID1234663629])