PDS Biotech Announces Publication of Positive PDS01ADC Interim Phase 2 Clinical Trial Data from Stage 1 of NCI-led Metastatic Colorectal Cancer (mCRC) Trial (Form 8-K)

PDS Biotech Announces Publication of Positive PDS01ADC Interim Phase 2 Clinical Trial Data from Stage 1 of NCI-led Metastatic Colorectal Cancer (mCRC) Trial

78% Objective Response Rate (ORR) with PDS01ADC; Parallel trial without PDS01ADC had 35% ORR

2-year survival rate of >80%; Parallel trial without PDS01ADC resulted in 2-year survival rate of ~35%

Trials performed in unresectable microsatellite stable (MSS) or mismatch repair-proficient p(MMR) colorectal liver metastases, which constitute the majority of mCRC, and in which immune checkpoint inhibitors have been unsuccessful

PRINCETON, N.J., April 15, 2026 -- PDS Biotechnology Corporation (Nasdaq: PDSB) ("PDS Biotech" or the "Company"), a late-stage immunotherapy company focused on transforming how the immune system targets and kills cancers, today announced the publication of clinical and immunological biomarker data from Stage 1 of a Phase 2 trial evaluating its tumor-targeted IL-12 immunocytokine, PDS01ADC, in the March 10, 2026 issue of Journal of Clinical Oncology (JCO) Oncology Advances.

The clinical trial, led by Dr. Jonathan Hernandez, MD, Investigator in the Surgical Oncology Program at the National Cancer Institute (NCI), part of the National Institutes of Health (NIH), combined subcutaneous injection of PDS01ADC with floxuridine (FUDR), delivered via hepatic artery infusion pump (HAIP), in patients with MSS or pMMR metastatic colorectal cancer with liver metastases who had failed at least one round of prior treatment (NCT05286814). Immune checkpoint inhibitors have been ineffective to date in about 95% of mCRC patients with MSS or pMMR disease¹. Patients interested in enrolling in this study may contact NCI's toll-free number 1-800-4-Cancer (1-800-422-6237) (TTY: 1-800-332-8615) and/or visit the web site: https://trials.cancer.gov and/or email NCIMO [email protected].

The open-label, single-center, non-randomized Phase 2 trial utilizes a Simon two-stage design and includes three disease cohorts: metastatic colorectal cancer, cholangiocarcinoma, and adrenocortical cancer. The publication reports data from the metastatic colorectal cancer cohort of the trial.

Key findings from Stage 1 (N=9) of the 22-patient study*

In colorectal cancer patients with liver metastases previously treated with at least one line of chemotherapy, who had failed prior treatment, the addition of PDS01ADC to HAIP therapy appears to enhance the immune response and clinical responses.:

*No head-to-head trials have been performed.

"HAIP was approved by the FDA in 2024 and is gaining prominence at leading oncology centers. Despite many meaningful advances in oncology, metastatic colorectal cancer remains an area of significant unmet need. These early results showing strong tumor response rates and promising patient survival are encouraging and support our approach of subcutaneously administering PDS01ADC to activate the immune system against the cancer," said Frank Bedu-Addo, PhD, President and Chief Executive Officer of PDS Biotech. "We believe these findings represent a meaningful step toward more precise immune-based treatments without the significant side effects that have historically limited traditional recombinant cytokine therapies."

The data were published in an article titled Tumor-Targeted IL-12 (PDS01ADC) With Hepatic Artery Infusion Pump Therapy for Colorectal Liver Metastases: Interim Analysis of a Nonrandomized Phase II Trial in the March 10, 2026 issue of JCO Oncology Advances (JCO Oncol Adv 3, e2500173(2026).

About PDS01ADC

PDS01ADC is a tumor-targeted immunocytokine designed to deliver Interleukin-12 (IL-12), a potent immune-activating agent, directly to the tumor while minimizing exposure to the rest of the body. The therapy uses the NHS76 antibody, which binds to DNA exposed in areas of tumor cell death, concentrating the drug where it is needed most. This targeted approach prevents the presence of free IL-12 in the body, and is designed to improve tolerability while enhancing anti-tumor potency. In clinical studies, PDS01ADC has been shown to:

PDS Biotechnology is a late-stage immunotherapy company focused on transforming how the immune system targets and kills cancers. The Company has initiated a pivotal clinical trial to advance its lead program in advanced HPV16-positive head and neck squamous cell cancers. PDS Biotech's lead investigational targeted immunotherapy PDS0101 is being developed in combination with a standard-of-care immune checkpoint inhibitor, and also in a triple combination including PDS01ADC, an IL-12 fused antibody drug conjugate (ADC), and a standard-of-care immune checkpoint inhibitor. PDS01ADC is being evaluated in multiple phase 2 trials in various cancer indications in combination with standard of care.