On May 11, 2026 Jabez Biosciences, Inc., a clinical-stage biopharmaceutical company developing novel therapies targeting cancer metabolism, reported the presentation of first-in-human pharmacokinetic (PK) and pharmacodynamic (PD) data from the ongoing Phase 1 clinical trial of JBZ-001 (HOSU-53) at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026. The poster, titled "Clinical Pharmacokinetic and Pharmacodynamic of JBZ-001 (HOSU-53): Comparison of First-in-Human Data with Translational Preclinical Predictions," was presented by investigators from The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James) and the START Center for Cancer Research.

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Phase 1 Clinical Data Highlights

Investigators reported PK and PD data from the first four dose levels (5 mg, 10 mg, 17.5 mg, and 25 mg) of the Phase 1 dose-escalation study (NCT06801002), with data as of March 2026. Key findings include:

No Dose-Limiting Toxicities: A total of 15 patients have been enrolled across the first four dose levels — 3 patients at 5 mg and 4 patients each at 10 mg, 17.5 mg, and 25 mg — with no dose-limiting toxicities reported as of March 2026. The best response observed to date is stable disease.

Dose-Proportional Pharmacokinetics: JBZ-001 demonstrated approximately dose-proportional increases in exposure following both single and multiple doses, with low to moderate interindividual variability across all dose levels evaluated. This linear PK behavior supports predictable exposure-response relationships as dose escalation continues.

Concordance with Preclinical Predictions: Observed human PK was broadly consistent with preclinical allometric predictions generated using a physiologically based pharmacokinetic (PBPK) model developed prior to trial initiation, with slightly higher Cmax, AUC, and half-life observed clinically compared to predictions. This concordance validates the model-informed drug development (MIDD) framework applied to JBZ-001 and supports its use in guiding ongoing dose escalation decisions.

Pharmacodynamic Biomarker Confirmation: Plasma dihydroorotate (DHO) — the direct substrate of DHODH — accumulated in blood with increasing JBZ-001 dose, confirming on-target DHODH inhibition in humans. DHO levels remained within the safety exposure threshold of <1,000 µM·h established across three preclinical species, and the concordance between predicted and observed DHO suppression provides confidence in the exposure-response assumptions guiding dose selection.

Enrollment Advancing to Dose Level 5: The trial is currently enrolling patients at Dose Level 5 (32.5 mg daily). Updated PK/PD data combined with model-informed simulations will continue to support optimal biological dose (OBD) selection and data-driven decision-making as the Phase 1 study progresses.

"The data presented at AACR (Free AACR Whitepaper) represent a significant milestone for JBZ-001 and validate the rigorous preclinical work conducted at Ohio State. Seeing the PBPK model predictions confirmed in humans — with no dose-limiting toxicities across four cohorts — gives us strong confidence as we advance to higher dose levels. We are committed to moving quickly and responsibly toward identifying the optimal biological dose that will define our path to Phase 2."

— Tamara Jovonovich, PhD, Chief Executive Officer, Jabez Biosciences, Inc.

Poster Presentation Details

Title Clinical Pharmacokinetic and Pharmacodynamic of JBZ-001 (HOSU-53): Comparison of First-in-Human Data with Translational Preclinical Predictions
Conference AACR Annual Meeting 2026
Presenting authors Min Hai, Nicole Abbott, James O. Larkin, Zhiliang Xie, Chris Coss, Tamara Jovonovich, Zuzana Jirakova Trnkova, Philippa Graham, William B. McKean, Asrar A. Alahmadi, Mitch Phelps
Institutions The Ohio State University College of Pharmacy; Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute; Jabez Biosciences Inc.; Bexon Clinical Consulting, LLC; START Center for Cancer Research–Mountain Region
Trial registration NCT06801002

About JBZ-001

JBZ-001 (HOSU-53) is an orally bioavailable, potent, and selective inhibitor of dihydroorotate dehydrogenase (DHODH), the rate-limiting enzyme in the de novo pyrimidine biosynthesis pathway. By blocking DHODH, JBZ-001 depletes pyrimidine nucleotides essential for the rapid division of cancer cells. The compound has demonstrated broad preclinical antitumor activity across lymphoma, leukemia, and solid tumor models, with a favorable safety profile.

JBZ-001 received IND approval from the FDA in 2024 and entered first-in-human clinical development in March 2025. The Phase 1 trial (NCT06801002) is currently enrolling patients with advanced solid tumors and Non-Hodgkin Lymphoma (NHL) at OSU-CCC and the START Center for Cancer Research–Mountain Region in Utah. The trial is funded by Jabez Biosciences, Inc.

(Press release, Jabez Biosciences, MAY 11, 2026, View Source [SID1234665474])