Iksuda Therapeutics has achieved a significant milestone by successfully dosing the first patient with IKS03, a CD19-directed antibody drug conjugate (ADC), in a Phase 1 first-in-human clinical trial targeting patients with advanced B-cell non-Hodgkin lymphoma. The UK-based biotechnology company announced on May 30, 2025, that the patient has successfully completed the safety evaluation period, marking a crucial step forward for this novel therapeutic approach.
Phase 1 Trial Design and Objectives
The first-in-human study (NCT05365659) is designed as a dose-escalation trial that will evaluate the safety, tolerability, preliminary antineoplastic activity, pharmacokinetics, and pharmacodynamics of increasing dose levels of IKS03. The primary objective is to determine the recommended dose for subsequent dose-expansion phases, with efficacy further evaluated in disease-specific expansion cohorts.
The international study is currently enrolling patients across clinical sites in Italy, Spain, Australia, United States, and Canada, demonstrating the global scope of this clinical investigation.
IKS03: A Best-in-Class CD19-Targeting ADC
IKS03 represents a novel approach to targeting CD19-positive B-cell malignancies through its unique design incorporating a tumor-activated prodrug pyrrolobenzodiazepine (PBD) payload. The compound was licensed from LigaChem Biosciences (formerly LegoChem Biosciences), highlighting the collaborative nature of modern drug development.
Preclinical testing has demonstrated promising results, with IKS03 showing best-in-class efficacy compared to in-clinic and marketed CD19-targeted therapies in in vivo xenograft models. Additionally, the compound achieved a significantly raised maximum tolerated dose (MTD) in non-human primate disease models, suggesting its potential to become the leading anti-CD19 therapy in B-cell cancers.
Addressing Unmet Medical Needs
Dr. Dave Simpson, Chief Executive Officer of Iksuda Therapeutics, emphasized the significance of this milestone: "With the first patient successfully completing the safety evaluation period with IKS03, Iksuda demonstrates its continued commitment to drive its differentiated ADCs through clinical proof of concept, further solidifying our position as a clinical-stage ADC-focused company."
Simpson acknowledged the therapeutic landscape, noting that "although there have been advances in the treatment of non-Hodgkin lymphoma in recent years, there remains a significant unmet patient need." The company hopes that IKS03 will build on the potential benefit-risk profile suggested by preclinical study data.
Company Pipeline and Technology Platform
This clinical milestone represents Iksuda's second asset to begin clinical testing, demonstrating the company's expanding pipeline of ADC therapeutics. Iksuda Therapeutics focuses on developing class-leading antibody drug conjugates targeting difficult-to-treat hematological and solid tumors.
The company's ADC pipeline centers on a portfolio of prodrug DNA and protein alkylating payloads combined with stable conjugation chemistries, including its proprietary PermaLink® platform. According to the company, these design concepts for ADCs are now clinically validated to significantly improve the therapeutic index of this important modality and enhance outcomes for patients living with cancer.
