Racura Oncology has treated the first patient in its Harness-1 Phase 1 lung cancer study evaluating RC220 with osimertinib in EGFR-mutant NSCLC.

Racura Oncology has treated the first patient in the Harness-1 Phase 1 clinical trial evaluating RC220 in combination with osimertinib in patients with EGFR-mutant non-small cell lung cancer (NSCLC), marking the start of dosing in the programme.

The patient received RC220 at 50 mg/m2 at Monash Health in Clayton, Victoria, under the care of principal investigator Associate Professor Surein Arulananda and his team. The company reported no adverse events during or after the infusion.

Harness-1 is assessing whether RC220 (E,E-bisantrene) can be safely combined with the standard-of-care tyrosine kinase inhibitor osimertinib in patients whose disease has developed resistance to targeted therapy. Osimertinib is widely used in EGFR-mutant NSCLC, but resistance remains a key clinical challenge, driving ongoing combination studies across the field.

The study begins with single-patient cohorts across three dose levels (50 mg/m2, 100 mg/m2 and 150 mg/m2), designed to enable cautious escalation while generating early safety and pharmacokinetic data. Patients will remain on treatment until disease progression, unacceptable toxicity, completion of one year of therapy, or other protocol-defined discontinuation criteria.

Racura Oncology CEO Dr Daniel Tillett said: “Treating the first patient in Harness-1 is an important step in the clinical development of RC220 and reflects the progress being made across Racura’s oncology pipeline. This trial is focused on a patient group where resistance to current targeted therapies remains a significant challenge. We are grateful to A/Prof Surein Arulananda and his team at Monash Health for their work in recruiting and treating the study’s first participant, and we thank the patients and families supporting this clinical research.”

The Harness-1 study includes an initial observational screening stage using circulating tumour DNA (ctDNA) to help identify eligible patients. ctDNA is being used increasingly in oncology trials as a blood-based marker of tumour activity and mutation status, supporting faster and less invasive patient selection.

Following dose escalation, the programme will move into a randomised, double-blind Phase 1b expansion stage. This will evaluate two RC220 dose levels in combination with osimertinib across approximately 40 patients. Endpoints include safety, pharmacokinetics, progression-free survival, overall survival and changes in ctDNA and tumour-specific mutations.

Between 12 and 40 patients are expected in the dose-escalation phase before the recommended dose is selected for expansion.

RC220 is Racura’s proprietary formulation of (E,E)-bisantrene, a small molecule designed to target cancer growth pathways through G4-DNA and RNA binding, including regulation of MYC-driven signalling. The company has positioned the programme across multiple oncology indications, including acute myeloid leukaemia and solid tumours, alongside combination studies.

The first patient dosing in Harness-1 represents an early clinical milestone for the programme as it progresses through Phase 1 development and generates initial safety and activity data in combination with targeted therapy.