Highlights

  • Racura Oncology has treated the first patient in its Phase 1 HARNESS-1 clinical trial evaluating RC220 in EGFR-mutant non-small cell lung cancer (NSCLC).
  • The first patient received RC220 at a dose of 50mg/m² alongside osimertinib, with no adverse events observed during or after the infusion.
  • Additional clinical trial sites are expected to open over the coming months to support patient recruitment.
  • The Phase 1 dose-escalation stage is expected to enrol between 12 and 40 patients before progressing to a randomised Phase 1b expansion study.
  • Racura shares traded 1.30% higher at AUD 2.34 during the afternoon session on 25 June 2026 and remain up 90.24% over the past year.

Racura Oncology Ltd (ASX:RAC) has reached an important milestone in the clinical development of its lead oncology candidate, RC220, after treating the first patient in the Phase 1 HARNESS-1 clinical trial. The study is evaluating RC220 in combination with the standard-of-care therapy osimertinib for patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC), where resistance to existing targeted therapies remains a clinical challenge.

Racura Oncology shares were trading 1.30% higher at AUD 2.34 during the afternoon session on 25 June 2026. The stock has also gained 90.24% over the past 12 months as investors have continued to monitor progress across the company's oncology development pipeline.

Racura Oncology is a clinical-stage biopharmaceutical company focused on developing cancer treatments. Its lead asset, RC220, is a proprietary formulation of (E,E)-bisantrene, a small-molecule anticancer agent designed to target cancer growth pathways through G4-DNA and RNA binding, including the MYC cancer growth regulator. Beyond the HARNESS-1 study, the company is progressing RC220 across multiple clinical programs, including a Phase 3 trial in acute myeloid leukaemia (AML) and a Phase 1a/b study in combination with doxorubicin for patients with solid tumours.

First Patient Receives RC220 in HARNESS-1 Trial

The latest announcement confirms that the first participant has now received treatment in the HARNESS-1 Phase 1 clinical trial.

The patient was administered RC220 at a dose of 50mg/m² in combination with osimertinib under the supervision of Principal Investigator Associate Professor Surein Arulananda and the clinical team at Monash Health in Clayton, Victoria.

According to the company, no adverse events were observed either during or after the RC220 infusion.

The dosing of the first patient formally marks the commencement of patient treatment within the HARNESS-1 clinical program.

Study Focuses on EGFR-Mutant Lung Cancer

HARNESS-1 is designed to investigate whether RC220 can be safely administered alongside osimertinib, a tyrosine kinase inhibitor marketed as Tagrisso® by AstraZeneca.

The study targets patients diagnosed with EGFR-mutant non-small cell lung cancer, a subgroup that often responds initially to targeted therapies but can later develop resistance.

Racura noted that overcoming resistance to tyrosine kinase inhibitor treatment remains a significant clinical challenge, providing the rationale for evaluating RC220 in combination with existing therapy.

The trial will examine both safety and pharmacokinetic characteristics while also assessing clinical activity as the study progresses.

Dose Escalation Begins With Single-Patient Cohorts

The Phase 1a portion of HARNESS-1 follows a staged dose-escalation design.

The first three dose levels—50mg/m², 100mg/m² and 150mg/m²—will each enrol a single patient before expanding into larger cohorts.

This approach has been adopted to enable careful monitoring of patient safety while generating early pharmacokinetic and tolerability data.

Patients enrolled in the study will continue receiving RC220 together with osimertinib until they complete one year of treatment, experience disease progression, develop unacceptable toxicity, withdraw consent or meet another protocol-defined discontinuation criterion.

Racura expects between 12 and 40 patients to participate during this dose-escalation stage.

Expansion Stage Planned Following Safety Review

After identifying the recommended dose and reviewing available safety and pharmacokinetic information, the study will advance into a randomised, double-blind Phase 1b expansion stage.

This second stage is expected to enrol approximately 40 patients.

Participants will receive one of two RC220 dose levels in combination with osimertinib.

Researchers will monitor multiple clinical endpoints, including safety, pharmacokinetic data, progression-free survival, overall survival, circulating tumour DNA (ctDNA) changes and alterations in cancer-specific mutations.

Blood-Based Screening Supports Patient Selection

The HARNESS-1 trial also incorporates an observational screening stage before treatment begins.

This process uses circulating tumour DNA (ctDNA), a blood-based biomarker associated with cancer activity, to identify patients who may be eligible to receive RC220.

According to the company, this screening process supports patient selection before participants enter the treatment phase of the study.

Additional Trial Sites Expected to Open

Racura indicated that patient recruitment is expected to expand over the coming months.

The company plans to activate additional clinical trial sites, supporting broader enrolment into the HARNESS-1 study as dose escalation continues.

Expanding the number of participating centres is expected to facilitate recruitment while supporting progression of the clinical program.

Information regarding recruiting sites has also been published through the Australian and New Zealand Clinical Trials Registry under trial code ACTRN12626000325303.

RC220 Forms Core of Broader Oncology Pipeline

RC220 remains the company's principal clinical asset and is currently being evaluated across several cancer indications.

The proprietary formulation of (E,E)-bisantrene has previously demonstrated therapeutic activity in cancer patients and has an established safety profile.

Racura has also lodged intellectual property filings intended to provide approximately 20 years of patent protection covering the formulation.

In addition to its internal development programs, the company has collaborated with research organisations including Astex, Emory University, Purdue University, MD Anderson Cancer Center, Sheba City of Health, UNC School of Medicine, the University of Wollongong and the University of Newcastle.

Racura also continues to explore partnership, licensing and commercial opportunities to support the future development of RC220.

What This Means for Investors

The treatment of the first patient represents an operational milestone for Racura's HARNESS-1 clinical program and marks the beginning of patient dosing in the Phase 1 study evaluating RC220 alongside osimertinib in EGFR-mutant non-small cell lung cancer. With no adverse events reported in the first treated patient and additional clinical sites expected to open over the coming months, the study will continue progressing through its planned dose-escalation phase before advancing to a larger randomised expansion stage.