Racura Oncology Advances RC220 to Next Dose Level in Phase 1 Trial

SYDNEY, Oct. 12, 2026 /CourierPR/ -- Racura Oncology Limited has cleared its lead oncology drug, RC220, to escalate to the next planned dose level of 100 mg/m2 in combination with osimertinib in a Phase 1 clinical trial. This advancement is part of the HARNESS-1 (RAC-020) trial, which evaluates RC220 in combination with osimertinib for patients with epidermal growth factor receptor-mutant (EGFR-mutant) non-small cell lung cancer (NSCLC).

The Safety Review Committee (SRC) for the HARNESS-1 trial reviewed the safety data from both Cohort 1 patients, who received RC220 at 50 mg/m2 by intravenous infusion in combination with osimertinib at 80 mg daily. No dose-limiting toxicities or treatment-related safety concerns were identified in either patient during the safety observation period. The second patient in Cohort 1 has also received three doses of RC220, administered 21 days apart, without any dose-limiting symptoms.

Cohort 1 initially enrolled two patients, with a second patient added after an observation of Grade 2 colitis in the first patient outside the trial safety period. Although the cause was undetermined, a contribution from RC220 could not be excluded. The second patient has reported no colitis or other dose-limiting symptoms after receiving three separate doses of RC220.

Pre-screening is now underway to enroll the single patient in Cohort 2, who is expected to receive RC220 at 100 mg/m2 with osimertinib at 80 mg daily. The SRC clearance relates to safety and dose escalation only, and does not include data on the clinical activity of RC220 in this indication.

The HARNESS-1 trial is designed to evaluate RC220 in combination with osimertinib in EGFR-mutant NSCLC. The study includes an observational screening stage using circulating tumor DNA (ctDNA) to help identify eligible patients and characterize tumor molecular status before treatment. The Phase 1a dose-escalation stage evaluates RC220 administered by intravenous infusion on Day 1 of each 21-day cycle, in combination with standard-of-care maintenance osimertinib. It uses an accelerated titration design, in which the first three dose levels of 50 mg/m2, 100 mg/m2, and 150 mg/m2 are each evaluated in a single-patient cohort. Each patient is monitored through a 21-day safety observation period, and the SRC reviews all available safety data before the trial moves to the next dose level.

Between 12 and 40 patients are expected to participate in the dose-escalation stage. Following review of available safety and pharmacokinetic data, the study is expected to advance into a double-blind, randomized Phase 1b expansion stage. In this dose expansion stage, 40 patients will receive one of two RC220 dose levels in combination with osimertinib. Patients will be monitored for safety, pharmacokinetics, and early signals of clinical activity, including progression-free survival, overall survival, ctDNA dynamics, and changes in cancer-specific mutations.

Further details about the HARNESS-1 trial, including open and recruiting sites, are available through the Australian New Zealand Clinical Trials Registry at www.anzctr.org.au under trial code ACTRN12626000325303.