- 01SRC clears RC220 dose rise in Harness-1.
- 02No dose-limiting toxicities in first two patients.
- 03Screening starts for 100mg/sqm Cohort 2; efficacy unproven.
Racura Oncology (ASX: RAC) has received safety review committee (SRC) clearance for lead candidate RC220 allowing it to advance a Phase 1 Harness-1 trial (RAC-020).
The RAC-020 trial is evaluating the safety and tolerability of the drug in combination with standard-of-care tyrosine kinase inhibitor osimertinib in patients with epidermal growth factor receptor-mutant non-small cell lung cancer (EGFRm NSCLC).
The committee reviewed all the safety data from two patients in Cohort 1 of the multi-centre trial, each of whom received a daily intravenous infusion of 50 milligrams per square metre (of body surface area) with 80mg of osimertinib (sold under brand names Tagrisso or AstraZeneca), and identified no dose-limiting toxicities or treatment-related safety concerns during the safety observation period.
It recommended that Racura proceed with a planned dose escalation to 100mg/sqm and pre-screening is now underway to recruit a single patient for Cohort 2.
Racura chief executive officer Dr Daniel Tillett said SRC clearance was an “important early milestone” for the trial that reflected the “disciplined execution of our clinical development plan”.
Harness-1 Design
Racura’s Harness-1 trial is based on an accelerated titration design that steadily increases the dose of RC220 from 50mg/sqm to 100mg/sqm to 150mg/sqm, with each dose monitored for safety and the results reviewed before moving to the next one.
This step-by-step approach helps the trial build safety information while limiting each patient’s exposure to higher doses of RC220 before the data has been reviewed.
Advancing to each new dose is guided by the SRC (made up of clinicians and trial experts) and trial protocol, which sets out the safety rules for the study.
The SRC does not decide whether the medicine is commercially valuable or effective and dose escalation does not prove that RC220 works against EGFRm NSCLC in combination with osimertinib.
Safety Data Determination
The SRC’s role is to determine whether all of the available safety data — including side effects (if any), laboratory test results, clinical observations, dose-limiting toxicities, treatment exposure, and any other information required by the protocol — supports moving to the next planned dose level and it can recommend a dose escalation be paused, or the dose reduced, if a dose-limiting toxicity or other safety concern is observed.
Once the accelerated titration stage is complete, Harness-1 will transition to a BOIN (Bayesian optimal interval) design where at least three patients are included at each dose level, providing additional RC220 safety data for Racura.
RC220 is a proprietary formulation of Racura’s lead asset (E,E)-bisantrene small molecule anti-cancer agent designed to silence cancer growth pathways through G4-DNA and RNA binding, including the cancer growth regulator MYC.
It is used for multiple oncology indications and its current clinical programs include a Phase 3 trial into acute myeloid leukaemia and a Phase 1a/b trial in combination with doxorubicin chemotherapy medication for solid tumour patients.
(E,E)-bisantrene has previously demonstrated therapeutic activity in cancer patients and has a well-characterised safety profile.
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