• Race’s Phase 1b/2 investigator-sponsored trial of RC110 bisantrene in relapsed or refractory acute myeloid leukaemia successfully concluded
  • Trial was being held at the Sheba Medical Centre in Israel with results 40% of patients with highly advanced disease showing a response to bisantrene
  • Findings support Race’s intention to initiate a new Phase 1/2 investigator-sponsored AML trial using RC220 bisantrene

 

Special Report: Race Oncology’s investigator-sponsored Phase 1b/2 trial of lead drug bisantrene in combination with clofarabine and fludarabine (Bis/Clo/Flu) in relapsed or refractory acute myeloid leukaemia (R/R AML) patients has been successfully concluded after reaching its primary endpoint for efficacy.

Race Oncology (ASX:RAC) says the trial at the Chaim Sheba Medical Centre in Israel under key opinion leader Professor Arnon Nagler builds on a prior Phase 2 RC110 bisantrene monotherapy clinical study in patients with R/R AML.

Together the results are highly supportive of future clinical studies.

Bisantrene is an anthracene-based chemotherapy drug originally developed in the 1970s in France, which is known to reduce cardiotoxicity when used with anthracyclines.

Despite bisantrene’s efficacy in treating AML in France, complex administration limited its success.

However, RAC has now reformulated Bisantrene for easy infusion and is exploring its anti-cancer and cardio-protective benefits.

 

Israel study design

The open-label, Phase 1b/2 clinical trial in Israel investigated intravenous Bis/Clo/Flu (bisantrene, clofarabine, fludarabine) in cohorts of adult patients with R/R AML using a Simon’s 2-stage design.

The design protocol included a Phase 1b lead-in dose escalation stage to establish the maximum tolerated dose (MTD) or recommended Phase 2 dose (RP2D) of Bis/Clo/Flu.

The Phase 2 expansion stage was designed to determine efficacy and confirm safety of the Bis/Clo/Flu regimen at the RP2D in up to 17 subjects.

 

Promising study results

In November 2023, RAC announced six of the 15 evaluable patients (40%) in the Phase 2 efficacy stage responded to the Bis/Clo/Flu treatment with five complete responses and one partial response.

Three of the clinical responders had active extramedullary disease, which is when myeloma cells form tumours outside the bone marrow in organs or soft tissue.

RAC says five of the six treatment-responsive patients were able to be bridged to a potentially curative stem cell transplant within one to three months of treatment.

The patient complete response rate exceeded the trial’s prespecified 2-stage Simon efficacy threshold of three or more complete responses.

 

Results supportive of future studies

The interim trial results were presented at the prestigious American Society of Hematology 65th Annual Conference held in December 2023.

It is expected that the final study outcomes will be published in a high impact peer-reviewed international journal later in 2024.

This trial’s clinical data builds on a prior Phase 2 RC110 bisantrene monotherapy clinical study in patients with R/R AML1 and together they are highly supportive of future AML clinical studies using bisantrene.

The investigator’s intention was to enrol two more participants in the trial, but due to the prevailing security situation in Israel and the achievement of the prespecified efficacy endpoint, it was determined by the researchers to conclude the study.

RAC CEO Dr Daniel Tillett said the Sheba team’s dedication and commitment has added to the strong historical evidence of bisantrene’s efficacy in treating patients with AML and has stimulated further clinician interest in taking the drug forward in new AML trials.

“We extend our gratitude to all patients and their families whose participation make the development of new AML treatments such as bisantrene possible,” he said.

“Race has plans to support a new Phase 1/2 investigator-sponsored AML clinical study using RC220 bisantrene and will provide an update as soon as all relevant contracts are concluded.”

 

This article was developed in collaboration with Race Oncology, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.