Prescient Therapeutics (ASX:PTX) has announced that its Phase 1b clinical study of PTX-200 and cytarabine in patients with relapsed and refractory acute myeloid leukemia (AML) will expand the cohort at 45 mg/m2 PTX-200 following another complete remission and no dose-limiting toxicities at this dose level.
The company said three patients were treated at 45 mg/m2 PTX-200 together with cytarabine, with no dose-limiting toxicities reported.
"One patient in the cohort achieved a CRi, meaning complete remission of disease, with neutrophils and/or platelets yet recover to normal levels," said the company.
"CR (complete remission) and CRi are typically ascribed the same predictive value of successful treatment outcome. This latest patient brings the total of complete remissions on this study to four patients. Additionally, one patient in the prior cohort at 35mg/m2 PTX-200 has been determined to have had a partial response (reduction in cancer burden)."
AML is a cancer of the bone marrow that prevents the formation of normal blood cells. It progresses quickly and has poor survival rates. After initial chemotherapy, most patients relapse, leading to an ongoing unmet medical need.
The study's principal Investigator Professor Jeffrey Lancet said, "It is encouraging to see a CRi at this dose level, which brings a total of four complete remissions on the study so far. It was also pleasing to see that this dose level was well tolerated by patients, with no reported dose-limiting toxicities. It is believed that 45mg/m2 may be a biologically effective dose of PTX-200, therefore we will recruit an additional three patients at this dose level to further investigate safety and efficacy in this fragile patient population."
Prescient CEO and managing director Steven Yatomi-Clarke added, "It is very satisfying to see another patient with remission in a disease that is so aggressive and fatal. Despite recent advancements, AML remains a disease of unmet medical need, and we look forward to advancing this study with the aim of benefiting more AML patients."
