The trial aims to demonstrate that PXS‐5505, the lead asset in Pharmaxis’ drug discovery pipeline, is safe and effective as a monotherapy in myelofibrosis patients, who are intolerant, unresponsive or ineligible for treatment with approved JAK inhibitor drugs.
The phase 1c/2a trial has been cleared by the US Food and Drug Administration (FDA) under the Investigational New Drug (IND) scheme.
High level of unmet need in myelofibrosis
Pharmaxis chief executive officer Gary Phillips said: “PXS‐5505 has demonstrated good tolerability and highly effective inhibition of the enzyme in phase 1 studies.
“Its potential to modify the course of the disease by directly targeting bone marrow fibrosis will make PXS‐5505 an ideal monotherapy or adjunct to approved therapies in this indication.
“There remains a high level of unmet need in myelofibrosis and many other drugs in development have challenging side effect profiles.”
Recruit up to 18 patients
Pharmaxis has completed site initiation at several Australian and South Korean hospitals.
The dose escalation phase of the study that aims to select the optimum dose of PXS‐5505, will recruit up to 18 patients.
This phase is expected to conclude and report in the second half of 2021, followed by a six‐month dose expansion phase (24 patients) to evaluate safety and efficacy.
Sites in other countries including the US will be added for the dose expansion phase.
PXS‐5505 is an orally taken drug that inhibits the lysyl oxidase family of enzymes.
In pre‐clinical models of myelofibrosis, PXS‐5505 reversed the bone marrow fibrosis that drives morbidity and mortality in myelofibrosis and reduced many of the abnormalities associated with this disease.
While Pharmaxis’ primary focus is the development of PXS‐5505 for myelofibrosis, the drug also has potential in several other cancers, including liver and pancreatic cancer, where it aims to breakdown the fibrotic tissue in the tumour and enhance the effect of chemotherapy treatment.