Pharmaxis Ltd (ASX:PXS) has dosed its first patient under its phase two bone marrow cancer trial.
The clinical-stage drug development company is trialling its lead drug candidate — PXS-5505 — and has already undertaken a phase one dosing escalation clinical study.
This phase two trial follows clearance from the Food and Drug Administration under the Investigational New Drug scheme, which allows clinical trials on patients with myelofibrosis — an uncommon type of bone marrow cancer — to commence.
Ultimately, an effective treatment candidate for this kind of cancer could open a market that’s conservatively estimated at US$1 billion per annum.
“Rapid start” to next stage
Pharmaxis CEO Gary Phillips said: “The first patients entering the phase 2 study were participants in the just-completed phase 1c dose-escalation study.
“We are pleased that these participants want to continue on PXS-5505, allowing us a rapid start to the next stage of the clinical trial.
“Having shown that the drug has a good tolerability profile at a dose which can fully inhibit all the family of lysyl oxidase (LOX) enzymes that are implicated in myelofibrosis, we are confident of being able to assess the impact of this mechanism of action in the upcoming study.
“The trial infrastructure and funding is in place and we are on track to complete the study by the end of 2022.”
Trial advances
Pharmaxis analysed the data from its phase 1c trial, which focused on dose escalation, and reported positive results earlier this month.
Specifically, at the highest dose, the drug candidate inhibited the two target LOX enzymes at greater than 90% over a 24-hour period at day seven and day 28.
Those enzymes are implicated in myelofibrosis’ progression, so a treatment candidate that inhibits their signalling could be disease-modifying.
On October 5, Phillips said: “We are very pleased to have completed the dose-escalation phase of this study with such clear and positive findings.
“We will now immediately progress to the phase two dose-expansion study where we aim to show PXS-5505 is safe to be taken longer-term with the disease-modifying effects that we have seen in the pre-clinical models."