PXS-5505 shows good tolerability and >90% inhibition of target enzymes LOX and LOXL2 in myelofibrosis phase 1c dose escalation study
Assessment with Pharmaxis’ proprietary assays of the highest dose has shown inhibition of the target enzymes, LOX and LOXL2, at greater than 90% over a 24-hour period at day 7 and day 28. The trial safety committee has reviewed the results and having identified no safety signals, has cleared the study to progress to the phase 2 dose expansion phase where 24 patients will be treated at the highest dose twice a day for 6 months.
Pharmaxis CEO Gary 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 2 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. The trial infrastructure and funding is in place and we are on track to complete the study by the end of 2022.”
Independent, peer-reviewed research has demonstrated the upregulation of several lysyl oxidase family members in myelofibrosis. The level of inhibition of LOX achieved in the current study at all three doses significantly exceeds levels that caused disease modifying effects with PXS-5505 in pre-clinical models of myelofibrosis with improvements in blood cell count, diminished spleen size and reduced bone marrow fibrosis. LOXL2 was inhibited to a similar degree and based on pre-clinical work such high inhibition is likely replicated for other LOX family members (LOXL1, 3 and 4). [1] Study data can be viewed in the full announcement.