Topical pan-LOX Inhibitor (PXS-6302)

Pharmaxis is developing a topical drug inhibiting all lysyl oxidase family members with potential anti-fibrotic application in severe fibrotic related scarring indications. Skin scarring after events such as accidents, surgery or burns place a substantial physical and psychological burden on patients and there is a need for effective new treatments. 

The Pharmaxis discovery, known as PXS-6302, has shown promising clinical results in inhibiting the enzymes that play a critical role in the development of scar tissue. PXS-6302 was discovered by the Pharmaxis research team at the company’s Frenchs Forest laboratories. The project was awarded initial National Health and Medical Research Council (NHMRC) funding for some of the pre-clinical development work done in collaboration with UWA’s Dr Mark Fear.

The program commenced an independent investigator phase 1 clinical trial in the first quarter of 2021. Read the announcement here

Distinguished surgeon and burns expert Professor Fiona Wood AM is leading a group of researchers from UWA and Fiona Stanley Hospital to test the treatment in world first human trials.

Professor Fiona Wood said, “It’s exciting for the research team to explore a novel path to reduce scarring and to be moving closer to that goal. Scar-less healing is the vision that has motivated our work over many decades.”

Dr Kylie Sandy-Hodgetts, Senior Research Fellow at the School of Biomedical Sciences, UWA, said, “Current treatments aim to rectify the scar in the acute phase such as during wound healing and scar maturation through options such as compression therapy, silicone gel sheeting or when the scar is established by cryotherapy, scar revision or laser with limited outcomes at times.”

“This new compound may potentially avoid the need for invasive procedures such as further surgery or laser procedures. What we’re hoping is that this new cream may have the potential to improve scar outcomes in patients following surgery,” Dr Sandy-Hodgetts said.

Watch a presentation by Professor Fiona Wood (UWA) here and Dr Mark Fear (UWA) here at our R&D Showcase Webinar in March on these clinical programs and the science behind them.

In September 2022, Pharmaxis announced positive interim data from the clinical trial with 8 patients treated for up to 3 months on active drug. Read the announcement here.

In addition, UWA researchers published the pre-clinical studies performed in collaboration with Pharmaxis in Nature Communications showing topically applied Pharmaxis pan-LOX inhibitors reduce collagen deposition and cross-linking and improve scar appearance without reducing tissue strength.

In May 2023 Pharmaxis announced the phase 1c trial of PXS-6302 had met its primary safety objective and two secondary biomarker endpoints in patients with established scars. 42 Australian patients with any type of scar older than 1 year and at least 10cm2 in size were recruited in the double‐blind three‐month study and applied either PXS‐6302 or placebo cream three times a week.

Applications of PXS‐6302 cream resulted in a mean 66% reduction in LOX activity when measured 2 days after the last dose (p<0.001) compared to baseline and to placebo group. LOX is responsible for the cross linking of collagen fibres implicated in adverse scarring. Professor Wood commented, “This exploratory clinical study has significantly enhanced our understanding of the role of LOX enzymes in scarring and the scar process itself.  PXS‐6302 safely inhibits these key enzymes to a significant degree and leads directly to an unprecedented change to the scar composition that we have not seen with any other form of treatment.  We estimate that up to 50% of the excess collagen in these patients’ scars has been removed and while the length of this Phase 1c safety study was not sufficient to change the appearance of an established scar the remodelling process will be ongoing and I’m confident we would see an improvement in scar appearance and physical characteristics if we observed them for longer.

“The collected data also bodes well for studying the effect of LOX inhibition on the prevention of scars after surgery and in younger scars where the remodelling process is more aggressive and probably more sensitive to intervention with a LOX inhibitor.  This work is a particular passion of mine and I am looking forward to extending our collaboration with Pharmaxis for future studies.” 

Read the announcement here 

Wound and Burns Scars

Phase I
Description Phase 1a Healthy Volunteers
Sites University of Western Australia and Fiona Stanley Hospital
Subjects 10
Status Complete
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Phase I
Description Phase 1c Established Scar Study
Sites University of Western Australia and Fiona Stanley Hospital
Subjects 50
Status In progress
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