Percheron Therapeutics completes toxicology study for avicursen ahead of US FDA discussions

Australian biotechnology company Percheron Therapeutics (ASX: PER) has completed a nine-month toxicology study in non-human primates for its lead program, avicursen.

Avicursen is an antisense oligonucleotide that targets the CD49d biomarker.

The study, which commenced in March 2023, concluded its final dosing on schedule in December.

Recovery phase

The majority of subjects in the study underwent pathological examination after being dosed, while the remainder then entered a six-month recovery phase during which avicursen was not administered.

The recovery phase aimed to establish that any observations seen during the dosing phase of the study had reversed once treatment had ceased.

It concluded in June, after which the recovery animals also underwent pathological examination.

The results of the study remained broadly consistent with an earlier six-month study, with no deaths, no new or unexpected toxicities observed and expected low-grade findings fully reversible during the recovery period.

Key requirement

Chief executive officer Dr James Garner said the toxicology study was a key regulatory requirement to enable Percheron to conduct future clinical trials and commercialisation activities in the US.

“We are very pleased to have this important piece of work completed on schedule,” he said.

“The results seem to be consistent with earlier observations, which we expect will have positive implications for the future development of avicursen.”

Dr Garner said the company would await pending clinical data from a recent Phase IIb clinical trial of avicursen before commencing regulatory discussions with the US Food and Drug Administration in the new year.

“We want to be able to present the agency with the strongest possible package of data, with a view to enabling the conduct of future clinical trials and supporting a potential product approval in that market,” he said.

Ongoing trial

Administration of avicursen has been shown to reduce CD49d-positive lymphocytes and exert an immunomodulatory effect that is potentially therapeutic in a range of inflammatory diseases.

The drug is currently the subject of an ongoing international Phase IIb randomised controlled trial in non-ambulant boys with Duchenne muscular dystrophy, which builds on an earlier study that showed promising signals of activity.

Initial data is expected before the year’s end.