Clinuvel Pharmaceuticals (ASX:CUV) said preliminary results from its second clinical study investigating its afamelanotide drug candidate as a treatment for arterial ischaemic stroke were positive, according to a Wednesday Australian bourse filing.

The CUV803 study enrolled nine adult patients with mild, moderate, and moderate-to-severe arterial ischaemic stroke, which is caused by a clot blocking blood supply to the brain, as measured by the National Institutes of Health Stroke Scale (NIHSS), at two European specialist stroke treatment units. They were administered afamelanotide daily for up to five days.

The drug candidate was shown to be well tolerated by all nine participants, and all treatment-related adverse events were mild, transient, and consistent with the established safety profile for afamelanotide, per the filing. The study's primary endpoint was to evaluate the drug's safety.

Two of the three patients with moderate-to-severe stroke passed away due to complications unrelated to the treatment.

By day 42 of the study, eight out of nine patients demonstrated an improvement in initial stroke symptoms and neurological disability following treatment with the candidate, as measured by reduced NIHSS and functional disability scores, as measured by the modified Rankin scale.

A review of the data for afamelanotide globally showed that thirteen of the arterial ischaemic stroke patients treated with it demonstrated functional improvement, while ten showed a reduction or stabilization of infarct size up to 42 days after treatment.

The firm's shares rose past 3% in early trading on Wednesday.