Samumed’s Candidate PF Therapy, SM04646, Found to Be Well-tolerated and Safe in Phase 1 Trial

Samumed’s nebulized inhalation solution SM04646, a candidate therapy to treat idiopathic pulmonary fibrosis (IPF), was found to be well-tolerated and to cause no serious adverse effects in a Phase 1 trial of healthy individuals in Australia.

These results support the launch of future clinical trials to test the drug’s efficacy in IPF patients.

According to San Diego-based Samumed, previous studies have shown that aerosolized SM04646 can reduce fibrosis-like changes in the lungs, compared to control treatment, in an animal model of lung fibrosis. The drug was also shown to have higher antifibrotic activity than Esbriet (pirfenidone) and Ofev (nintedanib) — two approved therapies for IPF — in both normal and IPF-diseased human lung cells.

SM04646 is believed to exert its beneficial effects by decreasing the expression of fibrotic genes.

The Australian Phase 1 trial (ACTRN12615001349538) enrolled 17 healthy subjects, aged 18 to 50 years, to study the safety and tolerability of four increasing doses of SM04646, and also to identify the drug’s maximum tolerated dose. This was the first time SM04646 was given to humans, after showing promising results in cells and in animal models.

Researchers evaluated its safety according to the incidence and severity of adverse effects induced by treatment, as well as changes in clinical laboratory analyses, vital signs, oxygen saturation levels, spirometry results (a test assessing lung function) and electrocardiograms.

Initially, only one subject was given SM04646 and followed for at least seven days, so that researchers could assess the drug’s effects before dosing other subjects. The team then divided the trial’s participants in four groups, one for each SM04646 dose: 0.7 mg, 2.0 mg, 7.0 mg and 20.0 mg.

Participants received a single inhalation of the drug for 10 minutes on day 1 and were observed for a total of 90 days. Those who were unable to tolerate and complete nebulization for 10 minutes without significant coughing were excluded.

The analysis showed that treatment with inhaled SM04646 induced no serious adverse effects, and that all doses tested were well-tolerated and safe.

Further details from the trial’s results, including information on how the body absorbs, distributes and removes the drug from the body, will be released at future medical conferences.