The completed Phase 2 clinical study evaluating ProMetic’s PBI-4050 in people with idiopathic pulmonary fibrosis (IPF) demonstrated positive trial results of the drug’s effectiveness and tolerability as a monotherapy and in combination with Ofev (nintedanib) or Esbriet (pirfenidone).

The study confirms preliminary results reported in November 2016 by ProMetic Life Sciences, the developer of the experimental drug PBI-4050.

The single-arm Phase 2 trial (NCT02538536) enrolled 40 IPF patients at six different locations in Canada. All participants completed the 12 weeks of treatment — nine participants received PBI-4050 alone; 16 patients (Combi-1) received a combination of the drug candidate and Ofev; and 15 patients (Combi-2) were administered a combination of PBI-4050 and Esbriet.

The profile of the study’s participants is similar to that of the patients enrolled in previous IPF studies, such as the ASCEND (NCT01366209) trial testing Esbriet, or INPULSIS (NCT03047031) testing Ofev.

IPF patients typically experience a progressive decline in respiratory function. In the ProMetic study, the respiratory function of the participants, measured through forced vital capacity (FVC), remained stabilized after 12 weeks of treatment for patients in Combi-1, and was superior to that of participants in Combi-2.

“PBI-4050, either used alone or in Combi-1, demonstrated very promising early indications of efficacy, considering that current drugs approved for IPF only slow (but do not reverse) the decline in lung respiratory function,” John Moran, ProMetic’s chief medical officer, said in a press release.

“It is also important to note that during our clinical trial, there were no deaths, nor did we see any subjects experiencing a decrease in FVC of 10 [percent] or more, contrary to the outcomes in the other IPF trials,” he said.

Moran added there were no serious adverse events requiring PBI-4050’s discontinuation, and the most frequent adverse event seen in all groups was diarrhea, “but this was clearly much less significant in the subjects treated with PBI-4050 alone than in the groups receiving either of the currently approved drugs for the treatment of IPF, which are well-known for their significant side effect profiles,” he said.

PBI-4050 is an oral drug with an excellent safety and effectiveness profile confirmed in a series of in vivo experiments targeting fibrosis, a process leading to the formation of scar tissue.

The proof-of-concept body of evidence generated to date confirms PBI-4050’s anti-fibrotic activity in the kidneys, heart, lungs and the liver.

Pierre Laurin, ProMetic’s president and CEO, said these results support the basis and study design for the Phase 2/3 IPF clinical trial the company expects to begin in the second quarter of this year.

“We expect to see PBI-4050, alone or in combination with one of the commercially approved IPF drugs, continue to outperform the current drugs in terms of efficacy, safety and tolerability,” Laurin said.