Proteolix presents positive preclinical data of antitumor drug

According to Proteolix, PR-047 is the first oral compound in a new class of highly specific proteasome inhibitors. PR-047 was designed by Proteolix scientists to combine the pharmacological properties of carfilzomib with the convenience of oral dosing.

Researchers have evaluated PR-047’s mechanism, bioavailability and activity in a series of preclinical studies. Like carfilzomib, PR-047 was shown to target the chymotrypsin-like activity of the proteasome and induce tumor cell death across multiple human cell lines. Oral administration of PR-047 in rodents and monkeys resulted in rapid and prolonged dose-dependent inhibition of the proteasome, the company said.

Significant proteasome inhibition was reportedly achieved at doses well below the maximum-tolerated dose even when administered over five consecutive days, suggesting that repeated daily dosing may be feasible with this molecule. Administration of PR-047 resulted in consistent anti-tumor responses in hematological and solid tumor xenograft models at doses below the maximum-tolerated dose.

Mark Bennett, vice president of research at Proteolix, said: “We are pleased by the preclinical data achieved to date with PR-047, which demonstrates a promising combination of proteasome inhibition, anti-tumor activity, bioavailability and tolerability.

“An effective and tolerable oral proteasome inhibitor would have the potential to provide the clinical benefits of intravenous proteasome inhibitors with added patient convenience and dosing flexibility. With these positive preclinical results in hand, we look forward to advancing PR-047 into clinical trials.”