Sunshine Biopharma Inc. (NASDAQ: SBFM) announced it has advanced its lead coronavirus drug candidate into investigational new drug (IND)-enabling studies, according to a company press release.

The drug candidate, a PLpro protease inhibitor, demonstrated nanomolar potency against the viral protease and broad-spectrum activity against SARS-CoV-2 variants in vitro. In animal studies using K18-hACE2 mice infected with human SARS-CoV-2, repeated oral doses of the compound produced dose-dependent suppression of pulmonary viral replication.

The compound showed high oral bioavailability in mice, rats, and dogs, and was preferentially enriched in lung tissue in both mice and rats. The company also conducted a general mammalian toxicology study in rats.

Sunshine Biopharma previously published laboratory results on its anti-coronavirus compound library in the Journal of Medicinal Chemistry in August 2024 and March 2026.

"Advancing our potent PLpro inhibitor is a strategically significant development for Sunshine Biopharma and a clear validation of the discovery infrastructure we've built," said Dr. Steve Slilaty, CEO of Sunshine Biopharma.

The Fort Lauderdale-based company currently markets 60 generic prescription drugs in Canada and has approximately 12 additional drugs scheduled for launch in the remainder of 2026. Its proprietary drug development pipeline also includes K1.1 mRNA, an mRNA-lipid nanoparticle candidate targeting liver cancer.