At low doses, the drug, called S-PAC-1, stunted tumor growth in three of six dogs tested and induced partial remission in a fourth. The results appear in this month's issue of Cancer Research.
The compound targets the procaspase-3 enzyme, which, when activated, emits a barrage of reactions that kill the cell, according to chemistry professor Paul Hergenrother, who co-led the study with Dr. Tim Fan, a professor of veterinary clinical medicine at the University of Illinois. According to Hergenrother, many tumors—including those found in lymphoma, lung cancer and breast cancer—contain high levels of procaspase-3.
If approved by the FDA as an effective and safe lymphoma treatment, S-PAC-1 could help fight cancer in both dogs and humans—though the approval process could take years, the researchers say. The drug showed mild side effects during the trials, and these effects were minimized or eliminated with recent adjustments to the treatment protocol, the researchers say.
What's next? A clinical trial of S=PAC-1 in companion animal dogs is being supported by a $525,000 grant from the National Cancer Institute at the National Institutes of Health.