TUCSON, Ariz.—ProlX Pharmaceuticals recently announced that the National Institutes of Health (NIH) awarded the company four SBIR grants totaling more than $1.2 million and covering preclinical work on four promising drug candidates.
The grants support ProlX's lead drug candidate, the thioredoxin-1 (Trx-1) inhibitor PX-12, as well as the hypoxia-inducible factor (HIF) inhibitor PX-478, the PI3-kinase inhibitor PX-866 and an early-stage thioredoxin reductase inhibitor (redox inhibitor).
Although ProlX considers PX-12 its lead compound, that grant was the second-largest of the bunch at approximately $200,000, representing a second year of NIH funding for work on the compound. The largest of the four grants, at $650,000, was for the HIF inhibitor and is the last year of a four-year grant cycle for that drug.
The other two grants are new grants, with approximately $195,000 going to the redox inhibitor work and roughly $190,000 to the PI3 kinase inhibitor.
ProlX holds great hope for PX-12 because of its potential for chemoprevention of cancer by inhibiting Trx-1—a protein that stimulates tumor growth and is over-expressed in a wide variety of human tumors including colon, gastric and pancreatic cancer. The compound has already completed a Phase I trial for the treatment of end-stage metastatic cancer but the funding allows ProlX to go back and pinpoint the drug's efficacy for prevention of tumors in people at risk and for early-stage treatment.
"Our preliminary data suggests that PX-12 may provide an effective agent for the prevention as well as aid in the therapy of human colon cancer," says Dr. D. Lynn Kirkpatrick, CEO and co-founder of ProlX. "This SBIR award will provide additional resources to study PX-12 in this critical area of colon cancer prevention for the patient population that may be genetically predisposed to the disease."
As for PX-478, the award is so much larger than the others, Kirkpatrick says, because it is intended to help bring the HIF inhibitor from the discovery stage into the "translational" work that will move it into clinical trials.
Good candidates for treatment with PX-478 are lung cancer, ovarian and some prostate cancers. Renal and head and neck cancers are also promising areas for treatment.
"PX-866, our PI3-kinase inhibitor, is in preclinical IND-defining studies," she adds. "It shows excellent anti-tumor activity but also shows good synergistic activity with agents like Avastin and Iressa, and synergy is something we're very interested in with these newer targeted agents."
The last compound under the SBIR funding is the redox inhibitor, which Kirkpatrick says has done well during in vitro studies. "This award will let us expand our studies to see how broad its activity is across animal models and to look more at the drug's pharmacokinetics."
