Threshold Pharmaceuticals, Inc. , a clinical-stage biopharmaceutical company developing novel therapies for cancer, today announced that it has entered into a collaboration with the National Cancer Institute , part of the National Institutes of Health , to study TH-3424, the company’s new drug candidate for the treatment of cancer. The collaboration will explore the effects of TH-3424 against T-cell acute lymphoblastic leukemia xenograft cell lines with high AKR1C3 expression.