Taiwanese biopharmaceutical company OBI Pharma acquired Threshold Pharmaceuticals’ preclinical-stage anticancer prodrug TH-3424 for an undisclosed, one-time up-front payment. The small-molecule prodrug, renamed OBI-3424, is designed to release a DNA alkylating agent only in cancers that overexpress the activating enzyme aldo-keto reductase 1C3 (AKR1C3).
Threshold will transfer to OBI Pharma ownership rights to OBI-3424, together with preclinical and manufacturing data and global IP. OBI Pharma retains development, commercialization, and manufacturing rights to the drug globally, except for China, Hong Kong, Macao, Taiwan, Japan, South Korea, Singapore, Malaysia, Thailand, Turkey, and India.
“AKR1C3 is highly overexpressed in a number of cancers that represent unmet medical needs, including hepatocellular carcinoma, castrate-resistant prostate cancer, and T-cell acute lymphoblastic leukemia,” said Tillman Pearce, M.D., Threshold’s CMO. “OBI-3424 offers the possibility of early efficacy readouts based on objective response rates in well-defined resistant patient populations.”
OBI Pharma will continue preclinical development of OBI-3424 and projects filing an IND with the FDA during early 2018. Preclinical development to date has demonstrated potent activity in preclinical models of hepatocellular carcinoma (HCC), including an HCC model that is resistant to sorafenib, OBI claims. The firm also aims to assess OBI-3424 in castrate-resistant prostate cancers, a tumor type in which AKR1C3 is upregulated as an adaptive response to castration.
The U.S. National Cancer Institute (NCI) is also carrying out preclinical evaluation of OBI-3424 as a potential treatment for T-cell acute lymphoblastic leukemia (T-ALL) through a collaboration agreement with Threshold signed in December 2016.
“We will continue the preclinical work and hope that OBI-3424 develops into a solid treatment option for patients with cancers that express AKR1C3,” commented Amy Huang, general manager at OBI Pharma. “This novel cancer therapeutic enhances our pipeline and moves us another step toward becoming a global cancer biopharma company.”
OBI Pharma is developing a clinical and preclinical pipeline of immunotherapies for hard-to-treat cancers. Lead candidate OBI-822 is a first-in-class active immunotherapy, licensed from the Memorial Sloan Kettering Cancer Center, which is undergoing Phase II/III evaluation in patients with metastatic breast cancer and is also in Phase II development for breast cancer.