With a $35 million Series B financing in hand, BiPar Sciences Inc. expects to generate Phase II data with lead product candidate BSI-201, advance a second compound into the clinic and get a third product through IND filing.

All of that should take about two to two-and-a-half years, according to president, CEO and co-founder Thomas White.

The $35 million Series B financing follows a $5 million venture-debt financing in June 2006 and a $13 million Series A in November 2004. New investor Domain Associates LLC served as the lead for the B round, with participation from all existing investors including Vulcan Capital, Canaan Partners, PolyTechnos Venture-Partners, Asset Management Co. and Quantum Technology Partners.

When searching for an investor to lead the round, White said a top priority was finding a group that would maintain the strong chemistry between the existing director team and investor syndicate. He also noted that Domain is "always interested in novel spaces where there is a significant commercial opportunity," such as with PARP inhibitors.

PARP, or poly-ADP-ribose polymerase, is an enzyme involved in cell repair, proliferation and signaling that is up-regulated in certain tumors and may contribute to chemotherapy resistance. Outside of the cancer space, PARP inhibitors block necrosis and inflammation, which may allow them to be utilized in cardiopulmonary bypass, myocardial infarction with angioplasty, ischemia/reperfusion diseases and inflammatory diseases.

So far, the few players in the PARP field have attracted significant partnering interest. Inotek Pharmaceuticals Corp. inked a $600 million deal last year with Genentech Inc., of South San Francisco, for its Phase II PARP inhibitor program in oncology with an option on cardiovascular indications. KuDOS Pharmaceuticals Ltd., which had a Phase I PARP inhibitor, was acquired by AstraZeneca plc for $210 million in late 2005. And Guilford Pharmaceuticals Inc., which was acquired by MGI Pharmaceuticals Inc. for $177.5 million in mid 2005, had among its many other assets a preclinical PARP program. (See BioWorld Today, Jul. 22, 2005, and Jul. 25, 2006.)

Regarding partnerships, White said Brisbane, Calif.-based BiPar "will make that decision when we have Phase II data." He pointed out that BiPar's PARP inhibitors are "radically different" from those of its competitors and that BSI-201 may work as a monotherapy, while most PARP programs in cancer are combination treatments.

BSI-201 is a novel, proprietary, small-molecule prodrug that potently inhibits PARP. It is being studied as a monotherapy in an open-label, dose-escalating Phase I trial in various types of cancer, and White said the data so far are "very encouraging." Last month, BiPar started a Phase Ib study of the drug in combination with four different cytotoxic regimens. That trial should complete enrollment by the end of the year. (See BioWorld Today, March 8, 2006.) In preclinical studies, BSI-201 has demonstrated tumor remission in vivo as well as in vitro efficacy in a wide range of tumor cells, including drug-resistant lines and primary human tumor lines.

Behind BSI-201 are BSI-401 and the BSI-300 series of compounds. BSI-401 is a PARP inhibitor with a different mechanism of action that may be applicable in treating prostate cancer. The BSI-300 series of compounds are iodothyronines, which target thyroid hormones and have shown antitumor activity against multiple cancers in preclinical studies. The decision regarding which program to move into the clinic next will not be made until later this year.