Six months after in-licensing its first cancer product, FK228, Gloucester Pharmaceuticals Inc. plans to start a pivotal trial of the drug with the proceeds from a $29 million Series B financing.

"It's a really critical point in the company's life cycle," said Jay Mohr, Gloucester's president and CEO. "In terms of where we go and the milestones we see in front of us, the primary use of this capital will be to fund a pivotal trial of FK228. This will carry us through and beyond the NDA submission and up to the NDA approval process."

That could happen as soon as 2006, if the pivotal trial in cutaneous T-cell lymphoma (CTCL) is completed in the first half of the year, as expected. The company intends to start the pivotal trial - either a Phase IIb or a Phase III - within the next few months. Gloucester is talking with the FDA to determine the trial design.

"It's probably safe to say that given this is a disease of high unmet medical need, and it's a type of lymphoma that is less common, more likely it will be a Phase IIb trial in its design," Mohr told BioWorld Today.

Earlier this week, Cambridge, Mass.-based Gloucester received fast-track designation for FK228 in CTCL patients who have relapsed following one other systemic therapy, or those who have become refractory to the therapy. The designation means the company can submit a rolling new drug application for FK228 and could receive a priority review of six months.

Mohr said the market potential for FK228 in CTCL is in the range of "triple-digit millions of dollars" in the U.S. and in Europe.

FK228 (depsipeptide) is in multiple clinical trials to treat hematologic and solid cancers. It is a histone deacetylase inhibitor and the only bicyclic peptide in its group. It is in Phase II studies for CTCL, as well as for renal-cell carcinoma and hormone-refractory prostate cancer.

"FK228 at this point - and it's very difficult to always have a crystal ball on what the competition is doing - but at this point, we believe it's the most advanced HDAC inhibitor today," Mohr said.

Preclinical studies performed by Osaka, Japan-based Fujisawa Pharmaceutical Co. Ltd., the National Cancer Institute and others, have shown that the inhibition of histone deacetylation caused cell-cycle arrest, differentiation and apoptotic cell death in cancer cells of various types. Phase II data of FK228 reported at the American Society of Clinical Oncology annual meeting in June showed an overall response rate of 50 percent in patients with CTCL. In peripheral T-cell lymphoma, the overall response rate was 25 percent.

Gloucester acquired the rights to FK228 from Fujisawa in April under an exclusive, worldwide license agreement. (See BioWorld Today, April 16, 2004.)

Founded in 2003 to develop and commercialize innovative products to treat cancer, Gloucester plans to in-license additional cancer products in the future, but initially will focus on the pivotal trial for FK228.

"Our goal is in the next 12 months to ensure that our pivotal trial is well under way and on target," Mohr said. "We will continue to look very selectively for other in-licensing candidates."

Once FK228 gets further along in the clinic, Gloucester will decide whether to select a marketing partner or to commercialize the drug itself, Mohr said.

Palo Alto, Calif.-based Prospect Venture Partners, San Diego-based ProQuest Investments and New York-based Rho Ventures led the Series B financing. CIBC Capital Partners and founding investor Apple Tree Partners, both of New York, also participated. As part of the financing agreement, David Schnell of Prospect Venture Partners and Jay Moorin of ProQuest will join Gloucester's board.

Apple Tree Partners was the sole investor in the company's Series A financing, which raised an undisclosed amount.

"It's great to have the support of leading venture groups," Mohr said. "And we look forward to bringing more data [on FK228] out to the public as it becomes available."