Less than a year after launching its cancer drug Abraxane in the U.S., American BioScience Inc. signed a deal potentially worth more than $50 million to license rights to the product in Japan.

The Santa Monica, Calif.-based company agreed to grant rights to Taiho Pharmaceuticals Co. Ltd., of Tokyo, for the development and commercialization of Abraxane in Japan to treat breast, lung, gastric and other solid tumor cancers. As part of the agreement, ABI and Taiho set up a joint steering committee to oversee the clinical work on Abraxane.

In exchange for Abraxane rights, Taiho agreed to pay ABI up-front and milestone payments exceeding $50 million, plus "substantial" royalties on any product sales. ABI will supply the drug to the Japanese market.

The company could not be reached for comment Wednesday, but estimates reported by ABI put annual sales of chemotherapy agents, including taxanes, in Japan around $3 billion. If approved there, Abraxane could succeed in garnering a significant portion of that market due to its safety profile and higher dosing capabilities.

Abraxane, described as paclitaxel protein-bound particles for injectable suspension, was developed by ABI using its nanoparticle albumin-bound (NAB) technology. It combines paclitaxel with the natural protein albumin, and then is formulated into a nanoparticle one-hundredth the size of a red blood cell. This administration allows for higher dosing levels because it eliminates the need for a toxicity-causing solvent. Before Abraxane hit the market, all taxanes required the use of solvents for administration, and these solvents increased the risk of hypersensitivity reactions and severe myelosuppression, and also could minimize antitumor activity by trapping the paclitaxel compound in the bloodstream.

The FDA approved Abraxane in January for the treatment of breast cancer in patients who have failed combination therapy for metastatic disease or who relapse within six months of adjuvant chemotherapy. The product is manufactured and marketed by American Pharmaceutical Partners Inc., of Schaumburg, Ill., a majority-owned subsidiary of ABI that specializes in injectable oncology drugs, mostly generics. (See BioWorld Today, Jan. 11, 2005.)

APP launched Abraxane in February and has recorded U.S. sales of $86.3 million through Sept. 30.

Earlier this year, ABI submitted a new drug application seeking approval in Canada for the treatment of metastatic breast cancer. The company also has said it plans to file for approval in Europe as well.

Meanwhile, ABI and APP are looking to expand the use of Abraxane. A number of studies are ongoing in breast, lung, ovarian, head and neck and melanoma cancers. These include a Phase II trial of dose dense Abraxane given as an adjuvant therapy following Adriamycin plus Cytoxan in early stage breast cancer. That trial recently completed patient accrual and is evaluating the safety of Adriamycin plus Cytoxan given every two weeks for four cycles, followed by 260 mg/m² of Abraxane administered in a dose dense regimen, every two weeks for four cycles.

Another Phase II study is testing Abraxane administered weekly with South San Francisco-based Genentech Inc.'s Herceptin as a first-line treatment of metastatic breast cancer. The primary endpoint of the trial is response rate, and secondary endpoints are designed to evaluate time to tumor progression, overall survival and toxicities.

Shares of APP (NASDAQ:APPX) lost 11 cents Wednesday to close at $45.44.