The US FDA has granted orphan drug designation to Oxigene's lead vascular disrupting agent, Combretastatin A4P (CA4P), for the treatment of ovarian cancer.

CA4P is being evaluated in a phase II clinical trial in combination with the widely used chemotherapy regimen, carboplatin and paclitaxel, for the treatment of platinum resistant ovarian cancer. Results previously reported from a phase Ib clinical trial showed a 67% response rate to the combined CA4P-chemotherapy treatment among women with advanced ovarian cancer (all types) who failed previous cancer therapy.

"United States orphan drug designation for ovarian cancer is a significant achievement for Oxigene; a milestone that we believe may provide a market advantage as we advance CA4P as a treatment under development in this key indication," commented Frederick Driscoll, president and CEO of Oxigene. "We believe that this designation further validates CA4P's clinical potential and we are optimistic about one day delivering a therapeutic treatment for an unmet medical need in ovarian cancer," he added.

In a subset of patients with all types of ovarian cancer, tumour response, as defined according to RECIST or CA125, was observed in 10 out of 15 evaluable patients. Two of the responses occurred in women who were deemed platinum resistant and who had failed carboplatin and/or paclitaxel therapy within the previous six months. Investigators also noted that no unexpected toxicities were observed above those typically observed from treatment with carboplatin or paclitaxel alone. Investigators reported that side effects were mild and self-limiting and no cardiac toxicity had occurred in patients.

Oxigene received orphan drug indication in 2003 for CA4P for the treatment of anaplastic thyroid cancer (ATC), as well as medullary, stage IV papillary and stage IV follicular thyroid cancers. In July 2004, the European Agency for the Evaluation of Medicinal Products (EMEA) awarded Oxigene the orphan medicinal product designation for CA4P as a treatment for anaplastic thyroid cancer (ATC). CA4P is currently being investigated in a phase II clinical trial for the treatment of advanced and regional ATC and a phase I/II trial in newly diagnosed ATC.