Phase III For Progenics' Cancer Vaccine

Progenics Pharmaceuticals has initiated a National Cancer Institute-sponsored pivotal Phase III clinical trial with its flagship product, GMK, a cancer vaccine for the prevention of relapse in melanoma.

The study is in the process of enrolling patients, and will be conducted at hundreds of cancer centers throughout the USA, enlisting the help of the NCI's Eastern Cooperative Oncology Group and the Southwest Oncology Group, among other foundations. Patients who have stage IIB and III disease, and who have undergone surgical removal of the diseased tissue, but are at risk from relapse will be involved. In a randomized study, patients will be grouped to receive either GMK or high-dose alpha-interferon, a compound that has significant toxicity to the patient. The study will also compare the survival rate and the quality of life of the patients.

GMK will be the first cancer vaccine based on a defined tumor antigen to enter this level of trials in the USA. The product is the first of a new class of ganglioside conjugate vaccines, incorporating the GM2 ganglioside, which is present in 95% of melanoma cells. Once vaccinated, antibodies are produced against GM2, and the melanoma cells are then selectively destroyed, causing no significant toxic side effects to the individual. According to the company, patients who are antibody-positive, live longer than those who have no antibodies that are able to mount a specific immune attack on GM2. Further Phase III trials with the product are planned for later this year in both Europe and Australia.