Melacine will be launched in Canada as soon as is practicable by Schering Canada, a wholly-owned subsidiary of Schering-Plough Corporation, which has worldwide marketing rights to the product under an exclusive licensing agreement.
"Scientists at Ribi Immunochem Research, Inc. have worked diligently for many years to make Melacine commercially available for patients in need of a viable treatment for metastatic melanoma," stated Steven Gillis, Ph.D., chairman and chief executive officer of Corixa. "It is gratifying to all of us at Corixa to see this product gain approval for a disease that is difficult to treat effectively, and we look forward to its introduction into the marketplace. We continue to await availability of data from additional Phase III Melacine trials. These include a randomized trial in Stage IV melanoma comparing the effects of Intron® A (Interferon alfa-2B) therapy versus the combination of Intron A therapy and Melacine vaccination. A second Phase III study, under the direction of the Southwest Oncology Group, is evaluating Melacine vaccination vs. observation in Stage II melanoma patients post-surgery. We expect both studies to reach their termination cutoffs within the next few months. Accordingly, the data from these studies could be analyzed by spring of 2000. The results of these studies will have significant impact on Corixa’s future Melacine regulatory approval strategies in the United States and Europe."
Canadian approval was granted based upon Phase III results demonstrating that Melacine provides superior quality of life during active therapy for Stage IV melanoma (late-stage, disseminated disease) as compared to a four-drug chemotherapy control. The two therapies achieved similar efficacy results. Survival data was also compared from the Phase III study with a comprehensive meta-analysis* of therapies for Stage IV melanoma showing that the median survival of 11 months among evaluable patients receiving Melacine was better than that achieved by other available therapies. Further, a significantly longer median survival of 18.2 months was observed in patients who were clinical responders to Melacine therapy.
Melacine melanoma therapeutic vaccine consists of lysed (broken) cells from two human melanoma cell lines combined with Corixa’s proprietary Detox adjuvant acquired from Ribi in October 1999. Detox adjuvant includes MPL adjuvant (monophosphoryl lipid A) and mycobacterial cell wall skeleton, both of which activate the human immune system in the context of vaccination. Melacine is administered as a two-shot vaccination once a week for five weeks, with a two-week break, and then a repeat of the weekly vaccinations for five weeks. Patients who respond may receive a second course of therapy as well as maintenance therapy of one vaccination a month.
Melanoma, if not detected and treated early, can be highly metastatic and is the most deadly form of skin cancer. The lethality of melanoma is indicated by the fact that even apparently tiny skin tumors are capable of metastasizing, or spreading to other parts of the body. Once this happens, the prognosis becomes increasingly dire. Death due to malignant melanoma is usually caused by complications after the disease has spread to the lungs, liver, brain or other visceral organs. Primary skin tumors are removed by surgery.
Current standard therapy includes surgery and observation follow-up for primary skin tumors. Certain chemotherapy drugs and alpha interferon therapy have been approved for treatment of melanoma.