A case study reported on two patients with advanced melanoma that had spread to the liver, who experienced progression-free long-term survival — of 4.5 and 12 years — following removal of the hepatic tumor and treatment with patient-specific immunotherapeutic vaccines.
The article, “Long-term Progression-free and Overall Survival in Two Melanoma Patients Treated with Patient-Specific Therapeutic Vaccine Eltrapuldencel-T After Resection of a Solitary Liver Metastasis,” was published in the journal Cancer Biotherapy and Radiopharmaceuticals.
Liver metastases from ocular or cutaneous melanomas are associated with an extremely poor prognosis. A small proportion of patients are considered to be suitable candidates for surgical removal of hepatic metastases. Those patients are usually in good medical condition and have a solitary tumor, or a few secondary tumors, limited to the liver and potentially operable. Still, the patients are prone to recurrences in the liver and elsewhere.
Dr. Robert O. Dillman, chief medical officer for NeoStem Oncology and the study’s author, said the potential exists to achieve long-term survival without disease progression in some patients using the eltrapuldencel-T vaccine. The vaccine uses the patient’s own dendritic cells, loaded with antigens from a self-renewing cell line of their tumor cells, to activate the immune system against the tumor.
The two patients in the study were diagnosed with solitary hepatic metastasis after earlier diagnoses of melanoma. One, a 50-year-old man, had an ocular melanoma with clinical behavior typical of uveal melanoma, and the other, a 56-year-old man, had a melanoma of unknown primary origin with previous lung and small bowel metastases. In addition to having a solitary liver metastasis, both men received aggressive local treatment and were rendered disease free in the liver by surgery before being treated with a patient-specific therapeutic vaccine.
Following the vaccine, one patient had no disease progression for more than 4.5 years, while the other remained disease-free for more than 12 years. Both patients survived more than 8.5 years from the original diagnosis of hepatic metastases, and received the vaccine in clinical trials (Nos. NCT00436930 and NCT00948480, respectively).
Co-editor of the journal, Donald J. Buchsbaum, PhD, with the division of Radiation Biology at the University of Alabama, called the report “exciting.”
“(The)results illustrate the potential for melanoma patient-specific therapeutic vaccines to enhance long-term survival and add to the progress being made on the immmunotherapy of melanom,” Dr. Buchsbaum said in a news release.