Melanoma Unknown Primary Brain Metastasis Treatment with ECHO-7 Oncolytic Virus Rigvir: A Case Report

Abstract

Melanoma is considered an aggressive malignancy with a tendency of forming metastasis in the brain. Less than 10% of all melanoma cases present with unknown primary tumor location. This diagnose is yet to be fully understood, because there are only theoretical assumptions about the nature of the disease. Melanoma brain metastases have many severe side effects and, unfortunately, any disease related to the brain has limited therapeutic options due to the blood–brain barrier. The course of the disease after a treatment course is complicated to predict, and it is difficult to obtain long-lasting remission. In this report, we describe a female patient with unknown primary melanoma brain metastasis treated with the oncolytic ECHO-7 virus Rigvir® after brain surgery. The patient has been stable, as monitored by magnetic resonance imaging, for more than 3.8 years with ongoing therapy. The median expected overall survival from the time of diagnosis is approximately 5 months. Additional positive effect could have been gained from use of the intranasal administration route, which is considered effective due to the direct anatomical connection between the nasal cavity and the central nervous system. However, further studies are required to fully understand this mode of drug administration.

Developing Picornaviruses for Cancer Therapy

“…Rigvir as a monotherapy and in combination with other therapies has also been tested in patients for whom the prognosis is especially poor. One patient with a basal cell carcinoma, a diagnosis with a median expected survival of five months, was treated with Rigvir post-surgery [101]. The treatment regime began with daily injections for three days, graduating step-wise to thrice-weekly for multiple years.…”

“…The treatment regime began with daily injections for three days, graduating step-wise to thrice-weekly for multiple years. At the time of publication, the patient’s condition has been stable for 3.9 years, with scans showing minimal residual metastasis [101]. Another study documented Rigvir treatment of a stage IV poorly-differentiated rectal adenocarcinoma, with a 5-year survival rate of 5% [102].…”

Brain Metastasis from Unknown Primary Tumour: Moving from Old Retrospective Studies to Clinical Trials on Targeted Agents

“…The problem of a lack of studies is even more evident in the subgroup of BM-CUP due to the rarity of cases, unfavourable prognosis, and frequent exclusion from clinical trials. Therefore, most information on innovative treatments comes from case reports [ 65 , 71 , 72 , 73 , 74 ]. Even if anecdotal, these reports offer good insight on feasible therapeutic strategies and potentially successful treatments in this rare and fatal disease ( Table 5 ).…”

Comment on McCarthy, C.; et al. Developing Picornaviruses for Cancer Therapy. Cancers 2019, 11, 685

“…However, there is no histological record available confirming the basal cell carcinoma diagnosis. In contrast, immunohistochemistry showed that the tumor cells were weakly positive for HMB-45 and Melan A, strongly positive for MART-1, S-100 and vimentin, and that the Ki-67 index was 35% [7].…”

“…However, the registered mode of administration of Rigvir is intramuscular [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ].…”