Autologous monocyte-derived dendritic cells (DCs) electroporated with synthetic mRNA (TriMixDC-MEL) in combination with ipilimumab was tolerable and resulted in highly durable responses in patients with pretreated advanced melanoma, a study published in the Journal of Clinical Oncology has shown.1

TriMixDC-MEL have previously been shown to be immunogenic and have antitumor activity in patients with pretreated advanced melanoma. Because ipilimumab, a cytotoxic T-lymphocyte-associated protein 4 antibody, improves overall survival in patients with advanced melanoma, researchers sought to investigate the combination of both in the pretreated population.

For the phase 2 study, researchers enrolled 39 patients. All participants received TriMixDC-MEL 4 × 106 cells administered intradermally and 20 × 106 cells administered intravenously, plus ipilimumab 10 mg/kg every 3 weeks for 4 doses. Patients who remained progression-free then received maintenance therapy every 12 weeks.

Results showed that the 6-month disease control rate was 51% (95% CI, 36 – 67) and the overall tumor response rate was 38%.

Eight patients achieved complete responses and 7 had partial responses. Of those, 7 complete responses and 1 partial response are ongoing after a median follow-up of 36 months.

In regard to safety, the most common treatment-emergent adverse events were local dendritic cell injection site reactions, transient post-dendritic cell infusion chills and flu-like symptoms, dermatitis, hypophysitis, diarrhea/colitis, and hepatitis.

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A total of 36% of patients experienced grade 3 or 4 immune-related adverse events, but no grade 5 events were reported.

Reference

  1. Wilgenhof S, Corthals J, Heirman C, et al. Phase II study of autologous monocyte-derived mRNA electroporated dendritic cells (TriMixDC-MEL) plus ipilimumab in patients with pretreated advanced melanoma [published online ahead of print February 29, 2016]. J Clin Oncol. doi: 10.1200/JCO.2015.63.4121.