Phase II study shows potential benefit of adenoviral vascular endothelial growth factor C (VEGF-C) and lymph node transfer in lymphedema

BACKGROUND: Breast cancer-related lymphedema (BCRL) is a common complication lacking medical treatment. Lymfactin® is an adenovirus type 5-based gene therapy and prolymphangiogenic growth factor vector that induces vascular endothelial growth factor C (VEGF-C) expression. Our aim was to evaluate the therapeutic effect of Lymfactin ® with vascularized lymph node transfer (VLNT). METHODS: This Phase II, double-blind, placebo-controlled, randomized multicenter study evaluated the efficacy and safety of Lymfactin ® in combination with VLNT. The primary endpoints were edema volume, quality of life (LyQoLI), and lymphoscintigraphy. All adverse events were recorded. A mixed model of repeated measures analysis of covariance was performed. This study was a continuation of a previous Phase I Lymfactin ® study. RESULTS: Thirty-nine patients with BCRL were recruited between June 2018 and December 2019 and randomized to receive either Lymfactin ® (n = 20) or placebo (n = 19). The primary endpoints showed a positive effect of VLNT in both groups compared to the baseline, but without statistical differences between groups at 12 months. Additionally, greater improvements were observed in the tissue dielectric constant ratios measuring skin interstitial fluid levels in the Lymfactin ® group compared to the placebo group (p = 0.020). No differences in adverse events were detected between the groups. CONCLUSIONS: This study was one of the few studies to objectively show a positive effect of VLNT in a prospective clinical multicenter setting. It was also the first-ever randomized prospective clinical study showing a quantitatively positive effect of a medical therapy on the edema of lymphedema although failing to show differences between groups in primary outcome measures.