Efficacy and Tolerability of Vinorelbine in the Cancer Therapy

Vinorelbine (VRN) is one of the most representative compounds of its class: the vinca alkaloids. VRN interferes with microtubule assembly. VRN shows a better therapeutic index than the parent compound vincristine and vinblastine probably because of its higher affinity for mitotic microtubules. VNR high affinity for mitotic microtubules causes a high clinical efficacy for the treatment of non-small cell lung cancer (NSCLC) and for breast cancer (BC), together with a good tolerability at therapeutically effective doses. The vinca alkaloids are structurally similar compounds comprised of 2 multiringed units, vindoline and catharanthine. Unlike other vinca alkaloids, the catharanthine unit is the site of structural modification for VRN. The antitumor activity of VNR is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, VNR may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca++-transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis. The VNR is also characterized by improved hematologic tolerance and less neurotoxicity compared to parent compound. The aim of this review is 1) to explore the efficacy and tolerability of VNR in cancer therapy and 2) to examine the more recent approaches to improve the efficacy and tolerability of VNR in cancer therapy.