No approved therapies exist for inoperable plexiform neurofibromas in patients with neurofibromatosis type 1.

Purpose: Interleukin-15 (IL-15) has significant potential in cancer immunotherapy as an activator of antitumor CD8 T and natural killer (NK) cells. The primary objectives of this trial were to determine safety, adverse event profile, dose-limiting toxicity, and maximum-tolerated dose of recombinant human IL-15 (rhIL-15) administered as a daily intravenous bolus infusion for 12 consecutive days in patients with metastatic malignancy. Patients and Methods: We performed a first in-human trial of Escherichia coli–produced rhIL-15. Bolus infusions of 3.0, 1.0, and 0.3 μg/kg per day of IL-15 were administered for 12 consecutive days to patients with metastatic malignant melanoma or metastatic renal cell cancer. Results: Flow cytometry of peripheral blood lymphocytes revealed dramatic efflux of NK and memory CD8 T cells from the circulating blood within minutes of IL-15 administration, followed by influx and hyperproliferation yielding 10-fold expansions of NK cells that ultimately returned to baseline. Up to 50-fold increases of serum levels of multiple inflammatory cytokines were observed. Dose-limiting toxicities observed in patients receiving 3.0 and 1.0 μg/kg per day were grade 3 hypotension, thrombocytopenia, and elevations of ALT and AST, resulting in 0.3 μg/kg per day being determined the maximum-tolerated dose. Indications of activity included clearance of lung lesions in two patients. Conclusion: IL-15 could be safely administered to patients with metastatic malignancy. IL-15 administration markedly altered homeostasis of lymphocyte subsets in blood, with NK cells and γδ cells most dramatically affected, followed by CD8 memory T cells. To reduce toxicity and increase efficacy, alternative dosing strategies have been initiated, including continuous intravenous infusions and subcutaneous IL-15 administration.

Paclitaxel is an antineoplastic agent derived from the bark of the western yew, Taxus brevifolia, with a broad spectrum of activity. Because paclitaxel promotes microtubule assembly, neurotoxicity is one of its side effects. Clinical use of paclitaxel has led to peripheral neuropathy and this has been demonstrated to be dependent upon the dose administered, the duration of the infusion, and the schedule of administration. Vehicles in the drug formulation, for example Cremophor in Taxol®, have been investigated for their potential to induce peripheral neuropathy. A variety of neuroprotective agents have been tested in animal and clinical studies to prevent paclitaxel neurotoxicity. Recently, novel paclitaxel formulations have been developed to minimize toxicities. This review focuses on recent advances in the etiology of paclitaxel-mediated peripheral neurotoxicity, and discusses current and ongoing strategies for amelioration of this side effect.