High-dose vitamin C enhances cancer immunotherapy.

Vitamin C (VitC) is known to directly impair cancer cell growth in preclinical models, but there is little clinical evidence on its antitumoral efficacy. In addition, whether and how VitC modulates anticancer immune responses is mostly unknown. Here, we show that a fully competent immune system is required to maximize the antiproliferative effect of VitC in breast, colorectal, melanoma, and pancreatic murine tumors. High-dose VitC modulates infiltration of the tumor microenvironment by cells of the immune system and delays cancer growth in a T cell-dependent manner. VitC not only enhances the cytotoxic activity of adoptively transferred CD8 T cells but also cooperates with immune checkpoint therapy (ICT) in several cancer types. Combination of VitC and ICT can be curative in models of mismatch repair-deficient tumors with high mutational burden. This work provides a rationale for clinical trials combining ICT with high doses of VitC.

Pharmacokinetics of cisplatin during open and minimally-invasive secondary cytoreductive surgery plus HIPEC in women with platinum-sensitive recurrent ovarian cancer: a prospective study.

OBJECTIVE: Evidences from animal models seem to suggest that minimally invasive surgery may enhance cisplatin diffusion when the drug is administered in the context of post-operative hyperthermic intraperitoneal chemotherapy (HIPEC). The present study evaluates the cisplatin pharmacokinetic profile in a prospective series of women with platinum sensitive recurrent epithelial ovarian cancer treated with open secondary cytoreductive surgery (O-SCS) or minimally-invasive secondary cytoreductive surgery (MI-SCS). METHODS: Cisplatin levels were assessed at 0, 20, 40, 60, and 120 minutes in: 1) blood samples, 2) peritoneal perfusate, and 3) peritoneal biopsies at the end of HIPEC. Median Cmax has been used to identify women with high and low drug levels. Progression-free survival (PFS) was calculated as the time elapsed between SCS+HIPEC and secondary recurrence or last follow-up visit. RESULTS: Nine (45.0%) women received MI-SCS, and 11 (55.0%) O-SCS. At 60 minutes, median cisplatin Cmax in peritoneal tissue was higher in patients treated with MI-SCS compared to O-SCS (Cmax=8.262 µg/mL vs. Cmax=4.057 µg/mL). Furthermore, median cisplatin plasma Cmax was higher in patients treated with MI-SCS compared to O-SCS (Cmax=0.511 vs. Cmax=0.254 µg/mL; p-value=0.012) at 120 minutes. With a median follow-up time of 24 months, women with higher cisplatin peritoneal Cmax showed a longer PFS compared to women with low cisplatin peritoneal levels (2-years PFS=70% vs. 35%; p-value=0.054). CONCLUSIONS: We demonstrate for the first time that minimally invasive route enhances cisplatin peritoneal tissue uptake during HIPEC, further evaluations are needed to confirm the correlation between peritoneal cisplatin levels after HIPEC and survival. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01539785.

High Penetration of Paclitaxel in Abdominal Wall of Rabbits after Hyperthermic Intraperitoneal Administration of Nab-Paclitaxel Compared to Standard Paclitaxel Formulation.

PURPOSE: Paclitaxel (PTX) is currently used in combination with cisplatin for Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for the treatment of peritoneal carcinomatosis. Albumin-bound PTX is a promising new drug for HIPEC because of its easy solubility in aqueous perfusion medium and possibly because of the tendency of albumin to cross physiological barriers and accumulate in tumor tissue. METHODS: We tested the feasibility of using nab-paclitaxel in rabbits treated by HIPEC for 60 min compared with the classical formulation at an equivalent PTX dose. Samples of perfusate and blood were collected at different time points and peritoneal tissues were collected at the end of perfusion. PTX concentrations were determined by HPLC. The depth of paclitaxel penetration through the peritoneal barrier was assessed by mass spectrometry imaging. RESULTS: PTX after nab-paclitaxel treatment penetrated up to 0.63 mm in the peritoneal wall, but after CRE-paclitaxel, it was not detectable in the peritoneum. Moreover, the peritoneal concentration after nab-paclitaxel was five times that after paclitaxel classical formulation. Despite the high levels reached in the peritoneum, systemic exposure of PTX was low. CONCLUSIONS: Our results show that nab-paclitaxel penetrates into the abdominal wall better than CRE-paclitaxel, in terms of effective penetration and peritoneal tissue concentration.

Phase ib of sorafenib in combination with everolimus in patients with advanced solid tumors, selected on the basis of molecular targets.

BACKGROUND: Molecular alterations of the PI3K and Ras pathways often occur in human cancer. In this trial, the pharmacokinetics, toxicity, and activity of two drugs inhibiting these pathways-everolimus and sorafenib-were investigated. METHODS: Thirteen patients with progressing solid tumors were treated with everolimus and sorafenib, according to a 3+3 scheme. Patients were selected on the basis of immunohistochemical expression of tumor molecular targets, including phospho-AKT, -p70S6K, and -ERK1/2. RESULTS: The daily recommended dose identified was 2.5 mg of everolimus and 600 mg of sorafenib. Dose-limiting toxicities included grade 3 asthenia and hand-foot skin reaction. No grade 4 adverse events were observed. The most frequent grade 3 toxicities were hypophosphatemia (30.8%), alanine aminotransferase level increase, asthenia, and anorexia (14%). No pharmacokinetic interactions were identified between everolimus and sorafenib. Of 12 evaluable patients, we observed 2 partial responses, with greater than 10% shrinkage in an additional 5 patients. Objective responses were observed in one patient with a thymoma and in one patient with a lung adenocarcinoma. Tumor shrinkage that did not qualify as a partial response was seen in an abdominal leiomyosarcoma and in adenoid cystic carcinomas. CONCLUSION: The combination of everolimus and sorafenib is safe. The tumor activity observed in different tumor types could be the result of the combined action of these drugs as well as the molecular selection of the treated population. Further research is warranted to better investigate drugs simultaneously blocking the PI3K and the Ras pathways and to refine patient selection.