Enzalutamide Reduces Oxycodone Exposure in Men with Prostate Cancer.

BACKGROUND AND OBJECTIVE: Up to 90% of patients with castration-resistant prostate cancer (CRPC) will develop symptomatic bone metastases requiring pain medication, with opioids being the mainstay of therapy in treating moderate and severe pain. Enzalutamide is an androgen receptor antagonist for the treatment of CRPC and a strong inducer of cytochrome P450 (CYP)3A4. Hereby, enzalutamide potentially reduces the exposure of oxycodone, an opioid metabolized by CYP3A4 and CYP2D6. Our objective was to evaluate the potential drug-drug interaction of enzalutamide and oxycodone. METHODS: A prospective, nonrandomized, open-label, two-arm parallel study was performed. All patients received a single dose of 15 mg normal-release oxycodone. Patients in the enzalutamide arm (ENZ-arm) received enzalutamide 160 mg once daily. Plasma concentrations of oxycodone and its metabolites were quantified using a validated liquid chromatography with tandem mass spectrometry (LC-MS/MS) method. RESULTS: Twenty-six patients (13 ENZ-arm; 13 control arm) were enrolled in the study. Enzalutamide decreased the mean AUC0-8 h and Cmax of oxycodone with, respectively, 44.7% (p < 0.001) and 35.5% (p = 0.004) compared with the control arm. The AUC0-8 h and Cmax of the active metabolite oxymorphone were 74.2% (p < 0.001) and 56.0% (p = 0.001) lower in the ENZ-arm compared with the control arm. In contrast, AUC0-8 h and Cmax of the inactive metabolites noroxycodone and noroxymorphone were significantly increased by enzalutamide. CONCLUSION: Co-administration of enzalutamide significantly reduced exposure to oxycodone and its active metabolite oxymorphone in men with prostate cancer. This should be taken into account when prescribing enzalutamide combined with oxycodone.

Randomized double-blind phase II trial comparing gemcitabine plus LY293111 versus gemcitabine plus placebo in advanced adenocarcinoma of the pancreas.

BACKGROUND: LY293111 (LY) is a novel oral anticancer agent with leukotriene B4 receptor antagonist and peroxisome proliferator-activated receptor gamma agonist properties, producing promising results alone and in combination with gemcitabine in pancreatic cancer xenograft models. A phase I study proved that the combination (gemcitabine plus LY) is safe and well tolerated. PATIENTS AND METHODS: Chemotherapy-naive patients with histologically confirmed locally advanced or metastatic adenocarcinoma of the pancreas were randomly assigned to gemcitabine 1000 mg/m on days 1, 8, and 15 of a 28-day cycle and continuously administered LY 600 mg twice daily or gemcitabine 1000 mg/m on days 1, 8, and 15 of a 28-day cycle and daily oral placebo. Arms were balanced for Eastern Cooperative Oncology Group performance status and disease stage. The primary end point was 6-month survival; secondary objectives include response rate (RR), progression-free survival, and overall survival. RESULTS: Six-month survival was not different between groups (P>0.2, 1-sided); progression-free survival and RR were not different (P>0.05, 2-sided). RR was also not impacted. LY did not increase grades 3-4 hematologic toxicities, but was associated with a trend toward more, grades 3-4 diarrhea. CONCLUSIONS: These results do not demonstrate any benefit to adding LY to gemcitabine in unpretreated patients with advanced pancreatic carcinoma.

Giant rectal gastrointestinal stromal tumors: a report of two cases.

Giant gastrointestinal stromal tumors (GISTs) of the rectum are rare and often difficult to remove surgically. At the time metastases are found, GISTs are considered to be incurable and until recently no adequate therapy was of any value for these patients. Recently, imatinib was introduced: a signal transducing inhibitor acting specifically on the KIT-tyrosine kinase, which can be used to downsize giant GIST (neo-adjuvant) before surgery or induce stable disease in case of metastases with few minor side-effects. Two patients with giant rectal GIST are presented, one of which was treated before the imatinib era, the other when imatinib was available.

Phase III trial of gemcitabine plus tipifarnib compared with gemcitabine plus placebo in advanced pancreatic cancer.

PURPOSE: To determine whether addition of the farnesyltransferase inhibitor tipifarnib (Zarnestra, R115777; Johnson and Johnson Pharmaceutical Research and Development, Beerse, Belgium) to standard gemcitabine therapy improves overall survival in advanced pancreatic cancer. PATIENTS AND METHODS: This randomized, double-blind, placebo-controlled study compared gemcitabine + tipifarnib versus gemcitabine + placebo in patients with advanced pancreatic adenocarcinoma previously untreated with systemic therapy. Tipifarnib was given at 200 mg bid orally continuously; gemcitabine was given at 1,000 mg/m(2) intravenously weekly x 7 for 8 weeks, then weekly x 3 every 4 weeks. The primary end point was overall survival; secondary end points included 6-month and 1-year survival rates, progression-free survival, response rate, safety, and quality of life. RESULTS: Six hundred eighty-eight patients were enrolled. Baseline characteristics were well balanced between the two treatment arms. No statistically significant differences in survival parameters were observed. The median overall survival for the experimental arm was 193 v 182 days for the control arm (P =.75); 6-month and 1-year survival rates were 53% and 27% v 49% and 24% for the control arm, respectively; median progression-free survival was 112 v 109 days for the control arm. Ten drug-related deaths were reported for the experimental arm and seven for the control arm. Neutropenia and thrombocytopenia grade > or = 3 were observed in 40% and 15% in the experimental arm versus 30% and 12% in the control arm. Incidences of nonhematologic adverse events were similar in two groups. CONCLUSION: The combination of gemcitabine and tipifarnib has an acceptable toxicity profile but does not prolong overall survival in advanced pancreatic cancer compared with single-agent gemcitabine.

[Malignant intracranial germ cell tumor treated with chemotherapy and radiotherapy without histopathological confirmation]. / Maligne intracerebrale kiemceltumor behandeld met chemotherapie en radiotherapie zonder histopathologische diagnose.

In two men aged 19 and 24 years, a rare malignant intracranial germ cell tumour was diagnosed in the pineal gland region and in the second patient in a suprasellar position as well. Although histological confirmation is required in general to diagnose a malignancy, obtaining it can be difficult and potentially dangerous in case of intracranial neoplasms. The clinical picture of a young patient with an intracerebral tumour localised in the midline of the brain and increased levels of the tumour markers alpha-foetoprotein and/or human chorion gonadotrophin (beta-HCG) in blood and/or CSF makes any other diagnosis highly unlikely. There is no place for radical surgery in the first-line treatment of malignant intracerebral germ cell tumours because of the sensitivity to radio- and chemotherapy. Also, the sensitivity to chemotherapy makes it possible to reduce radiation volume and dose in an effort to avoid the serious complications of craniospinal irradiation. Both patients responded well to chemotherapy based on cisplatin followed by radiotherapy.