Long-term rivaroxaban for the treatment of acute venous thromboembolism in patients with active cancer in a prospective multicenter trial.

BACKGROUND/AIMS: Limited data are available regarding the efficacy of rivaroxaban for the treatment of cancer-associated venous thromboembolism (VTE). The aim of this study was to evaluate the effectiveness and safety of rivaroxaban for the treatment of VTE in active cancer patients. METHODS: In this prospective, multicenter, open-label trial (NCT01989845), we enrolled patients with active cancer and objectively diagnosed lower-extremity deep vein thrombosis, pulmonary embolism (PE), or both from November 2013 to June 2016. Active cancer was defined as a histologically confirmed malignancy, which was diagnosed or treated within the previous 6 months, or as a recurrent/ metastatic cancer. Patients received oral rivaroxaban 15 mg twice daily for first 3 weeks, followed by 20 mg once daily for 6 months. The primary outcome was the symptomatic recurrent VTE and the secondary outcomes included any recurrent VTE, major or clinically relevant non-major (CRNM) bleeding events, and overall mortality. All study outcomes were validated by blinded central adjudication. RESULTS: Of 124 patients enrolled, 110 (88.7%) had solid cancer, 93 (75.0%) had metastatic disease, and 110 (88.7%) were receiving chemotherapy or radiotherapy. During the 6-month study period, seven patients experienced symptomatic recurrent VTE (cumulative incidence, 5.9%), and two patients experienced incidental recurrent PE (cumulative incidence of any recurrent VTE, 7.6%). Major bleeding events occurred in six patients (cumulative incidence, 5.3%) and CRNM bleeding events in 11 patients (cumulative incidence, 10.2%). Twenty-eight patients (overall mortality, 24.0%) died. CONCLUSION: Rivaroxaban is effective and safe for the treatment of VTE in patients with active cancer.

A phase II study of docetaxel and oxaliplatin combination in recurrent gastric cancer patients after fluoropyrimidine and/or cisplatin adjuvant treatment: a Korean Cancer Study Group Protocol ST06-02.

BACKGROUND: Surgery alone is no longer an adequate standard of care for patients with resectable gastric cancer. Thus, research efforts should focus on which regimens are the most effective for patients with recurrent gastric cancer after combined treatment with surgery and perioperative or adjuvant chemotherapy. METHODS: Patients with histologically confirmed and measurable advanced gastric cancer who showed a relapse even after fluoropyrimidine and/or cisplatin-based adjuvant chemotherapy received docetaxel (35 mg/m(2)) intravenously on day 1 and 8 plus oxaliplatin (100 mg/m(2)) intravenously on day 1 every 3 weeks until disease progression or unacceptable toxicity. RESULTS: A total of 34 patients with relapsed advanced gastric cancer who had received adjuvant chemotherapy with fluoropyrimidine and/or cisplatin for a median of 6 months (range, 1-48 months) were enrolled in this trial; 22 (64.7 %) patients had been exposed to both agents. Their median age was 58 years (range, 50-68 years). The overall response rate was 55.9 % (95 % confidence interval (CI), 38.3-73.5 %), including 1 complete response and 18 partial responses. At a median follow-up duration of 28.5 months (range, 9.2-50.7 months), the median progression-free survival for all patients was 5.3 months (95 % CI, 4.4-6.1 months) and the median overall survival was 13.8 months (95 % CI, 11.1-16.4 months). The most common grade 3 or 4 hematologic and nonhematologic toxicities were neutropenia (47.1 %) and diarrhea (17.6 %), respectively. Five patients (14.7 %) experienced febrile neutropenia. CONCLUSIONS: Docetaxel and oxaliplatin combination chemotherapy was active and tolerable in patients with recurrent gastric cancer after fluoropyrimidine and/or cisplatin-based adjuvant chemotherapy.

Sunitinib-induced hyperammonemic encephalopathy in gastrointestinal stromal tumors.

OBJECTIVE: To report 2 cases of hyperammonemic encephalopathy induced by sunitinib in patients with metastatic gastrointestinal stromal tumor (GIST). CASE SUMMARY: A 58-year-old man with imatinib-resistant metastatic GIST presented to the emergency department with confusion that developed 17 days after the initiation of sunitinib 50 mg/day. His serum ammonia level was markedly elevated (210 µg/dL). Sunitinib was discontinued, and an enema with lactulose was administered every hour. His neurologic status normalized within 24 hours and his serum ammonia level decreased to 64 µg/dL. A 68-year-old woman with imatinib-resistant metastatic GIST was admitted into the emergency department with confusion and irritability that developed 10 days after the start of sunitinib therapy. Her serum ammonia level was markedly elevated (389 µg/dL). Sunitinib was discontinued, and an enema with lactulose was administered every hour. Within 24 hours, her mental status was improved and her serum ammonia level was decreased to 116 µg/dL. Sunitinib was reintroduced, and the same symptoms occurred after day 7 of administration. Sunitinib was not prescribed afterward and the woman did not experience any further encephalopathic symptoms. DISCUSSION: Sunitinib is a small molecule that inhibits multiple receptor tyrosine kinases such as stem cell factor receptor, vascular endothelial growth factor, and platelet-derived growth factor. It is used as second-line therapy for patients with imatinib-resistant GIST. Hyperammonemic encephalopathy is an uncommon fatal complication of chemotherapy. According to the Naranjo probability scale, sunitinib was a probable cause of hyperammonemic encephalopathy in the patients described here. Although the mechanism of hyperammonemia is unclear, hyperammonemic encephalopathy might be caused by a vascular disorder related to the antiangiogenic properties of sunitinib, and it has ethnic differences associated with genetic polymorphisms. CONCLUSIONS: Sunitinib may induce hyperammonemic encephalopathy in some patients. Although further studies are warranted, clinicians should be aware of this severe adverse event when using sunitinib for treatment of GIST.