Abstract Cancer pain is a serious public health issue and more effective treatments are needed. This study evaluates the analgesic activity of tetrodotoxin, a highly selective sodium channel blocker. ...This randomized, placebo-controlled, parallel design study of subcutaneous tetrodotoxin, in patients with moderate or severe unrelieved cancer pain persisting despite best available treatment, involved 22 centers across Canada. The design called for tetrodotoxin administered subcutaneously over Days 1–4 with a period of observation to Day 15 or longer. All patients could enroll into an open-label extension efficacy and safety trial. The primary endpoint was the proportion of analgesic responders in each treatment arm. Eighty-two patients were randomized, and results on 77 were available for analysis. There was a nonstatistically significant trend toward more responders in the active treatment arm based on the primary endpoint (pain intensity difference). However, analysis of secondary endpoints, and an exploratory post hoc analysis, suggested there may be a robust analgesic effect if a composite endpoint is used, including either fall in pain level, or fall in opioid dose, plus improvement in quality of life. Most patients described transient perioral tingling or other mild sensory phenomena within about an hour of each treatment. Nausea and other toxicities were generally mild, but one patient experienced a serious, adverse event, truncal and gait ataxia. This trial suggests tetrodotoxin may potentially relieve moderate to severe, treatment-resistant cancer pain in a large proportion of patients, and often for prolonged periods following treatment, but further study is warranted using a composite primary endpoint.
Summary Background We compared standard adjuvant anthracycline chemotherapy with anthracycline–taxane combination chemotherapy in women with operable node-positive breast cancer. Here we report the ...final, 10-year follow-up analysis of disease-free survival, overall survival, and long-term safety. Methods BCIRG 001 was an open label, phase 3, multicentre trial in which 1491 patients aged 18–70 years with node-positive, early breast cancer and a Karnofsky score of 80% or more were randomly assigned to adjuvant treatment with docetaxel, doxorubicin, and cyclophosphamide (TAC) or fluorouracil, doxorubicin, and cyclophosphamide (FAC) every 3 weeks for six cycles. Randomisation was stratified according to institution and number of involved axillary lymph nodes per patient (one to three vs four or more). Disease-free survival was the primary endpoint and was defined as the interval between randomisation and breast cancer relapse, second primary cancer, or death, whichever occurred first. Efficacy analyses were based on the intention-to-treat principle. BCIRG 001 is registered with ClinicalTrials.gov , number NCT00688740. Findings Enrolement took place between June 11, 1997 and June 3, 1999; 745 patients were assigned to receive TAC and 746 patients were assigned to receive FAC. After a median follow-up of 124 months (IQR 90–126), disease-free survival was 62% (95% CI 58–65) for patients in the TAC group and 55% (51–59) for patients in the FAC group (hazard ratio HR 0·80, 95% CI 0·68–0·93; log-rank p=0·0043). 10-year overall survival was 76% (95% CI 72–79) for patients in the TAC group and 69% (65–72) for patients in the FAC group (HR 0·74, 0·61–0·90; log-rank p=0·0020). TAC improved disease-free survival relative to FAC irrespective of nodal, hormone receptor, and HER2 status, although not all differences were significant in these subgroup analyses. Grade 3–4 heart failure occurred in 26 (3%) patients in the TAC group and 17 (2%) patients in the FAC group, and caused death in two patients in the TAC group and four patients in the FAC group. A substantial decrease in left ventricular ejection fraction (defined as a relative decrease from baseline of 20% or more) was seen in 58 (17%) patients who received TAC and 41 (15%) patients who received FAC. Six patients who received TAC developed leukaemia or myelodysplasia, as did three patients who received FAC. Interpretation Our results provide evidence that the initial therapeutic outcomes seen at the 5-year follow-up with a docetaxel-containing adjuvant regimen are maintained at 10 years. However, a substantial percentage of patients had a decrease in left ventricular ejection fraction, probably caused by anthracycline therapy, which warrants further investigation. Funding Sanofi.
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