Longitudinal assessment of air conduction audiograms in a phase III clinical trial of difluoromethylornithine and sulindac for prevention of sporadic colorectal adenomas.

A phase III clinical trial assessed the recurrence of adenomatous polyps after treatment for 36 months with difluoromethylornithine (DFMO) plus sulindac or matched placebos. Temporary hearing loss is a known toxicity of treatment with DFMO, thus a comprehensive approach was developed to analyze serial air conduction audiograms. The generalized estimating equation method estimated the mean difference between treatment arms with regard to change in air conduction pure tone thresholds while accounting for within-subject correlation due to repeated measurements at frequencies. Based on 290 subjects, there was an average difference of 0.50 dB between subjects treated with DFMO plus sulindac compared with those treated with placebo (95% confidence interval, -0.64 to 1.63 dB; P = 0.39), adjusted for baseline values, age, and frequencies. In the normal speech range of 500 to 3,000 Hz, an estimated difference of 0.99 dB (-0.17 to 2.14 dB; P = 0.09) was detected. Dose intensity did not add information to models. There were 14 of 151 (9.3%) in the DFMO plus sulindac group and 4 of 139 (2.9%) in the placebo group who experienced at least 15 dB hearing reduction from baseline in 2 or more consecutive frequencies across the entire range tested (P = 0.02). Follow-up air conduction done at least 6 months after end of treatment showed an adjusted mean difference in hearing thresholds of 1.08 dB (-0.81 to 2.96 dB; P = 0.26) between treatment arms. There was no significant difference in the proportion of subjects in the DFMO plus sulindac group who experienced clinically significant hearing loss compared with the placebo group. The estimated attributable risk of ototoxicity from exposure to the drug is 8.4% (95% confidence interval, -2.0% to 18.8%; P = 0.12). There is a <2 dB difference in mean threshold for patients treated with DFMO plus sulindac compared with those treated with placebo.

Adherence assessment using medication weight in a phase IIb clinical trial of difluoromethylornithine for the chemoprevention of skin cancer.

OBJECTIVE: Adherence is a common and essential measurement in clinical trials. This study evaluates the association between participant self-reported study diary records and the weight of the medication vessel at each study visit, in the setting of a phase IIb topical chemoprevention trial. METHODS: One hundred and twenty-four eligible participants were randomized to one of four arms [34 to difluoromethylornithine (DFMO) plus triamcinolone, 31 to DFMO plus placebo, 31 to placebo plus triamcinolone, and 28 to double placebo] for 6 months of treatment for actinic keratosis. Adherence was assessed at each clinic visit by weighing each tube of dispensed and returned medication and the participant's study diary. RESULTS: Self-reported adherence was consistently higher than adherence measured by returned medication weight (96.5% versus 71.3%, 94.6% versus 82.4%, 95.3% versus 69.5%, and 95.8% versus 66.8% for DFMO, DFMO placebo, triamcinolone, and triamcinolone placebo, respectively; P < 0.001). Most participants (59.2%) recorded 100% adherence on the study diary; however, using the weight adherence, only 10.2% were completely adherent to the study regimen. CONCLUSIONS: Self-reported diary measures seem to overestimate adherence when compared with weighing the returned medication vessel. It is recommended that future clinical trials involving topical applications incorporate medication weights as a primary measure of adherence because it is objective, quantitative, inexpensive, noninvasive, and easy to use.

Potential for interferon-alpha-based therapy in mesothelioma: assessment in a murine model.

Malignant mesothelioma is an aggressive tumor, usually induced by asbestos exposure, that has a poor prognosis and is unresponsive to conventional therapy. The present study was aimed at assessing the potential for interferon-alpha (IFN-alpha)-based therapies in a murine model for malignant mesothelioma. The effect of recombinant human IFN-alpha B/D on tumor growth, alone and in combination with either of two immunomodulatory and antiproliferative agents beta-carotene or alpha-difluoromethylornithine (DFMO), was assessed. The data suggest that IFN-alpha treatment is most efficacious when commenced early in tumor development. Combination of IFN-alpha with either DFMO or dietary beta-carotene supplementation improved the effect of an otherwise suboptimal IFN-alpha therapy regimen. Both IFN-alpha and beta-carotene had in vivo stimulatory effects on immune cells, perhaps indirectly by inhibiting TGF-beta generation. The immunomodulatory effects may contribute, at least in part, to the positive antitumor and clinical activities of the treatments in this model.

[Current therapy of trypanosomiasis]. / Actualités thérapeutiques de la trypanosomiase.

The authors review the available products used for human african trypanosomiasis (HAT) chemotherapy: pentamidine, suramin, melarsoprol and the new compound DFMO. The administration of pentamidine at the beginning of the nervous stage, when the number of cells in the cerebrospinal fluid do not exceed 20/mn3 is a new approach for HAT treatment. At this time of the disease, patients generally are healthy and the pentamidine therapy avoids the use of the toxic melarsoprol (Arsobal). An alternative protocol for Arsobal therapy (2, 16 mg/kg/d for 10 consecutive days) has been described from pharmacokinetics data to decrease the rate of relapses and the duration of hospital care. Efficacy and tolerance of this new protocol must be evaluated by randomised clinical trials. Preliminary data of clinical trials using short-term DFMO therapy are encouraging. DFMO therapy be less expensive. From its efficacy and tolerance, DFMO is a choice chemotherapy for HAT treatment, especially in the case of resistance to usual trypanocides. Both MLD 73811 and IMOL 881 are new trypanocidal compounds, effective on Trypanosoma brucei rhodesiense and T. b. gambiense. In addition, IMOL 881 is effective on the animal trypanosomes, T. evansi and T. equiperdum. Waiting for the availability of these new products, classical trypanocides remain the basis of HAT treatment.

Phase II assessment of recombinant leukocyte A interferon with difluoromethylornithine in disseminated malignant melanoma.

Sixteen patients with advanced melanoma received IFN-alpha 2A, 36 X 10(6) U/m2 i.m., on days 3-7 with 2.25 g/m2 DFMO p.o. on days 1-7. We observed no objective regressions. Median time to progression was 1.2 months with a median survival of 5.2 months. A flu-type syndrome was the predominant sequela. From the dose and schedule that we utilized, this regimen holds little promise against disseminated malignant melanoma.