PURPOSE: Eribulin is approved for advanced breast cancers refractory to anthracyclines and taxanes. Efficacy according to sensitivity to previous therapies has been poorly explored. MATERIALS AND METHODS: Safety data were collected prospectively and we retrospectively collected efficacy data from the five French centres that participated in the Eribulin E7389-G000-398 expanded access program. Our main objectives were exploration of safety and analysis of eribulin efficacy (progression-free survival [PFS] and overall survival [OS]) according to sensitivity to the last microtubule-inhibiting agent administered. RESULTS: Median eribulin treatment duration was 3.3 months for the 250 patients included in this prospective single-arm study. Two hundreds and thirty-nine patients (95.6%) experienced an adverse event (AE) related to treatment including 129 (51.6%) with grade ≥ 3 AEs. The most frequently observed toxicities were cytopenias (59.6% of included patients), gastro-intestinal disorders (59.2%), and asthenia (56.4%). The most frequent grade 3-4 AE was neutropenia (37.2% with 4.8% febrile neutropenia). Median PFS and OS were 4.6 and 11.8 months, respectively. Patients classified as responders to the last microtubule-inhibiting therapy had a longer OS (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.51 to 0.94; p=0.017), and tended to display a better PFS (HR, 0.78; 95% CI, 0.58 to 1.04; p=0.086). OS improvement was still significant in multivariate analysis (adjusted HR, 0.53; 95% CI, 0.35 to 0.79; p=0.002). CONCLUSION: This work based on a prospective study suggests that identification of patients likely to be more sensitive to eribulin could be based on their previous response to microtubules inhibitors.
Anthracyclines ; Asthenia ; Breast Neoplasms* ; Breast* ; Humans ; Microtubules ; Multivariate Analysis ; Neutropenia ; Prospective Studies* ; Retrospective Studies ; Taxoids

In the present study, a 'novel' toxin, called Am IT from the venom of scorpion Androctonus mauretanicus is isolated and characterized. A detailed analysis of the action of Am IT on insect axonal sodium currents is reported. Am IT was purified through gel filtration followed by C18 reversed-phase HPLC. Toxicity of Am IT in vivo was assessed on male German cockroach (Blattella germanica) larvae and C57/BL6 mice. Cross-reactivity of Am IT with two β-toxins was evidenced using (125)I-iodinated toxin-based radioimmunoassays with synaptosomal preparations from rat brain. The complete amino acid sequence of Am IT was finally determined by Edman sequencing. Am IT was observed to compete with AaH IT4 purified from the venom of scorpion Androctonus australis in binding assays. It was recognized by an antibody raised against a β-type toxin, which indicated some structural similarity with β-toxins (or related toxin family). The 'novel' toxin exhibited dual activity since it competed with anti-mammal toxins in binding assays as well as showed contracting activity to insect. The toxin competed with radio-labeled β-toxin Css IV by binding to Na(+) channels of rat brain synaptosomes. Analysis of toxin amino acid sequences showed that Am IT shares high structural identity (92%) with AaH IT4. In conclusion, Am IT not only reveals an anti-insect compound properties secreted by 'Old World' scorpions, paralyzing insect larvae by binding to Na(+) channels on larvae's nerve-cell membranes, but also exerts toxic activity in mice, which is similar to anti-mammal toxins from 'New World' scorpions (North and South Americas). Therefore, Am IT appears to be structurally and functionally similar to AaH IT4.
Amino Acid Sequence ; Animals ; Chromatography, High Pressure Liquid ; Insecta ; Male ; Mice ; Neuropeptides ; Rats ; Scorpion Venoms ; chemistry ; Scorpions