The use of erythropoiesis-stimulating agents with ruxolitinib in patients with myelofibrosis in COMFORT-II: an open-label, phase 3 study assessing efficacy and safety of ruxolitinib versus best available therapy in the treatment of myelofibrosis

BACKGROUND: Anemia is considered a negative prognostic risk factor for survival in patients with myelofibrosis. Most patients with myelofibrosis are anemic, and 35–54 % present with anemia at diagnosis. Ruxolitinib, a potent inhibitor of Janus kinase (JAK) 1 and JAK2, was associated with an overall survival benefit and improvements in splenomegaly and patient-reported outcomes in patients with myelofibrosis in the two phase 3 COMFORT studies. Consistent with the ruxolitinib mechanism of action, anemia was a frequently reported adverse event. In clinical practice, anemia is sometimes managed with erythropoiesis-stimulating agents (ESAs). This post hoc analysis evaluated the safety and efficacy of concomitant ruxolitinib and ESA administration in patients enrolled in COMFORT-II, an open-label, phase 3 study comparing the efficacy and safety of ruxolitinib with best available therapy for treatment of myelofibrosis. Patients were randomized (2:1) to receive ruxolitinib 15 or 20 mg twice daily or best available therapy. Spleen volume was assessed by magnetic resonance imaging or computed tomography scan. RESULTS: Thirteen of 146 ruxolitinib-treated patients had concomitant ESA administration (+ESA). The median exposure to ruxolitinib was 114 weeks in the +ESA group and 111 weeks in the overall ruxolitinib arm; the median ruxolitinib dose intensity was 33 mg/day for each group. Six weeks before the first ESA administration, 10 of the 13 patients had grade 3/4 hemoglobin abnormalities. These had improved to grade 2 in 7 of the 13 patients by 6 weeks after the first ESA administration. The rate of packed red blood cell transfusions per month within 12 weeks before and after first ESA administration remained the same in 1 patient, decreased in 2 patients, and increased in 3 patients; 7 patients remained transfusion independent. Reductions in splenomegaly were observed in 69 % of evaluable patients (9/13) following first ESA administration. CONCLUSIONS: Concomitant use of an ESA with ruxolitinib was well tolerated and did not affect the efficacy of ruxolitinib. Further investigations evaluating the effects of ESAs to alleviate anemia in ruxolitinib-treated patients are warranted (ClinicalTrials.gov identifier, NCT00934544; July 6, 2009)

Eribulin mesylate versus ixabepilone in patients with metastatic breast cancer: a randomized Phase II study comparing the incidence of peripheral neuropathy

Peripheral neuropathy is a common toxicity associated with tubulin-targeted chemotherapeutic agents. This Phase II study compares the incidence and severity of neuropathy associated with eribulin mesylate or ixabepilone in metastatic breast cancer (MBC). The primary objective was to assess the incidence of neuropathy; the study was designed to detect a difference in neuropathy rate of 35 % for eribulin versus 63 % for ixabepilone (odds ratio 0.316, 80 % power, 0.05 two-sided significance level). Eligibility criteria included: MBC; prior taxane therapy; at least one chemotherapy for advanced disease; no or minimal pre-existing neuropathy (Grade 0 or 1). The intent-to-treat population comprised 104 patients randomized (1:1) to eribulin mesylate (1.4 mg/m 2 , 2–5 min intravenous on days 1 and 8) or ixabepilone (40 mg/m 2 , 3 h intravenous on day 1) on a 21-day cycle. 101 patients in the safety population received a median of 5.0 eribulin and 3.5 ixabepilone cycles. Incidence of neuropathy (any grade) was 33.3 and 48.0 %, and peripheral neuropathy was 31.4 and 44.0 % for eribulin and ixabepilone, respectively. After controlling for pre-existing neuropathy and number of prior chemotherapies, these differences were not significant. Compared with ixabepilone, fewer patients receiving eribulin discontinued treatment due to neuropathy (3.9 vs. 18.0 %) or adverse events (AEs) in general (11.8 vs. 32.0 %). Time to onset of neuropathy was 35.9 weeks for eribulin and 11.6 weeks for ixabepilone, and time to resolution was 48 versus 10 weeks, respectively; other AEs were comparable. Objective responses were 15.4 versus 5.8 % and clinical benefit rates were 26.9 versus 19.2 %. In conclusion, after controlling for pre-existing neuropathy and number of prior chemotherapies, the differences in the incidence of neuropathy with eribulin and ixabepilone were not statistically significant. Onset of neuropathy tended to occur later with eribulin and resolve later