er-086526 and Prostatic-Neoplasms

Eribulin mesylate, a synthetic analog of halichondrin B, is a novel tubulin-binding agent that inhibits cancer cell proliferation at low-nanomolar levels.. In a multicenter ECOG trial, patients with progressive metastatic CRPC, ECOG 0-2 were treated with eribulin 1.4 mg/m as an IV bolus over 5 minutes on days 1 and 8 of a 21-day cycle. This noncomparative study stratified points to either a chemonaive (CN), prior-taxane (Tax) only, or 2 prior cytotoxic (TCx) chemotherapy arm. The trial was powered to detect a 50% PSA reduction using Consensus Criteria in at least 40% versus 20% (90% power, one-sided α=0.10) for the CN stratum and 25% versus. 10% (power 87%, one-sided α=0.10) for the Tax and TCx strata.. In total, 119 pts received treatment of which 116 were eligible for the primary response determination in this study. Median age 70 years (range, 45 to 88); median number of treatment cycles 4 (range, 1 to 20+); ECOG 0-1 90%. Confirmed PSA response rates (50% decline from baseline) were 29% (90% [18.2%, 41.2%]; P=0.20), 10% (90% [5.2%, 27.1%]; P=1.00), and 4% ([0.2%, 18.3%]; P=0.59) in the chemonaive stratum, the prior-taxane stratum, and the 2-prior-chemotherapy stratum, respectively. Median progression-free survival was 3.5 months (95% CI, 2.0, 5.9), 2.3 months (95% CI, 2.0, 2.9) and 3.7 months (95% CI, 2.1, 4.2) for the chemonaive stratum, the prior-taxane stratum and the 2-prior-chemotherapy stratum, respectively. Nonhematological toxicities of any grade (mainly grade 1 and 2) were fatigue (74%), neuropathy (40%), alopecia (39%), nausea (35%), and anorexia (34%). Common hematological toxicities were decreased leukocytes (75%), decreased neutrophils (72%), and decreased hemoglobin (66%). The most common grade ≥ 3 toxicities were decreased neutrophils (55%), decreased leukocytes (42%), sensory neuropathy (13%), and fatigue (11%). Overall, there was a 4% rate of febrile neutropenia.. In summary, per the prespecified study endpoints, eribulin did not have adequate activity in chemotherapy naïve or chemotherapy pretreated patients with metastatic CRPC to support further study in this setting.

Topics: Aged; Aged, 80 and over; Follow-Up Studies; Furans; Humans; Ketones; Lymphatic Metastasis; Male; Middle Aged; Neoplasms, Hormone-Dependent; Prognosis; Prostatic Neoplasms; Survival Rate

Treatment options remain limited for patients with castration-resistant prostate cancer (CRPC). We evaluated eribulin mesylate (E7389), a nontaxane halichondrin B analog microtubule inhibitor, in patients with metastatic CRPC with or without previous taxane exposure.. Men with histologically proven CRPC, with or without prior taxane exposure, were enrolled in an open-label, single-arm phase II trial. Patients received eribulin mesylate 1.4 mg/m(2) as a 2- to 5-min i.v. bolus infusion on days 1 and 8 of a 21-day cycle. The primary efficacy end point was prostate-specific antigen (PSA) response rate.. In total, 108 patients were assessable for safety (50 were taxane-pretreated) and 105 for efficacy in the per-protocol population. The median age of patients was 71 years and median number of cycles was 4. PSA decreases of ≥ 50% were achieved in 22.4% and 8.5% of taxane-naive and taxane-pretreated patients, respectively. The most common grade 3/4 adverse event was neutropenia, seen in 22.4% of chemo-naive and 40% of taxane-pretreated men. Grade 3 peripheral neuropathy occurred in none of the taxane-naive patients and 6.0% of taxane-pretreated patients.. Eribulin mesylate demonstrated activity and a relatively favorable toxicity profile in metastatic CRPC.

Topics: Aged; Aged, 80 and over; Algorithms; Antineoplastic Agents; Carcinoma; Chemotherapy, Adjuvant; Drug Resistance, Neoplasm; Furans; Humans; Ketones; Male; Middle Aged; Neoplasm Metastasis; Orchiectomy; Patient Selection; Prostatic Neoplasms; Taxoids; Treatment Failure; Treatment Outcome

Despite that greater knowledge of prostate cancer biology has led to the isolation of many new and promising targets, treatment of metastatic prostate cancer is still challenging. New agents targeting these molecules are currently under development in large randomized phase III trials, to improve overall survival and the quality of life of patients with metastatic castrate-resistant prostatic cancer (CRPC). Cytotoxic chemotherapy (docetaxel-based chemotherapy) demonstrated clinical benefit on overall survival, but could be improved. Drugs targeting directly or not the androgen receptor such as abiraterone or new specific peripheral anti-androgens (MDV3100) are very promising. Bone targeted therapies (endothelin1 receptor A inhibitor, RANK ligant, metabolic irradiation) are also very promising and are in development in large phase III trials. Antiangiogenic therapies could also be effective in CRPC. Autologous vaccin against prostatic acid phosphatase seems to prolong overall survival and other vaccin and immunotherapy strategies are in development (anti-CTLA4 antibody). A recent analogue of thalidomide, probably more efficient, lenalidomide is also in development.

Topics: Androgen Antagonists; Androstenes; Androstenols; Angiogenesis Inhibitors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Hormonal; Bone Neoplasms; Castration; Denosumab; Epothilones; ErbB Receptors; Furans; Humans; Immunotherapy; Ketones; Male; Orchiectomy; Prostatic Neoplasms; Pyrrolidines; RANK Ligand

E7389, a macrocyclic ketone analog of the marine natural product halichondrin B, currently is undergoing clinical trials for cancer. This fully synthetic agent exerts its highly potent in vitro and in vivo anticancer effects via tubulin-based antimitotic mechanisms, which are similar or identical to those of parental halichondrin B. In an attempt to understand the impressive potency of E7389 in animal models of human cancer, its ability to induce apoptosis following prolonged mitotic blockage was evaluated. Treatment of U937 human histiocytic lymphoma cells with E7389 led to time-dependent collection of cells in the G2-M phase of the cell cycle, beginning as early as 2 h and becoming maximal by 12 h. Increased numbers of hypodiploid events were seen beginning at 12 h, suggesting initiation of apoptosis after prolonged E7389-induced mitotic blockage. The identity of hypodiploid events as apoptotic cells under these conditions was confirmed by two additional morphologic criteria: green to orange/yellow shifts on acridine orange/ethidium bromide staining, and cell surface annexin V binding as assessed by flow cytometry. Several biochemical correlates of apoptosis also were seen following E7389 treatment, including phosphorylation of the antiapoptotic protein Bcl-2, cytochrome c release from mitochondria, proteolytic activation of caspase-3 and -9, and cleavage of the caspase-3 substrate poly(ADP-ribose) polymerase (PARP). In LNCaP human prostate cancer cells, treatment with E7389 also led to generation of hypodiploid cells, activation of caspase-3 and -9, and appearance of cleaved PARP, indicating that E7389 can activate cellular apoptosis pathways under anchorage-independent and -dependent cell culture conditions. These results show that prolonged mitotic blockage by E7389 can lead to apoptotic cell death of human cancer cells in vitro and can provide a mechanistic basis for the significant in vivo anticancer efficacy of E7389.

Topics: Apoptosis; Caspase 3; Caspase 9; Caspases; Cell Line, Tumor; Cell Membrane; Cell Polarity; Cytochromes c; Diploidy; Enzyme Activation; Ethers, Cyclic; Furans; G2 Phase; Humans; Ketones; Male; Mitochondria; Mitosis; Phosphorylation; Poly(ADP-ribose) Polymerases; Prostatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; U937 Cells