bryostatin-1 and Ovarian-Neoplasms

The California Cancer Consortium has performed a Phase II trial of infusional bryostatin, a protein kinase C inhibitor isolated from the marine invertebrate bryozoan, Bugula Neritina, a member of the phylum Ectoprocta, in combination with cisplatin, in patients (pts) with recurrent platinum-sensitive or resistant ovarian cancer (OC).. Pts received bryostatin 45 mcg/m(2) as a 72 h continuous infusion followed by cisplatin 50 mg/m(2). Cycles were repeated every 3 weeks. Dosages were chosen based on phase I data obtained by the CCC in a population of pts with mixed tumor types.. Eight pts with recurrent or persistent epithelial OC received 23 cycles of treatment. All pts had received previous platinum-based chemotherapy; two pts had received one prior course, five had received two prior courses, and one had received three prior courses of chemotherapy. The median age was 64 (range 32-72), and Karnofsky performance status 90 (range 80-100). A median of 3 cycles of chemotherapy were delivered (range: 1-5). The median progression-free and overall survivals were 3 and 8.2 months respectively. Best responses included two partial responses (one in a platinum-resistant pt), three pts with stable disease, and three progressions. All pts experienced Grade 3 or 4 toxicities including severe myalgias/pain/fatigue/asthenia in six pts, and severe nausea/vomiting/constipation in two other pts. One pt experienced a seizure and liver function tests were elevated in one other.. A modest response rate is observed in pts with recurrent or persistent ovarian cancer treated with the combination of bryostatin and cisplatin. The toxicity profile, however, observed in this pt population (primarily severe myalgias), precludes tolerability and prevents this combination from further investigation at this dose and schedule. It is possible that platinum pre-exposure in OC patients exacerbates observed toxicity. Phase II dosages of investigational agents in OC pts that are determined by phase I trials in pts with other tumor types should be chosen cautiously.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Bryostatins; California; Carcinoma, Ovarian Epithelial; Cisplatin; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Kaplan-Meier Estimate; Middle Aged; Neoplasm Recurrence, Local; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Protein Kinase C; Protein Kinase Inhibitors; Time Factors; Treatment Outcome

Bryostatin-1 is a macrocyclic lactone whose main mechanism of action is protein kinase C modulation. We investigated its activity as a weekly 24-h infusion in recurrent ovarian carcinoma. In all, 17 patients were recruited and 11 had chemotherapy-resistant disease as defined by disease progression within 4 months of last cytotoxic therapy. All were evaluable for toxicity and 14 for response. There were no disease responses and the main toxicity was myalgia.

Topics: Adult; Aged; Antineoplastic Agents; Bryostatins; Disease Progression; Enzyme Activation; Female; Humans; Infusions, Intravenous; Lactones; Macrolides; Middle Aged; Neoplasm Recurrence, Local; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Treatment Outcome

The Gynecologic Oncology Group (GOG) performed a randomized phase II study to determine the antitumor activity and toxicity of two different schedules of bryostatin-1 administration in patients with recurrent or persistent platinum-sensitive epithelial ovarian cancer or primary peritoneal carcinoma.. Eligible patients were randomized to receive either bryostatin-1 25 microg/m2 as a 1h infusion weekly for 3 weeks followed by a 1-week rest (Regimen I) or bryostatin-1 120 microg/m2 as a 72 h continuous infusion every 2 weeks (Regimen II).. Fifty-five patients were enrolled on this study. There was one durable response among 27 eligible patients (response rate=3.7%) on Regimen II and no responses in the 27 eligible patients on Regimen I. Nineteen patients (eleven on Regimen I and eight on Regimen II) had stable disease. The most common adverse event was myalgia, with 12 of 27 patients (44%) on each regimen experiencing some degree of myalgia. There were no other significant toxicities on either treatment arm.. Both of these schedules and doses of bryostatin-1 are inactive as single agents in previously treated epithelial ovarian cancer.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Bryostatins; Drug Administration Schedule; Female; Humans; Lactones; Macrolides; Middle Aged; Neoplasm Recurrence, Local; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Peritoneal Neoplasms; Treatment Outcome

Bryostatin 1 is a novel antitumour agent derived from Bugula neritina of the marine phylum Ectoprocta. Nineteen patients with advanced solid tumours were entered into a phase I study to evaluate the toxicity and biological effects of bryostatin 1. Bryostatin 1 was given as a one hour intravenous infusion at the beginning of each 2 week treatment cycle. A maximum of three treatment cycles were given. Doses were escalated in steps from 5 to 65 micrograms m-2 in successive patient groups. The maximum tolerated dose was 50 micrograms m-2. Myalgia was the dose limiting toxicity and was of WHO grade 3 in all three patients treated at 65 micrograms m-2. Flu-like symptoms were common but were of maximum WHO grade 2. Hypotension, of maximum WHO grade 1, occurred in six patients treated at doses up to and including 20 micrograms m-2 and may not have been attributable to treatment with bryostatin 1. Cellulitis and thrombophlebitis occurred at the bryostatin 1 infusion site of patients treated at all dose levels up to 50 micrograms m-2, attributable to the 60% ethanol diluent in the bryostatin 1 infusion. Subsequent patients treated at 50 and 65 micrograms m-2 received treatment with an intravenous normal saline flush and they did not develop these complications. Significant decreases of the platelet count and total leucocyte, neutrophil and lymphocyte counts were seen in the first 24 h after treatment at the dose of 65 micrograms m-2. Immediate decreases in haemoglobin of up to 1.9g dl-1 were also noted in patients treated with 65 micrograms m-2, in the absence of clinical evidence of bleeding or haemodynamic compromise. No effect was observed on the incidence of haemopoietic progenitor cells in the marrow. Some patients' neutrophils demonstrated enhanced superoxide radical formation in response to in vitro stimulation with opsonised zymosan (a bacterial polysaccharide) but in the absence of this additional stimulus, no bryostatin 1 effect was observed. Lymphocyte natural killing activity was decreased 2 h after treatment with bryostatin 1, but the effect was not consistently seen 24 h or 7 days later. With the dose schedule examined no antitumour effects were observed. We recommend that bryostatin 1 is used at a dose of 35 to 50 micrograms m-2 two weekly in phase II studies in patients with malignancies including lymphoma, leukaemia, melanoma or hypernephroma, for which pre-clinical investigations suggest antitumour activity.

Topics: Adult; Aged; Antineoplastic Agents; Bone Marrow; Bryostatins; Colonic Neoplasms; Colony-Forming Units Assay; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Killer Cells, Natural; Lactones; Leukocytes; Macrolides; Mesothelioma; Middle Aged; Neoplasms; Neutrophils; Ovarian Neoplasms; Phagocytosis; Sarcoma

Protein kinase C (PKC) influences cellular sensitivity to cis-diamminedichloroplatinum(II) (cDDP). We have investigated whether the PKC signal transduction pathway is affected during the development of cellular resistance to cDDP. Activators of PKC, such as phorbol 12,13-dibutyrate (PDBu), enhanced the sensitivity of human small cell lung cancer H69 cells to cDDP by 2-fold but had no effect on the sensitivity of cDDP-resistant H69 cells (H69/CP) to cDDP. The maximum sensitization was achieved with 10 nM PDBu and blocked by down-regulation of PKC with higher concentrations of PDBu (1 microM) or bryostatin 1 (0.1 microM). PKC activity was decreased significantly in H69/CP cells compared to the drug-sensitive variant. A similar reduction in PKC activity was noted in ovarian carcinoma 2008 cells that were resistant to cDDP. A modest decrease in PKC activity was also observed in etoposide-resistant H69 (H69/VP-16) cells but not in Taxol-resistant H69 cells or bleomycin-resistant human head and neck carcinoma A-253 cells. H69 cells expressed conventional PKC alpha and-beta, novel PKC delta, atypical PKC zeta and-iota, and novel/atypical PKC mu. A decrease in cPKC alpha and-beta and an increase in nPKC delta were associated with the cDDP-resistant phenotype. The abundance of aPKC zeta or-iota was unaffected. H69/ VP-16 cells also displayed a reduction in cPKC beta and an increase in nPKC delta. Taxol-resistant H69 cells had no alteration in the expression of any of the PKC isozymes. Thus, a reduction in cPKCs and an increase in nPKC may be associated with cDDP resistance.

Topics: Antineoplastic Agents; Bleomycin; Bryostatins; Carcinoma; Carcinoma, Small Cell; Cisplatin; Drug Resistance, Neoplasm; Enzyme Activation; Etoposide; Female; Head and Neck Neoplasms; Herpes Simplex Virus Protein Vmw65; Humans; Lactones; Lung Neoplasms; Macrolides; Ovarian Neoplasms; Paclitaxel; Phorbol 12,13-Dibutyrate; Protein Kinase C; Signal Transduction; Tumor Cells, Cultured