bryostatin-1 and Anemia

The Gynecologic Oncology Group performed a randomized phase II study to determine the antitumor activity and toxicity of two different schedules of administration of bryostatin-1 in patients with persistent or recurrent squamous cell carcinoma of the cervix.. Eligible patients were randomized to receive either bryostatin-1 25 mug/m(2) as a 1-h infusion weekly for 3 weeks followed by a 1-week rest (Regimen I) or bryostatin-1 120 mug/m(2) as a 72-h continuous infusion every 2 weeks (Regimen II).. A total of 70 patients were enrolled on this study. There were 32 eligible patients on Regimen I and 33 eligible patients on Regimen II; all but 4 had had prior chemotherapy. There were two partial responses (one on each treatment arm) among the 65 eligible patients (response rates = 3.1 and 3.0%, respectively). Ten patients on each regimen had stable disease. The most common adverse event was myalgia; 8 of 32 patients (25%) on Regimen I and 16 of 33 patients (48%) on Regimen II had any grade of myalgia. There was no significant myelosuppression on either treatment arm.. Both of these schedules and doses of bryostatin-1 are inactive as single agents in the second-line treatment of squamous cell carcinoma of the cervix.

Topics: Adult; Aged; Anemia; Bryostatins; Carcinoma, Squamous Cell; Confidence Intervals; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Lactones; Macrolides; Middle Aged; Neoplasm Recurrence, Local; Uterine Cervical Neoplasms

Bryostatin 1 is a macrocyclic lactone derived from the marine invertebrate Bugula neritina. In vitro, bryostatin 1 activates protein kinase C (PKC), induces the differentiation of a number of cancer cell lineages, exhibits anti-tumour activity and augments the response of haemopoietic cells to certain growth factors. In vivo, bryostatin 1 is also immunomodulatory, but the range of tumours which respond to bryostatin 1 in xenograft tumour models is mostly the same as the in vitro tumour types, suggesting a direct mode of action. Nineteen patients with advanced malignancy were entered into a phase I study in which bryostatin 1 was given as a 24 h intravenous infusion, weekly, for 8 weeks. Myalgia was the dose-limiting toxicity and the maximum tolerated dose was 25 micrograms m-2 per week. The myalgia was cumulative and dose related, and chiefly affected the thighs, calves and muscles of extraocular movement. The mechanism of the myalgia is unknown. CTC grade 1 phlebitis affected every patient for at least one cycle and was caused by the diluent, PET, which contains polyethylene glycol, ethanol and Tween 80. Most patients experienced a 1 g dl-1 decrease in haemoglobin within 1 h of commencing the infusion which was associated with a decrease in haematocrit. Radiolabelled red cell studies were performed in one patient to investigate the anaemia. The survival of radiolabelled red cells during the week following treatment was the same as that seen in the week before treatment. However, there was a temporary accumulation of radiolabelled red cells in the liver during the first hour of treatment, suggesting that pooling of erythrocytes in the liver might account for the decrease in haematocrit. Total or activated PKC concentrations were measured in the peripheral blood mononuclear cells (PBMCs) of three patients for the first 4 h of treatment and during the last hour of the infusion. This showed that PKC activity was significantly modulated during the infusion. Bryostatin 1 is immunomodulatory in vitro, and we have confirmed this activity in vivo. An investigation of the first three cycles of treatment in seven patients showed an increased IL-2-induced proliferative response in peripheral blood lymphocytes and enhanced lymphokine-activated killer (LAK) activity. A previously reported rise in serum levels of interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF 1) was not confirmed in our study; of nine patients in this study, including patients at all dose l

Topics: Adult; Aged; Anemia; Antineoplastic Agents; Bryostatins; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Hematocrit; Humans; Infusions, Intravenous; Interleukin-6; Killer Cells, Lymphokine-Activated; Lactones; Leukocytes, Mononuclear; Macrolides; Male; Middle Aged; Neoplasms; Phlebitis; Protein Kinase C; Tumor Necrosis Factor-alpha