Phase I/II study of docetaxel and atrasentan in men with metastatic hormone-refractory prostate cancer (HRPC)

14504

Background: Docetaxel is first-line standard treatment for metastatic HRPC. New combinations with targeted therapies may improve clinical responses. . Atrasentan is an endothelin receptor A (ETA) inhibitor with an IC50 in the pM range. Clinical studies suggest atrasentan delays time to disease progression, bone turnover markers and PSA kinetics. Methods: We conducted a Phase I/II trial of docetaxel and atrasentan to define the maximum tolerated dose (MTD), dose limiting toxicity (DLT), pharmacokinetics (PK) and treatment response of this regimen. Patients were treated with docetaxel IV every 3 weeks at doses ranging from 60 to 75 mg/m2. Atrasentan was given orally at 10 mg daily starting on Day 3 and continuously thereafter. Initially, we defined DLT as grade IV neutropenia, but subsequently amended the protocol to redefine DLT as grade IV neutropenia lasting ≥ 7 days. Plasma PK evaluations were conducted for each drug when administered alone (Cycle 1 Day 1, 21) and together (Cycle 2 Day 1). Serial samples were evaluated by LC-MS and data were modeled using a standard, two-stage approach. Results: 18 patients were enrolled over 3 dose levels (9 at 60 mg/m2; 6 at 70 mg/m2 and 3 at 75 mg/m2) in the phase I portion and to date 9 more patients have been enrolled in a dose expansion cohort at a docetaxel dose of 70 mg/m2. Patient demographics include median age 69, PSA level 87.3 ng/ml, hemoglobin 12.7 g/dl, and KPS 90%. DLT, initially any grade IV neutropenia, was seen at every dose level, however no grade IV neutropenia has lasted ≥ 7 days and no MTD has been defined to date. Drug-related grade III/IV toxicities included only neutropenia (42%); grade I-II toxicities included fatigue, peripheral edema, and nausea. To date, 5 of 15 evaluable patients who have been treated with 70–75 mg/m2 of docetaxel and 10 mg of atrasentan demonstrate a sustained PSA response. Preliminary PK data in 11 patients show a mean docetaxel terminal half-life of 46 hr and systemic clearance of 55 L/hr. The median difference in systemic clearance between the cycles was 18% with values increasing in 67% of subjects. Conclusions: The combination of docetaxel and atrasentan appears to be well tolerated to date. The study is ongoing to more accurately determine safety, response and potential pharmacokinetic interactions.

[Table: see text]

Secondary myelodysplasia and acute leukemia in breast cancer patients after autologous bone marrow transplant

PURPOSE

To determine the incidence of myelodysplasia (MDS) and/or acute leukemia (AL) in breast cancer patients after high-dose chemotherapy (HDC) with a single conditioning regimen and autologous bone marrow transplant (ABMT), and analyze the cytogenetic abnormalities that arise after HDC.

PATIENTS AND METHODS

We retrospectively reviewed the records of 864 breast cancer patients who underwent ABMT at Duke University Medical Center, Durham, NC, from 1985 through 1996 who received the same preparative regimen of cyclophosphamide 1,875 mg/m2 for 3 days, cisplatin 55 mg/m2 for 3 days, and BCNU 600 mg/m2 for 1 day (CPB). Pretransplant cytogenetics were analyzed in all patients and posttransplant cytogenetics were evaluated in four of five patients who developed MDS/AL.

RESULTS

Five of 864 patients developed MDS/AL after HDC with CPB and ABMT. The crude cumulative incidence of MDS/AL was 0.58%. The Kaplan-Meier curve shows a 4-year probability of developing MDS/AL of 1.6%. Pretransplant cytogenetics performed on these five patients were all normal. Posttransplant cytogenetics were performed on four of five patients and they were abnormal in all four, although only one patient had the most common cytogenetic abnormality associated with secondary MDS/AL (chromosome 5 and/or 7 abnormality).

CONCLUSION

Whereas MDS/AL is a potential complication of HDC with CPB and ABMT, the incidence in this series of patients with breast cancer was relatively low compared with that reported in patients with non-Hodgkin's lymphoma who underwent ABMT. The cytogenetic abnormalities reported in this group of breast cancer patients were not typical of those seen in prior reports of secondary MDS/AL and appear to have occurred after HDC.

The Duke AFM Program. Intensive induction chemotherapy for metastatic breast cancer

Forty-five patients have completed treatment with AFM, an intensive induction chemotherapy regimen composed of Adriamycin (doxorubicin, Adria Laboratories, Columbus, Ohio), 5-fluorouracil, and methotrexate with folinic acid rescue. This regimen was designed to produce rapid and extensive tumor shrinkage prior to high-dose alkylating agent chemotherapy with autologous marrow support. The overall response rate was 91%, and 38% of patients achieved complete clinical responses after a mean of 70 days on treatment. Hematologic and mucosal toxicity were extensive, but no toxic deaths were noted. AFM is a potent remission induction regimen for metastatic breast cancer, but its considerable toxicity suggests caution in its use for routine breast cancer treatment.

Phase I studies of recombinant interferon-gamma

A phase I study of the effects of intravenous administration of interferon-gamma on 31 patients was performed. The effects of dose, schedule, and chronic administration were studied. In the first phase of the study, a dose range of 0.01-500 MU/m2 (0.0002-25 mg/m2) was tested and we found the maximum tolerated dose to be 400 MU/m2; the dose-limiting toxicity with this preparation was hypotension. In the second phase, three different schedules of administration were tested. There were no significant differences in toxicity between a 20 min, a 4 h, or a 24 h infusion of 60 MU/m2 (3 mg/m2). In the third phase, patients received chronic administration of either 1 or 30 MU/m2. Patients given 30 MU/m2 twice a week for 4 weeks showed more symptoms--fever, nausea, and orthostasis--than those treated with 1 MU/m2. No significant changes were seen in natural killer cell activity, antibody-dependent complement cytotoxicity, or monocyte cytotoxicity at any dose. Maximal stimulation of 2',5'-oligodenylate synthetase occurred at low doses (12 MU/m2). Depressed bone marrow colony formation for CFU-GM, BFU-E, and CFU-GEMM in vivo was noted. No objective antitumor responses were noted. This preparation of recombinant interferon-gamma can be given in doses as high as 400 MU/m2. Chronic administration would appear to be limited to 30 MU/m2. However, lower doses may give maximal biologic responses. These studies provide further information on the biologic effects of a wide dose range and a variety of schedules of recombinant interferon-gamma.

High-dose combination cyclophosphamide, cisplatin, and melphalan with autologous bone marrow support. A clinical and pharmacologic study

A total of 23 patients were treated at five dose escalations with high-dose combination cyclophosphamide, cisplatin, and melphalan with autologous bone marrow support. The maximum tolerated doses of cyclophosphamide, cisplatin, and melphalan were 5,625, 180, and 80 mg/m2, respectively. The dose-limiting toxicity was cardiac toxicity. Objective tumor regression occurred in 14 of 18 evaluable cases, with a median duration of 3.5 months. Pharmacokinetic evaluation of melphalan in 20 patients revealed a dose-related increase in maximum plasma concentration (Cmax) and area under the curve (AUC). Perturbation of the melphalan plasma half-life and AUC, associated with severe toxicity, resulted when renal insufficiency occurred. The results suggest that high-dose combination cyclophosphamide, cisplatin, and melphalan produces frequent, rapid responses in breast cancer, melanoma, and sarcoma, although with significant extramedullary toxicity. The pharmacokinetics suggest that modification of the treatment schedule may result in a reduction of treatment-related toxicity.

Clinical and pharmacologic effects of high dose single agent busulfan with autologous bone marrow support in the treatment of solid tumors

A Phase I-II clinical trial of high dose single agent busulfan (16-20 mg/kg) administered over a 4-day period was undertaken. Pharmacokinetic measurements reveal that steady state total plasma busulfan levels between 2 and 10 microM were achieved by the second day and maintained through the remaining treatment period. Urinary excretion of mutagenic activity monitored by the Salmonella mutagenesis assay persisted for up to 48 h following the last dose of busulfan. The treatment showed specificity for myelocytic precursors as evidenced by selective depression of granulocytes with relative sparing of lymphocytic elements, and by differences in DNA damage as measured by a nucleoid sedimentation assay. Dose limiting toxicity was mucositis, anorexia, and hepatic toxicity. Transient autoimmune disorders were observed in three of the six patients. Partial responses were seen in two of five patients with melanoma, but these lasted for only 2 and 3 months. High dose busulfan represents an alkylating agent with marked myelocytic selectivity and may be useful for inclusion in intensive combination regimens.

Effects of gamma-interferon on the endocrine system: results from a phase I study

Interferon causes profound biological changes when given to patients with cancer and many of these could not be predicted from in vitro or animal model systems. We documented significant changes in hormonal levels for a group of 18 patients who were participants in a Phase I gamma-interferon trial. Adrenocorticotropic hormone, cortisol, and growth hormone were all significantly elevated 2 h after treatment with gamma-interferon, with cortisol and adrenocorticotropic hormone returning to base line by 24 h. A placebo group failed to show this change, suggesting a specific interferon effect. Possible mechanisms for these findings and implications for the use of interferons are discussed.

Comparison of the efficacy of a two-day and a five-day schedule for infusing intravenous gamma globulin in the treatment of immune thrombocytopenic purpura in adults

The standard schedule for treating immune thrombocytopenia purpura in adults with intravenous immunoglobulin G infusion (IVIG), 400 mg/kg per day for five days, was compared with a shorter schedule using 1,000 mg/kg per day for two days. Both schedules were found to be effective in correcting thrombocytopenia. Eleven of the 17 patients treated with the five-day regimen and nine of 10 patients treated with the two-day regimen had significant responses. Patients with an initial platelet count of less than 20,000 platelets/mm3 or with an estimated in vivo platelet survival in excess of 90 hours were less likely to have a response than were other patients. There were no serious side effects in either group, but thrombophlebitis was observed in some patients receiving the five-day regimen when a single intravenous catheter was used for more than three days. Headaches and, less commonly, low-grade fever were noted in some patients receiving the two-day regimen when infusions were given at flow rates in excess of 0.04 ml/kg/minute. Since the two-day regimen requires shorter hospitalization and corrects thrombocytopenia slightly faster than the five-day course, it may be particularly useful in correcting thrombocytopenia in hospitalized patients requiring splenectomy or other surgery.