Nicole Onetto

BACKGROUND: The period of neutropenia after autologous bone marrow transplantation results in substantial morbidity and mortality. The results of previous phase I-II clinical trials suggest that recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) may accelerate neutrophil recovery and thereby reduce complications in patients after autologous bone marrow transplantation. METHODS: We conducted a randomized, double-blind, placebo-controlled trial at three institutions. The study design and treatment schedules were identical, and the results were pooled for analysis. One hundred twenty-eight patients were enrolled. Sixty-five patients received rhGM-CSF in a two-hour intravenous infusion daily for 21 days, starting within four hours of the marrow infusion, and 63 patients received placebo. RESULTS: No toxic effects specifically ascribed to rhGM-CSF were observed. The patients given rhGM-CSF had a recovery of the neutrophil count to 500 x 10(6) per liter 7 days earlier than the patients who received placebo (19 vs. 26 days, P less than 0.001), had fewer infections, required 3 fewer days of antibiotic administration (24 vs. 27 days, P = 0.009), and required 6 fewer days of initial hospitalization (median, 27 vs. 33 days; P = 0.01). There was no difference in the survival rate at day 100. CONCLUSIONS: In patients undergoing autologous bone marrow transplantation for lymphoid neoplasia, rhGM-CSF significantly lessens morbidity. Further studies will be required to establish its optimal dosage and schedule of administration.

The taxanes represent the first class of antimicrotubule agents with a new mechanism of cytotoxic action since the introduction of the vinca alkaloids several decades ago. These compounds may prove to be the "anticancer drugs of the 1990s," just as the anthracyclines and the platinum compounds were the "anticancer drugs" of the 1970s and 1980s. Like the platinums, taxol, the prototypic taxane, has shown significant antineoplastic activity in patients with advanced ovarian cancer, with response rates ranging from 20% to 50%. Moreover, taxol has been shown to be useful in patients with platinum-resistant ovarian cancer. Although phase II screening is not yet complete, the results of phase II studies of taxol in advanced cancers of the ovary, breast (response rates, 56% to 62%), and lung (response rates, 21% to 24%) have rekindled interest in the microtubule as a prime strategic target for cancer therapy. After briefly reviewing the mechanisms of antineoplastic action and resistance and the results of preliminary clinical and pharmacological studies, this review will discuss several critical issues that will be addressed in future clinical trials, developmental directions, and drug supply. Although this review will focus primarily on taxol, the results of preliminary investigations with the semisynthetic taxane analog taxotere will also be discussed.

PURPOSE: BMS-182248-1 (BR96-doxorubicin immunoconjugate) is a chimeric human/mouse monoclonal antibody linked to approximately eight doxorubicin molecules. The antibody is directed against the Lewis-Y antigen, which is expressed on 75% of all breast cancers but is limited in expression on normal tissues. Preclinical xenograft models demonstrated significant antitumor activity, including cures. A randomized phase II design was chosen to estimate the activity of the BR96-doxorubicin conjugate in metastatic breast cancer in a study population with confirmed sensitivity to single-agent doxorubicin. PATIENTS AND METHODS: Patients with measurable metastatic breast cancer and immunohistochemical evidence of Lewis-Y expression on their tumor received either BR96-doxorubicin conjugate 700 mg/m2 IV over 24 hours or doxorubicin 60 mg/m2 every 3 weeks. Patients were stratified on the basis of prior doxorubicin exposure, visceral disease, and institution. Cross-over to the opposite treatment arm was allowed with progressive or persistently stable disease. RESULTS: Twenty-three patients who had received a median of one prior chemotherapy regimen were assessable. There was one partial response (7%) in 14 patients receiving the BR96-doxorubicin conjugate and one complete response and three partial responses (44%) in nine assessable patients receiving doxorubicin. No patient experienced a clinically significant hypersensitivity reaction. The toxicities were significantly different between the two treatment groups, with the BR96-doxorubicin conjugate group having limited hematologic toxicity, whereas gastrointestinal toxicities, including marked serum amylase and lipase elevations, nausea, and vomiting with gastritis, were prominent. CONCLUSION: The BR96-doxorubicin immunoconjugate has limited clinical antitumor activity in metastatic breast cancer. The gastrointestinal toxicities likely represent binding of the agent to normal tissues expressing the target antigen and may have compromised the delivery of the immunoconjugate to the tumor sites.