Edith A. Perez

Recommendations for the Use of Antiemetics: Evidence-Based, Clinical Practice Guidelines

THE GOAL OF ANTIEMETIC therapy is to prevent nausea and vomiting completely. This goal is achieved for many patients receiving chemotherapy or radiation therapy, and is based on clinical and basic research that has steadily improved the control of emesis over the last 20 years. As therapy has become more effective, it has also become safer, with few side effects associated with the most commonly used regimens. These regimens are convenient for patients to receive and for health care professionals to administer. However, despite improvements, a significant number of patients still experience emesis, and efforts to reduce this side effect of treatment must continue. As antiemetic usage has grown, the classes of agents available for antiemetic treatment, the number of agents, and the indications for antiemetics have all increased as well. The prevention of delayed emesis and anticipatory emesis is equal in importance to the need to prevent acute chemotherapyand radiation-induced emesis. Additionally, managing special and difficult emetic problems and selecting the proper antiemetic approach necessitate identification of the patient’s emetic risk. Although the neuropharmacologic basis of emesis is still incompletely understood, the selection of an appropriate antiemetic regimen is possible and can have an impact on several aspects of clinical care. Goals related to the complete control of emesis, ie, no vomiting, include providing care that is convenient for the patient, treatment that reduces hospitalization and time in the ambulatory setting, and therapy that enhances the patient’s quality of life. Additionally, practitioners need to be mindful of reducing costs of treatment while achieving these goals. 1-3

Delayed emesis following high-dose cisplatin: A double-blind randomised comparative trial of ondansetron (GR 38032F) versus placebo

Despite recent advances in control of acute emesis, delayed nausea and vomiting following cisplatin-based chemotherapy remain a significant cause of treatment-related morbidity. Ondansetron, a selective 5HT3 receptor antagonist, is effective in preventing acute emesis in the initial 24-h period following high-dose cisplatin. The efficacy and safety of ondansetron in preventing the delayed emesis syndrome during days 2-5 after cisplatin (> or = 100 mg/m2) were evaluated in a double-blind, placebo-controlled multicentre trial. 50 patients having two or fewer emetic episodes during the first 24 h were randomised to receive ondansetron (16 mg) or placebo orally three times daily beginning 24 h after cisplatin. Rates of complete control of emesis were higher in ondansetron-treated patients during each study day, 59-78%, compared with 39-50% in placebo-treated patients, but the differences were statistically superior only on the third study day (P = 0.009). 40% of patients in the ondansetron treatment arm and 33% treated with placebo had complete control of emesis during the entire 4-day study period (P = 0.648). Withdrawal from study due to nausea and vomiting occurred in 13% of ondansetron-treated patients compared with 33% in the placebo arm (P = 0.102). Control of nausea was better with ondansetron, but differences were not statistically significant. Adverse effects of oral ondansetron given in this dose schedule were minimal. These data suggest that the delayed emesis syndrome may be partially mediated through the 5HT3 receptor, but that a serotonin antagonist alone provides inadequate control. Further investigation of ondansetron-based therapy in this clinical setting is warranted.

Dose-ranging evaluation of the antiemetic efficacy of intravenous dolasetron in patients receiving chemotherapy with doxorubicin or cyclophosphamide

Selective 5-HT3 antagonists have proven to be safe and effective for the prevention of chemotherapy-induced nausea and vomiting. Dolasetron is a new highly selective addition to this class of antiemetics that has been shown to have significant antiemetic activity in patients receiving cisplatin-containing regimens. This pilot study was designed to evaluate the antiemetic efficacy of dolasetron in cancer patients receiving doxorubicin and/or cyclophosphamide. This study used an openlabel, non-randomized design to evaluate the efficacy and safety of intravenous dolasetron in the prevention of emesis in patients receiving doxorubicin (25–75 mg/m2) and/or cyclophosphamide (400–1200 mg/m2). Sixty-nine patients received a single, intravenous dose of dolasetron over 15–20 min beginning 30 min prior to the start of chemotherapy. Dose levels of dolasetron studied were: 0.3, 0.6, 1.2, 1.8 and 2.4 mg/kg. Patients were monitored for emesis, nausea and adverse events for 24 h after the start of chemotherapy. Overall, 61% of patients experienced complete control of emesis. No significant trend towards increased antiemetic efficacy (P = 0.076) or nausea control with increasing dolasetron dose was noted, although the power to detect significant differences was limited by the small number of patients on the 0.3-mg/kg and 2.4-mg/kg dose levels. Age, gender, and type of chemotherapy were significant predictors of complete antiemetic control. Adverse events were generally mild and included headache, chills, light-headedness, fever, diarrhea, dizziness, and asymptomatic prolongation of ECG intervals. Intravenous dolasetron is safe and effective in the prevention of emesis induced by doxorubicin and/or cyclophosphamide.

Radiation Recall Dermatitis Induced by Edatrexate in a Patient with Breast Cancer

Enhancement of radiation injury to the skin and mucous membranes has been observed with a number of chemotherapeutic agents. A 32-year-old woman with metastatic breast cancer received local radiation therapy to the lumbosacral area. Six weeks later, systemic edatrexate therapy was initiated and a localized painful erythema with edema and a vesicular eruption occurred over the previous site of radiation therapy. Physicians should be aware that edatrexate can cause radiation recall, and that careful use of anti-inflammatory agents may allow continued chemotherapy treatment.

Rapidly alternating radiotherapy and high dose cisplatin chemotherapy in stage IIIB non-small cell lung cancer: Results of a phase I/II study

Alternating radiotherapy and chemotherapy increases tumor cure rates in some animal models with reduced normal tissue damage compared to sequential use of these modalities. To test this concept in non-small cell lung cancer, 23 patients with predominantly Stage IIIB disease were treated on a Northern California Oncology Group pilot study of alternating radiotherapy and high dose cisplatin. Radiotherapy consisted of 6000 cGy delivered in three separate 10-day courses of 200 cGy/fraction/day during weeks 1 and 2, 5 and 6, and 9 and 10. High dose cisplatin, 100 mg/m2 in 3% saline, was administered on weeks 3 and 4, 7 and 8, 11 and 12, and 15 and 16. The response rate in 22 eligible patients is 73% (16/22) with four complete responses and 12 partial responses. Feasibility of this approach is demonstrated by 20/22 patients completing radiotherapy and a median of 2.5 courses of chemotherapy administered. Median survival time is 14.2 months (range 2-40+ months). One- and 2-year survival rates are 64% (14/22) and 41% (9/22), respectively. Hematologic, renal, and radiation-related toxicities were significant but manageable. We conclude that rapid alternation of radiotherapy and a high dose intensity cisplatin regimen is feasible in Stage IIIB non-small cell lung cancer, with a high response rate and acceptable toxicity. The long-term impact on local control and survival remains unclear, although preliminary survival data are encouraging in this poor prognosis population. Further studies of this concept are warranted.

High-dose cisplatin and mitomycin C in advanced non-small cell lung cancer: a phase II study of the Northern California Oncology Group

SummaryTo investigate chemotherapeutic dose intensity in advanced non-small-cell lung cancer (NSCLC), we evaluated a pharmacokinetically designed schedule of high-dose cisplatin (200 mg/m2 per 28-day cycle) plus mitomycin C. Between March 1987 and March 1989, 62 patients were registered for a phase II study of the Northern California Oncology Group (NCOG). The treatment schedule consisted of cisplatin in hypertonic saline given on a divided days 1 and 8 schedule (100 mg/m2 on each day) plus mitomycin C given at a dose of 8 mg/m2 on day 1 of each cycle. In 61 patients evaluable for response analysis, the overall response rate was 39% (24/61), with a complete response being achieved in 6% (4/61) of cases and a partial response, in 33% (20/61). The response according to reviewed histologic subtype included squamous, 53% of patients (10/19); large cell, 31% (4/13); and adenocarcinoma, 34% (10/29). The median survival for all patients was 19.3 weeks. The mean cisplatin and mitomycin C delivered dose intensities in this study were 45 mg/m2 per week (90% of the projected dose) and 1.5 mg/m2 per week (75%). The toxicity of this combination regimen in the 62 enrolled patients was significant but manageable. Leukopenia (WBC, <1,000/mm3) and thrombocytopenia (platelets, <25,000/mm3) occurred in 3# and 8% of patients treated, respectively. Dose-limiting renal toxicity and clinically significant ototoxicity developed in 8 patients each (13%), and a peripheral sensory neuropathy was observed in 17 cases (27%). Whether this type of dose-intensive therapy results in an improved therapeutic index in NSCLC is currently being evaluated in a randomized comparative trial versus standard-dose cisplatin therapy.

Schedule-dependent synergism of edatrexate and cisplatin in combination in the A549 lung-cancer cell line as assessed by median-effect analysis

The methotrexate analog edatrexate has been shown to have greater antitumor activity and an improved therapeutic index as compared with its parent compound in preclinical systems. These studies suggest that edatrexate may have a broad role in the treatment of solid tumors. Information regarding edatrexate in combination with other chemotherapeutic agents is limited. We evaluated the interaction of edatrexate with cisplatin in vitro as assessed by median-effect analysis in the A549 human lung-cancer cell line. The effects of dose, exposure time, and schedule dependence were assessed. Cytotoxicity was evaluated using the tetrazolium-based colorimetric (MTT) assay. The inhibitory concentration producing 50% absorbance (IC50 for edatrexate with 1 h exposure was 1.4μM. For all combination experiments, the edatrexate dose was fixed at 0.2 μM (IC10) whereas cisplatin (CDDP) concentrations were varied for 1-, 3-, and 24-h exposures either before or after edatrexate treatment. Drug interactions were assessed using the combination-index method as defined by median-effect analysis. A synergistic interaction was documented in experiments when edatrexate was applied prior to CDDP (combination index, <1). The combination studies in which edatrexate was used prior to CDDP resulted in significant reduction of all three CDDP IC50 values: 1-h IC50, from 30.0 to 3.9 μM; 3-h IC50, from 21.3 to 1.4 μM; and 24-h IC50, from 1.7 to 0.03 μM. In contrast, synergism was not observed in experiments in which edatrexate treatment occurred after cisplatin exposure. Median-effect analysis is a useful method of determining drug interactions. In the present study, the combination of edatrexate and CDDP demonstrated schedule-dependent synergism, with the synergism being observed only in the setting of edatrexate treatment before CDDP exposure. Due to the potential broad spectrum of activity of edatrexate plus CDDP, further studies are warranted to determine the mechanism responsible for the synergism and to investigate this combination in a variety of tumor models.

Pharmacokinetics of cisplatin in patients receiving interleukin-2-containing treatment regimens.

SummaryPlasma cisplatin pharmacokinetics were determined in 6 patients enrolled in a phase I trial of combined high-dose cisplatin and Interleukin-2 (IL-2) therapy. Cisplatin (100 mg/m2) was given in 3% saline as a 3-h infusion on days 1 and 8 of each 28-day cycle; IL-2(2-4×106 units/m2) was given as an i.v. bolus on days 15–19 in a dose escalation trial. Peak total and ultrafiltrate plasma platinum concentrations were 1.15 and 0.172 μg/ml for cycle 1 and 1.2 and 0.124 μg/ml for cycle 3, respectively. The AUCs for total and ultrafiltrate plasma platinum were 7.33 and 0.965 μg/ml per hour for cycle 1 and 8.48 and 0.924 μg/ml per hour for cycle 3, respectively. Total body clearances for total and ultrafiltrate platinum were 0.051 and 0.525 ml/h for cycle 1 and 0.042 and 0.443 ml/h for cycle 3, respectively. These data demonstrate no significant effects of IL-2 on the plasma pharmacokinetics of cisplatin in the dose schedule given and support the feasibility of this combined modality therapy.

Chemotherapy of metastatic testicular cancer: Current status and future prospects

SummaryIntroduction of the chemotherapeutic agent cisplatin in 1974 initiated 15 years of progress in the management of metastatic testicular cancer at a pace virtually unprecedented in the history of medical oncology. With current cisplatin- and etoposide-based regimens, longterm survival of 80% is consistently achieved. Recently completed clinical trials have defined several prognostic variables that disthinguish good- and poor-prognosis subsets of patients. Since the great majority of patients with good-prognosis disease achieve complete remission and long-term survival, the current focus of research in this patient population has shifted to means of reducing treatment-related toxicity. By comparison, in poor-prognosis patients the cure rate remains an unacceptable 40%–50%. Clinical research in this population has focused primarily on methods of intensifying treatment, such as alternating non-cross-resistant drug combinations, increasing the dose intensity of cisplatin, and investigating new active agents such as ifosfamide. Even in the setting of relapsed or resistant disease, high-dose chemotherapy with or without autologous bone marrow transplant offers the potential for long-term remission in some patients. Future prospects for improving the therapeutic index may include colony-stimulating-factor support to circumvent chemotherapy-related myelosuppression, the use of chemosensitizers to reverse drug resistance, or the introduction of biologic response modifiers into the therapeutic armamentarium.