Leroy M. Parker

A Radioimmunoassay Using a Monoclonal Antibody to Monitor the Course of Epithelial Ovarian Cancer

The murine monoclonal antibody OC 125 reacts with an antigen (CA 125) common to most nonmucinous epithelial ovarian carcinomas. An assay has been developed to detect CA 125 in serum. By this assay, only 1 per cent of 888 apparently healthy persons and 6 per cent of 143 patients with nonmalignant disease had serum CA 125 levels above 35 U per milliliter. In contrast, 83 of 101 patients (82 per cent) with surgically demonstrated ovarian carcinoma had elevated levels of antigen. In 38 patients with epithelial ovarian carcinoma monitored on 2 to 18 occasions during 2 to 60 months, antigen levels ranged from less than 1 to more than 8000 U per milliliter. Rising or falling levels of CA 125 correlated with progression or regression of disease in 42 of 45 instances (93 per cent). Determination of CA 125 levels may aid in monitoring the response to treatment in patients with epithelial ovarian cancer.

Double-Blind, Randomized Trial Comparing the Efficacy and Tolerability of Fulvestrant Versus Anastrozole in Postmenopausal Women With Advanced Breast Cancer Progressing on Prior Endocrine Therapy: Results of a North American Trial

PURPOSE To compare the efficacy and tolerability of fulvestrant (formerly ICI 182,780) with anastrozole in the treatment of advanced breast cancer in patients whose disease progresses on prior endocrine treatment. PATIENTS AND METHODS In this double-blind, double-dummy, parallel-group study, postmenopausal patients were randomized to receive either an intramuscular injection of fulvestrant 250 mg once monthly or a daily oral dose of anastrozole 1 mg. The primary end point was time to progression (TTP). Secondary end points included objective response (OR) rate, duration of response (DOR), and tolerability. RESULTS Patients (n = 400) were followed for a median period of 16.8 months. Fulvestrant was as effective as anastrozole in terms of TTP (hazard ratio, 0.92; 95.14% confidence interval [CI], 0.74 to 1.14; P =.43); median TTP was 5.4 months with fulvestrant and 3.4 months with anastrozole. OR rates were 17.5% with both treatments. Clinical benefit rates (complete response + partial response + stable disease > or = 24 weeks) were 42.2% for fulvestrant and 36.1% for anastrozole (95% CI, -4.00% to 16.41%; P =.26). In responding patients, median DOR (from randomization to progression) was 19.0 months for fulvestrant and 10.8 months for anastrozole. Using all patients, DOR was significantly greater for fulvestrant compared with anastrozole; the ratio of average response durations was 1.35 (95% CI, 1.10 to 1.67; P < 0.01). Both treatments were well tolerated. CONCLUSION Fulvestrant was at least as effective as anastrozole, with efficacy end points slightly favoring fulvestrant. Fulvestrant represents an additional treatment option for postmenopausal women with advanced breast cancer whose disease progresses on tamoxifen therapy.

Clinical Activity of Trastuzumab and Vinorelbine in Women With HER2-Overexpressing Metastatic Breast Cancer

PURPOSE To determine the response rate and toxicity profile of trastuzumab administered concurrently with weekly vinorelbine in women with HER2-overexpressing advanced breast cancer. PATIENTS AND METHODS Forty women with HER2-positive (+3 by immunohistochemistry, n = 30; +2 or positive, n = 10) breast cancer were enrolled onto a study of trastuzumab (4 mg/kg x 1, 2 mg/kg weekly thereafter) and vinorelbine (25 mg/m2 weekly, with dose adjusted each week for neutrophil count). Eighty-two percent of women had received prior chemotherapy as part of adjuvant (30%), metastatic (25%), or both (28%) treatment, including substantial portions of patients who had previously received either anthracyclines (20%), taxanes (15%), or both types (38%) of chemotherapy. RESULTS Responses were observed in 30 of 40 patients (overall response rate, 75%, conditional corrected 95% confidence interval, 57% to 89%). The response rate was 84% in patients treated with trastuzumab and vinorelbine as first-line therapy for metastatic disease, and 80% among HER2 +3 positive patients. High response rates were also seen in women treated with second- or third-line therapy, and among patients previously treated with anthracyclines and/or taxanes. Combination therapy was feasible; patients received concurrent trastuzumab and vinorelbine in 93% of treatment weeks. Neutropenia was the only grade 4 toxicity. No patients had symptomatic heart failure. Grade 2 cardiac toxicity was observed in three patients. Prior cumulative doxorubicin dose in excess of 240 mg/m2 and borderline pre-existing cardiac function were associated with grade 2 cardiac toxicity. CONCLUSION Trastuzumab in combination with vinorelbine is highly active in women with HER2-overexpressing advanced breast cancer and is well tolerated.

Preoperative therapy with trastuzumab and paclitaxel followed by sequential adjuvant doxorubicin/cyclophosphamide for HER2 overexpressing stage II or III breast cancer: a pilot study.

PURPOSE Trastuzumab combined with chemotherapy improves outcomes for women with human epidermal growth factor receptor 2 (HER2) overexpressing advanced breast cancer. We conducted a pilot study of preoperative trastuzumab and paclitaxel, followed by surgery and adjuvant doxorubicin and cyclophosphamide chemotherapy in earlier stage breast cancer. PATIENTS AND METHODS Patients with HER2-positive (2+ or 3+ by immunohistochemistry) stage II or III breast cancer received preoperative trastuzumab (4 mg/kg x 1, then 2 mg/kg/wk x 11) in combination with paclitaxel (175 mg/m(2) every 3 weeks x 4). Patients received adjuvant doxorubicin and cyclophosphamide chemotherapy following definitive breast surgery. Clinical and pathologic response rates were determined after preoperative therapy. Left ventricular ejection fraction and circulating levels of HER2 extracellular domain were measured serially. RESULTS Preoperative trastuzumab and paclitaxel achieved clinical response in 75% and complete pathologic response in 18% of the 40 women on study. HER2 3+ tumors were more likely to respond than 2+ tumors (84% v 38%). No unexpected treatment-related noncardiac toxicity was encountered. Four patients developed grade 2 cardiotoxicity (asymptomatic declines in left ventricular ejection fraction). Baseline HER2 extracellular domain was elevated in 24% of patients and declined with preoperative therapy. Immunohistochemical analyses of posttherapy tumor specimens indicated varying patterns of HER2 expression following trastuzumab-based treatment. CONCLUSION Preoperative trastuzumab and paclitaxel is active against HER2 overexpressing early-stage breast cancer and may be feasible as part of a sequential treatment program including anthracyclines. The observed changes in cardiac function merit further investigation. Correlative analyses of HER2 status may facilitate understanding of tumor response and resistance to targeted therapy.

Docetaxel Administered on a Weekly Basis for Metastatic Breast Cancer

PURPOSE To evaluate the safety and efficacy of weekly docetaxel in women with metastatic breast cancer. PATIENTS AND METHODS Twenty-nine women were enrolled onto a study of weekly docetaxel given at 40 mg/m(2)/wk. Each cycle consisted of 6 weeks of therapy followed by a 2-week treatment break, repeated until disease progression or removal from study for toxicity or patient preference. Fifty-two percent of patients had been previously treated with adjuvant chemotherapy; 21% had received prior chemotherapy for metastatic breast cancer, and 31% had previously received anthracyclines. All patients were assessable for toxicity; two patients were not assessable for response but are included in an intent-to-treat analysis. RESULTS Patients received a median of 18 infusions, with a median cumulative docetaxel dose of 720 mg/m(2). There were no complete responses. Twelve patients had partial responses (overall response rate, 41%; 95% confidence interval, 24% to 61%), all occurring within the first two cycles. Similar response rates were observed among subgroups of patients previously treated either with any prior chemotherapy or with anthracyclines. An additional 17% of patients had stable disease for at least 6 months. The regimen was generally well tolerated. There was no grade 4 toxicity. Only 28% of patients had any grade 3 toxicity, most commonly neutropenia and fatigue. Acute toxicity, including myelosuppression, was mild. Fatigue, fluid retention, and eye tearing/conjunctivitis became more common with repetitive dosing, although these side effects rarely exceeded grade 2. Dose reductions were made for eight of 29 patients, most often because of fatigue (n = 5). CONCLUSION Weekly docetaxel is active in treating patients with metastatic breast cancer, with a side effect profile that differs from every-3-weeks therapy.

New Approaches to Cancer Chemotherapy with Methotrexate

THE folic acid antagonists were shown to have antileukemic activity by Farber and his colleagues in 1948.1 Since then the prototypical folic acid antagonist, methotrexate, has been found effective ...

High dose methotrexate with leucovorin rescue: Rationale and spectrum of antitumor activity

Methotrexate (MTX) in high doses (3 to 7.5 g/m2) with leucovorin rescue (HDMTX-LCV) can be delivered on a weekly basis in a setting of proper pharmacologic monitoring. Myelosuppression occurs in 28 per cent of the patients and in 8 per cent of the courses and usually results from delayed MTX excretion secondary to mild reversible nephrotoxicity. The incidence of tumor regression was 50 per cent in head and neck cancer; 59 per cent in non-Hodgkins lymphoma; 40 per cent in small cell lung cancer; 24 to 50 per cent in breast cancer and 50 per cent in osteogenic carcinoma, for an over-all response rate of 39 per cent (70 of 178) in patients with disseminated cancer. HDMTX-LCV is not recommended for the conventional treatment of metastatic cancer because of the potential for toxicity and the fact that the response rates cited are probably not superior to those which can be achieved by conventional doses of MTX. However, the relative lack of myelosuppression and mucositis, when compared to conventional unrescued MTS, and the achievement of therapeutic concentrations of MTX in the central nervous system with the HDMTX-LCV program have led to its incorporation into clinical trials of combination chemotherapy.

VEGF as a marker for outcome among advanced breast cancer patients receiving anti-VEGF therapy with bevacizumab and vinorelbine chemotherapy.

Background: Anti-vascular endothelial growth factor therapy (VEGF) is an important new treatment modality in oncology. We sought to determine the efficacy and safety of the humanized monoclonal anti-VEGF antibody, bevacizumab, and vinorelbine as treatment for refractory breast cancer and to explore the role of plasma VEGF as a predictor of treatment outcome. Experimental Design: Eligible patients had received one or two prior chemotherapy regimens for metastatic breast cancer or recurred within 12 months of adjuvant therapy and had measurable disease and adequate end-organ function. Patients received bevacizumab 10 mg/kg every 2 weeks, and vinorelbine each week, until tumor progression or prohibitive toxicity. Plasma VEGF was measured at baseline. Results: Among 56 women treated on protocol, bevacizumab and vinorelbine yielded a 34% response rate (95% confidence interval, 22-48%) and median time to progression of 5.5 months. Activity was observed regardless of tumor hormone receptor status or type or extent of prior chemotherapy. Side effects included uncomplicated neutropenia, hypertension, nasal congestion/epistaxis, and neuropathy, consistent with well-described side effects of the respective agents. Three patients had impaired wound healing following surgical procedures. There were only rare instances of thrombosis or clinically significant proteinuria. Lower levels of baseline VEGF were associated with longer time to progression. Conclusions: Bevacizumab and vinorelbine are well tolerated and effective as treatment for refractory breast cancer. Plasma VEGF warrants further evaluation as a prognostic marker for treatment outcome in advanced breast cancer patients receiving anti-VEGF therapy.

Clinical studyHigh dose methotrexate with leucovorin rescue: Rationale and spectrum of antitumor activity☆

Methotrexate (MTX) in high doses (3 to 7.5 g/m2) with leucovorin rescue (HDMTX-LCV) can be delivered on a weekly basis in a setting of proper pharmacologic monitoring. Myelosuppression occurs in 28 per cent of the patients and in 8 per cent of the courses and usually results from delayed MTX excretion secondary to mild reversible nephrotoxicity. The incidence of tumor regression was 50 per cent in head and neck cancer; 59 per cent in non-Hodgkins lymphoma; 40 per cent in small cell lung cancer; 24 to 50 per cent in breast cancer and 50 per cent in osteogenic carcinoma, for an over-all response rate of 39 per cent (70 of 178) in patients with disseminated cancer. HDMTX-LCV is not recommended for the conventional treatment of metastatic cancer because of the potential for toxicity and the fact that the response rates cited are probably not superior to those which can be achieved by conventional doses of MTX. However, the relative lack of myelosuppression and mucositis, when compared to conventional unrescued MTS, and the achievement of therapeutic concentrations of MTX in the central nervous system with the HDMTX-LCV program have led to its incorporation into clinical trials of combination chemotherapy.

Pharmacokinetic Profile of Intramuscular Fulvestrant in Advanced Breast Cancer

ObjectiveTo characterise the pharmacokinetics of a long-acting formulation of fulvestrant following intramuscular administration of single and multiple doses. Study design: Pharmacokinetic investigations of single and multiple doses of fulvestrant were conducted within two global phase III efficacy studies that compared intramuscular fulvestrant with oral anastrozole in postmenopausal women with hormone-sensitive advanced breast cancer (study 0020, conducted in Europe, Australia and South Africa, and study 0021, conducted in North America).MethodsPatients received once-monthly intramuscular injections of fulvestrant 250mg (1 × 5mL for ≤21 months in study 0020; 2 × 2.5mL for ≤30 months in study 0021). Serial blood samples were collected for the first 28 days after the initial dose and immediately prior to all subsequent monthly doses. Plasma fulvestrant concentrations were determined by high-performance liquid chromatography-tandem mass spectrometry.PatientsTwenty-six (study 0020) and 193 (study 0021) postmenopausal women, comprising the pharmacokinetic subgroups of the phase III efficacy trials, were studied. Patients had shown disease progression or recurrence following previous hormonal therapy for advanced disease or had relapsed after adjuvant endocrine therapy with a nonsteroidal antiestrogen.Outcome measures and resultsFor single-dose fulvestrant 250mg, area under the concentration-time curve from time zero to 28 days (AUC28), maximum observed plasma concentration (Cmax), minimum observed plasma concentration at 28 days (Cmin) and time to maximum plasma concentration (tmax) were determined. For multiple-dose fulvestrant 250mg once monthly, steady-state trough concentrations (Ctrough) were determined. Plasma fulvestrant concentrations reached a peak at a median of 7 days (range 2–8 days) postdose, and declined biexponentially with a slower phase commencing approximately 2–3 weeks postdose. Intersubject variability in Cmax and AUC28 was approximately 6-fold and 4-fold, respectively. Mean parameters for single-dose fulvestrant were: AUC28, 148 μg · day/L; Cmax, 8.2 μg/L; Cmin, 2.6 μg/L; tmax, 7.0 days. Geometric mean Ctrough increased from 2.57 to 6.15 μg/L (study 0020) and from 2.38 to 6.52 μg/L (study 0021) over the first 6 months, reaching steady-state concentrations of approximately 6–7 μg/L (study 0020) or 9 μg/L (study 0021). Preliminary pharmacokinetic analysis, using a naive pooled data approach, suggests that observed single- and multiple-dose plasma profiles can be adequately described with a two-compartment kinetic model. Model-generated steady-state AUC28 values were approximately 300 μg · day/L.ConclusionsThe intramuscular formulation of fulvestrant displays predictable kinetics and approximately 2-fold accumulation on administration once monthly. At the proposed therapeutic dosage (250mg once monthly), plasma fulvestrant concentrations are maintained within a narrow range throughout the administration interval, thus ensuring stable systemic drug exposure during long-term treatment.