Andrew D. Seidman

Cardiac Dysfunction in the Trastuzumab Clinical Trials Experience

PURPOSE This study sought to estimate cardiac dysfunction (CD) risk for patients receiving trastuzumab; to characterize observed CD by severity, treatment, and clinical outcome; to assess effects of baseline clinical risk factors on CD; and to assess effects of cumulative doses of anthracyclines and trastuzumab on CD. PATIENTS AND METHODS A retrospective review of records for patients enrolled onto any of seven phase II and III trastuzumab clinical trials was performed. Predefined criteria were used for the diagnosis, and the New York Heart Association functional classification system was used to document CD severity. Product-limit estimates were used to summarize the cumulative anthracycline and trastuzumab doses at the time of CD onset. RESULTS Patients treated with trastuzumab were found to be at an increased risk for CD. The incidence was greatest in patients receiving concomitant trastuzumab and anthracycline plus cyclophosphamide (27%). The risk was substantially lower in patients receiving paclitaxel and trastuzumab (13%) or trastuzumab alone (3% to 7%); however, most of these patients had received prior anthracycline therapy. CD was noted in 8% of patients receiving anthracycline plus cyclophosphamide and 1% receiving paclitaxel alone. Most trastuzumab-treated patients developing CD were symptomatic (75%), and most improved with standard treatment for congestive heart failure (79%). CONCLUSION Trastuzumab is associated with an increased risk of CD, which is greatest in patients receiving concurrent anthracyclines. In most patients with metastatic breast cancer, the risk of CD can be justified given the improvement in overall survival previously reported with trastuzumab.

Phase I Studies of Anti–Epidermal Growth Factor Receptor Chimeric Antibody C225 Alone and in Combination With Cisplatin

PURPOSE The epidermal growth factor (EGF) receptor is frequently overexpressed in epithelial tumors. C225 is a human-to-murine chimeric monoclonal antibody that binds to the receptor and inhibits growth of cancer cells expressing the receptor. We evaluated the pharmacokinetics and toxicity of C225 in patients with advanced tumors overexpressing EGF receptors. PATIENTS AND METHODS We treated 52 patients in three successive phase I clinical trials of C225 as a single dose (n = 13), weekly multiple dose (n = 17), and weekly multiple dose with cisplatin (n = 22). C225 dose levels were 5, 20, 50, and 100 mg/m(2). In the study combining C225 with cisplatin, limited to patients with either head and neck or non-small-cell lung cancer, C225 was further escalated to 200 and 400 mg/m(2). Cisplatin was given at a dose of 60 mg/m(2) once every 4 weeks, and treatment was continued for up to 12 weeks if no disease progression occurred. RESULTS C225 displayed nonlinear pharmacokinetics, with antibody doses in the range of 200 to 400 mg/m(2) being associated with complete saturation of systemic clearance. C225 clearance did not change with repeated administration or with coadministration of cisplatin. Antibodies against C225 were detected in only one patient, and C225-associated toxicity was minimal. Patients experiencing disease stabilization were seen in all studies. In the study combining C225 and cisplatin, nine (69%) of 13 patients treated with antibody doses >/= 50 mg/m(2) completed 12 weeks of therapy, and two partial responses were observed. CONCLUSION C225 has dose-dependent pharmacokinetics, and doses that achieve saturation of systemic clearance are well tolerated. C225 given in combination with cisplatin has biologic activity at pharmacologically relevant doses.

Weekly Trastuzumab and Paclitaxel Therapy for Metastatic Breast Cancer With Analysis of Efficacy by HER2 Immunophenotype and Gene Amplification

PURPOSE This phase II study evaluated weekly trastuzumab and paclitaxel therapy in women with HER2-normal and HER2-overexpressing metastatic breast cancer. Efficacy was correlated with immunohistochemical and fluorescent in situ hybridization (FISH) assay results. PATIENTS AND METHODS Eligible patients had bidimensionally measurable metastatic breast cancer. Up to three prior chemotherapy regimens, including prior anthracycline and taxane therapy, were allowed. Trastuzumab 4 mg/kg and paclitaxel 90 mg/m2 were administered on week 1, with trastuzumab 2 mg/kg and paclitaxel 90 mg/m2 administered on subsequent weeks. HER2 status was evaluated using four different immunohistochemical assays and FISH. RESULTS Patients received a median of 25 weekly infusions (range, one to 85 infusions). Median delivered paclitaxel dose-intensity was 82 mg/m2/wk (range, 52 to 90 mg/m2/wk). The intent-to-treat response rate for all 95 patients enrolled was 56.8% (95% confidence interval, 47% to 67%). A response rate of 61.4% (4.5% complete response, 56.8% partial response) was observed in 88 fully assessable patients. In patients with HER2-overexpressing tumors, overall response rates ranged from 67% to 81% compared with 41% to 46% in patients with HER2-normal expression (ranges reflect the different assay methods used to assess HER2 status). Differences in response rates between patients with HER2-overexpressing tumors and those with normal HER2 expression were statistically significant for all assay methods, with CB11 and TAB250 antibodies and FISH having the strongest significance. Therapy was generally well tolerated, although three patients had serious cardiac complications. CONCLUSION Weekly trastuzumab and paclitaxel therapy is active in women with metastatic breast cancer. Therapy was relatively well tolerated; however, attention to cardiac function is necessary.

Randomized Phase III Trial of Weekly Compared With Every-3-Weeks Paclitaxel for Metastatic Breast Cancer, With Trastuzumab for all HER-2 Overexpressors and Random Assignment to Trastuzumab or Not in HER-2 Nonoverexpressors: Final Results of Cancer and Leukemia Group B Protocol 9840

PURPOSE Phase II trials suggested that weekly paclitaxel might be more effective and less toxic than every-3-weeks administration for metastatic breast cancer (MBC). Cancer and Leukemia Group B (CALGB) protocol 9840 was initiated to address this question. Subsequently trastuzumab was demonstrated to improve outcomes of paclitaxel therapy for human epidermal growth factor receptor-2 (HER-2)-positive patients, and was therefore incorporated. Because inhibition of HER-family signaling had potential efficacy even without HER-2 overexpression, we randomly assigned for trastuzumab in this population. PATIENTS AND METHODS Patients were randomly assigned to paclitaxel 175 mg/m(2) every 3 weeks or 80 mg/m(2) weekly. After the first 171 patients, all HER-2-positive patients received trastuzumab; HER-2 nonoverexpressors were randomly assigned for trastuzumab, in addition to paclitaxel schedule. A total of 577 patients were treated on 9840. An additional 158 patients were included in analyses, for combined sample of 735. The primary end point was response rate (RR); secondary end points were time to progression (TTP), overall survival, and toxicity. Primary comparisons were between weekly versus every-3-weeks paclitaxel, and trastuzumab versus no trastuzumab in HER-2 nonoverexpressors. RESULTS In the combined sample, weekly paclitaxel was superior to every-3-weeks administration: RR (42% v 29%, unadjusted odds ratio [OR] = 1.75; P = .0004), TTP (median, 9 v 5 months; adjusted HR = 1.43; P < .0001), and survival (median, 24 v 12 months; adjusted HR = 1.28; P = .0092). For HER-2 nonoverexpressors, trastuzumab did not improve efficacy. Grade 3 neuropathy was more common with weekly dosing (24% v 12%; P = .0003). CONCLUSION Weekly paclitaxel is more effective than every-3-weeks administration for MBC. Trastuzumab did not improve efficacy for HER-2 nonoverexpressors. Neurotoxicity is a treatment-limiting toxicity for weekly paclitaxel.

Dose-dense therapy with weekly 1-hour paclitaxel infusions in the treatment of metastatic breast cancer.

PURPOSE To evaluate the efficacy and toxicity of paclitaxel administered as a 1-hour infusion on weekly basis, without interruption, to patients with metastatic breast cancer who had received prior therapy. PATIENTS AND METHODS Thirty patients with metastatic breast cancer received sustained weekly paclitaxel therapy at an initial dose of 100 mg/m2 until disease progression. Prior therapy included adjuvant only (n=17), metastatic only (n=7), or both (n=6). Eighteen patients had received prior anthracycline therapy, 12 of whom had demonstrated progression of disease within 12 months of it. All patients were assessable for efficacy; 29 patients were assessable for toxicity. Pharmacokinetic studies of paclitaxel were also performed. RESULTS A total of 469 weekly paclitaxel infusions were administered to 30 patients (median, 14 infusions/patient). The median delivered dose-intensity was 91 mg/m2/wk (range, 80 to 108). The overall response rate was 53% (95% confidence interval [CI], 34% to 72%), with 10% complete responses (CRs) and 43% partial responses (PRs). Median response duration was 7.5 months (range, 2 to 11+). Responses were observed in nine of 18 (50%) patients with prior anthracycline therapy, including six of 12 (50%) with disease progression on anthracycline within 1 year (three of four within 6 months). Therapy was well tolerated and remarkable for a lack of overall and cumulative myelosuppression. Grade 3/4 neutropenia occurred in four patients; febrile neutropenia was not observed. Peripheral neuropathy prohibited dose escalation above 100 mg/m2, and grade 3 neuropathy was observed in two of 21 patients at < or = 100 mg/m2. CONCLUSION Weekly paclitaxel therapy is active and well tolerated in patients with metastatic breast cancer. Weekly therapy should be considered as a current clinical option for these patients and should be incorporated into future comparative clinical trials.

Paclitaxel and recombinant human granulocyte colony-stimulating factor as initial chemotherapy for metastatic breast cancer.

PURPOSE A phase II study of Taxol (paclitaxel; Bristol-Myers Squibb Co, Princeton, NJ) as initial chemotherapy for metastatic breast cancer was conducted. Recombinant human granulocyte colony-stimulating factor (rhG-CSF) was used to ameliorate myelosuppression, the anticipated dose-limiting toxicity. PATIENTS AND METHODS Twenty-eight patients with bidimensionally measurable breast cancer who had not received prior chemotherapy for metastatic disease were treated. Taxol was administered at 250 mg/m2 as a continuous 24-hour intravenous (i.v.) infusion every 21 days. rhG-CSF was administered at 5 micrograms/kg/d subcutaneously on days 3 through 10. RESULTS Objective responses were observed in 16 of 26 assessable patients (62%; 95% confidence interval, 41% to 80%). There were three (12%) complete responses (CRs) and 13 (50%) partial responses (PRs). Ten of 16 patients (63%) who had received prior adjuvant chemotherapy responded, which included one CR and four PRs among eight patients who had received prior doxorubicin-containing therapy. Responses were observed in all sites of metastatic disease. The median time to first objective response was 5 weeks (range, 1 to 14). Administration of rhG-CSF was associated with a short duration of neutropenia (median, 2 days with absolute neutrophil count < 500 cells/microL). Eight of 26 patients (31%) who received more than one course received subsequent therapy without dose reduction. One hundred seventy-eight cycles of treatment were administered, with a median of six cycles per patient (range, one to 19). Eight courses (4.5%) were associated with admissions for neutropenic fever. Twenty-two patients (79%) did not require admission for neutropenic fever. Treatment was well tolerated. Adverse effects included generalized alopecia in all patients. Myalgias, arthralgias, and peripheral neuropathy were mild. No hypersensitivity reactions and no cardiac toxicity were observed. CONCLUSION Taxol is highly active as initial chemotherapy for metastatic breast cancer. Administration of rhG-CSF reduced the incidence, depth, and duration of neutropenia, compared with published prior experience. Further studies of Taxol in breast cancer, including combinations with other active agents, are clearly warranted.

Paclitaxel as second and subsequent therapy for metastatic breast cancer : activity independent of prior anthracycline response

PURPOSE Two phase II clinical trials were performed to determine efficacy and tolerability of paclitaxel (Taxol; Bristol-Myers Squibb Co, Wallingford, CT) and granulocyte colony-stimulating factor ([G-CSF] Neupogen; Amgen, Inc, Thousand Oaks, CA) as second or subsequent therapy for metastatic breast cancer. PATIENTS AND METHODS Paclitaxel plus G-CSF was administered as a second stage IV regimen to 25 patients with metastatic breast cancer at a dose of 250 mg/m2 intravenously over 24 hours. Fifty-two patients received paclitoxel plus G-CSF at 200 mg/m2 as a third or subsequent regimen (no restriction on number of prior regimens or on prior high-dose chemotherapy). All patients had received prior anthracycline treatment, and ultimately had progressive bidimensionally measurable disease. RESULTS Twenty-five of 76 patients (32.8%) had a major objective response (95% confidence interval [CI], 14% to 37%). The median duration of response was 7 months (range, 1 to 20+). Responses were as likely in patients with disease demonstrated to be unresponsive to anthracycline, ie, de novo resistance (11 of 37, or 30%) as in those with disease that once exhibited anthracycline sensitivity, ie, acquired resistance, (10 of 31, or 32%). G-CSF administration was associated with febrile neutropenic episodes in 36 of 402 cycles (9%) in 16 of 76 patients (21%). CONCLUSION Paclitaxels clinically significant activity against metastatic breast cancer extends to patients with many prior chemotherapy regimens. The lack of impact of prior doxorubicin therapy on the likelihood of subsequent response to paclitaxel suggests an important role for this agent in the treatment of refractory metastatic breast cancer.

Phase II trial of paclitaxel by 3-hour infusion as initial and salvage chemotherapy for metastatic breast cancer.

PURPOSE To evaluate the efficacy and safety of paclitaxel administered by 3-hour infusion as initial and salvage chemotherapy for metastatic breast cancer. PATIENTS AND METHODS Forty-nine patients with metastatic breast cancer received paclitaxel via 3-hour intravenous infusion after standard premedication. Prophylactic granulocyte colony-stimulating factor (G-CSF) was not used, and chemotherapy was cycled every 3 weeks. For 25 patients who received paclitaxel as initial therapy (group I), the starting dose was 250 mg/m2. Twenty-four patients who had received two or more prior regimens, including an anthracycline (group II), started at 175 mg/m2. Paclitaxel pharmacokinetics were evaluated in 23 patients in group I. RESULTS Grade 3 and 4 toxicities included (groups I/II) neutropenia (36%/33%), thrombocytopenia (0%/8%), anemia (0%/13%), neuropathy (8%/0%), arthralgia/myalgia (16%/4%), and mucositis (4%/4%). No significant hypersensitivity-type reactions or cardiac arrhythmias were seen. Six patients who received paclitaxel at > or = 250 mg/m2 experienced transient photopsia, without apparent chronic neuro-ophthalmologic sequelae. The mean peak plasma paclitaxel concentration was 5.87 mumol/L (range, 1.99 to 7.89) for these patients, and 6.08 mumol/L (range, 0.81 to 13.81) for 17 of 19 patients who did not experience visual symptoms. In 25 assessable patients in group I at a median follow-up time of 12 months, one complete response (CR) and seven partial responses (PRs) have been observed, for a total response rate of 32% (95% confidence interval [CI], 15% to 53%). In group II, five PRs were noted in 24 assessable patients (20.8%; 95% CI, 7% to 42%). Median response durations were 7 months for group I and 4 months for group II. CONCLUSION Paclitaxel via 3-hour infusion, without prophylactic G-CSF, is active and safe as initial and subsequent therapy for metastatic breast cancer. The transient visual symptoms noted at higher doses seem unrelated to peak plasma paclitaxel concentration. Further studies that compare 3- and 24 hour (or other) infusion schedules are necessary to determine the optimal administration of paclitaxel in metastatic breast cancer.

Estramustine and vinblastine: use of prostate specific antigen as a clinical trial end point for hormone refractory prostatic cancer.

The combination of estramustine phosphate and vinblastine sulfate, 2 agents with separate and unique antimicrotubular effects, has demonstrated additive cytotoxicity against the DU145 human prostate derived cell line in vitro. We evaluated this combination in 25 patients with progressive hormone refractory prostate cancer. Of 24 patients with an elevated prostate specific antigen (PSA) level at the start of treatment 13 (54%, 95% confidence limits 34 to 74%) had a greater than 50% decrease in PSA levels on at least 3 consecutive biweekly determinations. The median decrease in PSA in responding patients was 64% (mean 71.7%) and the median duration of response was 7 months. In 5 patients with bidimensionally measurable disease 2 partial responses were observed. Treatment was well tolerated, with mild and manageable toxicity. This is a well tolerated outpatient treatment regimen for patients with hormone-refractory prostatic cancer which deserves further investigation.

Prospective study of paclitaxel-induced peripheral neuropathy with quantitative sensory testing.

Background. Paclitaxel-induced peripheral neuropathy (PN) may be severeand dose-limiting at initial doses ≥ 275 mg/M2, but itsneurotoxicity at doses ≤ 250 mg/M2 has been incompletelycharacterized. The purposes of this study were to characterize and quantifypaclitaxel-induced PN and to determine the utility of quantitative sensorytesting (QST). Methods. We prospectively examined clinically and by QST 37women with metastatic breast cancer, treated with paclitaxel (200–250mg/m2) (average number of cycles = 7.3 over an average of 20.1weeks). QST included thermal threshold (TT) and vibration threshold (VT).Results. Paresthesias appeared in 31 (84%) patients after an averageof 1.7 cycles and an average cumulative dose of 371.5 mg/M2. Symptomsoccurred after the first or second dose in 26 (84%) patients and thenstabilized in 10 (32%), improved in 13 (42%) despite continuedtreatment, resolved completely in 6 (19%), and were progressive in 2(7%). Paclitaxel was discontinued in only 1 (3%) patientbecause of neurotoxicity and no patient required dose reduction because ofPN. Thirty-six (97%) developed signs of PN. The most sensitive QSTwas great toe VT but QST did not predict or identify subclinical PN in anypatient. Neurologic syndromes other than PN developed in 12 (32%)patients, and 7 were due to metastatic cancer. Conclusions. 1)Paclitaxel-induced PN is mostly sensory, and begins after the first orsecond dose. At these doses the neuropathy is mild, and rarelydose-limiting. 2) QST quantified the neuropathy but was less sensitive thanthe clinical examination. 3) Knowledge of the features of paclitaxels PNallows it to be differentiated from other neurologic syndromes which maysignal tumor progression.