Charles L. Vogel

Efficacy and Safety of Trastuzumab as a Single Agent in First-Line Treatment of HER2-Overexpressing Metastatic Breast Cancer

PURPOSE To evaluate the efficacy and safety of first-line, single-agent trastuzumab in women with HER2-overexpressing metastatic breast cancer. PATIENTS AND METHODS One hundred fourteen women with HER2-overexpressing metastatic breast cancer were randomized to receive first-line treatment with trastuzumab 4 mg/kg loading dose, followed by 2 mg/kg weekly, or a higher 8 mg/kg loading dose, followed by 4 mg/kg weekly. RESULTS The objective response rate was 26% (95% confidence interval [CI], 18.2% to 34.4%), with seven complete and 23 partial responses. Response rates in 111 assessable patients with 3+ and 2+ HER2 overexpression by immunohistochemistry (IHC) were 35% (95% CI, 24.4% to 44.7%) and none (95% CI, 0% to 15.5%), respectively. The clinical benefit rates in assessable patients with 3+ and 2+ HER2 overexpression were 48% and 7%, respectively. The response rates in 108 assessable patients with and without HER2 gene amplification by fluorescence in situ hybridization (FISH) analysis were 34% (95% CI, 23.9% to 45.7%) and 7% (95% CI, 0.8% to 22.8%), respectively. Seventeen (57%) of 30 patients with an objective response and 22 (51%) of 43 patients with clinical benefit had not experienced disease progression at follow-up at 12 months or later. The most common treatment-related adverse events were chills (25% of patients), asthenia (23%), fever (22%), pain (18%), and nausea (14%). Cardiac dysfunction occurred in two patients (2%); both had histories of cardiac disease and did not require additional intervention after discontinuation of trastuzumab. There was no clear evidence of a dose-response relationship for response, survival, or adverse events. CONCLUSION Single-agent trastuzumab is active and well tolerated as first-line treatment of women with metastatic breast cancer with HER2 3+ overexpression by IHC or gene amplification by FISH.

Multinational Study of the Efficacy and Safety of Humanized Anti-HER2 Monoclonal Antibody in Women Who Have HER2-Overexpressing Metastatic Breast Cancer That Has Progressed After Chemotherapy for Metastatic Disease

PURPOSE Overexpression of the HER2 protein occurs in 25% to 30% of human breast cancers and leads to a particularly aggressive form of the disease. Efficacy and safety of recombinant humanized anti-HER2 monoclonal antibody as a single agent was evaluated in women with HER2-overexpressing metastatic breast cancer that had progressed after chemotherapy for metastatic disease. PATIENTS AND METHODS Two hundred twenty-two women, with HER2-overexpressing metastatic breast cancer that had progressed after one or two chemotherapy regimens, were enrolled. Patients received a loading dose of 4 mg/kg intravenously, followed by a 2-mg/kg maintenance dose at weekly intervals. RESULTS Study patients had advanced metastatic disease and had received extensive prior therapy. A blinded, independent response evaluation committee identified eight complete and 26 partial responses, for an objective response rate of 15% in the intent-to-treat population (95% confidence interval, 11% to 21%). The median duration of response was 9.1 months; the median duration of survival was 13 months. The most common adverse events, which occurred in approximately 40% of patients, were infusion-associated fever and/or chills that usually occurred only during the first infusion, and were of mild to moderate severity. These symptoms were treated successfully with acetaminophen and/or diphenhydramine. The most clinically significant adverse event was cardiac dysfunction, which occurred in 4.7% of patients. Only 1% of patients discontinued the study because of treatment-related adverse events. CONCLUSION Recombinant humanized anti-HER2 monoclonal antibody, administered as a single agent, produces durable objective responses and is well tolerated by women with HER2-overexpressing metastatic breast cancer that has progressed after chemotherapy for metastatic disease. Side effects that are commonly observed with chemotherapy, such as alopecia, mucositis, and neutropenia, are rarely seen.

Phase II Study of the Antibody Drug Conjugate Trastuzumab-DM1 for the Treatment of Human Epidermal Growth Factor Receptor 2 (HER2) –Positive Breast Cancer After Prior HER2-Directed Therapy

PURPOSE The antibody-drug conjugate trastuzumab-DM1 (T-DM1) combines the biologic activity of trastuzumab with targeted delivery of a potent antimicrotubule agent, DM1, to human epidermal growth factor receptor 2 (HER2)-overexpressing cancer cells. Based on results from a phase I study that showed T-DM1 was well tolerated at the maximum-tolerated dose of 3.6 mg/kg every 3 weeks, with evidence of efficacy, in patients with HER2-positive metastatic breast cancer (MBC) who were previously treated with trastuzumab, we conducted a phase II study to further define the safety and efficacy of T-DM1 in this patient population. PATIENTS AND METHODS This report describes a single-arm phase II study (TDM4258g) that assessed efficacy and safety of intravenous T-DM1 (3.6 mg/kg every 3 weeks) in patients with HER2-positive MBC who had tumor progression after prior treatment with HER2-directed therapy and who had received prior chemotherapy. RESULTS With a follow-up of ≥ 12 months among 112 treated patients, the objective response rate by independent assessment was 25.9% (95% CI, 18.4% to 34.4%). Median duration of response was not reached as a result of insufficient events (lower limit of 95% CI, 6.2 months), and median progression-free survival time was 4.6 months (95% CI, 3.9 to 8.6 months). The response rates were higher among patients with confirmed HER2-positive tumors (immunohistochemistry 3+ or fluorescent in situ hybridization positive) by retrospective central testing (n = 74). Higher response rates were also observed in patients whose tumors expressed ≥ median HER2 levels by quantitative reverse transcriptase polymerase chain reaction for HER2 expression, compared with patients who had less than median HER2 levels. T-DM1 was well tolerated with no dose-limiting cardiotoxicity. Most adverse events (AEs) were grade 1 or 2; the most frequent grade ≥ 3 AEs were hypokalemia (8.9%), thrombocytopenia (8.0%), and fatigue (4.5%). CONCLUSION T-DM1 has robust single-agent activity in patients with heavily pretreated, HER2-positive MBC and is well tolerated at the recommended phase II dose.

Breast Cancer Subtypes and Response to Docetaxel in Node-Positive Breast Cancer: Use of an Immunohistochemical Definition in the BCIRG 001 Trial

PURPOSE To investigate the prognostic and predictive significance of subtyping node-positive early breast cancer by immunohistochemistry in a clinical trial of a docetaxel-containing regimen. METHODS Pathologic data from a central laboratory were available for 1,350 patients (91%) from the BCIRG 001 trial of docetaxel, doxorubicin, and cyclophosphamide (TAC) versus fluorouracil, doxorubicin, and cyclophosphamide (FAC) for operable node-positive breast cancer. Patients were classified by tumor characteristics as (1) triple negative (estrogen receptor [ER]-negative, progesterone receptor [PR]-negative, HER2/neu [HER2]-negative), (2) HER2 (HER2-positive, ER-negative, PR-negative), (3) luminal B (ER-positive and/or PR-positive and either HER2-positive and/or Ki67(high)), and (4) luminal A (ER-positive and/or PR-positive and not HER2-positive or Ki67(high)), and assessed for prognostic significance and response to adjuvant chemotherapy. RESULTS Patients were subdivided into triple negative (14.5%), HER2 (8.5%), luminal B (61.1%), and luminal A (15.9%). Three-year disease-free survival (DFS) rates (P values with luminal B as referent) were 67% (P < .0001), 68% (P = .0008), 82% (referent luminal B), and 91% (P = .0027), respectively, with hazard ratios of 2.22, 2.12, and 0.46. Improved 3-year DFS with TAC was found in the luminal B group (P = .025) and a combined ER-positive/HER2-negative group treated with tamoxifen (P = .041), with a marginal trend in the triple negatives (P = .051) and HER2 (P = .068) subtypes. No DFS advantage was seen in the luminal A population. CONCLUSION A simple immunopanel can divide breast cancers into biologic subtypes with strong prognostic effects. TAC significantly complements endocrine therapy in patients with luminal B subtype and, in the absence of targeted therapy, is effective in the triple-negative population.

Cardioprotection with dexrazoxane for doxorubicin-containing therapy in advanced breast cancer.

PURPOSE To determine the cardioprotective effect of dexrazoxane (DZR) used in a doxorubicin-based combination therapy in advanced breast cancer. PATIENTS AND METHODS Between November 1988 and January 1991, 534 patients with advanced breast cancer were randomized to two multicenter, double-blind studies (088001 and 088006). Patients received fluorouracil, doxorubicin, and cyclophosphamide (FAC) with either DZR (DZR-to-doxorubicin ratio, 10:1) or placebo (PLA) every 3 weeks and were monitored with serial multiplegated acquisition (MUGA) scans. RESULTS The hazards ratio (HR) of PLA to DZR for a cardiac event, which was predefined ejection fraction changes or congestive heart failure (CHF), was 2.63 (95% confidence interval [CI], 1.61 to 4.27; P < .001) for 088001 and 2.00 (95% CI, 1.01 to 3.96; P = .038) for 088006. The objective response rates for 088001 were 46.8% for DZR and 60.5% for PLA, a difference of 14% (95% CI, -25% to -2%; P = .019), and for 088006 were 53.7% for DZR and 49.3% for PLA, a difference of 4% (95% CI, -13% to 22%; P = .63). Time to progression and survival were not significantly different between treatment arms in either study. Toxicities on the DZR arms included lower granulocyte and platelet counts at nadir (P = .009 and P = .004, respectively) and more pain on injection (P = .001), with no difference in the rates of fever, infection, or hemorrhage. CONCLUSION DZR had a significant cardioprotective effect as measured by noninvasive testing and clinical CHF. One of the two studies (088001) showed a lower response rate with DZR, but time to progression and survival were not significantly different. DZR is the first agent shown to reduce cardiotoxicity from doxorubicin.

A phase III trial comparing anastrozole (1 and 10 milligrams), a potent and selective aromatase inhibitor, with megestrol acetate in postmenopausal women with advanced breast carcinoma

Anastrozole is a new oral aromatase inhibitor with highly potent and selective activity for the aromatase enzyme. In a Phase III trial, the efficacy and tolerability of anastrozole, given in doses of 1 and 10 mg orally once daily, and megestrol acetate, given in doses of 40 mg orally 4 times daily, were compared in 386 postmenopausal women with advanced breast carcinoma who progressed after tamoxifen therapy.

Randomized Phase III Trial of Pegylated Liposomal Doxorubicin Versus Vinorelbine or Mitomycin C Plus Vinblastine in Women With Taxane-Refractory Advanced Breast Cancer

PURPOSE To compare the efficacy of pegylated liposomal doxorubicin (PLD) with that of a common salvage regimen (comparator) in patients with taxane-refractory advanced breast cancer. PATIENTS AND METHODS Following failure of a first- or second-line taxane-containing regimen for metastatic disease, 301 women were randomly assigned to receive PLD (50 mg/m(2) every 28 days); or comparator-vinorelbine (30 mg/m(2) weekly) or mitomycin C (10 mg/m(2) day 1 and every 28 days) plus vinblastine (5 mg/m(2) day 1, day 14, day 28, and day 42) every 6 to 8 weeks. Patients were stratified before random assignment based on number of previous chemotherapy regimens for metastatic disease and presence of bone metastases only. RESULTS Progression-free survival (PFS) and overall survival (OS) were similar for PLD and comparator (PFS: hazard ratio [HR], 1.26; 95% CI, 0.98 to 1.62; P =.11; median, 2.9 months [PLD] and 2.5 months [comparator]; OS: HR, 1.05; 95% CI, 0.82 to 1.33; P =.71; median, 11.0 months [PLD] and 9.0 months [comparator]). In anthracycline-naïve patients, PFS was somewhat longer with PLD, relative to the comparator (n = 44; median PFS, 5.8 v 2.1 months; HR, 2.40; 95% CI, 1.16 to 4.95; P =.01). Most frequently reported adverse events were nausea (23% to 31%), vomiting (17% to 20%), and fatigue (9% to 20%) and were similar among treatment groups. PLD-treated patients experienced more palmar-plantar erythrodysesthesia (37%; 18% grade 3, 1 patient grade 4) and stomatitis (22%; 5% grades 3/4). Neuropathy (11%), constipation (16%), and neutropenia (14%) were more common with vinorelbine. Alopecia was low in both the PLD and vinorelbine groups (3% and 5%). CONCLUSION PLD has efficacy comparable to that of common salvage regimens in patients with taxane-refractory metastatic breast cancer, thereby representing a useful therapeutic option.

First-Line Herceptin® Monotherapy in Metastatic Breast Cancer

The pivotal phase II and III Herceptin® trials proved the efficacy and safety of second- or third-line single-agent Herceptin and first-line Herceptin in combination with chemotherapy, respectively. In the current trial, 114 patients were randomized to one of two dose groups of first-line Herceptin monotherapy: standard dose of 4 mg/ kg initial dose followed by 2 mg/kg intravenous (i.v.) weekly; or high dose of 8 mg/kg initial dose followed by 4 mg/kg i.v. weekly. The regimen was generally well tolerated. A similar incidence of adverse events was demonstrated in the two dose groups with the possible exception of acute infusion-related events such as fever and chills as well as rash and dyspnea, which appear to be more prevalent in the higher dose group. The overall response rate was 26% and response rates were similar between the two dose groups (24% for the standard Herceptin dose group and 28% for the high Herceptin dose group). Subgroup analysis determined a higher response rate in IHC 3+ patients (35%) and FISH-positive patients (41%). When women with stable disease for ≧6 months were included with responders, the clinical benefit rate in IHC 3+ patients was 47%. Median survival was 24.4 months, which is comparable with the survival rate seen in the pivotal phase III combination trial (25 months). Therefore, single-agent Herceptin is an important new option for the first-line treatment of HER2-positive metastatic breast cancer patients.

First-line, single-agent Herceptin(trastuzumab) in metastatic breast cancer: a preliminary report.

Following confirmation of the appropriate dosage, safety and potential efficacy of Herceptin(trastuzumab) in small-scale phase I and II trials involving patients with refractory disease, a large trial was conducted in 222 patients with breast cancer who had relapsed after one or two chemotherapy regimens for their metastatic disease. The results showed a positive and durable overall response rate (15% according to a response evaluation committee (REC) assessment) using trastuzumab monotherapy (initial dose 4 mg/kg intravenously (i.v.) followed by 2 mg/kg i.v. weekly). In another recently completed phase II trial, 113 patients were randomised to two dose levels (initial dose of 4 mg/kg i.v. dose followed by 2 mg/kg i.v. weekly, or initial dose of 8 mg/kg followed by 4 mg/kg i.v. weekly) of single-agent trastuzumab as first-line therapy for metastatic disease. The preliminary overall response rate was 23% based on investigator assessment, and tolerability was excellent as in previous trials; efficacy was similar in both dose groups, but the side-effects tended to be more frequent in the higher dose group. The preferred dosage is therefore the same as that currently recommended, i.e. an initial dose of 4 mg/kg i.v. followed by 2 mg/kg weekly i.v. until disease progression.

Secretion of methotrexate into human milk

Abstract After oral administration to a lactating patient with choriocarcinoma, the cancer chemotherapeutic agent methotrexate (MTX) was found to be excreted in milk at low but readily detectable levels. The highest milk:plasma concentration ratio, 0.08:1, was observed 10 hr. after administration of the drug. The kinetics of the MTX secretion process correspond to those which would be anticipated for a weak organic acid transferred from plasma to milk by passive diffusion of the nonionized form.