Paul K. Marcom

Phase I Safety, Pharmacokinetics, and Clinical Activity Study of Lapatinib (GW572016), a Reversible Dual Inhibitor of Epidermal Growth Factor Receptor Tyrosine Kinases, in Heavily Pretreated Patients With Metastatic Carcinomas

PURPOSE This study (EGF10004) assessed the safety/tolerability, pharmacokinetics, and clinical activity of daily oral dosing with lapatinib (GW572016) in patients with ErbB1-expressing and/or ErbB2-overexpressing advanced-stage refractory solid tumors. PATIENTS AND METHODS Heavily pretreated patients with ErbB1-expressing and/or ErbB2-overexpressing metastatic cancers were randomly assigned to one of five dose cohorts of lapatinib administered once daily. Pharmacokinetic samples were obtained on days 1 and 20. Clinical response was assessed every 8 weeks. RESULTS Sixty-seven patients with metastatic solid tumors were treated with lapatinib. The most frequently reported drug-related adverse events were diarrhea (42%) and rash (31%). No grade 4 drug-related adverse events were reported. Five grade 3 drug-related toxicities (gastrointestinal events and rash) were experienced by four patients. Drug-related interstitial pneumonitis or cardiac dysfunction associated with other ErbB-targeted therapies was not reported. Four patients with trastuzumab-resistant metastatic breast cancer-two of whom were classified as having inflammatory breast cancer-had partial responses (PRs). Twenty-four patients with various other carcinomas experienced stable disease, of whom 10 received lapatinib for > or = 6 months. The relationships between lapatinib dose or serum concentration and clinical response could not be adequately characterized due to the limited response data. The incidence of diarrhea increased with increasing dose, whereas the incidence of rash was not related to dose. CONCLUSION Lapatinib was well tolerated at doses ranging from 500 to 1,600 mg once daily. Clinical activity was observed in heavily pretreated patients with ErbB1-expressing and/or ErbB2-overexpressing metastatic cancers, including four PRs in patients with trastuzumab-resistant breast cancers and prolonged stable disease in 10 patients.

Circulating Tumor Cells from Patients with Advanced Prostate and Breast Cancer Display Both Epithelial and Mesenchymal Markers

During cancer progression, malignant cells undergo epithelial-mesenchymal transitions (EMT) and mesenchymal-epithelial transitions (MET) as part of a broad invasion and metastasis program. We previously observed MET events among lung metastases in a preclinical model of prostate adenocarcinoma that suggested a relationship between epithelial plasticity and metastatic spread. We thus sought to translate these findings into clinical evidence by examining the existence of EMT in circulating tumor cells (CTC) from patients with progressive metastatic solid tumors, with a focus on men with castration-resistant prostate cancer (CRPC) and women with metastatic breast cancer. We showed that the majority (>80%) of these CTCs in patients with metastatic CRPC coexpress epithelial proteins such as epithelial cell adhesion molecule (EpCAM), cytokeratins (CK), and E-cadherin, with mesenchymal proteins including vimentin, N-cadherin and O-cadherin, and the stem cell marker CD133. Equally, we found that more than 75% of CTCs from women with metastatic breast cancer coexpress CK, vimentin, and N-cadherin. The existence and high frequency of these CTCs coexpressing epithelial, mesenchymal, and stem cell markers in patients with progressive metastases has important implications for the application and interpretation of approved methods to detect CTCs. Mol Cancer Res; 9(8); 997–1007. ©2011 AACR.

Study of the Biologic Effects of Lapatinib, a Reversible Inhibitor of ErbB1 and ErbB2 Tyrosine Kinases, on Tumor Growth and Survival Pathways in Patients With Advanced Malignancies

PURPOSE This was a pilot study to assess the biologic effects of lapatinib on various tumor growth/survival pathways in patients with advanced ErbB1 and/or ErbB2-overexpressing solid malignancies. PATIENTS AND METHODS Heavily pretreated patients with metastatic cancers overexpressing ErbB2 and/or expressing ErbB1 were randomly assigned to one of five dose cohorts of lapatinib (GW572016) administered orally once daily continuously. The biologic effects of lapatinib on tumor growth and survival pathways were assessed in tumor biopsies obtained before and after 21 days of therapy. Clinical response was determined at 8 weeks. RESULTS Sequential tumor biopsies from 33 patients were examined. Partial responses occurred in four patients with breast cancer, and disease stabilization occurred in 11 others with various malignancies. Responders exhibited variable levels of inhibition of p-ErbB1, p-ErbB2, p-Erk1/2, p-Akt, cyclin D1, and transforming growth factor alpha. Even some nonresponders demonstrated varying degrees of biomarker inhibition. Increased tumor cell apoptosis (TUNEL) occurred in patients with evidence of tumor regression but not in nonresponders (progressive disease). Clinical response was associated with a pretreatment TUNEL score > 0 and increased pretreatment expression of ErbB2, p-ErbB2, Erk1/2, p-Erk1/2, insulin-like growth factor receptor-1, p70 S6 kinase, and transforming growth factor alpha compared with nonresponders. CONCLUSION Lapatinib exhibited preliminary evidence of biologic and clinical activity in ErbB1 and/or ErbB2-overexpressing tumors. However, the limited sample size of this study and the variability of the biologic endpoints suggest that further work is needed to prioritize biomarkers for disease-directed studies, and underscores the need for improved trial design strategies in early clinical studies of targeted agents.

Intratumor Heterogeneity and Precision of Microarray-Based Predictors of Breast Cancer Biology and Clinical Outcome

PURPOSE Identifying sources of variation in expression microarray data and the effect of variance in gene expression measurements on complex predictive and diagnostic models is essential when translating microarray-based experimental approaches into clinical assays. The technical reproducibility of microarray platforms is well established. Here, we investigate the additional impact of intratumor heterogeneity, a largely unstudied component of variance, on the performance of several microarray-based assays in breast cancer. PATIENTS AND METHODS Genome-wide expression profiling was performed on 50 core needle biopsies from 18 breast cancer patients using Affymetrix GeneChip Human Genome U133 Plus 2.0 arrays. Global profiles of expression were characterized using unsupervised clustering methods and variance components models. Array-based measures of estrogen receptor (ER) and progesterone receptor (PR) status were compared with immunohistochemistry. The precision of genomic predictors of ER pathway status, recurrence risk, and sensitivity to chemotherapeutics was evaluated by interclass correlation. RESULTS Global patterns of gene expression demonstrated that intratumor variation was substantially less than the total variation observed across the patient population. Nevertheless, a fraction of genes exhibited significant intratumor heterogeneity in expression. A high degree of reproducibility was observed in single-gene predictors of ER (intraclass correlation coefficient [ICC] = 0.94) and PR expression (ICC = 0.90), and in a multigene predictor of ER pathway activation (ICC = 0.98) with high concordance with immunohistochemistry. Substantial agreement was also observed for multigene signatures of cancer recurrence (ICC = 0.71) and chemotherapeutic sensitivity (ICC = 0.72 and 0.64). CONCLUSION Intratumor heterogeneity, although present at the level of individual gene expression, does not preclude precise microarray-based predictions of tumor behavior or clinical outcome in breast cancer patients.

Improved Surgical Outcomes for Breast Cancer Patients Receiving Neoadjuvant Aromatase Inhibitor Therapy: Results from a Multicenter Phase II Trial

BACKGROUND Neoadjuvant aromatase inhibitor therapy has been reported to improve surgical outcomes for postmenopausal women with clinical stage II or III hormone receptor-positive breast cancer. A multicenter phase II clinical trial was conducted to investigate the value of this approach for US surgical practice. STUDY DESIGN One hundred fifteen postmenopausal women with >2 cm, estrogen receptor (ER) or progesterone receptor (PgR)-positive breast cancer were enrolled in a trial of 16 to 24 weeks of letrozole 2.5 mg daily before operation. RESULTS One hundred six patients were eligible for primary analysis, 96 underwent operations, 7 received chemotherapy after progressive disease, and 3 did not undergo an operation. Baseline surgical status was marginal for breast-conserving surgery (BCS) in 48 (45%), 47 were definitely ineligible for BCS (44%), and 11 were inoperable by standard mastectomy (10%). Overall Response Evaluation Criteria In Solid Tumors clinical response rate in the breast was 62%, with 12% experiencing progressive disease. Fifty percent underwent BCS, including 30 of 46 (65%) patients who were initially marginal for BCS and 15 of 39 (38%) patients who were initially ineligible for BCS. All 11 inoperable patients successfully underwent operations, including 3 (27%) who had BCS. Nineteen percent of patients undergoing mastectomy had a pathologic T1 tumor, suggesting that some highly responsive tumors were overtreated surgically. CONCLUSIONS Neoadjuvant aromatase inhibitor improves operability and facilitates BCS, but there was considerable variability in responsiveness. Better techniques to predict response, determine residual tumor burden before operation, and greater willingness to attempt BCS in responsive patients could additionally improve the rate of successful BCS.

Phase I study of Doxil and vinorelbine in metastatic breast cancer

BACKGROUND Vinorelbine and Doxil (liposomal doxorubicin) are active chemotherapeutic agents in metastatic breast cancer. A phase I study was designed to evaluate combination therapy. PATIENTS AND METHODS Thirty women with metastatic breast cancer were enrolled. Dose-limiting toxicity was determined through a dose escalation scheme, and defined for the first treatment cycle, only. Pharmacokinetic studies were performed during the first cycle of treatment. RESULTS In the first cohort of Doxil 30 mg/m2 day 1 and vinorelbine 25 mg/m2 days 1 and 8, patients experienced severe neutropenia. Vinorelbine administration was changed thereafter to days 1 and 15 of each cycle. Dose limiting toxicity was observed at Doxil 50 mg/m2 and vinorelbine 25 mg/m2. Doxil 40 mg/m2 and vinorelbine 30 mg/m2 was defined as the maximally tolerated dose. Few toxicities (principally neutro penia) were seen at this dose level, with the notable absence of significant nausea, vomiting, or alopecia. Though 63% of patients had received prior anthracycline-based chemotherapy, only one patient developed grade 2 cardiac toxicity. Pharmacokinetic studies revealed prolonged exposure to high doxorubicin concentrations for several days following Doxil administration. CONCLUSIONS Combination chemotherapy with Doxil and vinorelbine affords treatment with two active drugs in women with metastatic breast cancer, and appears to have a favorable toxicity profile. A schedule of Doxil 40 mg/m2 day 1 and vinorelbine 30 mg/m2 days 1 and 15 given every 28 days is recommended for phase II studies.

Retinoic Acid Receptor-β2 Promoter Methylation in Random Periareolar Fine Needle Aspiration

Methylation of the retinoic acid receptor-β2 (RARβ2) P2 promoter is hypothesized to be an important mechanism for loss of RARβ2 function during early mammary carcinogenesis. The frequency of RARβ2 P2 methylation was tested in (a) 16 early stage breast cancers and (b) 67 random periareolar fine needle aspiration (RPFNA) samples obtained from 38 asymptomatic women who were at increased risk for breast cancer. Risk was defined as either (a) 5-year Gail risk calculation ≥1.7%; (b) prior biopsy exhibiting atypical hyperplasia, lobular carcinoma in situ, or ductal carcinoma in situ; or (c) known BRCA1/2 mutation carrier. RARβ2 P2 promoter methylation was assessed at two regions, M3 (−51 to 162 bp) and M4 (104-251 bp). In early stage cancers, M4 methylation was observed in 11 of 16 (69%) cases; in RPFNA samples, methylation was present at M3 and M4 in 28 of 56 (50%) and 19 of 56 (38%) cases, respectively. RPFNAs were stratified for cytologic atypia using the Masood cytology index. The distribution of RARβ2 P2 promoter methylation was reported as a function of increased cytologic abnormality. Methylation at both M3 and M4 was observed in (a) 0 of 10 (0%) of RPFNAs with Masood scores of ≤10 (nonproliferative), (b) 3 of 20 (15%) with Masood scores of 11 to 12 (low-grade proliferative), (c) 3 of 10 (30%) with Masood scores of 13 (high-grade proliferative), and (d) 7 of 14 (50%) with Masood scores of 14 of 15 (atypia). Results from this study indicate that the RARβ2 P2 promoter is frequently methylated (69%) in primary breast cancers and shows a positive association with increasing cytologic abnormality in RPFNA.

Breast Cancer Patients' Treatment Expectations after Exposure to the Decision Aid Program Adjuvant Online: The Influence of Numeracy

The decision aid called ‘‘Adjuvant Online’’ (Adjuvant! for short) helps breast cancer patients make treatment decisions by providing numerical estimates of treatment efficacy (e.g., 10-y relapse or survival). Studies exploring how patients’ numeracy interacts with the estimates provided by Adjuvant! are lacking. Pooling across 2 studies totaling 105 women with estrogen receptor—positive, early-stage breast cancer, the authors explored patients’ treatment expectations, perceived benefit from treatments, and confidence of personal benefit from treatments. Patients who were more numerate were more likely to provide estimates of cancer-free survival that matched the estimates provided by Adjuvant! for each treatment option compared with patients with lower numeracy (odds ratios of 1.6 to 2.4). As estimates of treatment efficacy provided by Adjuvant! increased, so did patients’ estimates of cancer-free survival (0.37 > rs > 0.48) and their perceptions of treatment benefit from hormonal therapy (rs = 0.28) and combined therapy (rs = 0.27). These relationships were significantly more pronounced for those with higher numeracy, especially for perceived benefit of combined therapy. Results suggest that numeracy influences a patient’s ability to interpret numerical estimates of treatment efficacy from decision aids such as Adjuvant!.

Urinary Biomarkers of Oxidative Status in a Clinical Model of Oxidative Assault

Background: We used doxorubicin-based chemotherapy as a clinical model of oxidative assault in humans. Methods: The study recruited newly diagnosed breast cancer patients (n = 23). Urine samples were collected immediately before (T0) and at 1 hour (T1) and 24 hours (T24) after i.v. administration of treatment. Measurements included allantoin and the isoprostanes iPF(2α)-III, iPF(2α)-VI, and 8,12-iso-iPF(2α)-VI along with the prostaglandin 2,3-dinor-iPF(2α)-III, a metabolite of iPF(2α)-III. All biomarkers were quantified using liquid chromatography–tandem mass spectrometry. Results: In all subjects, the levels of the biomarkers increased at T1: allantoin by 22% (P = 0.06), iPF(2α)-III by 62% (P < 0.05), iPF(2α)-VI by 41% (P < 0.05), 8,12-iso-iPF(2α)-VI by 58% (P < 0.05), and 2,3-dinor-iPF(2α)-III by 52% (P < 0.05). At T24, the F2-isoprostanes returned to their baseline levels; the levels of allantoin continued to increase, although the T24-T0 difference was not statistically significant. Conclusions: These results indicate that urinary F2-isoprostanes are valid biomarkers and allantoin is a promising biomarker of oxidative status in humans. Impact: The levels of biomarkers change quickly in response to oxidative assault and can be used to monitor oxidative status in humans in response to treatments related either to generation of free radicals (chemotherapy and radiation therapy) or to antioxidants (inborn metabolic diseases and Down syndrome). Cancer Epidemiol Biomarkers Prev; 19(6); 1506–10. ©2010 AACR.

Long term disease-free survival and T cell and antibody responses in women with high-risk Her2+ breast cancer following vaccination against Her2

BackgroundThe HER2-inhibiting antibody trastuzumab, in combination with chemotherapy, significantly improves survival of women with resected, HER2-overexpressing breast cancers, but is associated with toxicities including a risk of cardiomyopathy. Additionally, the beneficial effect of trastuzumab is expected to decrease once the drug is discontinued. We proposed to address these concerns by using cancer vaccines to stimulate HER2 intracellular domain (ICD)-specific T cell and antibody responses.MethodsSubjects with stage II (≥ 6 +LN), III, or stage IV breast cancerwith > 50% HER2 overexpressing tumor cells who were disease-free after surgery and adjuvant therapy were eligible. Vaccines consisted of immature, cultured DC (n = 3), mature cultured DC (n = 3), or mature Flt3-ligand mobilized peripheral blood DC (n = 1) loaded with ICD, or tetanus toxoid, keyhole limpet hemocyanin or CMV peptide as controls, and were administered intradermally/subcutaneously four times at 3 week intervals. ICD-specific T cell and antibody responses were measured. Cardiac function was determined by MUGA or ECHO; long term disease status was obtained from patient contact.ResultsAll seven patients successfully underwent DC generation and five received all 4 immunizations. There were no toxicities greater than grade 1 or ejection fraction decrements below normal. Delayed-type hypersensitivity (DTH) reactions at the injection site occurred in 6/7 patients and HER2 specificity was detected by cytokine flow cytometry or ELISPOT in 5 patients. At more than 5 years of follow-up, 6/7 had detectable anti-ICD antibodies. One patient experienced a pulmonary recurrence at 4 years from their study immunizations. This recurrence was resected and they are without evidence of disease. All patients are alive and disease-free at 4.6–6.7 years of follow-up.ConclusionAlthough this was a small pilot study, the well-tolerated nature of the vaccines, the lack of cardiac toxicity, significant immunogenicity, and a 100% 4.5-year survival rate suggest that vaccination with HER2 ICD protein-containing DC is appropriate for further study in this population.Trial RegistrationClinicalTrials.gov NCT00005956