Tufia C. Haddad

Adaptive Randomization of Veliparib–Carboplatin Treatment in Breast Cancer

BACKGROUND The genetic and clinical heterogeneity of breast cancer makes the identification of effective therapies challenging. We designed I-SPY 2, a phase 2, multicenter, adaptively randomized trial to screen multiple experimental regimens in combination with standard neoadjuvant chemotherapy for breast cancer. The goal is to match experimental regimens with responding cancer subtypes. We report results for veliparib, a poly(ADP-ribose) polymerase (PARP) inhibitor, combined with carboplatin. METHODS In this ongoing trial, women are eligible for participation if they have stage II or III breast cancer with a tumor 2.5 cm or larger in diameter; cancers are categorized into eight biomarker subtypes on the basis of status with regard to human epidermal growth factor receptor 2 (HER2), hormone receptors, and a 70-gene assay. Patients undergo adaptive randomization within each biomarker subtype to receive regimens that have better performance than the standard therapy. Regimens are evaluated within 10 biomarker signatures (i.e., prospectively defined combinations of biomarker subtypes). Veliparib-carboplatin plus standard therapy was considered for HER2-negative tumors and was therefore evaluated in 3 signatures. The primary end point is pathological complete response. Tumor volume changes measured by magnetic resonance imaging during treatment are used to predict whether a patient will have a pathological complete response. Regimens move on from phase 2 if and when they have a high Bayesian predictive probability of success in a subsequent phase 3 neoadjuvant trial within the biomarker signature in which they performed well. RESULTS With regard to triple-negative breast cancer, veliparib-carboplatin had an 88% predicted probability of success in a phase 3 trial. A total of 72 patients were randomly assigned to receive veliparib-carboplatin, and 44 patients were concurrently assigned to receive control therapy; at the completion of chemotherapy, the estimated rates of pathological complete response in the triple-negative population were 51% (95% Bayesian probability interval [PI], 36 to 66%) in the veliparib-carboplatin group versus 26% (95% PI, 9 to 43%) in the control group. The toxicity of veliparib-carboplatin was greater than that of the control. CONCLUSIONS The process used in our trial showed that veliparib-carboplatin added to standard therapy resulted in higher rates of pathological complete response than standard therapy alone specifically in triple-negative breast cancer. (Funded by the QuantumLeap Healthcare Collaborative and others; I-SPY 2 TRIAL ClinicalTrials.gov number, NCT01042379.).

Patient Satisfaction with Physician Discussions of Treatment Impact on Fertility, Menopause and Sexual Health among Pre-menopausal Women with Cancer

PURPOSE: Pre-menopausal women with cancer are at risk of therapy-associated infertility, premature menopause, and sexual dysfunction. However, it is unknown whether oncologists adequately address these risks during treatment planning. We conducted a study to evaluate physician-patient discussions addressing the impact of cancer treatment and actual treatment effects on fertility, menopause status, and general sexual health. METHODS: A questionnaire was administered in four oncology clinics specializing in breast, gynecologic, general hematology-oncology, and blood and marrow transplantation (BMT) cancer care at a single institution. Eligible participants were pre-menopausal at the time of diagnosis and either actively receiving or within 24 months from completion of treatment. Participants completed the questionnaire at enrollment and at 1-year follow-up. RESULTS: Of the 104 eligible women, a majority were satisfied with the quality (68%) and length (66%) of reproductive health discussions, with the highest satisfaction levels in the gynecologic cancer clinic (85%) and the lowest levels in the BMT clinic (53%). Fertility preservation was desired by 20% of women, including some >40 years old. Women were more interested in discussing treatment impact on menopause status and sexual health than fertility. Rates of discussions on treatment impact on sexual health were low despite 77% of women reporting severe sexual dysfunction at 1-year follow-up. CONCLUSIONS: One-third of women are dissatisfied with the quality and length of discussions regarding the impact of cancer treatment on reproductive health. There is notably inadequate counseling on the effect of treatment on fertility in women > 40 and on sexual function in all women. Oncologists must offer better resources and improve communication on the effect of treatment on reproductive health to pre-menopausal women with cancer.

The Neoadjuvant Model is Still the Future for Drug Development in Breast Cancer

The many improvements in breast cancer therapy in recent years have so lowered rates of recurrence that it is now difficult or impossible to conduct adequately powered adjuvant clinical trials. Given the many new drugs and potential synergistic combinations, the neoadjuvant approach has been used to test benefit of drug combinations in clinical trials of primary breast cancer. A recent FDA-led meta-analysis showed that pathologic complete response (pCR) predicts disease-free survival (DFS) within patients who have specific breast cancer subtypes. This meta-analysis motivated the FDAs draft guidance for using pCR as a surrogate endpoint in accelerated drug approval. Using pCR as a registration endpoint was challenged at ASCO 2014 Annual Meeting with the presentation of ALTTO, an adjuvant trial in HER2-positive breast cancer that showed a nonsignificant reduction in DFS hazard rate for adding lapatinib, a HER-family tyrosine kinase inhibitor, to trastuzumab and chemotherapy. This conclusion seemed to be inconsistent with the results of NeoALTTO, a neoadjuvant trial that found a statistical improvement in pCR rate for the identical lapatinib-containing regimen. We address differences in the two trials that may account for discordant conclusions. However, we use the FDA meta-analysis to show that there is no discordance at all between the observed pCR difference in NeoALTTO and the observed HR in ALTTO. This underscores the importance of appropriately modeling the two endpoints when designing clinical trials. The I-SPY 2/3 neoadjuvant trials exemplify this approach. Clin Cancer Res; 21(13); 2911–5. ©2015 AACR.

Hexapeptide Libraries for Enhanced Protein PTM Identification and Relative Abundance Profiling in Whole Human Saliva

Dynamic range compression (DRC) by hexapeptide libraries increases MS/MS-based identification of lower-abundance proteins in complex mixtures. However, two unanswered questions impede fully realizing DRCs potential in shotgun proteomics. First, does DRC enhance identification of post-translationally modified proteins? Second, can DRC be incorporated into a workflow enabling relative protein abundance profiling? We sought to answer both questions analyzing human whole saliva. Addressing question one, we coupled DRC with covalent glycopeptide enrichment and MS/MS. With DRC we identified ∼2 times more N-linked glycoproteins and their glycosylation sites than without DRC, dramatically increasing the known salivary glycoprotein catalog. Addressing question two, we compared differentially stable isotope-labeled saliva samples pooled from healthy and metastatic breast cancer women using a multidimensional peptide fractionation-based workflow, analyzing in parallel one sample portion with DRC and one portion without. Our workflow categorizes proteins with higher absolute abundance, whose relative abundance ratios are altered by DRC, from proteins of lower absolute abundance detected only after DRC. Within each of these salivary protein categories, we identified novel abundance changes putatively associated with breast cancer, demonstrating feasibility and benefits of DRC for relative abundance profiling. Collectively, our results bring us closer to realizing the full potential of DRC for proteomic studies.

Smoking and quality of life among female survivors of breast, colorectal and endometrial cancers in a prospective cohort study.

PurposeTo examine the association of smoking and quality of life (QOL) among survivors of breast, colorectal, or endometrial cancers.MethodsThe study included women who joined the Iowa Women’s Health Study in 1986 and were subsequently diagnosed with breast, colorectal, or endometrial cancers through 2004 (n = 1920). Smoking status was reported at baseline and in 2004; QOL was assessed in 2004 using the Medical Outcomes Study Short Form-36. Multivariate-adjusted odds ratios were calculated to examine the associations of smoking status and poor QOL (score lower than one-half a standard deviation below the mean of the non-smokers).ResultsCompared with non-smokers, persistent smokers had higher likelihood of reporting poor Physical Functioning (odds ratio [OR] = 2.40, 95% confidence interval [CI] = 1.32–4.37), Mental Health (OR = 1.92, CI = 1.09–3.40), and Role Emotional (OR = 2.01, CI = 1.10–3.66), whereas former smokers had higher likelihood of reporting poor Physical Functioning (OR = 1.65, CI = 1.10–2.45), Mental Health (OR = 1.62, CI = 1.11–2.37), and General Health (OR = 1.51, CI = 1.03–2.21). A statistically significant trend toward higher likelihood of poor QOL was observed across smoking groups in Vitality, Physical Functioning, Mental Health, and Role Emotional. Further adjustment for physical activity resulted in attenuation of the odds ratios and p-values for trend.ConclusionAmong women with breast, colorectal, or endometrial cancers, smokers were more likely than former or non-smokers to have poor QOL. Physical activity explained, in part, the association between smoking status and QOL in our study.

Pregnancy and thrombophilia

The physiological changes that occur during pregnancy create a hypercoagulable milieu. This hypercoagulable state is thought to be protective, especially at the time of labor, preventing excessive hemorrhage. The presence of hereditary or acquired causes of thrombophilia during pregnancy tilts the balance in favor of unwanted venous thromboembolism and adverse pregnancy outcomes due to vascular uteroplacental insufficiency. These adverse pregnancy outcomes include recurrent pregnancy losses, intrauterine fetal death, intrauterine growth retardation, preeclampsia and placental abruption. Much of the current data with regards to the association of the different thrombophilias and pregnancy-related complications are based on retrospectively designed studies. This lack of randomization, in-homogeneity of patient populations, varying case definitions, selection biases and inadequately matched control populations, have given rise to conflicting data with regard to screening for, and treatment of, pregnant women with suspected thrombophilias. The limited data that we have support the use of anticoagulant drugs for the prevention of pregnancy-related complications in the setting of thrombophilia. Heparin and low-molecular-weight heparins are the anticoagulant drugs of choice as they do not cross the placental barrier and, hence, do not cause fetal anticoagulation or teratogenicity. Warfarin can be used from the 12th week of gestation onwards but is preferably reserved for the postpartum period.

Insulin and Interleukin-4 Induce Desensitization to the Mitogenic Effects of Insulin-like Growth Factor-I PIVOTAL ROLE FOR INSULIN RECEPTOR SUBSTRATE-2

Insulin-induced desensitization to insulin-like growth factor-I (IGF-I) stimulated mitogenesis in bovine fibroblasts involves steps distal to IGF-I binding to its tyrosine kinase receptor. When quiescent cultures of bovine fibroblasts were stimulated with 10 nm IGF-I and total cell lysates immunoblotted with anti-phosphotyrosine antibody, we observed a band at ∼97 kDa, representing the β-subunit of the IGF-I receptor, and a predominant tyrosyl-phosphorylated species migrating as a broad band between 170 and 190 kDa. The majority of proteins in this latter band were immunoprecipitated by antibodies against insulin receptor substrate (IRS)-2 and not by antibodies against IRS-1. Pretreatment of bovine fibroblasts with 10 nm insulin for 48 h blocked subsequent IGF-I-stimulated DNA synthesis and the IGF-I-induced increase in tyrosyl-phosphorylated IRS-2. Insulin pretreatment did not alter IRS-1 or IRS-2 expression by these cells, as assessed by metabolic labeling and direct immunoblotting with IRS antibodies. The interleukin-4 (IL-4) cytokine receptor also has IRS-2 as its major substrate for tyrosine phosphorylation. Although 10 nm IL-4 was as effective as 10 nm IGF-I in stimulating IRS-2 phosphorylation, 10 nm IL-4 did not have comparable mitogenic power in these cells. Nonetheless, pretreatment of bovine fibroblasts with IL-4 inhibited IGF-I-stimulated DNA synthesis by 50–60%, concomitant with a decrease in IGF-I-induced IRS-2 phosphorylation. Insulin-induced desensitization could be prevented if a specific inhibitor of phosphatidylinositol 3-kinase (LY294002), but not an inhibitor of mitogen-activated protein kinase (PD98059), was present during the preincubation period. LY294002 also prevented the shift in IRS-2 molecular mass in response to prolonged incubation of cells with insulin. These data indicate that, in a nontransformed cell system, IRS-2 plays a key role in cellular desensitization to IGF-I-stimulated mitogenesis most likely through a feedback mechanism in the phosphatidylinositol 3-kinase pathway. Furthermore, they suggest that signaling through IRS-2 may provide an important point of integration for hormone, growth factor, and cytokine receptor systems that regulate critical cellular growth responses.

First-in-Human Phase I Study of the Tamoxifen Metabolite Z-Endoxifen in Women With Endocrine-Refractory Metastatic Breast Cancer

Purpose Endoxifen is a tamoxifen metabolite with potent antiestrogenic activity. Patients and Methods We performed a phase I study of oral Z-endoxifen to determine its toxicities, maximum tolerated dose (MTD), pharmacokinetics, and clinical activity. Eligibility included endocrine-refractory, estrogen receptor-positive metastatic breast cancer. An accelerated titration schedule was applied until moderate or dose-limiting toxicity occurred, followed by a 3+3 design and expansion at 40, 80, and 100 mg per day. Tumor DNA from serum (circulating cell free [cf); all patients] and biopsies [160 mg/day and expansion]) was sequenced. Results Of 41 enrolled patients, 38 were evaluable for MTD determination. Prior endocrine regimens during which progression occurred included aromatase inhibitor (n = 36), fulvestrant (n = 21), and tamoxifen (n = 15). Patients received endoxifen once daily at seven dose levels (20 to 160 mg). Dose escalation ceased at 160 mg per day given lack of MTD and endoxifen concentrations > 1,900 ng/mL. Endoxifen clearance was unaffected by CYP2D6 genotype. One patient (60 mg) had cycle 1 dose-limiting toxicity (pulmonary embolus). Overall clinical benefit rate (stable > 6 months [n = 7] or partial response by RECIST criteria [n = 3]) was 26.3% (95% CI, 13.4% to 43.1%) including prior tamoxifen progression (n = 3). cfDNA mutations were observed in 13 patients ( PIK3CA [n = 8], ESR1 [n = 5], TP53 [n = 4], and AKT [n = 1]) with shorter progression-free survival ( v those without cfDNA mutations; median, 61 v 132 days; log-rank P = .046). Clinical benefit was observed in those with ESR1 amplification (tumor; 80 mg/day) and ESR1 mutation (cfDNA; 160 mg/day). Comparing tumor biopsies and cfDNA, some mutations ( PIK3CA, TP53, and AKT) were undetected by cfDNA, whereas cfDNA mutations ( ESR1, TP53, and AKT) were undetected by biopsy. Conclusion In endocrine-refractory metastatic breast cancer, Z-endoxifen provides substantial drug exposure unaffected by CYP2D6 metabolism, acceptable toxicity, and promising antitumor activity.

Aurora-A Kinase as a Promising Therapeutic Target in Cancer

Mammalian Aurora family of serine/threonine kinases are master regulators of mitotic progression and are frequently overexpressed in human cancers. Among the three members of the Aurora kinase family (Aurora-A, -B, and -C), Aurora-A and Aurora-B are expressed at detectable levels in somatic cells undergoing mitotic cell division. Aberrant Aurora-A kinase activity has been implicated in oncogenic transformation through the development of chromosomal instability and tumor cell heterogeneity. Recent studies also reveal a novel non-mitotic role of Aurora-A activity in promoting tumor progression through activation of epithelial–mesenchymal transition reprograming resulting in the genesis of tumor-initiating cells. Therefore, Aurora-A kinase represents an attractive target for cancer therapeutics, and the development of small molecule inhibitors of Aurora-A oncogenic activity may improve the clinical outcomes of cancer patients. In the present review, we will discuss mitotic and non-mitotic functions of Aurora-A activity in oncogenic transformation and tumor progression. We will also review the current clinical studies, evaluating small molecule inhibitors of Aurora-A activity and their efficacy in the management of cancer patients.

Of Mice and (Wo)Men: Is This Any Way to Test a New Drug?

Mouse models are undeniably vital to our understanding of the molecular basis and pathogenesis of breast cancer. In addition, they provide valuable information for the development of novel antineoplastic agents with regard to basic pharmacokinetics, pharmacogenomics, and toxicity analysis. Their role in evaluating cancer drug efficacy, however, has been limited by inconsistencies in the translation of basic science into effective clinical treatments. Ideally, mimicking the intricacies of human tumorigenesis and metastasis in model systems would simplify the development of targeted therapeutics; however, modeling such interplay between the tumor and its surrounding stroma, matrix proteins, immune cells, endothelia, and lymphatics in mice is a seemingly insurmountable task. Xenograft models employ human tumor cells isolated from metastatic deposits that may have been passaged in vitro hundreds of times before injection into an orthotopic site of an immunodeficient mouse host. Although some of the original molecular and cellular pathways of the tumor cells are preserved in cell lines, the macroand microenvironment surrounding such tumors are artificial, and the true heterogeneity within the tumor is likely compromised. Their value in the historical development of cytotoxic chemotherapeutic agents, however, is supported by an extensive retrospective analysis from the National Cancer Institute. This study compared drug activity between xenograft model systems and phase II human participants. It demonstrated that clinical activity was absent in all six chemotherapy drugs in which xenograft activity was observed in less than one third of the xenografts tested, whereas 45% of the drugs that were active in more than one third of the xenografts were also active in clinical subjects. Although this is the best evidence to support the correlation between drug efficacy in preclinical xenograft mouse and early phase clinical studies in humans, it is tempered by the fact that only 17% of all cancer therapies that are evaluated in human studies will survive phase II evaluation. More recently, genetically engineered mouse models have become a promising alternative to traditional xenograft models in that they provide in situ tumor development in an immunocompetent setting. Their major limitation is their inability to replicate advanced cancer states and metastases—characteristics shared by participants in early-phase human clinical trials. Thus, their role in drug development yet remains to be defined. This can be particularly troublesome for monoclonal antibodies directed against human targets. Unless there is substantial cross-reactivity between mouse and human epitopes, host/antibody interactions cannot be modeled. Orthotopic transplantation of human tumor xenografts, on the other hand, promotes the establishment of high tumor volume and distant metastases. Although this seems preferable to other assessable systems, the technology is labor intensive, expensive, requires small-animal imaging to monitor response to therapy, and may not be easily reproducible. Although no one mouse model system can perfectly simulate human cancer biology, the ability of scientists to humanize these models will likely require a combination of such methodologies. As contemporary drug development takes aim at specific molecular targets, compared with their cytotoxic chemotherapeutic predecessors, it is fair to question whether mouse models are even appropriate for evaluating their efficacy. Despite such flaws, imperfect mouse models have provided important insights into breast cancer therapy. Cultured human estrogen receptor (ER)-positive breast cancer MCF-7 cells were found to be estrogen-dependent in vitro and in xenograft models. This model system was important in discovering the mechanisms of action and in vivo effects of antiestrogen therapy. Indeed, early studies of tamoxifen demonstrated its capacity to induce regression of ER-positive human breast cancer cell lines in nude mice. Such growth inhibition, however, was not observed in the ER-negative cell lines. These results were consistent with those of subsequent human clinical trials in which women with advanced, ER-positive, metastatic disease were found to have a significantly higher response rate to tamoxifen than did those with ER-negative tumors. Similar results were also observed in the adjuvant setting, and it is clear that tamoxifen significantly reduces the odds of recurrence and death resulting from breast cancer in women with ER-positive, but not ER-negative, disease. Studies in mice have also been crucial to the development of targeted cancer therapies against the epidermal growth factor receptor (EGFR) family, including HER-2 (human epidermal growth factor receptor 2). As the role of HER-2/neu in the pathogenesis and progression of breast cancer was defined, inhibitors against the surface membrane receptor were generated in mouse models. The 4D5 murine monoclonal antibody was shown to have specific dose-dependent antiproliferative effects in human tumor cell lines that overexpress HER-2. This led to the development of trastuzumab, a recombinant, humanized murine anti–HER-2 antibody that has demonstrated significant clinical benefit in the treatment of women with HER-2– overexpressing metastatic breast cancer and for adjuvant therapy in women with resected early-stage disease. Both ER and HER-2 have proven to be important prognostically and as biomarkers for JOURNAL OF CLINICAL ONCOLOGY E D I T O R I A L VOLUME 26 NUMBER 6 FEBRUARY 2