Phase 1 and pharmacokinetic study of everolimus, a mammalian target of rapamycin inhibitor, in combination with docetaxel for recurrent/refractory nonsmall cell lung cancer

BACKGROUND

Everolimus is a novel inhibitor of the mammalian target of rapamycin pathway, which is aberrantly activated in nonsmall cell lung cancer (NSCLC). The authors conducted a phase 1 and pharmacokinetic study of everolimus and docetaxel for recurrent NSCLC.

METHODS

Patients with advanced stage NSCLC and progression after prior platinum-based chemotherapy were eligible. Sequential cohorts were treated with escalating doses of docetaxel (Day 1) and everolimus (orally daily, Days 1-19) every 3 weeks. Pharmacokinetic sampling of everolimus and docetaxel was done in Cycle 1. The primary endpoint was determination of the recommended phase 2 doses of the combination.

RESULTS

Twenty-four patients were enrolled (median age, 62 years; women, 11; number of prior regimens, 1 [n=13], 2 [n=6], >or=3 [n=5]; Eastern Cooperative Oncology Group performance status, 0 [n=6], 1 [n=17]). The dose-limiting toxicities (DLTs) were fever with grade 3/4 neutropenia, grade 3 fatigue, and grade 3 mucositis. None of the 7 patients treated at the recommended phase 2 dose (docetaxel 60 mg/m2 and everolimus 5 mg daily) experienced DLT. Everolimus area under the concentration time curve (AUC) was not different with 60 or 75 mg/m2 docetaxel. Mean+/-standard deviation AUC-based accumulation factors for everolimus on Days 8 and 15 were 1.16+/-0.37 and 1.42+/-0.42, respectively. Docetaxel Day 1 half-life was 9.4+/-3.4 hours. Among 21 patients evaluable, 1 had a partial response, and 10 had disease stabilization.

CONCLUSIONS

The recommended phase 2 doses of docetaxel and everolimus for combination therapy are 60 mg/m2 and 5 mg orally daily, respectively. Promising anticancer activity has been noted.

Abstract 5428: Histone deacetylase (HDAC) enzyme inhibition potentiates taxanes and doxorubicin activity in thyroid cancer cell lines

Thyroid cancer is the fastest growing cancer in the US. Doxorubicin, the only approved medical therapy, has limited efficacy; therefore alternative treatment options are warranted. We previously showed increased cytotoxicity when HDAC inhibitor was combined with taxanes and carboplatin in lung cancer cell lines. We now studied the combination of HDAC inhibitor and cytotoxic agents in thyroid cancer cell lines. Exponentially growing cells (Cal 62, PTC1, and BCPAP) were treated by continuous exposure for 72 hrs to vehicle or increasing concentrations of doxorubicin, paclitaxel or docetaxel ± fixed concentration of LBH589. Surviving cell fraction was estimated by sulforhodamine B (SRB) colorimetric assay. IC50 concentration was determined by non-linear regression modeling of OD measurements. In a separate experiment, Western blot assay for markers of apoptosis (caspase and PARP cleavage), cell cycle regulation (p21, p27) and tubulin acetylation was performed using cell lysates from cells treated for 48 hrs with IC50 concentration of chemotherapy drugs ± LBH589. Similarly treated cells were analyzed for changes in cell cycle distribution using propidium iodide staining and flow cytometry. Doxorubicin, docetaxel and paclitaxel showed potent nanomolar activity with up to 80% reduction in the IC50 concentrations when combined with LBH589 (paclitaxel: 0% - 70%; docetaxel: 60% - 84%; doxorubicin: 2% - 65%). Flow cytometry showed qualitative evidence for increased cell death with a 1.5 to 6-fold increase in the subG1 apoptotic cell fraction with combined doxorubicin and LBH589 versus doxorubicin alone. The increased cytotoxicity correlated with increased PARP cleavage and increased p21 protein expression; p27 induction by doxorubicin was not augmented by co-treatment with LBH589. HDAC inhibition augments in vitro cytotoxicity of microtubule and DNA-damaging agents in thyroid cancer cell lines. This combination deserves further evaluation in this disease.DrugIC50 Concentrations in Thyroid Cancer Cell Lines (nM)  BCPAPCAL 62PTC1  − L+L− L+L− L+L Paclitaxel3.60.641.310.538.6631.365Docetaxel6.9852.1450.710.282.252.25Doxorubicin34.2512.142278.6778.7188.542LBH569 16.84 11.94 22.71Flow Cytometry Analysis Following Propidium Iodide Staining BCPAPCAL 62PTC1TreatmentVDoxDox + LVDoxDox + LVDoxDox + L%Sub G145.5456.362.286.825.6766.775.456.914.21V: Vehicle;Dox: Doxorubicin;L: LBH589Full details of Western blot assay and complete flow analysis to be presented at the meeting.Acknowledgement: Taofeek Owonikoko, Suresh Ramalingam, Fadlo Khuri and Shi-Yong Sun are all supported by the Georgia Cancer Coalition as Distinguished Cancer Scholars.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5428.

Maintenance therapy for advanced non-small cell lung cancer: current status, controversies, and emerging consensus

Maintenance therapy refers to the use of an active therapeutic agent for extended duration following frontline induction therapy for patients with advanced stage non-small cell lung cancer (NSCLC). Multiple clinical trials reported within the last few months have shown a beneficial role for maintenance therapy especially in select patient groups characterized by histology and/or molecular profile. With the recent approval by the U.S. Food and Drug Administration and European Medicines Agency of pemetrexed for maintenance therapy, a new treatment paradigm has been introduced to the treatment of NSCLC. This article reviews recent data with maintenance therapy in advanced NSCLC and discusses the implications for routine patient care and future drug development.

Vorinostat increases carboplatin and paclitaxel activity in non-small-cell lung cancer cells

We observed a 53% response rate in non-small cell lung cancer (NSCLC) patients treated with vorinostat plus paclitaxel/carboplatin in a Phase I trial. Studies were undertaken to investigate the mechanism (s) underlying this activity. Growth inhibition was assessed in NSCLC cells by MTT assay after 72 hr of continuous drug exposure. Vorinostat (1 microM) inhibited growth by: 17% +/- 7% in A549, 28% +/- 6% in 128-88T, 39% +/- 8% in Calu1 and 41% +/- 7% in 201T cells. Vorinostat addition to carboplatin or paclitaxel led to significantly greater growth inhibition than chemotherapy alone in all 4 cell lines. Vorinostat (1 microM) synergistically increased the growth inhibitory effects of carboplatin/paclitaxel in 128-88T cells. When colony formation was measured after drug withdrawal, vorinostat significantly increased the effects of carboplatin but not paclitaxel. The % colony formation was control 100%; 1 microM vorinostat, 83% +/- 10%; 5 microM carboplatin, 41% +/- 11%; carboplatin/vorinostat, 8% +/- 4%; 2 nM paclitaxel, 53% +/- 11%; paclitaxel/vorinostat, 46% +/- 21%. In A549 and 128-88T, vorinostat potentiated carboplatin induction of gamma-H2AX (a DNA damage marker) and increased alpha-tubulin acetylation (a marker for stabilized mictrotubules). In A549, combination of vorinostat with paclitaxel resulted in a synergistic increase in alpha-tubulin acetylation, which reversed upon drug washout. We conclude that vorinostat interacts favorably with carboplatin and paclitaxel in NSCLC cells, which may explain the provocative response observed in our clinical trial. This likely involves a vorinostat-mediated irreversible increase in DNA damage in the case of carboplatin and a reversible increase in microtubule stability in the case of paclitaxel.

The role of cetuximab in the management of non-small-cell lung cancer

Inhibition of the epidermal growth factor receptor (EGFR) pathway has emerged as a proven strategy for the treatment of advanced-stage non-small-cell lung cancer (NSCLC). Cetuximab is a chimeric monoclonal antibody that inhibits EGFR by binding to the extracellular domain of the receptor. The relatively modest anticancer activity as monotherapy in NSCLC has prompted the evaluation of cetuximab as part of novel combination regimens. The safety of cetuximab in combination with the commonly used platinum-based 2-drug regimens in NSCLC has been established in several phase II studies. Recently, the addition of cetuximab to the regimen of cisplatin and vinorelbine resulted in improved overall survival in patients with advanced NSCLC with EGFR-expressing tumors. In contrast, a study in unselected advanced NSCLC patients failed to demonstrate a statistically significant improvement in overall survival with cetuximab in combination with a carboplatin and taxane regimen. It is hoped that identification of predictive biomarkers would lead to the optimal utilization of cetuximab in combination with chemotherapy. The combination of cetuximab with radiotherapy for patients with locally advanced NSCLC has demonstrated promising results in a phase II study and is now being evaluated in a confirmatory trial. This article reviews the clinical data with cetuximab in NSCLC.

The role of targeted agents in the treatment of elderly patients with non-small cell lung cancer (NSCLC)

The introduction of targeted biological agents represents the most promising approach to improve the disease control and outcome for patients with non-small cell lung cancer. The epidermal growth factor and the vascular endothelial growth factor signaling pathways have been successfully targeted using both orally administered small molecule tyrosine kinase inhibitors and monoclonal antibodies, with associated improvement in overall survival. Although the trials that established the efficacy of these agents allowed the enrollment of patients older than 70 years, the elderly patients constituted the minority. Given the stringent enrolment criteria in terms of organ function and performance status for most clinical trials, the elderly patients on clinical trials are not entirely representative of the overall elderly patient population. Therefore, the applicability of these data to the overall patient population deserves critical appraisal in the absence of trials dedicated specifically to the elderly. Preplanned and unplanned subset analysis of registration trial data is becoming increasingly common as a substitute measure to provide valuable information to guide the use of targeted agents in the elderly. Using this approach, it has been demonstrated that elderly patients are able to tolerate targeted biological therapies but suffer increased rate of toxicities. However, they derive benefit from such agents when they are carefully selected and have their drug doses adjusted appropriately to minimize potential toxicities. This article reviews the use of targeted agents for the treatment of NSCLC in elderly patients.

Small Cell Lung Cancer in Elderly Patients: A Review

Small cell lung cancer (SCLC) accounts for approximately 13% of all lung cancer cases. Approximately 40% of those cases are diagnosed in patients older than 70 years, and this proportion continues to rise in contrast to the continued decline in incidence of SCLC among the general population. The optimal strategy to manage limited-stage SCLC involves a combined modality approach with platinum-based chemotherapy and external-beam thoracic radiation therapy. For extensive-stage disease, platinum-based combination chemotherapy is a mainstay of therapy. Elderly patients present unique challenges in terms of drug metabolism and organ reserve, which impact the outcome of therapeutic interventions. However, limited data are available to guide management decisions for SCLC in elderly patients, and therefore this article discusses recommendations for treatment.

Lung Cancer in Elderly Patients: An Analysis of the Surveillance, Epidemiology, and End Results Database

Purpose

To study the burden and outcome of lung cancer in the elderly, particularly for patients aged 80 years and older.

Patients and Methods

The national Surveillance, Epidemiology, and End Results database was analyzed for lung cancer outcomes during the period 1988 to 2003. A comparison was carried out between patients with lung cancer 80 years and older, 70 to 79 years, and younger than 70 years for demographics; stage distribution; 5-year relative survival; and survival based on histology, sex, race, stage, and treatment. The temporal trends in survival during the years 1988 to 1997 and 1998 to 2003 were also analyzed.

Results

Of 316,682 patients eligible for the analysis, 45,912 (14%) were 80 years or older (ie, very elderly); 103,963 (33%) were 70 to 79 years; and 166,807 (53%) were younger than 70 years. The distribution by stage and histology was comparable for all the three groups. Overall survival rate at 5 years was lower in the very elderly (7.4% v 12.3% v 15.5%; P < .0001) across sex, histologic subtypes, stages, and racial categories. Patients aged 80 years or older were less likely to receive local therapy (no surgery or radiation) than younger patients (47% v 28% and 19% for the age subgroups ≥ 80 years, 70 to 79 years, and < 70 years, respectively). Overall outcomes for patients who underwent surgical therapy or radiation were comparable across the three age groups. In general, survival outcomes for the subgroup aged 70 to 79 years were similar to those of the subgroup aged 80 years and older who received single modality local therapy.

Conclusion

Patients 80 years or older account for 14% (70 years or older accounted for 47%) of all lung cancers, are less likely to be subjected to surgery or radiation, and have inferior outcomes when compared with younger patients.

In vivo investigation of estrogen regulation of adrenal and renal angiotensin (AT1) receptor expression by PET

The renin angiotensin system (RAS) has been implicated as one mediator of the cardiovascular effects of estrogen. Since changes in angiotensin type 1 (AT(1)) receptor expression are central to modulation of the RAS, we used the noninvasive PET imaging technique to study for the in vivo effects of estrogen on membrane and intracellular AT(1) receptors.

METHODS

Dynamic PET measurements of canine AT(1) (cAT(1)) receptors using the radiolabeled AT(1) receptor antagonist, (11)C-L-159,884, were performed during 2-wk consecutive periods of estrogen deprivation induced by ovariectomy and 17beta-estradiol (E(2)) replacement.

RESULTS

Kinetic modeling of time-activity curves in the kidney and adrenal showed lower receptor expression in the estrogen replete state (21% and 30% decrease in Gjedde-Patlak slope, influx constant, respectively). These in vivo findings correlated with in vitro radioligand-binding assays with (125)I-[Sar(1),Ile(8)]angiotensin II showing reduced AT(1) receptor number in the adrenal (35%), glomeruli (30%), myocardium (35%), and liver (21%) in the estrogen-replenished compared with estrogen-depleted animals.

CONCLUSION

Although other endogenous systems are known to regulate AT(1) receptors and could compete with estrogenic actions, these PET studies reveal that estrogen attenuates AT(1) receptor expression in vivo. Thus, estrogen modulation of AT(1) receptors may contribute to the cardiovascular protective effects associated with estrogen.

Colorectal neoplasms: a retrospective study

A total of 254 cases of colorectal neoplasms were studied. A male predominance was noted with both benign and malignant neoplasms (M:F of 4.6:1 and 1.1:1 respectively). The peak incidence was in the fifth decade. The rectum was the commonest site for both benign and malignant neoplasms (75% and 63% respectively) followed by the sigmoid colon (11% and 16% respectively). Right-sided cancers presented commonly as fungating masses (74%) while left sided cancers were predominantly of the ulcerating/infiltrating pattern (81%). The commonest benign neoplasm was tubular adenoma (39%) while the commonest malignant neoplasm was adenocarcinoma (90%) followed by squamous cell carcinoma (4%). Advanced stage on presentation was noted with these cancers, especially the mucinous adenocarcinoma variant. This may be explained by the usual late presentation of patients to orthodox doctors in our environment.