Neoadjuvant chemotherapy and Avelumab in early stage resectable nonsmall cell lung cancer

Multiple randomized studies have shown that combination of chemotherapy and immune checkpoint inhibitors (ICIs) leads to better response rates and survival as compared to chemotherapy alone in the advanced stage of NSCLC. Data suggesting a benefit to using ICIs in the neoadjuvant therapy of patients with early stage NSCLC are emerging. Eligible subjects were treatment naïve patients with stage IB, II, and resectable IIIA NSCLC. Patients received three cycles of neoadjuvant chemotherapy with four doses of avelumab every 2 weeks. Patients with squamous cell cancer received cisplatin or carboplatin on day 1 and gemcitabine on days 1 and 8 of each cycle of chemotherapy. Patients with nonsquamous histology received cisplatin or carboplatin with pemetrexed on day 1 of each cycle. Patients then proceeded to their planned surgery. Out of 15 patients accrued as part of stage 1 of the study, four had a radiologic response (1 complete response), lower than the minimum of six responses needed to continue to phase 2 of the study. The study was therefore terminated. Majority had adenocarcinoma histology and stage IIIA disease. The treatment was well tolerated with no unexpected side effects. Four patients (26.7%) had grade III/IV CTCAE toxicity. This study confirms that the preoperative administration of chemotherapy and avelumab is safe. There was no indication of increased surgical complications. The benefit of adding immunotherapy to chemotherapy did not appear to enhance the overall response rate of patients in the neoadjuvant setting in patients with resectable NSCLC because this study failed to meet its primary endpoint.

Deep targeted sequencing analysis of hot spot mutations in non-small cell lung cancer patients from the Middle Eastern population

Background

The overall 5-year survival of lung cancer remains dismal despite the current treatment regimens. Testing for driver mutations has become routine practice for oncologists due to the presence of targeted therapy readily available for patients. Deep targeted sequencing through next generation sequencing (NGS) is an adequate methodology to detect mutations at multi-genetic levels. The molecular pathology of non-small cell lung cancer (NSCLC) is poorly understood in the Middle East and, to date, no other reports have been published on deep targeted sequencing of lung adenocarcinoma (LUAD) tissues.

Methods

Deep targeted sequencing using TruSeq Amplicon Cancer panel of 48 genes was performed on 85 formalin-fixed paraffin-embedded tissues from patients with LUAD who were treatment-naive at the time of the collection. Variants with an allele frequency higher than 10% were retained.

Results

Variant calling identified a total of 2,455 variants of which missense mutations were the most frequent (75.6%). All of our samples showed at least one mutation in one of the 10 most commonly mutated genes with FLT3 being the gene with the highest mutation rate (67%). TP53, KRAS and STK11 were the second, third and fourth most commonly mutated genes, respectively while EGFR mutation rate reached 22.4%.

Conclusions

To the best of our knowledge, this is the first hot spot profiling study on patients from this area. The frequencies of mutated genes presented in our study showed similarity to other reported outcomes. At least one mutation was detected in our cohort of LUAD.

Phase 1b study of chemoprevention with green tea polyphenon E (PPE) and epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (Erlotinib) in patients (pts) with advanced premalignant (AP) lesions of the head and neck

6049

Background: Based on the strong synergistic effects between green tea polyphenon E (PPE) and EGFR-TKI in our preclinical studies (Int J Cancer, 2008; Cancer Prev Res, 2009; JCO, 2009), we conducted a phase 1b study with PPE and erlotinib combination for APL (mild-, moderate-, severe-dysplasia or carcinoma in situ [CIS]) of the oral cavity and larynx from 2/2011 to 11/2017 at Emory Winship Cancer Institute. Methods: All pts were enrolled after signing the IRB approved Informed Consent Form. Tissue biopsy before and at 6-months (6-M) treatment was mandatory, and cytobrushed samples of the APL and normal buccal mucosa at 3-, 6-, and 12-M were obtained for biomarker studies. Treatment included fixed dose of PPE (200 mg, P.O.,TID) and dose escalation of erlotinib P.O., (50mg [level 1], 75mg [level 2] and 100mg [level 3]) for 6-M. The primary endpoint was safety and toxicity, and secondary endpoints were evaluation of pathologic responses, cancer free survival (CFS) and biomarker modulation. Results: Out of 27 enrolled pts, 6 control subjects for biomarker studies, 2 ineligible, and 19 were treated with PPE and erlotinib for 6-M. Clinical characteristics of treated patients included median age, 63 yrs. (range,33-78); 9 M/10 F; 10 former or current smokers/9 never smokers; 15 severe dysplasia or CIS, 2 moderate dysplasia, 2 mild dysplasia; 13 had surgical resection; 17 oral cavity primary; and 2 at larynx. 3 pts were treated at dose level 1, 4 at level 2, and 12 at level 3. Toxicity (G0 or G1 excluded) were: skin rash (1 G3, 1 G2), pruritus/dry skin (1 G2), fatigue (1 G2), diarrhea (1 G2), epistaxis (1 G2), and hypertension (2 G3, 1 G2). Skin rash (associated with erlotinib) may be DLT and MTD has not been reached. The recommend doses for phase 2 or 3 studies will be PPE 200mg TID plus erlotinib 100mg QD. 17 pts were assessed for pathologic responses at 6-M: pCR 7/17 (41%), pPR 2/17 (12%), pSD 5/17 (29%) and pPD (3/17 (18%). The median follow up was 32 months. Median CFS has not been reached. 16 pts are alive at the time of data analyses and 1 pt died (by noncancerous reason). Biomarker studies are ongoing for tissues and/or cytobrushed samples. Conclusions: The treatment of the combination of green tea PPE plus erlotinib for 6-M was well tolerated in pts with APL of the head and neck, and showed significant pathologic response rates (pCR and pPR, 53%). This combination therefore deserves further investigation for efficacy testing. Clinical trial information: NCT01116336.

A randomized phase II study of tremelimumab and durvalumab with or without radiation for patients with relapsed small cell lung cancer (SCLC)

8515

Background: The combination of PD-1 and CTLA-4 inhibition has demonstrated activity in the second line therapy setting for SCLC. Radiotherapy enhanced the effectiveness of immunotherapy in NSCLC. We conducted this signal finding study to assess the efficacy of combined ICI with or without radiation in relapsed SCLC. Methods: Patients with relapsed SCLC who have received not more than 2 lines of therapy were enrolled and randomized to either Arm A: [Tremelimumab (T) 1500mg/durvalumab (D) 75mg i.v. every 4 weeks without SBRT] or Arm B: T/D with immune sensitizing SBRT to one selected tumor site (9 Gy x 3 fractions). Treatment continued until progression or maximum of 2 years. Paired tumor biopsies and serial samples of peripheral blood were employed for correlative endpoints (changes in intratumoral and circulating lymphocyte repertoire and immune cytokines). The study was designed to show a promising efficacy signal in either Arm with a hypothesized median PFS of 7 months (10 patients give 87% power at 1-sided alpha of 0.1). Results: Study randomized 17 patients to Arm A (8 patients) or B (9 patients); median age of 70 yrs; females 41.2%; White, 70%, Black 17.6%. Best response in 14 overall evaluable patients was PD in 9 (64.3%), PR in 2 (14%) and SD in 3 (21.4%); median PFS of 2.76 months and OS of 4.47 months. There was no significant difference in efficacy between Arms A and B but a trend of improved PFS and OS with T/D plus SBRT (see table): Median PFS of 2.1 vs. 3.3 months [HR: 2.44 (0.75-7.93); p = 0.122] and median OS of 2.6 vs. 5.7 months [HR: 1.50 (0.45-4.99); p = 0.5068]. Observed grade ≥ 3 adverse events were: Cytopenia (4), Dyspnea (1), and endocrine disorders (3) in Arm A; diarrhea (3) and cytopenias (1) in Arm B. There was an increase in circulating CD8(+) lymphocytes on treatment versus baseline in patients with objective tumor response. Conclusions: The study did not show sufficient signal of efficacy for ICI with or without SBRT in relapsed SCLC. Detailed result of the biomarker analysis will be available at the meeting. Clinical trial information: NCT02701400. [Table: see text]

Abstract 2333: Modulation of Bax and mTOR for cancer therapeutics

Pharmacologic manipulation of the serine (S)184 phosphorylation site of Bax protein to functionally regulate its proapoptotic activity is an attractive anticancer strategy. We recently identified three small molecule Bax agonists. SMBA1 was selected as the lead compound based on its chemical structure and its drug-like properties, from which a more effective analog, CYD-2-11, was generated. CYD-2-11 targets the structural pocket around S184 in the C-terminal tail of Bax, directly activating its proapoptotic activity via 6A7 conformational change and formation of Bax homo-oligomers in mitochondrial membranes. CYD-2-11 suppresses tumor growth in SCLC, NSCLC and patient-derived lung cancer xenografts as well as the genetically engineered mutant KRAS-driven lung cancer model with no significant normal tissue toxicity. Inhibition of mTOR by RAD001 enhances S184 Bax phosphorylation in lung cancer cell lines and tumor tissues from lung cancer patients treated with RAD001, which inactivates the propaoptotic function of Bax, contributing to rapalog-resistance. Combined CYD-2-11 and RAD001 treatment not only displays strong synergistic activity against lung cancer but also overcomes rapalog-resistance in vitro and in vivo. Therefore, a mechanism-driven combination of Bax agonist and mTOR inhibitor represents a highly attractive therapeutic strategy to improve lung cancer patient outcomes.

Citation Format: Rui Li, Chunyong Ding, Jun Zhang, Maohua Xie, Dongkyoo Park, Ye Ding, Guo Chen, Guojing Zhang, Melissa Gilbert-Ross, Wei Zhou, Adam Marcus, Shi-Yong Sun, Zhuo Chen, Gabriel Sica, Suresh Ramalingam, Andrew Magis, Haian Fu, Fadlo Khuri, Walter Curran, Taofeek Owonikoko, Dong Shin, Jia Zhou, Xingming Deng. Modulation of Bax and mTOR for cancer therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2333. doi:10.1158/1538-7445.AM2017-2333

Abstract A17: Glutamate dehydrogenase 1 signals through antioxidant glutathione peroxidase 1 to regulate redox homeostasis and tumor growth

How mitochondrial glutaminolysis contributes to redox homeostasis in cancer cells remains unclear. Here we report that the mitochondrial enzyme glutamate dehydrogenase 1 (GDH1), commonly upregulated in human cancers, is predominantly important for redox homeostasis in cancer cells by controlling the intracellular levels of its product alpha-ketoglutarate (a-KG) and subsequent metabolite fumarate. Mechanistically, fumarate binds to and activates a ROS scavenging enzyme glutathione peroxidase 1 (GPx1) to regulate redox homeostasis, which provides a proliferative advantage to cancer cells and tumor growth. Our findings not only provide novel insights into understanding of the role of glutaminolysis in redox homeostasis but also suggest a novel signaling function of fumarate that regulates GPx1, allowing additional crosstalk between glutaminolysis, TCA cycle and redox status. Targeting GDH1 by shRNA or a newly identified small molecule inhibitor R162 resulted in imbalanced redox homeostasis, leading to attenuated cancer cell proliferation and tumor growth. Thus, our findings provide proof-of-principle suggesting GDH1 as a promising therapeutic target in the treatment of human cancers associated with elevated glutamine metabolism.

Citation Format: Lingtao Jin, Dan Li, Gina Alesi, Jun Fan, Hee-Bum Kang, Lu Zhou, Titus Boggon, Peng Jin, Robert Egnatchik, Ralph DeBerardinis, Kelly Magliocca, Chuan He, Martha Arellano, Hanna Khoury, Dong Shin, Fadlo Khuri, Sumin Kang. Glutamate dehydrogenase 1 signals through antioxidant glutathione peroxidase 1 to regulate redox homeostasis and tumor growth. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A17.

Abstract 2922: Development of Bcl2 BH4 antagonist for cancer therapy

The BH4 domain of Bcl2 is required for its antiapoptotic function, thus constituting a promising anticancer target. We identified a novel small molecule Bcl2-BH4 domain-antagonist (BDA-366) that binds BH4 with high affinity and selectivity. BDA-366-Bcl2 binding induces conformational change in Bcl2 that abrogates its antiapoptotic function, converting it from a survival to a cell death inducer. BDA-366 induces regression of lung cancer xenografts derived from cell line and patient without significant normal tissue toxicity at effective doses. mTOR inhibition up-regulates Bcl2 in lung cancer cells and tumor tissues from clinical trial patients. Combined BDA-366 and RAD001 treatment exhibits strong synergy against lung cancer in vivo. Development of this Bcl2-BH4 antagonist may provide a novel strategy to improve lung cancer outcome.

Citation Format: Bingshe Han, Dongkyoo Park, Rui Li, Maohua Xie, Taofeek Owonikoko, Gabriel Sica, Chunyong Ding, Jia Zhou, Andrew Magis, Suresh Ramalingam, Fadlo Khuri, Walter Curran, Xingming Deng. Development of Bcl2 BH4 antagonist for cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2922. doi:10.1158/1538-7445.AM2015-2922

Abstract 3046: Glutamate dehydrogenase 1 signals through antioxidant glutathione peroxidase 1 to regulate redox homeostasis and tumor growth

How mitochondrial glutaminolysis contributes to redox homeostasis in cancer cells remains unclear. Here we report that the mitochondrial enzyme glutamate dehydrogenase 1 (GDH1), commonly upregulated in human cancers, is predominantly important for redox homeostasis in cancer cells by controlling the intracellular levels of its product alpha-ketoglutarate (a-KG) and subsequent metabolite fumarate. Mechanistically, fumarate binds to and activates a ROS scavenging enzyme glutathione peroxidase 1 (GPx1) to regulate redox homeostasis, which provides a proliferative advantage to cancer cells and tumor growth. Our findings not only provide novel insights into understanding of the role of glutaminolysis in redox homeostasis but also suggest a novel signaling function of fumarate that regulates GPx1, allowing additional crosstalk between glutaminolysis, TCA cycle and redox status. Targeting GDH1 by shRNA or a newly identified small molecule inhibitor R162 resulted in imbalanced redox homeostasis, leading to attenuated cancer cell proliferation and tumor growth. Thus, our findings provide proof-of-principle suggesting GDH1 as a promising therapeutic target in the treatment of human cancers associated with elevated glutamine metabolism.

Citation Format: Lingtao Jin, Dan Li, Gina Alesi, Jun Fan, Hee-Bum Kang, Lu Zhou, Titus Boggon, Kelly Magliocca, Chuan He, Martha Arellano, Hanna Khoury, Dong Shin, Fadlo Khuri, Sumin Kang. Glutamate dehydrogenase 1 signals through antioxidant glutathione peroxidase 1 to regulate redox homeostasis and tumor growth. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3046. doi:10.1158/1538-7445.AM2015-3046

Clinical outcomes in elderly patients with human papillomavirus-positive squamous cell carcinoma of the oropharynx treated with definitive chemoradiation therapy

BACKGROUND

The benefit of combined chemoradiation in elderly patients with human papillomavirus (HPV)-positive locally advanced oropharyngeal squamous cell carcinoma (SCC) must be balanced with the potential for higher toxicity rates. We performed a retrospective review of our institutional experience.

METHODS

Patients 70 years or older with p16-positive oropharyngeal SCC treated with definitive chemoradiation from 2005 to 2013 were evaluated. Overall survival (OS), disease-free survival (DFS), and locoregional failure-free survival were calculated.

RESULTS

Twenty-one eligible patients had a follow-up of 22.4 months. Estimated 5-year OS, DFS, and locoregional failure-free survival were 76.0%, 40%, and 95%, respectively. There was 1 death from acute toxicity, and 50% had unplanned hospitalizations. Sixty percent had late toxicity, and 6-month feeding tube dependence was 25%.

CONCLUSION

Elderly patients with HPV-positive locally advanced SCC of the oropharynx treated with definitive chemoradiation had good OS but high rates of acute and long-term toxicity. © 2015 Wiley Periodicals, Inc. Head Neck 38: 846-851, 2015.

Dose escalation with over-dose and under-dose controls in Phase I/II clinical trials

To save valuable time and resources in new drug development, Phase I/II clinical trials with toxicity control and drug efficacy as dual primary endpoints have become increasingly popular. Escalation with over-dose control (the EWOC) is a Bayesian adaptive Phase I clinical trial design that can accurately estimate the maximum tolerated dose (MTD) level and control the probability of overdosing patients during the dose allocation phase. In this paper, we extend EWOC to Phase I/II clinical trials by controlling for under-dosing with a Gumbel Copula model to provide patients with at least minimum drug efficacy. We propose a utility function to measure the composite effect of toxicity and efficacy and select the optimal dose. To deal with the common issue that the efficacy endpoint often cannot be quickly ascertained, we employ Bayesian data augmentation to handle delayed efficacy and allow for flexible patient accrual without a waiting period. Extensive simulations demonstrate that the proposed new design not only provides better therapeutic effect by reducing the probability of treating patients at under-dose levels while protecting patients from being overdosed, but also improves trial efficiency and increases the accuracy of dose recommendation for subsequent clinical trials. We apply the proposed design to a Phase I/II solid tumor trial.

A randomized phase II study of ganetespib, a heat shock protein 90 inhibitor, in combination with docetaxel in second-line therapy of advanced non-small cell lung cancer (GALAXY-1)

BACKGROUND

This trial was designed to evaluate the activity and safety of ganetespib in combination with docetaxel in advanced non-small cell lung cancer (NSCLC) and to identify patient populations most likely to benefit from the combination.

PATIENTS AND METHODS

Patients with one prior systemic therapy for advanced disease were eligible. Docetaxel (75 mg/m(2) on day 1) was administered alone or with ganetespib (150 mg/m(2) on days 1 and 15) every 3 weeks. The primary end points were progression-free survival (PFS) in two subgroups of the adenocarcinoma population: patients with elevated lactate dehydrogenase (eLDH) and mutated KRAS (mKRAS).

RESULTS

Of 385 patients enrolled, 381 were treated. Early in the trial, increased hemoptysis and lack of efficacy were observed in nonadenocarcinoma patients (n = 71); therefore, only patients with adenocarcinoma histology were subsequently enrolled. Neutropenia was the most common grade ≥3 adverse event: 41% in the combination arm versus 42% in docetaxel alone. There was no improvement in PFS for the combination arm in the eLDH (N = 114, adjusted hazard ratio (HR) = 0.77, P = 0.1134) or mKRAS (N = 89, adjusted HR = 1.11, P = 0.3384) subgroups. In the intent-to-treat adenocarcinoma population, there was a trend in favor of the combination, with PFS (N = 253, adjusted HR = 0.82, P = 0.0784) and overall survival (OS) (adjusted HR = 0.84, P = 0.1139). Exploratory analyses showed significant benefit of the ganetespib combination in the prespecified subgroup of adenocarcinoma patients diagnosed with advanced disease >6 months before study entry (N = 177): PFS (adjusted HR = 0.74, P = 0.0417); OS (adjusted HR = 0.69, P = 0.0191).

CONCLUSION

Advanced lung adenocarcinoma patients treated with ganetespib in combination with docetaxel had an acceptable safety profile. While the study's primary end points were not met, significant prolongation of PFS and OS was observed in patients >6 months from diagnosis of advanced disease, a subgroup chosen as the target population for the phase III study.

Abstract 773: Restoration of LKB1 defect in EKVX cells leads to resistance to microtubule targeting agents

LKB1 is frequently inactivated in non-small cell lung cancers, probably because of its role in suppressing tumor metastasis. Here, we identified a novel LKB1 mutation in the EKVX lung adenocarcinoma cell line, where serine216 in the kinase domain was mutated to phenylalanine. Genomic sequencing revealed this change to be homozygous, suggesting that the other allele was probably eliminated through a loss of heterozygosity mechanism. We also demonstrated that EKVX cells are defective in energetic stress-induced AMPK phosphorylation, which can be restored by the re-establishment of wild-type but not mutant LKB1 expression. This is consistent with the role of LKB1 as an upstream kinase for AMPK in energetic stress conditions. Interestingly, expression of wild-type LKB1 in EKVX cells was found to be resistant to microtubule targeting agents, such as paclitaxel or vinblastine by SRB analysis. Cell cycle analysis indicated that while the parental or LKB1-mutant expressing cells enter mitotic arrest after 25nM paclitaxel treatment, EKVX-LKB1 cells failed to enter G2/M arrest. Immunofluorescence analysis also revealed a decrease in microtubule bundling after 50nM paclitaxel treatment in EKVX cells with wild-type LKB1 expression. This phenomenon, however, was not observed in other natural LKB1-null A549 or H460 cells. Therefore, our data suggest that the re-establishment of LKB1 expression might lead to resistance to microtubule targeting agents in a subset of non-small cell lung cancer cells with LKB1 mutation.

Citation Format: Kaisheng Mao, Fakeng Liu, Xiuju Liu, Yulong He, Fadlo Khuri, Adam Marcus, Mingsong Li, Wei Zhou. Restoration of LKB1 defect in EKVX cells leads to resistance to microtubule targeting agents. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 773. doi:10.1158/1538-7445.AM2014-773

Randomized safety and efficacy study of fosbretabulin with paclitaxel/carboplatin against anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid cancer (ATC), a rare highly vascularized tumor, has a dismal outcome. We conducted an open-label study of doublet carboplatin/paclitaxel chemotherapy with or without fosbretabulin in patients with ATC.

METHODS

Patients were randomly assigned in a 2:1 ratio to 6 cycles of paclitaxel 200 mg/m(2) followed by carboplatin AUC 6 on day 1 every 3 weeks (CP), or these drugs were given on day 2 after fosbretabulin 60 mg/m(2) (CP/fosbretabulin) on days 1, 8 and 15. After 6 cycles, patients on the fosbretabulin arm without progression could continue to receive fosbretabulin on days 1 and 8 of a 3-week schedule until progression. The primary end point was overall survival (OS).

RESULTS

Eighty patients were assigned (planned, 180) when enrollment was stopped due to rarity of disease and very low accrual. Median OS was 5.2 months [95% confidence interval (CI) 3.1, 9.0] for the CP/fosbretabulin arm (n=55; hazard ratio 0.73 [95% CI 0.44, 1.21]) and 4.0 months [95% CI 2.8, 6.2] for the CP arm (n=25; p=0.22 [log rank test]). One-year survival for CP/fosbretabulin versus CP was 26% versus 9%, respectively. There was no significant difference in progression-free survival between the two arms. Grade 1-2 hypertension and grade 3-4 neutropenia were more common with CP/fosbretabulin. There were no significant adverse cardiovascular side effects.

CONCLUSIONS

Although the study did not meet statistical significance in improvement in OS with the addition of fosbretabulin to carboplatin/paclitaxel, it represents the largest prospective randomized trial ever conducted in ATC. The regimen is well tolerated, with AEs and deaths primarily related to ATC and disease progression.

Gefitinib versus placebo in completely resected non-small-cell lung cancer: results of the NCIC CTG BR19 study

PURPOSE

Survival of patients with completely resected non-small-cell lung cancer (NSCLC) is unsatisfactory, and in 2002, the benefit of adjuvant chemotherapy was not established. This phase III study assessed the impact of postoperative adjuvant gefitinib on overall survival (OS).

PATIENTS AND METHODS

Patients with completely resected (stage IB, II, or IIIA) NSCLC stratified by stage, histology, sex, postoperative radiotherapy, and chemotherapy were randomly assigned (1:1) to receive gefitinib 250 mg per day or placebo for 2 years. Study end points were OS, disease-free survival (DFS), and toxicity.

RESULTS

As a result of early closure, 503 of 1,242 planned patients were randomly assigned (251 to gefitinib and 252 to placebo). Baseline factors were balanced between the arms. With a median of 4.7 years of follow-up (range, 0.1 to 6.3 years), there was no difference in OS (hazard ratio [HR], 1.24; 95% CI, 0.94 to 1.64; P = .14) or DFS (HR, 1.22; 95% CI, 0.93 to 1.61; P = .15) between the arms. Exploratory analyses demonstrated no DFS (HR, 1.28; 95% CI, 0.92 to 1.76; P = .14) or OS benefit (HR, 1.24; 95% CI, 0.90 to 1.71; P = .18) from gefitinib for 344 patients with epidermal growth factor receptor (EGFR) wild-type tumors. Similarly, there was no DFS (HR, 1.84; 95% CI, 0.44 to 7.73; P = .395) or OS benefit (HR, 3.16; 95% CI, 0.61 to 16.45; P = .15) from gefitinib for the 15 patients with EGFR mutation-positive tumors. Adverse events were those expected with an EGFR inhibitor. Serious adverse events occurred in ≤ 5% of patients, except infection, fatigue, and pain. One patient in each arm had fatal pneumonitis.

CONCLUSION

Although the trial closed prematurely and definitive statements regarding the efficacy of adjuvant gefitinib cannot be made, these results indicate that it is unlikely to be of benefit.

Abstract 1975: AICAR induces cell death in LKB1-deficient NSCLC

AICAR is a well known AMPK activator, and AICAR-induced AMPK activation has been shown to inhibit cell proliferation or induce apoptosis through various mechanisms, such as the inactivation of metabolic enzyme involved ATP consumption, the inhibition of the of fatty acid synthesisPI3K/AKT pathway, the activation of cell cycle regulators, or the activation of the JNK pathway. LKB1 is an upstream AMPK kinase, and energetic stress-induced AMPK activation usually requires LKB1. Interestingly, AICAR has also been shown to induce caspase-3 cleavage in LKB1- null MEF and ovarian cancer cells, indicating AICAR can induce cell killing through an AMPK- independent mechanism. Because LKB1 is most frequently inactivated in non-small cell lung cancer, we evaluated the effect of AICAR in lung cancer cell lines. AICAR preferentially induced caspase-3 cleavage in LKB1- mutant NSCLC cell lines H157, A549, H460 and H1944, but not in LKB1- wild type cell lines H1299, H358, H1650 and H1792. Transient depletion of LKB1 by RNAi in H1299 and H1792 cells promoted AICAR-induced caaspase-3 cleavage in the absence of AMPK activation, supporting the notion that AICAR induces cell killing in LKB1-depleted cells through an AMPK- independent mechanism. In LKB1-null H460 cells, AICAR treatment led to a significant increase in S phase cell populations, and G1 cell cycle arrest by serum starvation is was sufficient to prevent AICAR-induced cell death. These data indicated that AICAR-induced cell killing in LKB1- deficient cells is cell cycle dependent. In summary, the ability of AICAR to preferentially induce cell death in LKB1- deficient NSCLC suggestsed that LKB1 deficiency may be a therapeutic target for the treatment of NSCLC.

Citation Format: Fakeng Liu, Wei Zhou, Xiuju Liu, Shi-yong Sun, Fadlo Khuri, Yu-long He, Diansheng Zhong. AICAR induces cell death in LKB1-deficient NSCLC. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1975. doi:10.1158/1538-7445.AM2013-1975

Induction chemotherapy followed by concurrent chemoradiotherapy (sequential chemoradiotherapy) versus concurrent chemoradiotherapy alone in locally advanced head and neck cancer (PARADIGM): a randomised phase 3 trial

BACKGROUND

The relative efficacy of the addition of induction chemotherapy to chemoradiotherapy compared with chemoradiotherapy alone for patients with head and neck cancer is unclear. The PARADIGM study is a multicentre open-label phase 3 study comparing the use of docetaxel, cisplatin, and fluorouracil (TPF) induction chemotherapy followed by concurrent chemoradiotherapy with cisplatin-based concurrent chemoradiotherapy alone in patients with locally advanced head and neck cancer.

METHODS

Adult patients with previously untreated, non-metastatic, newly diagnosed head and neck cancer were eligible. Patients were eligible if their tumour was either unresectable or of low surgical curability on the basis of advanced tumour stage (3 or 4) or regional-node stage (2 or 3, except T1N2), or if they were a candidate for organ preservation. Patients were randomly assigned (in a 1:1 ratio) to receive either induction chemotherapy with three cycles of TPF followed by concurrent chemoradiotherapy with either docetaxel or carboplatin or concurrent chemoradiotherapy alone with two cycles of bolus cisplatin. A computer-generated randomisation schedule using minimisation was prepared and the treatment assignment was done centrally at one of the study sites. Patients, study staff, and investigators were not masked to group assignment. Stratification factors were WHO performance status, primary disease site, and stage. The primary endpoint was overall survival. Analysis was by intention to treat. Patient accrual was terminated in December, 2008, because of slow enrolment. The trial is registered with ClinicalTrials.gov, number NCT00095875.

FINDINGS

Between Aug 24, 2004, and Dec 29, 2008, we enrolled 145 patients across 16 sites. After a median follow-up of 49 months (IQR 39-63), 41 patients had died-20 in the induction chemotherapy followed by chemoradiotherapy group and 21 in the chemoradiotherapy alone group. 3-year overall survival was 73% (95% CI 60-82) in the induction therapy followed by chemoradiotherapy group and 78% (66-86) in the chemoradiotherapy alone group (hazard ratio 1·09, 95% CI 0·59-2·03; p=0·77). More patients had febrile neutropenia in the induction chemotherapy followed by chemoradiotherapy group (16 patients) than in the chemoradiotherapy alone group (one patient).

INTERPRETATION

Although survival results were good in both groups there was no difference noted between those patients treated with induction chemotherapy followed by chemoradiotherapy and those who received chemoradiotherapy alone. We cannot rule out the possibility of a difference in survival going undetected due to early termination of the trial. Clinicians should still use their best judgment, based on the available data, in the decision of how to best treat patients. The addition of induction chemotherapy remains an appropriate approach for advanced disease with high risk for local or distant failure.

FUNDING

Sanofi-Aventis.

Laryngeal tumor volume as a predictor for thyroid cartilage penetration

BACKGROUND

Review of laryngectomy specimens demonstrated that preoperative CT scanning is suboptimal in predicting both thyroid cartilage penetration and extralaryngeal spread. We investigated the association between the CT-based gross tumor volume (GTV) with pathologic evidence of thyroid cartilage penetration among patients undergoing laryngectomy for squamous cell carcinoma (SCC) of the larynx.

METHODS

Ninety-four patients were identified who underwent total laryngectomy for SCC of the larynx. GTV, as defined by preoperative diagnostic CT scan, was contoured and analyzed using treatment-planning software.

RESULTS

Among the 49 nonirradiated patients, the mean GTVs of patients with (n = 15) and without (n = 34) thyroid cartilage penetration was 60.1 and 28.0 cm(3) (p = .004). When the nonirradiated patients were divided into 3 GTV groups (≤25 cm(3), 25-50 cm(3), >50 cm(3)), the rates of thyroid cartilage penetration were 23%, 17%, and 78%, respectively (p = .003).

CONCLUSIONS

Laryngeal tumor volume is associated with pathologic evidence of thyroid cartilage penetration in nonirradiated patients.

Abstract A41: The ASK1/IKK signaling axis mediates crosstalk between inflammation and apoptosis

Inflammation plays a well-established role in the promotion of tumorigenesis. The inflammatory response is mediated in large part by the inhibitor of kappa b (IKK) and nuclear factor κB (NfκB) signaling pathway. This signaling pathway can promote inflammation induced-tumorigenesis and inhibit apoptosis through protection against reactive oxygen species (ROS). The action of ROS is in part controlled by the apoptosis signal regulating kinase 1 (ASK1). ASK1 activation can initiate pro-apoptotic signaling cascades through mitogen activated protein kinases (MAPKs) Jun N-terminal Kinase (JNK) and p38. Improper regulation of ASK1 has been implicated in a wide array of diseases, including cancer. NfκB promotes tumor growth through activation of pro-growth and survival genes and decreases apoptosis through impairing JNK activation. This work has identified an unexpected, direct, non-genetic method of cell death inhibition by an upstream regulator of NfκB, IKK.

We have found that IKK can phosphorylate ASK1 Ser967, which leads to the recruitment of 14–3–3 proteins, decreased ASK1 kinase activity and ASK1-mediated apoptosis. To further elucidate the relationship between ASK1 and IKK, the interaction interface was identified and the consequences on ASK1-mediated signaling were studied. IKK and ASK1 were shown to interact in cells by immunoprecipitation of both overexpressed and endogenous proteins. Furthermore, the direct interaction between these kinases was confirmed through time resolved – fluorescence resonance energy transfer (TR-FRET). The ASK1/IKK interaction interface was dissected through iterative deletional mutagenesis and protein complementation assays. ASK1 activity was assessed by measuring H2O2 induced apoptosis, neurite outgrowth of ASK1-inducible cells, and phosphorylation of ASK1 Ser967 and downstream targets under several IKK states. IKK prevented stress-induced dephosphorylation of ASK1 and inhibited ASK1 mediated apoptosis.

These data suggest the existence of an IKK/ASK1 signaling node that negatively regulates apoptosis in response to pro-survival conditions. Characterization of this interaction could lead to development of targeted agents for ASK1 and IKK related diseases.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A41.

Abstract 2567: Preclinical evaluation of Poly (ADP) Ribose Polymerase (PARP) enzyme inhibitor, ABT-888, in combination with cytotoxic agents in small cell lung cancer (SCLC)

The induction of DNA damage underlies the efficacy of cytotoxic chemotherapy agents for the treatment of SCLC. Poly (ADP) Ribose Polymerase (PARP) enzyme plays a key role in the cellular machinery responsible for DNA damage repair. Although inhibition of this enzyme using pharmacological inhibitor is postulated to enhance the cytotoxicity of DNA-damaging cytotoxic chemotherapy, this has not been previously studied in SCLC. The present work evaluated the interaction between ABT-888 and cytotoxic chemotherapy in SCLC.

A panel of SCLC cell lines (H146, H69, H187, H209, and H182) was employed for this work. Exponentially growing cells were treated by continuous exposure for 48-72 h to vehicle, ABT-888 and cytotoxic agents (cisplatin, carboplatin, etoposide) in the presence and absence of ABT-888. Surviving cell fraction and growth inhibition was determined using MTS assay. Sequence dependence interaction was assessed by alternating the sequence of administration of ABT-888 relative to the cytotoxic agents. Western blot assay was performed to assess for PARP inhibition, changes in markers of apoptosis (cleaved PARP and caspase), DNA damage (gamma-H2AX) and other DNA damage repair pathway proteins (ERCC1, DNA-PK, Ku80, ATM, ATR and BRCA1) under different treatment conditions. ABT-888 showed negligible cytotoxicity as a single agent. Co-administration of ABT-888 and chemotherapeutic agents resulted in enhanced cytotoxicity of cisplatin, carboplatin and to a lesser extent, etoposide, in a cell specific and dose-dependent manner. High concentrations (50uM) of ABT-888 produced up to 7-fold reduction in IC50 concentrations of cytotoxic agents while low concentration (5uM) of ABT-888 produced up to 2-fold reduction in IC50 concentrations. There was no sequence dependence interaction between ABT-888 and the cytotoxic agents. Time-course experiments showed down modulation of DNA protein kinase (DNA-PK) levels at 24 hours, which correlated with onset of apoptosis as assessed by PARP and caspase cleavage. Moreover, high basal expression of DNA-PK correlated with reduced potentiation of cytotoxicity by ABT-888 in H128 cell line. These results would support clinical evaluation of ABT-888 plus cytotoxic chemotherapy in patients with SCLC. Furthermore, DNA-PK level may serve as a predictive biomarker of efficacy of PARP inhibitor therapy. Our in vitro finding is currently being tested using in vivo animal model. (This work was supported through the Georgia Cancer Coalition Distinguished Scholar Award to TK Owonikoko, SS Ramalingam, FR Khuri and S Sun and the NIH/NCI Program Project P01 grant CA116676).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2567. doi:10.1158/1538-7445.AM2011-2567

Abstract 1011: NNK promotes migration and invasion of cancer cells through activation of c-Src, PKCι and FAK loop

Cigarette smoking, either active or passive, is the most important risk factor in the development of human lung cancer. Mounting evidence indicates that cigarette smoke constituents not only contribute to tumorigenesis but also may increase the spread of cancer in the body. Nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is formed by nitrosation of nicotine and has been identified as the most potent carcinogen. NNK, an important component in cigarette smoke, may also promote tumor metastasis by regulating cell motility. Here we found that NNK can induce activation of a functionally interdependent protein kinase cascade, including c-Src, PKCι and FAK, in association with increased migration and invasion of human lung cancer cells. c-Src, PKCι and FAK are extensively co-localized in the cytoplasm. Treatment of cells with α7 nAChR specific inhibitor α-bungarotoxin (α-BTX) blocks NNK-stimulated activation of c-Src, PKCι and FAK and suppresses cell migration and invasion. Intriguingly, NNK enhances c-Src/PKCι and PKCι/FAK bindings, indicating a potential mechanism by which these kinases activate each other. Specific disruption of c-Src, PKCι or FAK expression by RNA interference significantly reduces NNK-induced cell migration and invasion. These findings suggest that NNK-induced migration and invasion may occur in a mechanism through activation of a c-Src/PKCι/ FAK loop, which can contribute to metastasis and/or development of human lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1011. doi:10.1158/1538-7445.AM2011-1011

Mono- or double-site phosphorylation distinctly regulates the proapoptotic function of Bax

Bax is the major multidomain proapoptotic molecule that is required for apoptosis. It has been reported that phosphorylation of Bax at serine(S) 163 or S184 activates or inactivates its proapoptotic function, respectively. To uncover the mechanism(s) by which phosphorylation regulates the proapoptotic function of Bax, a series of serine (S)→ alanine/glutamate (A/E) Bax mutants, including S163A, S184A, S163E, S184E, S163E/S184A (EA), S163A/S184E (AE), S163A/S184A (AA) and S163E/S184E (EE), were created to abrogate or mimic, respectively, either single or double-site phosphorylation. The compound Bax mutants (i.e. EA and AE) can flesh out the functional contribution of individual phosphorylation site(s). WT and each of these Bax mutants were overexpressed in Bax^−/− MEF or lung cancer H157 cells and the proapoptotic activities were compared. Intriguingly, expression of any of Bax mutants containing the mutation S→A at S184 (i.e. S184A, EA or AA) represents more potent proapoptotic activity as compared to WT Bax in association with increased 6A7 epitope conformational change, mitochondrial localization/insertion and prolonged half-life. In contrast, all Bax mutants containing the mutation S→E at S184 (i.e. S184E, AE or EE) have a mobility-shift and fail to insert into mitochondrial membranes with decreased protein stability and less apoptotic activity. Unexpectedly, mutation either S→A or S→E at S163 site does not significantly affect the proapoptotic activity of Bax. These findings indicate that S184 but not S163 is the major phosphorylation site for functional regulation of Bax's activity. Therefore, manipulation of the phosphorylation status of Bax at S184 may represent a novel strategy for cancer treatment.

Abstract 34: Oncogenic tyrosine kinases phosphorylate and inhibit PKM2 to provide a metabolic advantage to tumor growth

Cancer cells show increased aerobic glycolysis and enhanced lactate production compared to healthy cells, a phenomenon known as the Warburg effect. Cell surface growth factor receptors, which often carry tyrosine kinase activities in their cytoplasmic domains, are overexpressed in many human cancers and are believed to play a key role in determining cell metabolism. Thus, we explored the hypothesis that tyrosine kinase signaling, which is commonly increased in tumors, regulates the Warburg effect and contributes to tumorigenesis and maintenance of the tumor.

We performed phospho-proteomics studies and found that oncogenic forms of fibroblast growth factor (FGF) receptor type 1 (FGFR1) inhibit the pyruvate kinase M2 isoform (PKM2) in cancer cells. Pyruvate kinase is a rate-limiting enzyme during glycolysis and catalyzes the production of pyruvate and ATP from phosphoenolpyruvate (PEP) and ADP. Recent studies demonstrated that the enzymatic activity of the pyruvate kinase M2 isoform (PKM2) is inhibited by phosphotyrosine binding; moreover, these researchers found that PKM2 is crucial for aerobic glycolysis and provides a growth advantage to tumors. However, it remains unclear which tyrosine kinase pathways are physiologically responsible for this inhibition of PKM2 activity and which protein factors undergo tyrosine phosphorylation, allowing them to bind to and thereby inhibit PKM2. We found that PKM2 is itself tyrosine phosphorylated in cancer cells and such a physiological modification of PKM2 promotes the switch to aerobic glycolysis from oxidative phosphorylation. FGFR1 directly phosphorylates PKM2 at tyrosine residue 105 (Y105). This inhibits the formation of active, tetrameric PKM2 by disrupting binding of the PKM2 cofactor fructose-1,6-bisphosphate (FBP). Moreover, we found that phosphorylation of PKM2 Y105 is common in human cancers. Immunoblotting revealed that PKM2 is phosphorylated at Y105 in diverse human breast cancer, lung cancer, prostate cancer and leukemia cell lines. Oncogenic tyrosien kianses including BCR-ABL, FLT3-ITD and JAK2 also directly phosphorylate PKM2 Y105 in in vitro kinase assays using purified proteins. Furthermore, the presence of a PKM2 mutant in which phenylalanine is substituted for Y105 (Y105F) in cancer cells leads to decreased cell proliferation under hypoxic conditions, increased oxidative phosphorylation with reduced lactate production, and reduced tumor growth in xenografts in nude mice.

Our findings suggest that tyrosine phosphorylation regulates PKM2 to provide a metabolic advantage to tumor cells, thereby promoting tumor growth. This may represent a common, short-term molecular mechanism underlying the Warburg effect in both leukemias and solid tumors, in addition to the chronic changes believed to be regulated by transcription factors, including hypoxia inducible factor 1 and Myc.

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 34.

Abstract 1201: Inhibition of ASK1 through phosphorylation of serine 967 by PI3K/Akt-mediated pathways

Cancer is characterized in part by dysregulation of cell survival and cell death signals. In particular, many tumors show upregulated PI3K/Akt activity, leading to sustained cell survival and suppressed cell death. Here we report the identification of the apoptosis signal-regulating kinase 1 (ASK1) as a downstream effector of the PI3K/Akt survival signaling pathway. ASK1 can be suppressed by PI3K/Akt signaling, leading to inhibition of apoptotic signaling. ASK1 normally functions as a mitogen activated protein kinase kinase kinase (MAP3K) that, when activated by stress signals, can evoke a signaling cascade leading to activation of the MAPKs JNK and p38. This activation can result in many cellular responses, but ASK1 is most notably known for its role as a critical regulator of apoptosis. Because of its crucial role in the balance between survival and death, ASK1 activity is tightly controlled. In particular, 14-3-3 can bind ASK1 and inhibit its activity when the kinase is phosphorylated at serine 967. However, the signals that regulate this phosphorylation event are currently unknown. Recent evidence suggests that PI3K/Akt mediated pathways may be involved in phosphorylation of serine 967 and, subsequently, inhibition of ASK1. Specifically, treatment of cells with growth factors including IGF-1 and PDGF increased phosphorylation of serine 967, as did overexpression of a constitutively active Akt mutant. In addition, expression of a kinase dead Akt mutant blocked growth factor induced serine 967 phosphorylation, indicating that Akt plays a role in mediating survival signals leading to inhibition of ASK1. In support of this notion, treatment with the inhibitors of Akt and PI3K also reduced serine 967 phosphorylation. Interestingly, treatment of cells with IGF-1 or overexpression of Akt was also able to protect serine 967 from H2O2 induced dephosphorylation. Taken together, our study reveals a novel effector site in ASK1 for the action of PI3K/Akt, which may offer a potential target for cancer therapeutic development. This work was supported by the NIH Pharmacological Sciences Training Grant T32 GM008602 and NIH/NCI Grant PO1CA116676 and USAMRMC05075002 to FRK and HF.

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 1201.

Proportion of subjects with an ethically acceptable reason for enrolling in a phase I trial

2512

Background: Concern persists that phase I subjects, who frequently enter trials for personal benefit, are deluded. They may suffer from therapeutic misconception (TM) - conflating research and clinical care, or from therapeutic misestimation (TMis) - misestimating benefits or risks. Methods: To estimate the proportion of phase I subjects who have an ethically acceptable reason for participation, we both interviewed and surveyed subjects to obtain qualitative and quantitative data. Ethically acceptable reasons included 1) Altruism (sole motive for entering trial was to help others or advance science); 2) Self-regarding motives but no TM (correctly identifying that the trial mostly intends to help research and gain knowledge, the study decides the treatments and the subjects get different doses of drug); 3) Self-regarding motives, TM but no TMis (chance of benefit < 20% and chance of risk > 0%); or 4) Self-regarding motives, TM, overestimation of benefits but broad view of benefit (with collateral benefits like getting careful disease monitoring or access to an academic center listed) and chance of risk > 0%. This generous interpretation of ethically acceptable reasons hinges on the view that subjects at least must recognize there is some risk, that chance of disease benefit is not high and that collateral benefits count. Results: The 86 subjects were mostly white, male, with incomes more than $60,000. 49% were college educated with a mean age of 60. 53.5% had an ethical reason for participation, with 10.5% altruistic, 16.3% no TM, 8.1% TM but no TMis, and 18.5% overestimating benefit but including collateral benefits. In both univariate and multivariate analyses age younger than 60 yo and having at least a college education were the only characteristics significantly correlated with having an ethically acceptable reason for participation. Those who reported strong religious beliefs (p = 0.01) were significantly more likely not to have an ethically acceptable reason. Conclusions: With almost half of participants lacking an ethically acceptable reason for participation, interventions are necessary to bolster understanding. Older participants lacking a college education are particularly at risk and could be the target for an intervention trial.

No significant financial relationships to disclose.

Efficacy and safety of PF-00299804 (PF299) in patients (pt) with advanced NSCLC after failure of at least one prior chemotherapy regimen and prior treatment with erlotinib (E): A two-arm, phase II trial

8063

Background: Options are limited for pts with NSCLC following chemotherapy and E. PF299 is an oral irreversible small molecule inhibitor of the HER-1,-2, and -4 tyrosine kinases. Based on non-clinical and phase I NSCLC data, this ongoing phase II U.S. trial evaluates PF299 in pts with NSCLC (KRAS wild-type) who have progressive disease after at least 1 prior chemotherapy regimen and after E. Methods: Pts were enrolled by histology: adenocarcinoma (Arm A) and non-adenocarcinoma (Arm B), and received PF299 45 mg QD. Endpoints include objective response rate, duration of response, progression-free survival, survival, safety/tolerability, and pharmacokinetics. Pharmacodynamic endpoints include assessment of serum levels of HER2 and EGFR extracellular domains. Tissue and blood KRAS assays, and EGFR studies on available tissue, are also being performed. Forty-four and 22 response-evaluable pts were planned to be enrolled into Arms A and B respectively. Results: Thirty-four pts with progressive NSCLC (25 female, 14 smoker) have enrolled to date (Arm A: 30; Arm B: 4): median duration of prior E: 11.5 months; median time since E: 2.5 months. Among 20 response-evaluable pts, stable disease (SD) was observed in 9/18 pts in Arm A, and 1/2 pts in Arm B: median duration of SD: 11.5 weeks [range 6+, 32+ weeks]. Observation of disease control included pts who had recently (≤8 weeks) discontinued E; and also pts whose tumor had known EGFR T790M mutations. At time of data cutoff, confirmation per RECIST of 2 partial responses is pending. The most common treatment-related AEs were skin and gastrointestinal disorders, with grade 3 AEs in 19% and 13% of pts, respectively. Two pts experienced grade 4 pulmonary embolus/dyspnea deemed possibly treatment-related, both in the setting of progressive disease. Conclusions: PF299 shows encouraging activity in NSCLC pts after failure of prior chemotherapy and E. The AE profile was predictable and consistent with the prior phase I trial. At submission, enrollment in the adenocarcinoma arm is complete and enrollment in the non-adenocarcinoma arm continues; updated efficacy data and tumor characterization will be presented.

[Table: see text]

Abstract B106: Inhibition of IKKb and NFκB signaling by a novel curcumin analogue

B106

The nuclear factor kappa-B (NF-κB) signaling pathway has been targeted for therapeutic applications in a variety of human diseases such as cancer. A number of naturally occurring substances including curcumin have been investigated for their actions on the NF-κB pathway because of their significant therapeutic potential and safety profile. A synthetic monoketone compound termed EF24 was developed from curcumin and exhibited a potent anticancer activity. Here we report a mechanism by which EF24 potently suppresses the NF-κB signaling pathway in both head and neck cancer and lung cancer cell lines through direct action on the I-κB kinase (IKK). We demonstrate that (i) EF24 induces death of lung, head and neck, breast, ovarian, and cervical cancer cells with a potency about 10 times higher than curcumin does, (ii) EF24 rapidly blocks the nuclear translocation of NF-κB with an IC50 of 1.3 μM compared with curcumin with an IC50 of 13 μM, (iii) EF24 effectively inhibits TNFα-induced I-κB phosphorylation and degradation, suggesting a role of this compound in targeting IKK, and (iv) EF24 indeed directly inhibits the catalytic activity of IKK in an in vitro reconstituted system. This study identifies IKK as an effective target for EF24 and provides a molecular explanation for a superior activity of EF24 over curcumin. The effective inhibition of TNFα-induced NF-κB signaling by EF24 extends the therapeutic application of EF24 to other NF-κB-dependent diseases, including inflammatory diseases such as rheumatoid arthritis.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B106.

Proliferative changes in the bronchial epithelium of former smokers treated with retinoids

BACKGROUND

Retinoids have shown antiproliferative and chemopreventive activity. We analyzed data from a randomized, placebo-controlled chemoprevention trial to determine whether a 3-month treatment with either 9-cis-retinoic acid (RA) or 13-cis-RA and alpha-tocopherol reduced Ki-67, a proliferation biomarker, in the bronchial epithelium.

METHODS

Former smokers (n = 225) were randomly assigned to receive 3 months of daily oral 9-cis-RA (100 mg), 13-cis-RA (1 mg/kg) and alpha-tocopherol (1200 IU), or placebo. Bronchoscopic biopsy specimens obtained before and after treatment were immunohistochemically assessed for changes in the Ki-67 proliferative index (i.e., percentage of cells with Ki-67-positive nuclear staining) in the basal and parabasal layers of the bronchial epithelium. Per-subject and per-biopsy site analyses were conducted. Multicovariable analyses, including a mixed-effects model and a generalized estimating equations model, were used to investigate the treatment effect (Ki-67 labeling index and percentage of bronchial epithelial biopsy sites with a Ki-67 index > or = 5%) with adjustment for multiple covariates, such as smoking history and metaplasia. Coefficient estimates and 95% confidence intervals (CIs) were obtained from the models. All statistical tests were two-sided.

RESULTS

In per-subject analyses, Ki-67 labeling in the basal layer was not changed by any treatment; the percentage of subjects with a high Ki-67 labeling in the parabasal layer dropped statistically significantly after treatment with 13-cis-RA and alpha-tocopherol treatment (P = .04) compared with placebo, but the drop was not statistically significant after 9-cis-RA treatment (P = .17). A similar effect was observed in the parabasal layer in a per-site analysis; the percentage of sites with high Ki-67 labeling dropped statistically significantly after 9-cis-RA treatment (coefficient estimate = -0.72, 95% CI = -1.24 to -0.20; P = .007) compared with placebo, and after 13-cis-RA and alpha-tocopherol treatment (coefficient estimate = -0.66, 95% CI = -1.15 to -0.17; P = .008).

CONCLUSIONS

In per-subject analyses, treatment with 13-cis-RA and alpha-tocopherol, compared with placebo, was statistically significantly associated with reduced bronchial epithelial cell proliferation; treatment with 9-cis-RA was not. In per-site analyses, statistically significant associations were obtained with both treatments.

Lipid rafts and nonrafts mediate tumor necrosis factor related apoptosis-inducing ligand induced apoptotic and nonapoptotic signals in non small cell lung carcinoma cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is capable of inducing apoptosis in non-small cell lung carcinoma (NSCLC). However, many of the human NSCLC cell lines are resistant to TRAIL, and TRAIL treatment of the resistant cells leads to the activation of nuclear factor-kappaB (NF-kappaB) and extracellular signal-regulated kinase 1/2 (ERK1/2). TRAIL can induce apoptosis in TRAIL-sensitive NSCLC cells through the induction of death-inducing signaling complex (DISC) assembly in lipid rafts of plasma membrane. In the DISC, caspase-8 is cleaved and initiates TRAIL-induced apoptosis. In contrast, TRAIL-DISC assembly in the nonraft phase of the plasma membrane leads to the inhibition of caspase-8 cleavage and NF-kappaB and ERK1/2 activation in TRAIL-resistant NSCLC cells. Receptor-interacting protein (RIP) and cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP) mediates the DISC assembly in nonrafts and selective knockdown of either RIP or c-FLIP with interfering RNA redistributes the DISC from nonrafts to lipid rafts, thereby switching the DISC signals from NF-kappaB and ERK1/2 activation to caspase-8-initiated apoptosis. Chemotherapeutic agents inhibit c-FLIP expression, thereby enhancing the DISC assembly in lipid rafts for caspase-8-initiated apoptosis. These studies indicate that RIP and c-FLIP-mediated assembly of the DISC in nonrafts is a critical upstream event in TRAIL resistance and thus targeting of either RIP or c-FLIP may lead to the development of novel therapeutic strategies that can overcome TRAIL resistance in human NSCLC.

14-3-3 Integrates prosurvival signals mediated by the AKT and MAPK pathways in ZNF198-FGFR1-transformed hematopoietic cells

Human 8p11 stem cell leukemia/lymphoma syndrome usually presents as a myeloproliferative disorder (MPD) that evolves to acute myeloid leukemia and/or lymphoma. The syndrome associated with t(8;13)(p11;q12) results in expression of the ZNF198-FGFR1 fusion tyrosine kinase that plays a pathogenic role in hematopoietic transformation. We found that ZNF198-FGFR1 activated both the AKT and mitogen activated protein kinase (MAPK) prosurvival signaling pathways, resulting in elevated phosphorylation of the AKT target FOXO3a at T32 and BAD at S112, respectively. These phosphorylated residues subsequently sequestered the proapoptotic FOXO3a and BAD to 14-3-3 to prevent apoptosis. We used a peptide-based 14-3-3 competitive antagonist, R18, to disrupt 14-3-3-ligand association. Expression of R18 effectively induced apoptosis in hematopoietic Ba/F3 cells transformed by ZNF198-FGFR1 compared with control cells. Moreover, purified recombinant transactivator of transcription (TAT)-conjugated R18 proteins effectively transduced into human leukemia cells and induced significant apoptosis in KG-1a cells expressing FGFR1OP2-FGFR1 fusion tyrosine kinase but not in control HL-60 and Jurkat T cells. Surprisingly, R18 was only able to dissociate FOXO3a, but not BAD as previously proposed, from 14-3-3 binding and induced apoptosis partially through liberation and reactivation of FOXO3a. Our findings suggest that 14-3-3 integrates prosurvival signals in FGFR1 fusion-transformed hematopoietic cells. Disrupting 14-3-3-ligand association may represent an effective therapeutic strategy to treat 8p11 stem cell MPD.

Phase I/II Study of Docetaxel, Cisplatin, and Concomitant Boost Radiation for Locally Advanced Squamous Cell Cancer of the Head and Neck

Purpose

To investigate the feasibility of combining concomitant boost accelerated radiation with docetaxel and cisplatin and assess the regimen's toxicity, locoregional control rate, and survival in patients with locally advanced head and neck cancer (HNSCC).

Patients and Methods

Patients with stage III-IV HNSCC were eligible. Phase I included two schedules of docetaxel and cisplatin: arm 1, once per week during weeks 1 to 4; arm 2, every 21 days for weeks 1 and 4. Radiation consisted of 72 Gy in 42 fractions over 6 weeks (concomitant boost).

Results

Twenty patients were enrolled in phase I. The arm 1 maximum-tolerated dose (MTD) was defined at docetaxel 15 mg/m2 and cisplatin 20 mg/m2 based on prolonged mucositis in 29% of patients. The initial dose level in arm 2 was above the MTD. In total, 52 patients were treated using the arm 1 regimen in phase II. Acute toxicity included grade 3 mucositis and dermatitis in 81% and 44% of patients. The 2-year locoregional control rate was 71%. The 2-year progression-free and overall survival rates were 61% and 65%. Median survival was 37.8 months. Late effects included feeding tube dependence in 17% of patients alive and free of disease.

Conclusion

Locoregional control, survival, and acute toxicity with this regimen were comparable with other trials utilizing taxanes and/or platins and concomitant conventional or altered fractionation radiation. Our data suggest that chemotherapy added to concomitant boost fractionation may increase rates of long-term feeding tube dependence. Phase III trials are needed to assess the contribution of concomitant boost fractionation to chemoradiotherapy.

Identification of insulin-like growth factor binding protein-3 as a farnesyl transferase inhibitor SCH66336-induced negative regulator of angiogenesis in head and neck squamous cell carcinoma

The farnesyl transferase inhibitor (FTI) SCH66336 has been shown to have antitumor activities in head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. However, its mechanism of action has not been well defined. Here, we report that the insulin-like growth factor (IGF) binding protein (IGFBP)-3 mediates antitumor activities of SCH66336 in HNSCC by inhibiting angiogenesis. SCH66336 significantly suppressed HNSCC tumor growth and angiogenesis via mechanisms that are independent of H-Ras and RhoB. By inducing IGFBP-3 secretion from HNSCC cells, this compound suppresses angiogenic activities of endothelial cells, including vessel formation in chorioallantoic membranes of chick, endothelial cell sprouting from chick aorta, and capillary tube formation of human umbilical vascular endothelial cells (HUVEC). Knockdown of IGFBP-3 expression in HNSCC cells by RNA interference or depletion of IGFBP-3 in HUVECs by neutralizing antibody effectively blocked the effects of IGFBP-3 secreted from SCH66336-treated HNSCC cells on HUVECs. These findings suggest that IGFBP-3 could be a primary target for antitumor activities of FTIs and that IGFBP-3 is an effective therapeutic approach against angiogenesis in HNSCC.

A phase I/II study of neoadjuvant chemotherapy followed by radiation with boost chemotherapy for advanced T-stage nasopharyngeal carcinoma

PURPOSE

Local recurrence is the most common site of failure for locally advanced nasopharyngeal carcinoma (NPC) treated with neoadjuvant cisplatin/5-fluorouracil (PF) and definitive radiation at our center. Based on this, we studied the addition of chemotherapy during the boost phase of radiation after neoadjuvant PF for advanced T-stage (T3-T4) NPC. This strategy was based on theoretical radiosensitization with chemotherapy during accelerated repopulation of the tumor with relatively radioresistant clonogens.

METHODS AND MATERIALS

Three cycles of neoadjuvant PF was followed by conventionally fractionated radiation with additional PF during the boost portion of the radiation course. An initial Phase I study was done to establish the maximum tolerated dose of concurrent PF.

RESULTS

Forty-four patients were enrolled. Six patients in Phase I defined the MTD for concurrent PF as: cisplatin 10 mg/m2/day and PF 320 mg/m2/day, on Days 1-5 during Weeks 6 and 7 of radiation therapy based on dose-limiting toxicities of mucositis, neutropenia, and thrombocytopenia. Forty-one patients were treated with concurrent therapy per protocol: complete, partial, and minor responses were seen in 23, 16, and 2 patients, respectively. Progression-free and overall survival rates at 5 years were 55% (95% CI, 41-75%) and 66% (95% CI, 52-85%), respectively. Seven of 11 tumor-related deaths were due to local recurrence. Nine of 10 patients with local recurrence had T4-stage disease at presentation. Local control of T4 disease was achieved in 74% of patients overall, and in 25% (1/4) with World Health Organization (WHO) type 1, 76% (16/21) with WHO type 2, and 90% (9/10) with WHO type 3 histology. Common toxicities included mucositis, dermatitis, fatigue, vomiting, and weight loss.

CONCLUSIONS

This regimen was feasible and associated with promising overall survival. Local recurrence remains the major reason for treatment failure in advanced T-stage NPC, especially WHO types 1 and 2. Other strategies to improve local control in these patients should be investigated.

Farnesyltransferase Inhibitor SCH66336 Induces Rapid Phosphorylation of Eukaryotic Translation Elongation Factor 2 in Head and Neck Squamous Cell Carcinoma Cells

Farnesyltransferase inhibitors (FTI) are a class of therapeutic agents designed to target tumors with mutations of the ras oncogene. However, the biological effect of FTIs is often independent of ras mutation status, which suggests the existence of additional mechanisms. In this study, we investigated the molecular effects of SCH66336, an FTI, in head and neck squamous cell carcinoma cells using proteomic approaches. We showed that SCH66336 induced phosphorylation (inactivation) of eukaryotic translation elongation factor 2 (eEF2), an important molecule for protein synthesis, as early as 3 hours after SCH66336 administration. Protein synthesis was subsequently reduced in the cells. Paradoxically, activation of eEF2 kinase (eEF2K), the only known kinase that regulates eEF2, was observed only at 12 hours after SCH66336 treatment. Consistent with this observation, the inhibition of phosphorylated-MEK and phosphorylated-p70S6K, the two key signaling molecules responsible for activation of eEF2K, also occurred at least 12 hours after SCH66336 administration. Our data suggest that inhibition of protein synthesis through inactivation of eEF2 is a novel mechanism of SCH66336-mediated growth inhibition and that this effect is independent of ras-MEK/p70S6K-eEF2K signaling cascades.

Phase I Study of the Farnesyltransferase Inhibitor BMS-214662 Given Weekly in Patients with Solid Tumors

Purpose: A phase I trial of BMS-214662, a selective farnesyltransferase inhibitor with significant preclinical antitumor activity in which drug was given as a weekly 1-hour infusion for four of six weeks, was conducted to evaluate the tolerability, pharmacokinetics, and pharmacodynamic effect on farnesyltransferase activity in peripheral blood mononuclear cells.

Experimental Design: BMS-214662 was given to 27 patients with solid tumors at 10 escalating dose levels (28-220 mg/m2) allowing intrapatient dose escalation; pharmacokinetics and pharmacodynamics were done at the first seven dose levels.

Results: Grade 4 neutropenia (four patients) was the most common dose-limiting toxicity followed by aminotransferase elevation (grade 3 alanine aminotransferase and grade 4 aspartate aminotransferase) and grade 3 dehydration. Most frequent toxicities were neutropenia in 11 (14%), anemia in 15 (19%), fatigue in 9 (12%), and nausea and diarrhea in 6 (8%) of courses, respectively. One minor response lasting 18 weeks in a patient with non–small cell lung cancer, serum calcitonin level reduction accompanied by disease stabilization in two of four patients with medullary thyroid carcinoma, and stable disease in 16 of 25 evaluable patients was seen. No correlation was observed between dose and Cmax, total body clearance (mean, 26.15 ± 10.88 L per hour per m2), volume of distribution at steady state (mean, 39.51 ± 17.91 L/m2), or half-life (mean, 2.63 ± 1.81 hours); a moderate correlation existed between dose given and systemic drug exposure (AUC). Substantial inhibition of peripheral blood mononuclear cell farnesyltransferase activity but near complete recovery by 24 hours was seen.

Conclusion: BMS-214667 was well tolerated as a weekly 1-hour i.v. infusion for four of six weeks with evidence of pharmacodynamic effect. The study was terminated before maximum tolerated dose was reached. Alternative schedules of drug administration might result in improved pharmacodynamic profile.