Inhibition of autophagy induced by overexpression of mda-7/interleukin-24 strongly augments the antileukemia activity in vitro and in vivo

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) is a novel candidate of tumor suppressor that can selectively induce apoptosis experimentally in a spectrum of human cancer cells including leukemia cells. However, a recent study suggests that mda-7/IL-24 promotes the survival of chronic lymphocytic leukemia B-cells. In this study, we showed that mda-7/IL-24 was constitutively expressed in leukemia cell lines and primary acute myeloid leukemia samples. Using a conditionally replicating adenovirus expressing mda-7/IL-24 (ZD55-IL-24), we showed that enforced expression of mda-7/IL-24 in leukemia cells induced autophagy, which was triggered by the upregulation of Beclin-1. Immunofluorescence and coimmunoprecipitation studies suggested that mda-7/IL-24 protein interacts with Beclin-1. Class III PI3K/Beclin-1 complex was shown involved in the mda-7/IL-24-induced autophagy. Moreover, autophagy inhibition by phosphatidylinositol 3-kinase inhibitor, wortmannin, resulted in a reduced Beclin-1 expression and autophagosome formation associated with significantly enhanced cell death. Importantly, the combination of ZD55-IL-24 with wortmannin elicited a strongly enhanced antileukemia efficacy in established leukemia xenografts. These results suggest that mda-7/IL-24-induced autophagy in leukemia cells may provide survival advantage and mda-7/IL-24 combined with agents that disrupt autophagy is a promising new strategy for the treatment of leukemia.

Serine-385 phosphorylation of inwardly rectifying K+ channel subunit (Kir6.2) by AMP-dependent protein kinase plays a key role in rosiglitazone-induced closure of the K(ATP) channel and insulin secretion in rats

AIMS/HYPOTHESIS

Rosiglitazone, an insulin sensitiser, not only improves insulin sensitivity but also enhances insulin secretory capacity by ameliorating gluco- and lipotoxicity in beta cells. Rosiglitazone can stimulate insulin secretion at basal and high glucose levels via a phosphatidylinositol 3-kinase (PI3K)-dependent pathway. We hypothesised that regulation of phosphorylation of the ATP-sensitive potassium (K(ATP)) channel might serve as a key step in the regulation of insulin secretion.

METHODS

Insulin secretory responses were studied in an isolated pancreas perfusion system, cultured rat islets and MIN6 and RINm5F beta cells. Signal transduction pathways downstream of PI3K were explored to link rosiglitazone to K(ATP) channel conductance with patch clamp techniques and insulin secretion measured by ELISA.

RESULTS

Rosiglitazone stimulated AMP-activated protein kinase (AMPK) activity and induced inhibition of the K(ATP) channel conductance in islet beta cells; both effects were blocked by the PI3K inhibitor LY294002. Following stimulation of AMPK by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), a pharmacological activator, both AICAR-stimulated insulin secretion and inhibition of K(ATP) channel conductance were unaffected by LY294002, indicating that AMPK activation occurs at a site downstream of PI3K activity. The serine residue at amino acid position 385 of Kir6.2 was found to be the substrate phosphorylation site of AMPK when activated by rosiglitazone or AICAR.

CONCLUSIONS/INTERPRETATION

Our data indicate that PI3K-dependent activation of AMPK is required for rosiglitazone-stimulated insulin secretion in pancreatic beta cells. Phosphorylation of the Ser(385) residue of the Kir6.2 subunit of the K(ATP) channel by AMPK may play a role in insulin secretion.

Phase IIb/III double-blind randomized trial of BIBW 2992, an irreversible, dual inhibitor of EGFR and HER2 plus best supportive care (BSC) versus placebo plus BSC in patients with NSCLC failing 1–2 lines of chemotherapy (CT) and erlotinib or gefitinib (LUX- Lung1): A preliminary report

8062

Background: No approved therapy exists for NSCLC patients (pts) who have failed chemotherapy (CT) and the reversible epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), erlotinib (E) or gefitinib (G). The efficacy of BIBW 2992 (Tovok), a potent, irreversible inhibitor of EGFR and human epidermal growth factor receptor 2 (HER2) with preclinical activity against the secondary resistance mutation T790M, in pts progressing after initial clinical benefit on E/G is being assessed in this randomized trial. Methods: Pts with advanced adenocarcinoma of the lung (Stage IIIB/IV; ECOG 0–2), who have failed one or two lines of CT (including platinum) and progressed following at least 12 weeks of E or G are randomized in a 2:1 ratio to receive BSC plus either oral BIBW 2992 50 mg qd or placebo until disease progression or unacceptable toxicity. Primary endpoint is overall survival, with progression-free survival, objective response and clinical benefit rate and duration, safety and quality of life being secondary endpoints. Enrollment of 400 pts is planned (HR=0.70, 85% power). An unblinded interim analysis of tumor response and safety by the independent Data Monitoring Committee (DMC) after the first 40 evaluable pts treated with BIBW 2992 will determine continuation to full accrual. Results: From May to November 2008, 145 pts have been randomized and 76 are still on treatment. Demographics (n=145): median age 59 (range: 30–82); female 68%, current/ex-smokers 38%; metastatic disease 91%, ECOG 0–1 92%; Asian origin 68%. 50% had one prior line of CT. Main prior EGFR-TKI was G in Asians (70%) and E in non-Asians (85%). 40% of pts had achieved a PR or CR on previous treatment with E/G. Duration of prior E/G treatment was >24 weeks and >48 weeks in 80% and 40% of pts, respectively. As expected, diarrhea, rash, anorexia, stomatitis, paronychia, nausea and vomiting were the most frequently observed adverse events. Conclusions: The trial is continuing recruitment after DMC review of efficacy and safety and updated demographics and blinded safety data will be reported.

[Table: see text]

Quality of life in advanced non-small cell lung cancer patients receiving first-line gefitinib monotherapy

9614

Background: Gefitinib is a potential first-line treatment option for patients with advanced non-small cell lung cancer (NSCLC), especially for patients with activating mutations in the EGFR gene. However, little is known about patient-reported health-related quality of life (HRQOL) in this patient population. The aims of this study were to explore the prognostic values of baseline HRQOL for time-to-treatment failure (TTF), as well as the predictors of repeatedly measured posttreatment HRQOL, in advanced NSCLC patients receiving first-line gefitinib. Methods: A total of 106 chemonaive patients with advanced NSCLC were enrolled in a phase II trial. Gefitinib was given at a dose of 250 mg/d. HRQOL was assessed monthly with the EuroQoL instrument (EQ-5D) and the Lung Cancer Symptom Scale (LCSS) questionnaire. Baseline HRQOL and clinical/molecular predictors of TTF were jointly examined by multiple Cox's proportional hazards model. The associations between the clinical/molecular factors and repeatedly measured posttreatment HRQOL were analyzed by fitting marginal linear regression model using the generalized estimating equations (GEE) method. Results: In this prospective study, HRQOL data were obtained from 94 patients. Baseline EQ-5D index (estimated hazard ratio = 0.286, 95% C.I.: 0.135–0.603, p = 0.001) and the presence of L858R EGFR mutation in adenocarcinoma (estimated hazard ratio = 0.520, 95% C.I.: 0.307–0.880, p = 0.015) were retained as independent prognostic factors in the final multiple Cox's proportional hazards model for TTF. According to preliminary GEE analysis of repeatedly measured posttreatment HRQOL, the patients with wild-type EGFR consistently had worse HRQOL in EQ-5D index (p < 0.0001), EQ-5D VAS score (p = 0.0002), and LCSS global score (p < 0.0001), respectively. Conclusions: In advanced NSCLC patients receiving first-line gefitinib, better baseline EQ-5D index and L858R EGFR mutation in adenocarcinoma predict longer TTF. In addition, patients with wild-type EGFR had worse posttreatment HRQOL.

No significant financial relationships to disclose.

Prognostic factors of survival in 236 advanced hepatocellular carcinoma patients enrolled in prospective clinical trials of systemic therapy

e15632

Background: Hepatocellular carcinoma (HCC) is a common malignant disease. Promising results of prospective clinical trials using systemic therapy for patients with advanced HCC are emerging. The aim of this study was to explore prognostic factors of survival in advanced HCC patients eligible for clinical trials of systemic therapy. Methods: From December 1990 to July 2005, 236 patients with unresectable HCC were enrolled into 6 phase II trials of systemic therapy using the following regimens: (1) oral etoposide + tamoxifen, (2)doxorubicin + tamoxifen, (3)IFN-α2b + doxorubicin + tamoxifen, (4)pegylated liposomal doxorubicin, (5)thalidomide, and (6)arsenic trioxide. Univariate and multivariate analyses of 23 relevant clinical characteristics/staging systems were used to identify prognostic factors of survival. Results: Baseline characteristics: median age 55; male/female: 192/44; HBsAg(+) 71%; anti-HCV(+) 30%; Okuda stage I/II/III: 42%/55%/3%; AJCC stage III/IV: 30%/61%; BCLC stage B/C/D: 1%/94%/5%; CLIP score 0–3/4–6: 70%/30%; portal vein thrombosis 53%; extrahepatic metastasis 59%; prior chemoembolization 46%. The objective response rate according to WHO criteria was 11.4%. The median overall survival was 118 days (95% CI, 103–133). In the multivariate analysis, significant predictors of a shorter overall survival were: HBsAg(+) with a hazard ratio (HR) = 1.808 (95% CI, 1.121–2.916; P= 0.015), symptomatic with HR = 1.745 (95% CI, 1.072–2.840; P= 0.025), ECOG≥2 with HR = 1.763 (95% CI, 1.040–2.988; P= 0.035), and high BCLC stage with HR = 3.282 (95% CI, 1.129–9.541; P= 0.029). Conclusions: Patients with advanced HCC who are eligible for systemic therapeutic trials have patient- and disease-related prognostic factors. Positive HBsAg, symptomatic, ECOG performance≥2, and high BCLC stage predict a shorter overall survival.

No significant financial relationships to disclose.

Pharmacoeconomic study in head and neck cancer patients: Impact of prospective DPD deficiency screening with 5-fluorouracil (5-FU) dose tailoring on toxicities-related costs

6515

Background: Dihydropyrimidine dehydrogenase (DPD) plays a pivotal role in the detoxification of 5-FU. We studied the impact of screening DPD impairment in head and neck cancer (HNC) patients, both on reduction of drug-related toxicities and as a pharmacoeconomic endpoint. Methods: A total of 148 consecutive patients with HNC treated with 5-FU+platinum were monitored. Seventy-four patients (Arm A - before 2006) were treated with standard dosage, whereas 74 other patients (Arm B - after 2006) had their DPD status phenotypically evaluated prior to receiving 5-FU, with subsequent dose reduction if DPD deficiency were suspected. Severe toxicities and response were compared. Additionally, direct and indirect costs required to manage the treatment-related toxicities and to establish DPD status were calculated. Results: Sepsis was observed in 16.2% of patients treated with standard dosage. In Arm B, DPD deficiency was suspected in 35% of the patients and 5-FU dosage was subsequently reduced. Consequently, only 1.8% of them experienced sepsis. Of note, response rates were comparable between Arm A and B (62 vs 61%, p>0.05), thus demonstrating that 5-FU dose tailoring did not negatively impact on treatment efficacy, while reducing the occurrence of severe toxicities. Managing toxicities required an average 23-days of extra-hospitalization (4–96 days), including an average 1.6-day stay in ICU. No patients from Arm B had to stay in ICU. Drugs required for managing toxicities cost an average of $339 per patient (Arm A) and was reduced down to $38 per patient (Arm B). Similarly, mean extra-hospitalization cost was $5,940/patient in Arm A and $245/patient in Arm B. Testing DPD cost $49/patient in Arm B. Conclusions: Developing an adaptative dosing strategy based upon DPD status evaluation led to a dramatic reduction of the incidence of 5-FU-related severe toxicities, while maintaining optimal efficacy. Subsequently, extra-cost (medication + hospitalization costs) required to manage the toxicities fell down from $6,279 to $294/patient. Overall, this study advocates that systematic screening for DPD deficiency could be cost-efficient in the setting of 5-FU-based chemotherapies, with a reduction of 95% of the extra-costs.

No significant financial relationships to disclose.

Biomarker analyses from a phase III, randomized, open-label, first-line study of gefitinib (G) versus carboplatin/paclitaxel (C/P) in clinically selected patients (pts) with advanced non-small cell lung cancer (NSCLC) in Asia (IPASS)

8006^

Background: IPASS demonstrated overall superiority of first-line G vs C/P for progression-free survival (PFS) in never/light ex-smokers with stage IIIB/IV adenocarcinoma NSCLC in Asia. PFS favored CP initially and then G. Outcome was correlated with biomarkers (preplanned exploratory objective). Methods: 683 patients provided tissue samples. Analyses included primary endpoint PFS (Cox proportional hazards) and secondary endpoint objective response rate (ORR; logistic regression) by biomarker status. Results: EGFR mutation (M) status was evaluable in 437 pts by Amplification Refractory Mutation System (ARMS; 60% M+). M+ pts had significantly longer PFS and higher ORR and M- pts significantly shorter PFS and lower ORR with G than C/P. In M unknown pts PFS and ORR were similar to overall population. Post hoc analysis of overall survival favored G in M+ pts (31% maturity; HR 0.78; 95% CI 0.50–1.20) and C/P in M- pts (53% maturity; HR 1.38; 95% CI 0.92–2.90); differences were not statistically significant and follow-up is ongoing. EGFR gene-copy number was evaluable in 406 pts by fluorescence in situ hybridization (FISH; 61% FISH +). Similar PFS and ORR results to analyses by M status were observed, driven by the overlap in EGFR FISH and M status. EGFR protein expression (PE) was evaluable in 365 pts by immunohistochemistry (73% PE+). PFS outcomes did not differ statistically between PE+ and PE-. ORR favored G in both PE+ and - pts. Conclusions: EGFR M status was a strong predictive biomarker for the efficacy of G vs C/P in this clinically selected first-line setting.

[Table: see text]

No significant financial relationships to disclose.

ASCO Conflict of Interest Policy and Exceptions

In compliance with the guidelines established by the ASCO Conflict of Interest Policy (J Clin Oncol. 2006 Jan 20;24[3]:519–521) and the Accreditation Council for Continuing Medical Education (ACCME), ASCO strives to promote balance, independence, objectivity, and scientific rigor through disclosure of financial and other interests, and identification and management of potential conflicts. According to the ASCO Conflict of Interest Policy, the following financial and other relationships must be disclosed: employment or leadership position, consultant or advisory role, stock ownership, honoraria, research funding, expert testimony, and other remuneration (J Clin Oncol. 2006 Jan 20;24[3]:520). The ASCO Conflict of Interest Policy disclosure requirements apply to all authors who submit abstracts to the Annual Meeting.

For clinical trials that began accrual on or after April 29, 2004, ASCO's Policy places some restrictions on the financial relationships of principal investigators (J Clin Oncol. 2006 Jan 20;24[3]:521). If a principal investigator holds any restricted relationships, his or her abstract will be ineligible for placement in the 2009 Annual Meeting unless the ASCO Ethics Committee grants an exception. Among the circumstances that might justify an exception are that the principal investigator (1) is a widely acknowledged expert in a particular therapeutic area; (2) is the inventor of a unique technology or treatment being evaluated in the clinical trial; or (3) is involved in international clinical oncology research and has acted consistently with recognized international standards of ethics in the conduct of clinical research. NIH-sponsored trials are exempt from the Policy restrictions. Abstracts for which authors requested and have been granted an exception in accordance with ASCO's Policy are designated with a caret symbol (^) in the Annual Meeting Proceedings.

For more information about the ASCO Conflict of Interest Policy and the exceptions process, please visit www.asco.org/conflictofinterest .

Efficacy of pemetrexed-cisplatin (PC) in East Asian patients (pts): Subgroup analysis of a phase III study comparing PC versus gemcitabine-cisplatin (GC) in first-line treatment of advanced non-small cell lung cancer (NSCLC)

8045

Background: East Asian ethnicity is a recognized favorable prognostic factor in the treatment of NSCLC in trials with either chemotherapy or EGFR tyrosine-kinase inhibitors (TKIs). In a global phase III study (Scagliotti JCO 2008), superior efficacy of PC was shown for pts with nonsquamous NSCLC, while Asian ethnicity was prognostic in the overall population. The purpose of this analysis is to describe the patient and disease characteristics of the East Asian pts enrolled in this study and assess efficacy according to histology and smoking history. Methods: This retrospective analysis of a large phase III study included only patients enrolled from Korea and Taiwan. For survival and progression-free survival (PFS), Cox-adjusted analyses were used to estimate the hazard ratio and 95% CI, while medians were estimated using Kaplan-Meier method. Results: Results for PFS and response rate showed trends similar to overall survival in East Asian pts, favoring PC therapy in nonsquamous pts. The use of post-discontinuation targeted therapies such as EGFR-TKIs was similar between treatment arms in the overall population and in nonsquamous pts. In East Asian pts, EGFR-TKI use was slightly higher in the GC arm, in both the overall population and in nonsquamous pts. In a further subgroup analysis defined by smoking status, East Asian nonsquamous pts treated with PC had longer survival (not statistically significant). Conclusions: Pt and disease characteristics between the East Asian subgroup and the overall population were similar, with notable differences in the percentage of pts with no smoking history and the greater use of EGFR-TKIs as post-discontinuation therapy. This analysis shows the improved efficacy outcomes for East Asian nonsquamous pts treated with PC is consistent with the previously observed treatment effect of PC on nonsquamous NSCLC.

[Table: see text]

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A phase II study of BIBW 2992, a novel irreversible dual EGFR and HER2 tyrosine kinase inhibitor (TKI), in patients with adenocarcinoma of the lung and activating EGFR mutations after failure of one line of chemotherapy (LUX-Lung 2)

8013

Background: EGFR mutations are associated with exquisite sensitivity to EGFR TKIs in NSCLC. A phase II trial evaluating the efficacy of BIBW 2992 (Tovok), a novel, potent, irreversible, dual EGFR and HER2 TKI with preclinical activity in cell lines harboring activating (H3255, IC50=0.7 nM) and resistant (H1975, IC50=99 nM) EGFR mutations, is reported. Methods: Objective response rate is the primary endpoint of this 2-stage trial. Based on 16 or more unconfirmed PRs in an interim analysis of the first 40 2nd line patients (pts) completing 1 course (28 days), accrual will continue to a total of 120 1st and 2nd line pts (expected completion of accrual by May 2009. Data on 2nd line pts only are presented). Eligible pts have stage IIIB/IV lung adenocarcinoma, EGFR mutation in exons 18–21 (tested by direct sequencing), measurable disease, ECOG PS 0–2 and adequate end organ function. Pts receive 50 mg BIBW 2992 qd until progression. Tumor assessments are performed every 4 weeks for 12 weeks, then every 8 weeks. Results: Since Oct 2007, samples from 289 pts (222 from Taiwan and 67 from the US) have been sequenced. 100 had detectable EGFR mutations including del19 (n=39), L858R (n=45) and others (n=16). 69 pts have started treatment. The trial was moved to stage 2 after 21 of the first 38 treated pts had objective response at 28 days. Of 55 evaluable 2nd line pts, 29 (53%) had PR, and 23 (42%) had SD. Median follow up is 5.1 months. Most common related AEs were diarrhea and skin-related AEs, reported in 87% and 88% of pts, respectively. 27 pts (42.9 %) had dose reduction to 40 mg and 7 pts (11%) to 30 mg but only 1 pt permanently discontinued due to AEs. Diarrhea and rash were main causes of dose reduction. Conclusions: In the 2nd line setting, BIBW 2992 shows efficacy in NSCLC harboring EGFR activating mutations. Diarrhea and skin disorders, the most frequently observed AEs, are manageable with supportive care and dose reduction. Updated response and disease control rates and preliminary progression-free survival data will be presented. An international Phase III trial program investigating BIBW 2992 in NSCLC, LUX-Lung, is now recruiting.

[Table: see text]