A phase I/II study of sepantronium bromide (YM155, survivin suppressor) with paclitaxel and carboplatin in patients with advanced non-small-cell lung cancer

BACKGROUND

This phase I/II study examined the safety and efficacy of Sepantronium Bromide (S), a small-molecule selective survivin suppressant, administered in combination with carboplatin (C) and paclitaxel (P).

PATIENTS AND METHODS

Forty-one patients were treated on study. Twenty-two patients received escalating doses of S (3.6-12 mg/m(2)) and 19 with untreated stage IV non-small-cell lung cancer (NSCLC) were treated with the maximum tolerated dose of 10 mg/m(2) in combination with standard doses of C (AUC6) and P (200 mg/m(2)) for six cycles. S was administered as a continuous intravenous infusion (CIVI) over 72 h in 21-day treatment cycles. Study end points included safety and toxic effect, response rate, progression-free and overall survival (PFS and OS), as well as exploratory pharmacodynamic correlates.

RESULTS

Treatment with S was well tolerated, and toxic effects were mostly hematological in the phase II study. Two (11%) partial responses were observed with a median PFS of 5.7 months and median OS 16.1 months. Pharmacodynamic analysis did not demonstrate an association with response.

CONCLUSION

The combination of S (10 mg/m(2)/day 72-h CIVI) administered with C and P every 3 weeks exhibited a favorable safety profile but failed to demonstrate an improvement in response rate in advanced NSCLC.

CLINICAL TRIAL NUMBER

NCT01100931.

Optimization of reorganization energy drives evolution of the designed Kemp eliminase KE07

Understanding enzymatic evolution is essential to engineer enzymes with improved activities or to generate enzymes with tailor-made activities. The computationally designed Kemp eliminase KE07 carries out an unnatural reaction by converting of 5-nitrobenzisoxazole to cyanophenol, but its catalytic efficiency is significantly lower than those of natural enzymes. Three series of designed Kemp eliminases (KE07, KE70, KE59) were shown to be evolvable with considerable improvement in catalytic efficiency. Here we use the KE07 enzyme as a model system to reveal those forces, which govern enzymatic evolution and elucidate the key factors for improving activity. We applied the Empirical Valence Bond (EVB) method to construct the free energy pathway of the reaction in the original KE07 design and the evolved R7 1/3H variant. We analyzed catalytic effect of residues and demonstrated that not all mutations in evolution are favorable for activity. In contrast to the small decrease in the activation barrier, in vitro evolution significantly reduced the reorganization energy. We developed an algorithm to evaluate group contributions to the reorganization energy and used this approach to screen for KE07 variants with potential for improvement. We aimed to identify those mutations that facilitate enzymatic evolution, but might not directly increase catalytic efficiency. Computational results in accord with experimental data show that all mutations, which appear during in vitro evolution were either neutral or favorable for the reorganization energy. These results underscore that distant mutations can also play role in optimizing efficiency via their contribution to the reorganization energy. Exploiting this principle could be a promising strategy for computer-aided enzyme design. This article is part of a Special Issue entitled: The emerging dynamic view of proteins: Protein plasticity in allostery, evolution and self-assembly.

P3-10-01: Alternative Dosing Regimens with the EGFr Inhibitors (Gefitinib and Lapatinib) in Mammary Cancer Models: Prevention and Therapeutic Efficacy

The EGFR inhibitors are effective in treatment of lung and pancreatic cancers (erlotinib, gefitinib) and Neu overexpressing breast cancer (lapatinib) in humans; as well as preventing multiple cancers in animal models. However, the development of toxicities (Iressa, skin rashes; Lapatinib, diarrhea) limit their potential use in prevention; and perhaps even in an adjuvant setting. We examined whether alternative dosing regimens which might reduce toxicity would still achieve preventive and therapeutic efficacy. Female Sprague-Dawley rats were administered a single IV dose of methylnitrosourea (MNU) at 50 days of age. In a prevention study, MNU treated rats administered Gefitinib daily (10 mg/kg BW/day, 7x/week) or Gefitinib (70 mg/kg BW, 1x/week) beginning 5 days after MNU resulted in 94 and 75% reductions, respectively, in cancer multiplicity. Simultaneous measurements of tumor load (number of tumors x tumor weight) showed that both regimens resulted in greater than a 90% decrease. In the therapeutic study (initiating treatment when animals developed a small palpable cancer), both regimens were again highly effective. A prevention study was also performed with Lapatinib (75 mg/kg BW/day, 7x/week or 525 mg/kg BW, 1x/week). While the daily dose reduced cancer multiplicity 90%, the weekly dose caused a 70% reduction. Finally, we examined the effects of daily or weekly dosing with Iressa (100 mg/kg BW/day, 5x/week or 500 or 250 mg/kg BW, 1x/week) in an ER− mouse model (using MMTV-Neu; p53+/− mice). This study showed that while daily dosing with Iressa decreased tumor multiplicity roughly 80%, weekly dosing at either dose caused roughly a 50% decrease. These data show that even a significant alteration in the dosing of Gefitinib (EGFR 1) or Lapatinib (EGFR 2/1) still resulted in a large reduction in mammary cancers. The important clinical question will be whether this altered dosing will diminish the toxicities associated with these agents. We cannot determine this in animal models since, at the effective doses employed, the typical toxicities observed in humans are not observed. Supported by NCI contract number HHSN261200433001C.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-10-01.

Abstract P1-08-03: Alternative Dosing Regimens with Tarceva in a Mammary Cancer Model: Effects on Efficacy and Potential Effects on Toxicity

The EGFR inhibitors (e.g., Tarceva) have been effective in preventing cancer in multiple animal models, including ER positive breast, head and neck, and urinary bladder cancers. Although Tarceva is less toxic than most classical cytotoxic therapies, the development of a skin rash in greater than 35% of patients is a significant impediment to its use in a preventive setting. We, therefore, tested whether alternative dosing regimens would still achieve preventive efficacy. Female Sprague-Dawley rats were administered a single IV dose of methylnitrosourea at 50 days of age. Beginning 5 days later, rats were administered Tarceva (6 mg/kg BW) by gavage. In the first study, three different protocols were employed: (1) dosing with Tarceva daily (7X/week), (2) dosing with Tarceva for one day followed by one day of vehicle treatment, and (3) two days of dosing with Tarceva followed by two days of dosing with vehicle treatment. These treatment regimens resulted in 94, 58, and 77% decreases, respectively, in cancer multiplicity when compared to rats receiving vehicle alone. In a second ongoing study, we are evaluating the following alternative dosing schedules. MNU treated rats are receiving either: (1) daily dosing with 6 mg/kg BW (total of 42 mg/week); (2) dosing 6 mg/kg BW, 2 days on-2 days off (total of 21 mg/week): (3) weekly dosing with a single dose of 42 mg; and (4) daily dosing with the vehicle. The various Tarceva treatment regimens have currently reduced palpable mammary tumor multiplicity by 82, 66, and 71%, respectively. These data imply that by significantly altering the dosing of Tarceva, including a dose of once per week, most of the preventive efficacy is retained. Pharmacokinetic studies from these protocols showed a t½ of <8 hours; implying that sub-effective serum levels were achieved within 48 hours of the last dose. Whether these altered protocols may affect the induced skin rash in women is a significant and practical question. Supported by NCI contract number HHSN261200433001C.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-08-03.

Randomized phase II trial of budesonide versus placebo in high-risk population with screening-detected lung nodules: Update on secondary endpoints

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Background: Lung cancer phase II chemoprevention trials have not focused so far on the peripheral lung. CT discovers small, undetermined peripheral nodules, which may be preinvasive lesions. In a recent phase II trial the glucocorticoid Budesonide reduced peripheral nodules at spiral CT. Methods: We performed a randomized, double-blind, placebo-controlled, phase IIb clinical trial of inhaled budesonide in current (CS) or former smokers (FS) with CT-detected peripheral nodules. Primary endpoint: shrinkage effect on nodules. Secondary endpoints: decrease in size/number of the target lesions, modulation of tumor markers in sputum and plasma, toxicity, effect on pulmonary function. Two hundred and two subjects received 800μg budesonide (B) twice daily or placebo (P) for 1 year. CT scans at 0 and 12 months (mts), and clinical evaluation + serum/plasma collection at 0, 3, 6, and 12 months were performed. Subjects were stratified according to gender, smoking habits (CS vs. FS), and nodule characteristics (solid vs. non-solid). Results: Preliminary data had shown no shrinkage of the nodules in the B treated arm in a per subject analysis (primary objective). We present now results on serum markers (ultrasensitive C-reactive protein, CRP), emphysema and pulmonary function. As compared to baseline, CRP median levels show at 12 months a nonsignificant (p = 0.85) reduction: -0.25 ± 0.63 (B) vs. -1.16 ± 0.97 (P). 12-month values are significantly (p = 0.01) associated with baseline values and smoking status, with higher mean values at 12 months in FS (B 2.1 ± 2.0 vs. P 3.4 ± 1.9). Emphysema values at 12 months are significantly higher (p = 0.0022) in the B (+ 0.29 ± 0.06) versus P arm (+ 0.12 ± 0.07). This difference is not correlated to sex (p = 0.7062) and smoking status (p = 0.8044). As regards spirometry, no significant difference on FEV 1% and DLC/VA appears between arms at 12 months: median FEV 1% values 3.7 ± 1.0 for B versus 2.9 ± 1.0 for P (p = 0.6221); median DLC/VA increase of 0.3 ± 1.9 (B) versus decrease of -3.8 ± 1.6 (P) (p = 0.4191). Conclusions: A significant effect of B on ultrasensitive-CRP and pulmonary function has not been shown. CRP results may indicate the lack of systemic absorption of B. Emphysema appears slightly worse in the B arm, particularly in FS; this is worth further investigation.

No significant financial relationships to disclose.

Additional data on Mycoplasma disease of goslings

Epidemiological, pathomorphological, histological and microbiological studies on 272 gosling from 51 flocks showed that disease occurred generally at 3 to 4 weeks of age with morbidity of 15 to 25% and mortality of 3 to 8%. It was characterized by respiratory and nervous symptoms accompanied by serous-fibrinous inflammation of the mucosal membrane of the respiratory tract, pericardium and cerebral membranes. Mycoplasmas of 1220 type were isolated from trachea and airsac walls of 50% of the samples tested, but no adeno or reoviruses could be detected in homogenates of trachea and airsac wall, and no serological response indicative of Derzsy's disease could be demonstrated. E. coli, Ps. aeruginosa, S. typhimurium and Sir. pyogenes were occasionally cultured from the heart and liver of goslings. Cloacal and oviduct swabs and phallus lympha samples from five parent goose flocks also frequently revealed 1220 type mycoplasmas.

Chromosome 18 deletions are common events in classical midgut carcinoid tumors

Classical midgut carcinoids are rare intestinal neuroendocrine tumors that often present with metastases at diagnosis. In contrast to foregut carcinoids, midgut carcinoids are not related to the multiple endocrine neoplasia type 1 syndrome, and the mechanisms involved in their tumorigenesis are unknown. Eight classical midgut carcinoids were analyzed by genome-wide screening for loss of heterozygosity. Deletions on chromosome 18 were found in 88% of the tumors. DNA sequencing and immunohistochemical staining for Smad4/DPC4, which often is homozygously mutated in pancreatic and colon carcinomas, revealed no aberrations. In 1 tumor, a region telomeric to the Smad4/DPC4/DCC genes at 18q21 was deleted. Other chromosomes were affected in 3 lesions only. The high frequency of chromosome 18 deletions strongly indicates a genetic alteration of importance in classical midgut carcinoid tumorigenesis, apparently not involving the Smad4/DPC4 gene.

[Primary hyperparathyroidism is common among postmenopausal women. Identification of genetic risk factors can contribute to individualized treatment]

Primary hyperparathyroidism (pHPT) is commonly seen in postmenopausal women. Along with the clinical characterisation of the disease, studies of molecular genetics have contributed to increased understanding of the etiology of pHPT. Genetic association studies have revealed that certain vitamin D receptor polymorphisms relate to the development of sporadic pHPT. A new type of familial pHPT was recently discovered. Studies of parathyroid adenomas have demonstrated that the tumor suppressor gene MEN1 and the oncogene cyclinD1 are of importance for the tumorigenesis.

The role of CC10 in pulmonary carcinogenesis: from a marker to tumor suppression

CC10 is infrequently expressed in human non-small cell lung cancers (NSCLCs), despite being abundantly produced by progenitor cells for normal and neoplastic epithelium. Many abnormalities in the surrounding lung associated with field carcinogenesis, which reflect prolonged exposure to such carcinogens as tobacco smoke, also revealed altered expression of CC10. Exposure of hamsters and mice to the tobacco-specific carcinogen NNK led to reduced CC10 expression, which was partially reversible. Overexpression of CC10 in immortalized bronchial epithelial cells delayed the induction of anchorage-independent growth in response to NNK. The data suggest that downregulation of CC10 contributes to carcinogenesis because CC10 antagonizes the neoplastic phenotype.

Role of nitric oxide in vascular permeability after combined burns and smoke inhalation injury

Patients with severe burn and/or smoke inhalation injury suffer both systemic and pulmonary vascular hyperpermeability. We hypothesized that nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) plays a role in the changes in microvascular permeability seen with this injury. To test the hypothesis, we administered mercaptoethylguanidine (MEG), a selective iNOS inhibitor, to conscious sheep subjected to a combined smoke inhalation and third-degree burn injury to 40% of total body surface area. The sheep were surgically prepared for chronic study with lung and prefemoral lymph fistulas in order to estimate microvascular permeability. Both the groups and a control group of animals showed an increase in iNOS protein and message in their lungs. The control animals showed significant increases in either plasma or lymph NO2-/NO3- (NOx) concentration at 24 h after injury, with associated cardiac depression and hemoconcentration. The airway epithelium stained for nitrotyrosine. In the treatment group, NOx did not increase significantly in plasma or lymph throughout the experiment, there was no nitrotyrosine staining, hemodynamic depression was not observed, and the fluid requirement was significantly less than in the control group. Changes in pulmonary microvascular permeability were significantly suppressed by inhibition of iNOS. However, there was no significant difference between the two study groups in the microvascular permeability of burned tissue. These data suggest that NO produced by iNOS plays an important role in the changes in systemic and pulmonary microvascular permeability in combined smoke inhalation/third-degree burn injury, but does not affect the vascular permeability of third-degree-burned tissue in this type of injury.

Familial hypercalcemia and hypercalciuria caused by a novel mutation in the cytoplasmic tail of the calcium receptor

Familial hyperparathyroidism (HPT), characterized by hypercalcemia and hypercalciuria, and familial benign hypocalciuric hypercalcemia (FHH) are the most common causes of hereditary hypercalcemia. The calcium-sensing receptor (CaR) regulates PTH secretion and renal calcium excretion. Heterozygous inactivating mutations of the gene cause FHH, whereas CaR gene mutations have not been demonstrated in HPT. In a kindred with 20 affected individuals, the hypercalcemic disorder segregated with inappropriately higher serum PTH and magnesium levels and urinary calcium levels than in unaffected members. Subtotal parathyroidectomy revealed parathyroid gland hyperplasia/adenoma and corrected the biochemical signs of the disorder in seven of nine individuals. Linkage analysis mapped the condition to markers flanking the CaR gene on chromosome 3q. Sequence analysis revealed a mutation changing phenylalanine to leucine at codon 881 of the CaR gene, representing the first identified point mutation located within the cytoplasmic tail of the CaR. A construct of the mutant receptor (F881L) was expressed in human embryonic kidney cells (HEK 293), and demonstrated a right-shifted dose-response relationship between the extracellular and intracellular calcium concentrations. The hypercalcemic disorder of the present family is caused by an inactivating point mutation in the cytoplasmic tail of the CaR and displays clinical characteristics atypical of FHH and primary HPT.

Induction of differentiation and apoptosis by ligands of peroxisome proliferator-activated receptor gamma in non-small cell lung cancer

The peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-activated transcription factor belonging to the steroid receptor superfamily. It is a key regulator of adipogenic differentiation, the ligands of which have also been demonstrated to induce differentiation in human breast and colon cancer cell lines. This study examined PPARgamma, in non-small cell lung cancer (NSCLC). PPARgamma mRNA and protein were expressed in NSCLC cell lines, with highest levels in adenocarcinomas. PPARgamma protein was also expressed in 50% of primary lung cancers by immunohistochemistry. Treatment of multiple cell lines with two distinct PPARgamma ligands in the presence of serum resulted in growth arrest, irreversible loss of capacity for anchorage-independent growth, decreased activity and expression of matrix metalloproteinase 2, and modulation of multiple markers in a manner consistent with differentiation. Specifically, there was up-regulation of general markers of the differentiated state such as gelsolin, Mad, and p21. Down-regulation of specific markers of progenitor lineages for the peripheral lung, i.e., the type II pneumocyte lineage markers MUC1 and surfactant protein-A and the Clara cell lineage marker CC10, also occurred. In addition, HTI56, a marker of terminally differentiated type I pneumocytes, was also induced. Consistent with a more mature, less malignant phenotype, ligand treatment also inhibited the expression of cyclin D1 and led to hypophosphorylation of the retinoblastoma protein. In contrast, in the absence of serum, ligand treatment rapidly resulted in apoptosis and substantially earlier onset of differentiation. Taken together, these results show that depending on the growth milieu, ligands of PPARgamma induce differentiation and apoptosis in NSCLC, suggesting clinical utility for these agents.

Induction of differentiation accompanies inhibition of Cdk2 in a non-small cell lung cancer cell line

Induction of differentiation in a variety of model systems is accompanied by cell cycle exit and inhibition of Cdk2 kinase activity. We asked whether inhibition of Cdk2 activity is sufficient to allow differentiation to occur in a non-small cell lung cancer cell line. Treatment of NCI-H358 with flavopiridol, an inhibitor of multiple Cdk's, resulted in growth arrest and induction of mucinous differentiation. The onset of differentiation coincided temporally with loss of Cdk2 kinase activity. Western analysis revealed that flavopiridol treatment resulted in depletion of both cyclin E and D1, suggesting that loss of the regulatory subunits is at least partially responsible for the loss of Cdk kinase activity. Similarly, roscovitine, an inhibitor of Cdk's 1, 2, and 5, but not Cdk4, also induced differentiation in NCI-H358, although the resulting pattern of expression of cell cycle regulatory genes differed from the pattern obtained with flavopiridol. Furthermore, stable expression of an antisense Cdk2 construct in NCI-H358 also resulted in the appearance of a marker of mucinous differentiation. These results show that the inhibition of activity of cyclin dependent kinases, particularly Cdk2, by multiple different mechanisms is accompanied by differentiation. Thus, induction of differentiation is one potential mechanism of action for agents that down-regulate Cdk activity.