Oncological outcomes of standard versus prolonged time to surgery after neoadjuvant chemoradiotherapy for oesophageal cancer in the multicentre, randomised, controlled NeoRes II trial

BACKGROUND

The optimal time to surgery (TTS) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer is unknown and has traditionally been 4-6 weeks in clinical practice. Observational studies have suggested better outcomes, especially in terms of histological response, after prolonged delay of up to 3 months after nCRT. The NeoRes II trial is the first randomised trial to compare standard to prolonged TTS after nCRT for oesophageal cancer.

PATIENTS AND METHODS

Patients with resectable, locally advanced oesophageal cancer were randomly assigned to standard delay of surgery of 4-6 weeks or prolonged delay of 10-12 weeks after nCRT. The primary endpoint was complete histological response of the primary tumour in patients with adenocarcinoma (AC). Secondary endpoints included histological tumour response, resection margins, overall and progression-free survival in all patients and stratified by histologic type.

RESULTS

Between February 2015 and March 2019, 249 patients from 10 participating centres in Sweden, Norway and Germany were randomised: 125 to standard and 124 to prolonged TTS. There was no significant difference in complete histological response between AC patients allocated to standard (21%) compared to prolonged (26%) TTS (P = 0.429). Tumour regression, resection margins and number of resected lymph nodes, total and metastatic, did not differ between the allocated interventions. The first quartile overall survival in patients allocated to standard TTS was 26.5 months compared to 14.2 months after prolonged TTS (P = 0.003) and the overall risk of death during follow-up was 35% higher after prolonged delay (hazard ratio 1.35, 95% confidence interval 0.94-1.95, P = 0.107).

CONCLUSION

Prolonged TTS did not improve histological complete response or other pathological endpoints, while there was a strong trend towards worse survival, suggesting caution in routinely delaying surgery for >6 weeks after nCRT.

Structural and Biochemical Investigation of Selected Pathogenic Mutants of the Human Dihydrolipoamide Dehydrogenase

Clinically relevant disease-causing variants of the human dihydrolipoamide dehydrogenase (hLADH, hE3), a common component of the mitochondrial α-keto acid dehydrogenase complexes, were characterized using a multipronged approach to unravel the molecular pathomechanisms that underlie hLADH deficiency. The G101del and M326V substitutions both reduced the protein stability and triggered the disassembly of the functional/obligate hLADH homodimer and significant FAD losses, which altogether eventually manifested in a virtually undetectable catalytic activity in both cases. The I12T-hLADH variant proved also to be quite unstable, but managed to retain the dimeric enzyme form; the LADH activity, both in the forward and reverse catalytic directions and the affinity for the prosthetic group FAD were both significantly compromised. None of the above three variants lent themselves to an in-depth structural analysis via X-ray crystallography due to inherent protein instability. Crystal structures at 2.89 and 2.44 Å resolutions were determined for the I318T- and I358T-hLADH variants, respectively; structure analysis revealed minor conformational perturbations, which correlated well with the residual LADH activities, in both cases. For the dimer interface variants G426E-, I445M-, and R447G-hLADH, enzyme activities and FAD loss were determined and compared against the previously published structural data.

P10.20.A Mechanisms of synergistic glioma growth suppression by radiotherapy and MET inhibition

Background

Glioblastoma remains to be one of the most lethal solid cancers. Despite multi-modal therapy including surgery as safely feasible, radiotherapy and chemotherapy with the alkylating agent temozolomide, the median survival of affected patients is still limited to approximately one year on a population level. Thus, novel therapies are urgently needed. There is increasing interest in the role of the HGF/MET pathway in the response of glioblastoma to radiotherapy since MET may be involved in radioresistance via proinvasive and DNA damage response pathways.

Material and Methods

Here we assessed the role of the MET pathway in the response to radiotherapy in vitro and in vivo in syngeneic mouse glioma models and explored potential modes of action responsible for the synergistic effects of MET pathway inhibition and irradiation on tumor growth in vivo.

Results

Murine glioma cells express HGF and MET and show increased MET phosphorylation upon exposure to exogenous HGF. In vitro, glioma cell viability and proliferation are not affected by pharmacological MET inhibition using tepotinib or genetic MET inhibition using CRISPR/Cas9-engineered Met gene knockout and sensitization to irradiation by MET inhibition is not seen. In vivo, the combination of MET inhibition with focal radiotherapy mediates prolonged survival of syngeneic orthotopic glioma-bearing mice compared with either treatment alone. Complementary studies demonstrate that synergy is lost when gliomas are established and treated in immunodeficient mice, but also if MET gene expression is disrupted in the tumor of wildtype mice. Combination therapy suppresses a set of pro-inflammatory mediators that are upregulated by radiotherapy alone and which are positively regulated by transforming growth factor (TGF)-β. In line with this data, ex vivo analysis of mouse brains reveal increased TGF-β pathway activity upon irradiation alone that is counteracted by concomitant MET inhibition.

Conclusion

In summary, we demonstrate synergistic suppression of syngeneic glioma growth by irradiation and MET inhibition that requires MET expression in the tumor as well as an intact immune system. Clinical evaluation of this combined treatment approach in newly diagnosed glioblastoma is warranted.

Structure of the dihydrolipoamide succinyltransferase (E2) component of the human alpha-ketoglutarate dehydrogenase complex (hKGDHc) revealed by cryo-EM and cross-linking mass spectrometry: Implications for the overall hKGDHc structure

BACKGROUND

The human mitochondrial alpha-ketoglutarate dehydrogenase complex (hKGDHc) converts KG to succinyl-CoA and NADH. Malfunction of and reactive oxygen species generation by the hKGDHc as well as its E1-E2 subcomplex are implicated in neurodegenerative disorders, ischemia-reperfusion injury, E3-deficiency and cancers.

METHODS

We performed cryo-EM, cross-linking mass spectrometry (CL-MS) and molecular modeling analyses to determine the structure of the E2 component of the hKGDHc (hE2k); hE2k transfers a succinyl group to CoA and forms the structural core of hKGDHc. We also assessed the overall structure of the hKGDHc by negative-stain EM and modeling.

RESULTS

We report the 2.9 Å resolution cryo-EM structure of the hE2k component. The cryo-EM map comprises density for hE2k residues 151-386 - the entire (inner) core catalytic domain plus a few additional residues -, while residues 1-150 are not observed due to the inherent flexibility of the N-terminal region. The structure of the latter segment was also determined by CL-MS and homology modeling. Negative-stain EM on in vitro assembled hKGDHc and previous data were used to build a putative overall structural model of the hKGDHc.

CONCLUSIONS

The E2 core of the hKGDHc is composed of 24 hE2k chains organized in octahedral (8 × 3 type) assembly. Each lipoyl domain is oriented towards the core domain of an adjacent chain in the hE2k homotrimer. hE1k and hE3 are most likely tethered at the edges and faces, respectively, of the cubic hE2k assembly.

GENERAL SIGNIFICANCE

The revealed structural information will support the future pharmacologically targeting of the hKGDHc.

Underlying molecular alterations in human dihydrolipoamide dehydrogenase deficiency revealed by structural analyses of disease-causing enzyme variants

Human dihydrolipoamide dehydrogenase (hLADH, hE3) deficiency (OMIM# 246900) is an often prematurely lethal genetic disease usually caused by inactive or partially inactive hE3 variants. Here we report the crystal structure of wild-type hE3 at an unprecedented high resolution of 1.75 Å and the structures of six disease-causing hE3 variants at resolutions ranging from 1.44 to 2.34 Å. P453L proved to be the most deleterious substitution in structure as aberrations extensively compromised the active site. The most prevalent G194C-hE3 variant primarily exhibited structural alterations close to the substitution site, whereas the nearby cofactor-binding residues were left unperturbed. The G426E substitution mainly interfered with the local charge distribution introducing dynamics to the substitution site in the dimer interface; G194C and G426E both led to minor structural changes. The R460G, R447G and I445M substitutions all perturbed a solvent accessible channel, the so-called H+/H2O channel, leading to the active site. Molecular pathomechanisms of enhanced reactive oxygen species (ROS) generation and impaired binding to multienzyme complexes were also addressed according to the structural data for the relevant mutations. In summary, we present here for the first time a comprehensive study that links three-dimensional structures of disease-causing hE3 variants to residual hLADH activities, altered capacities for ROS generation, compromised affinities for multienzyme complexes and eventually clinical symptoms. Our results may serve as useful starting points for future therapeutic intervention approaches.

Retinoprotective Effects of TAT-Bound Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase Activating Polypeptide

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) belong to the same peptide family and exert a variety of biological functions. Both PACAP and VIP have protective effects in several tissues. While PACAP is known to be a stronger retinoprotective peptide, VIP has very potent anti-inflammatory effects. The need for a non-invasive therapeutic approach has emerged and PACAP has been shown to be retinoprotective when administered in the form of eye drops as well. The cell penetrating peptide TAT is composed of 11 amino acids and tagging of TAT at the C-terminus of neuropeptides PACAP/VIP can enhance the traversing ability of the peptides through the biological barriers. We hypothesized that TAT-bound PACAP and VIP could be more effective in exerting retinoprotective effects when given in eye drops, by increasing the traversing efficacy and enhancing the activation of the PAC1 receptor. Rats were subjected to bilateral carotid artery occlusion (BCCAO), and retinas were processed for histological analysis 14 days later. The efficiency of the TAT-bound peptides to reach the retina was assessed as well as their cAMP increasing ability. Our present study provides evidence, for the first time, that topically administered PACAP and VIP derivatives (PACAP-TAT and VIP-TAT) attenuate ischemic retinal degeneration via the PAC1 receptor presumably due to a multifactorial protective mechanism.

Retinoprotective Effects of TAT-Bound Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase Activating Polypeptide

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) belong to the same peptide family and exert a variety of biological functions. Both PACAP and VIP have protective effects in several tissues. While PACAP is known to be a stronger retinoprotective peptide, VIP has very potent anti-inflammatory effects. The need for a non-invasive therapeutic approach has emerged and PACAP has been shown to be retinoprotective when administered in the form of eye drops as well. The cell penetrating peptide TAT is composed of 11 amino acids and tagging of TAT at the C-terminus of neuropeptides PACAP/VIP can enhance the traversing ability of the peptides through the biological barriers. We hypothesized that TAT-bound PACAP and VIP could be more effective in exerting retinoprotective effects when given in eye drops, by increasing the traversing efficacy and enhancing the activation of the PAC1 receptor. Rats were subjected to bilateral carotid artery occlusion (BCCAO), and retinas were processed for histological analysis 14 days later. The efficiency of the TAT-bound peptides to reach the retina was assessed as well as their cAMP increasing ability. Our present study provides evidence, for the first time, that topically administered PACAP and VIP derivatives (PACAP-TAT and VIP-TAT) attenuate ischemic retinal degeneration via the PAC1 receptor presumably due to a multifactorial protective mechanism.

Crystal structures of the disease-causing D444V mutant and the relevant wild type human dihydrolipoamide dehydrogenase

We report the crystal structures of the human (dihydro)lipoamide dehydrogenase (hLADH, hE3) and its disease-causing homodimer interface mutant D444V-hE3 at 2.27 and 1.84 Å resolution, respectively. The wild type structure is a unique uncomplexed, unliganded hE3 structure with the true canonical sequence. Based on the structural information a novel molecular pathomechanism is proposed for the impaired catalytic activity and enhanced capacity for reactive oxygen species generation of the pathogenic mutant. The mechanistic model involves a previously much ignored solvent accessible channel leading to the active site that might be perturbed also by other disease-causing homodimer interface substitutions of this enzyme.

Morbidity of cholecystectomy and gastric bypass in a national database

Background

There is a strong association between obesity and gallstones. However, there is no clear evidence regarding the optimal order of Roux-en-Y gastric bypass (RYGB) and cholecystectomy when both procedures are clinically indicated.

Methods

Based on cross-matched data from the Swedish Register for Cholecystectomy and Endoscopic Retrograde Cholangiopancreatography (GallRiks; 79 386 patients) and the Scandinavian Obesity Surgery Registry (SOReg; 36 098 patients) from 2007 to 2013, complication rates, reoperation rates and operation times related to the timing of RYGB and cholecystectomy were explored.

Results

There was a higher aggregate complication risk when cholecystectomy was performed after RYGB rather than before (odds ratio (OR) 1·35, 95 per cent c.i. 1·09 to 1·68; P = 0·006). A complication after the first procedure independently increased the complication risk of the following procedure (OR 2·02, 1·44 to 2·85; P < 0·001). Furthermore, there was an increased complication risk when cholecystectomy was performed at the same time as RYGB (OR 1·72, 1·14 to 2·60; P = 0·010). Simultaneous cholecystectomy added 61·7 (95 per cent c.i. 56·1 to 67·4) min (P < 0·001) to the duration of surgery.

Conclusion

Cholecystectomy should be performed before, not during or after, RYGB.

Muscle and Myotendinous Tissue Properties at the Distal Tibia as Assessed by High-Resolution Peripheral Quantitative Computed Tomography

High-resolution peripheral quantitative computed tomography (HR-pQCT) quantifies bone microstructure and density at the distal tibia where there is also a sizable amount of myotendinous (muscle and tendon) tissue (M_T); however, there is no method for the quantification of M_T. This study aimed (1) to assess the feasibility of using HR-pQCT distal tibia scans to estimate M_T properties using a custom algorithm, and (2) to determine the relationship between M_T properties at the distal tibia and mid-leg muscle density (MD) obtained from pQCT. Postmenopausal women from the Hamilton cohort of the Canadian Multicenter Osteoporosis Study had a single-slice (2.3 ± 0.5 mm) 66% site pQCT scan measuring muscle cross-sectional area (MCSA) and MD. A standard HR-pQCT scan was acquired at the distal tibia. HR-pQCT-derived M_T cross-sectional area (M_TCSA) and M_T density (M_TD) were calculated using a custom algorithm in which thresholds (34.22-194.32 mg HA/cm³) identified muscle seed volumes and were iteratively expanded. Pearson and Bland-Altman plots were used to assess correlations and systematic differences between pQCT- and HR-pQCT-derived muscle properties. Among 45 women (mean age: 74.6 ± 8.5 years, body mass index: 25.9 ± 4.3 kg/m²), M_TD was moderately correlated with mid-leg MD across the 2 modalities (r = 0.69-0.70, p < 0.01). Bland-Altman analyses revealed no evidence of directional bias for M_TD-MD. HR-pQCT and pQCT measures of M_TCSA and MCSA were moderately correlated (r = 0.44, p < 0.01). Bland-Altman plots for M_TCSA revealed that larger MCSAs related to larger discrepancy between the distal and the mid-leg locations. This is the first study to assess the ability of HR-pQCT to measure M_T size, density, and morphometry. HR-pQCT-derived M_TD was moderately correlated with mid-leg MD from pQCT. This relationship suggests that distal M_T may share common properties with muscle throughout the length of the leg. Future studies will assess the value of HR-pQCT-derived M_T properties in the context of falls, mobility, and balance.

Outcomes of laparoscopic gastric bypass in a randomized clinical trial compared with a concurrent national database

BACKGROUND

RCTs are the standard for assessing medical interventions, but they may not be feasible and their external validity is sometimes questioned. This study aimed to compare results from an RCT on mesenteric defect closure during laparoscopic gastric bypass with those from a national database containing data on the same procedure, to shed light on the external validity of the RCT.

METHODS

Patients undergoing laparoscopic gastric bypass surgery within an RCT conducted between 1 May 2010 and 14 November 2011 were compared with those who underwent the same procedure in Sweden outside the RCT over the same time interval. Primary endpoints were severe complications within 30 days and surgery for small bowel obstruction within 4 years.

RESULTS

Some 2507 patients in the RCT were compared with 8485 patients in the non-RCT group. There were no differences in severe complications within 30 days in the group without closure of the mesenteric defect (odds ratio (OR) for RCT versus non-RCT 0·94, 95 per cent c.i. 0·64 to 1·36; P = 0·728) or in the group with closure of the defect (OR 1·34, 0·96 to 1·86; P = 0·087). There were no differences between the RCT and non-RCT cohorts in reoperation rates for small bowel obstruction in the mesenteric defect non-closure (cumulative incidence 10·9 versus 9·4 per cent respectively; hazard ratio (HR) 1·20, 95 per cent c.i. 0·99 to 1·46; P = 0·065) and closure (cumulative incidence 5·7 versus 7·0 per cent; HR 0·82, 0·62 to 1·07; P = 0·137) groups. The relative risk for small bowel obstruction without mesenteric defect closure compared with closure was 1·91 in the RCT group and 1·39 in the non-RCT group.

CONCLUSION

The efficacy of mesenteric defect closure was similar in the RCT and national registry, providing evidence for the external validity of the RCT.

Cancer prevention in the era of precision oncology

Cancer is a highly heterogeneous disease, both between and within different target organs. Precision cancer prevention requires understanding the molecular pathways leading to cancer on a "per-person" level, identification of individuals most at risk for developing cancer, and tailoring interventions to accommodate pathogenesis, risk, and individual responses to interventions. This commentary will discuss how an investment in precision prevention research can accelerate cancer prevention agent development-the key to reducing cancer incidence and mortality.

The Protective Role of PAC1-Receptor Agonist Maxadilan in BCCAO-Induced Retinal Degeneration

A number of studies have proven that pituitary adenylate cyclase activating polypeptide (PACAP) is protective in neurodegenerative diseases. Permanent bilateral common carotid artery occlusion (BCCAO) causes severe degeneration in the rat retina. In our previous studies, protective effects were observed with PACAP1-38, PACAP1-27, and VIP but not with their related peptides, glucagon, or secretin in BCCAO. All three PACAP receptors (PAC1, VPAC1, VPAC2) appear in the retina. Molecular and immunohistochemical analysis demonstrated that the retinoprotective effects are most probably mainly mediated by the PAC1 receptor. The aim of the present study was to investigate the retinoprotective effects of a selective PAC1-receptor agonist maxadilan in BCCAO-induced retinopathy. Wistar rats were used in the experiment. After performing BCCAO, the right eye was treated with intravitreal maxadilan (0.1 or 1 μM), while the left eye was injected with vehicle. Sham-operated rats received the same treatment. Two weeks after the operation, retinas were processed for standard morphometric and molecular analysis. Intravitreal injection of 0.1 or 1 μM maxadilan caused significant protection in the thickness of most retinal layers and the number of cells in the GCL compared to the BCCAO-operated eyes. In addition, 1 μM maxadilan application was more effective than 0.1 μM maxadilan treatment in the ONL, INL, IPL, and the entire retina (OLM-ILM). Maxadilan treatment significantly decreased cytokine expression (CINC-1, IL-1α, and L-selectin) in ischemia. In summary, our histological and molecular analysis showed that maxadilan, a selective PAC1 receptor agonist, has a protective role in BCCAO-induced retinal degeneration, further supporting the role of PAC1 receptor conveying the retinoprotective effects of PACAP.

Selumetinib with and without erlotinib in KRAS mutant and KRAS wild-type advanced nonsmall-cell lung cancer

BACKGROUND

KRAS mutations in NSCLC are associated with a lack of response to epidermal growth factor receptor inhibitors. Selumetinib (AZD6244; ARRY-142886) is an oral selective MEK kinase inhibitor of the Ras/Raf/MEK/ERK pathway.

PATIENTS AND METHODS

Advanced nonsmall-cell lung cancer (NSCLC) patients failing one to two prior regimens underwent KRAS profiling. KRAS wild-type patients were randomized to erlotinib (150 mg daily) or a combination of selumetinib (150 mg daily) with erlotinib (100 mg daily). KRAS mutant patients were randomized to selumetinib (75 mg b.i.d.) or the combination. The primary end points were progression-free survival (PFS) for the KRAS wild-type cohort and objective response rate (ORR) for the KRAS mutant cohort. Biomarker studies of ERK phosphorylation and immune subsets were carried out.

RESULTS

From March 2010 to May 2013, 89 patients were screened; 41 KRAS mutant and 38 KRAS wild-type patients were enrolled. Median PFS in the KRAS wild-type arm was 2.4 months [95% confidence interval (CI) 1.3-3.7] for erlotinib alone and 2.1 months (95% CI 1.8-5.1) for the combination. The ORR in the KRAS mutant group was 0% (95% CI 0.0% to 33.6%) for selumetinib alone and 10% (95% CI 2.1% to 26.3%) for the combination. Combination therapy resulted in increased toxicities, requiring dose reductions (56%) and discontinuation (8%). Programmed cell death-1 expression on regulatory T cells (Tregs), Tim-3 on CD8+ T cells and Th17 levels were associated with PFS and overall survival in patients receiving selumetinib.

CONCLUSIONS

This study failed to show improvement in ORR or PFS with combination therapy of selumetinib and erlotinib over monotherapy in KRAS mutant and KRAS wild-type advanced NSCLC. The association of immune subsets and immune checkpoint receptor expression with selumetinib may warrant further studies.

Morbidity and mortality after surgery for cancer of the oesophagus and gastro-oesophageal junction: A randomized clinical trial of neoadjuvant chemotherapy vs. neoadjuvant chemoradiation

OBJECTIVE

To compare the incidence and severity of postoperative complications after oesophagectomy for carcinoma of the oesophagus and gastro-oesophageal junction (GOJ) after randomized accrual to neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy (nCRT).

BACKGROUND

Neoadjuvant therapy improves long-term survival after oesophagectomy. To date, evidence is insufficient to determine whether combined nCT, or nCRT alone, is the most beneficial.

METHODS

Patients with carcinoma of the oesophagus or GOJ, resectable with a curative intention, were enrolled in this multicenter trial conducted at seven centres in Sweden and Norway. Study participants were randomized to nCT or nCRT followed by surgery with two-field lymphadenectomy. Three cycles of cisplatin/5-fluorouracil was administered in all patients, while 40 Gy of concomitant radiotherapy was administered in the nCRT group.

RESULTS

Of the randomized 181 patients, 91 were assigned to nCT and 90 to nCRT. One-hundred-and-fifty-five patients, 78 nCT and 77 nCRT, underwent resection. There was no statistically significant difference between the groups in the incidence of surgical or nonsurgical complications (P-value = 0.69 and 0.13, respectively). There was no 30-day mortality, while the 90-day mortality was 3% (2/78) in the nCT group and 6% (5/77) in the nCRT group (P = 0.24). The median Clavien-Dindo complication severity grade was significantly higher in the nCRT group (P = 0.001).

CONCLUSION

There was no significant difference in the incidence of complications between patients randomized to nCT and nCRT. However, complications were significantly more severe after nCRT.

REGISTRATION TRIAL DATABASE

The trial was registered in the Clinical Trials Database (registration number NCT01362127).

Long-term effects of inhaled budesonide on screening-detected lung nodules

BACKGROUND

A previously carried out randomized phase IIb, placebo-controlled trial of 1 year of inhaled budesonide, which was nested in a lung cancer screening study, showed that non-solid and partially solid lung nodules detected by low-dose computed tomography (LDCT), and not immediately suspicious for lung cancer, tended to regress. Because some of these nodules may be slow-growing adenocarcinoma precursors, we evaluated long-term outcomes (after stopping the 1-year intervention) by annual LDCT.

PATIENTS AND METHODS

We analyzed the evolution of target and non-target trial nodules detected by LDCT in the budesonide and placebo arms up to 5 years after randomization. The numbers and characteristics of lung cancers diagnosed during follow-up were also analyzed.

RESULTS

The mean maximum diameter of non-solid nodules reduced significantly (from 5.03 mm at baseline to 2.61 mm after 5 years) in the budesonide arm; there was no significant size change in the placebo arm. The mean diameter of partially solid lesions also decreased significantly, but only by 0.69 mm. The size of solid nodules did not change. Neither the number of new lesions nor the number of lung cancers differed in the two arms.

CONCLUSIONS

Inhaled budesonide given for 1 year significantly decreased the size of non-solid nodules detected by screening LDCT after 5 years. This is of potential importance since some of these nodules may progress slowly to adenocarcinoma. However, further studies are required to assess clinical implications.

CLINICAL TRIAL NUMBER

NCT01540552.

Oregonator generalization as a minimal model of quorum sensing in Belousov–Zhabotinsky reaction with catalyst confinement in large populations of particles

The Oregonator demonstrates that quorum sensing in populations of Belousov–Zhabotinsky oscillators arises from modification of the stoichiometry by catalyst confinement.

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.

A comparative analysis on the efficacy and safety of intaxel® and taxol® in advanced metastatic breast cancer

BACKGROUND

Among the presently available cytotoxic drugs, paclitaxel, in combination with doxorubicin and carboplatin, come under the highly active therapy for metastatic breast cancer. Between the two brands of paclitaxel (Intaxel, which is marketed by Fresenius Kabi and Taxol, the original paclitaxel which is manufactured by BMS) the similarity has not been evaluated in clinical trial settings till date. This prospective, controlled, randomized, multicentre, open-label phase IV study was planned to compare the safety and efficacy of Intaxel with Taxol, when they were used in combination with carboplatin or doxorubicin, as a second line treatment for metastatic breast cancer.

METHODS

Fourty nine eligible patients were randomized to receive Intaxel or Taxol with either doxorubicin or carboplatin. The patients who had received a prior anthracycline based chemotherapy were randomized to the paclitaxel/carboplatin arm. The patients were evaluated in three phases i.e. at baseline, during the treatment and at follow up for the tumour response, the time period till the disease progression and the toxicity. The time till the disease progression was assessed by the Kaplan-Meier method. The continuous and categorical variables were assessed by using the ANOVA test and Fisher's exact test, respectively.

RESULTS

After 3 cycles, an objective response rate of 55.56% (CR = 3, PR = 7) was noted in the Intaxel group and that of 59.09% (CR = 1, PR = 12) was noted in the Taxol group. After 6 cycles, an objective response rate of 50% was noted in both the groups. No significant difference was observed in the response rate of the two groups after 3 cycles (p > 0.05) and at the end of the treatment (p > 0.05). The patients who received Intaxel had a lower incidence of thrombocytopaenia (p = 0.0146) and neurosensory loss (p = 0.008) as compared to those who received Taxol.

CONCLUSION

The results of this study demonstrated that the safety and efficacy of Intaxel and Taxol are equivalent when they are used in combination with other cytotoxic agents as the second line of treatment for metastatic stage IV breast cancer.

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 &lt;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.