VLPs generated by the fusion of RSV-F or hMPV-F glycoprotein to HIV-Gag show improved immunogenicity and neutralizing response in mice

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) vaccines have been long overdue. Structure-based vaccine design created a new momentum in the last decade, and the first RSV vaccines have finally been approved in older adults and pregnant individuals. These vaccines are based on recombinant stabilized pre-fusion F glycoproteins administered as soluble proteins. Multimeric antigenic display could markedly improve immunogenicity and should be evaluated in the next generations of vaccines. Here we tested a new virus like particles-based vaccine platform which utilizes the direct fusion of an immunogen of interest to the structural human immunodeficient virus (HIV) protein Gag to increase its surface density and immunogenicity. We compared, in mice, the immunogenicity of RSV-F or hMPV-F based immunogens delivered either as soluble proteins or displayed on the surface of our VLPs. VLP associated F-proteins showed better immunogenicity and induced superior neutralizing responses. Moreover, when combining both VLP associated and soluble immunogens in a heterologous regimen, VLP-associated immunogens provided added benefits when administered as the prime immunization.

Spatial and temporal studies of metabolic activity: contrasting biochemical kinetics in tissues and pathways during fasted and fed states

The regulation of nutrient homeostasis, i.e., the ability to transition between fasted and fed states, is fundamental in maintaining health. Since food is typically consumed over limited (anabolic) periods, dietary components must be processed and stored to counterbalance the catabolic stress that occurs between meals. Herein, we contrast tissue- and pathway-specific metabolic activity in fasted and fed states. We demonstrate that knowledge of biochemical kinetics that is obtained from opposite ends of the energetic spectrum can allow mechanism-based differentiation of healthy and disease phenotypes. Rat models of type 1 and type 2 diabetes serve as case studies for probing spatial and temporal patterns of metabolic activity via [²H]water labeling. Experimental designs that capture integrative whole body metabolism, including meal-induced substrate partitioning, can support an array of research surrounding metabolic disease; the relative simplicity of the approach that is discussed here should enable routine applications in preclinical models.

Structure-Activity Relationship of Novel and Selective Biaryl-Chroman GPR40 AgoPAMs

A series of biaryl chromans exhibiting potent and selective agonism for the GPR40 receptor with positive allosteric modulation of endogenous ligands (AgoPAM) were discovered as potential therapeutics for the treatment of type II diabetes. Optimization of physicochemical properties through modification of the pendant aryl rings resulted in the identification of compound AP5, which possesses an improved metabolic profile while demonstrating sustained glucose lowering.

GPR40 partial agonists and AgoPAMs: Differentiating effects on glucose and hormonal secretions in the rodent

GPR40 agonists are effective antidiabetic agents believed to lower glucose through direct effects on the beta cell to increase glucose stimulated insulin secretion. However, not all GPR40 agonists are the same. Partial agonists lower glucose through direct effects on the pancreas, whereas GPR40 AgoPAMs may incorporate additional therapeutic effects through increases in insulinotrophic incretins secreted by the gut. Here we describe how GPR40 AgoPAMs stimulate both insulin and incretin secretion in vivo over time in diabetic GK rats. We also describe effects of AgoPAMs in vivo to lower glucose and body weight beyond what is seen with partial GPR40 agonists in both the acute and chronic setting. Further comparisons of the glucose lowering profile of AgoPAMs suggest these compounds may possess greater glucose control even in the presence of elevated glucagon secretion, an unexpected feature observed with both acute and chronic treatment with AgoPAMs. Together these studies highlight the complexity of GPR40 pharmacology and the potential additional benefits AgoPAMs may possess above partial agonists for the diabetic patient.

GPR40 reduces food intake and body weight through GLP-1

G protein-coupled receptor 40 (GPR40) partial agonists lower glucose through the potentiation of glucose-stimulated insulin secretion, which is believed to provide significant glucose lowering without the weight gain or hypoglycemic risk associated with exogenous insulin or glucose-independent insulin secretagogues. The class of small-molecule GPR40 modulators, known as AgoPAMs (agonist also capable of acting as positive allosteric modulators), differentiate from partial agonists, binding to a distinct site and functioning as full agonists to stimulate the secretion of both insulin and glucagon-like peptide-1 (GLP-1). Here we show that GPR40 AgoPAMs significantly increase active GLP-1 levels and reduce acute and chronic food intake and body weight in diet-induced obese (DIO) mice. These effects of AgoPAM treatment on food intake are novel and required both GPR40 and GLP-1 receptor signaling pathways, as demonstrated in GPR40 and GLP-1 receptor-null mice. Furthermore, weight loss associated with GPR40 AgoPAMs was accompanied by a significant reduction in gastric motility in these DIO mice. Chronic treatment with a GPR40 AgoPAM, in combination with a dipeptidyl peptidase IV inhibitor, synergistically decreased food intake and body weight in the mouse. The effect of GPR40 AgoPAMs on GLP-1 secretion was recapitulated in lean, healthy rhesus macaque demonstrating that the putative mechanism mediating weight loss translates to higher species. Together, our data indicate effects of AgoPAMs that go beyond glucose lowering previously observed with GPR40 partial agonist treatment with additional potential for weight loss.

GPR40 partial agonist MK-2305 lower fasting glucose in the Goto Kakizaki rat via suppression of endogenous glucose production

GPR40 (FFA1) is a fatty acid receptor whose activation results in potent glucose lowering and insulinotropic effects in vivo. Several reports illustrate that GPR40 agonists exert glucose lowering in diabetic humans. To assess the mechanisms by which GPR40 partial agonists improve glucose homeostasis, we evaluated the effects of MK-2305, a potent and selective partial GPR40 agonist, in diabetic Goto Kakizaki rats. MK-2305 decreased fasting glucose after acute and chronic treatment. MK-2305-mediated changes in glucose were coupled with increases in plasma insulin during hyperglycemia and glucose challenges but not during fasting, when glucose was normalized. To determine the mechanism(s) mediating these changes in glucose metabolism, we measured the absolute contribution of precursors to glucose production in the presence or absence of MK-2305. MK-2305 treatment resulted in decreased endogenous glucose production (EGP) driven primarily through changes in gluconeogenesis from substrates entering at the TCA cycle. The decrease in EGP was not likely due to a direct effect on the liver, as isolated perfused liver studies showed no effect of MK-2305 ex vivo and GPR40 is not expressed in the liver. Taken together, our results suggest MK-2305 treatment increases glucose stimulated insulin secretion (GSIS), resulting in changes to hepatic substrate handling that improve glucose homeostasis in the diabetic state. Importantly, these data extend our understanding of the underlying mechanisms by which GPR40 partial agonists reduce hyperglycemia.

Design and Synthesis of Novel, Selective GPR40 AgoPAMs

GPR40 is a G-protein-coupled receptor expressed primarily in pancreatic islets and intestinal L-cells that has been a target of significant recent therapeutic interest for type II diabetes. Activation of GPR40 by partial agonists elicits insulin secretion only in the presence of elevated blood glucose levels, minimizing the risk of hypoglycemia. GPR40 agoPAMs have shown superior efficacy to partial agonists as assessed in a glucose tolerability test (GTT). Herein, we report the discovery and optimization of a series of potent, selective GPR40 agoPAMs. Compound 24 demonstrated sustained glucose lowering in a chronic study of Goto Kakizaki rats, showing no signs of tachyphylaxis for this mechanism.

Discovery of benzofuran propanoic acid GPR120 agonists: From uHTS hit to mechanism-based pharmacodynamic effects

The transformation of an aryloxybutanoic acid ultra high-throughput screening (uHTS) hit into a potent and selective series of G-protein coupled receptor 120 (GPR120) agonists is reported. uHTS hit 1 demonstrated an excellent rodent pharmacokinetic profile and selectivity over the related fatty acid receptor GPR40, but only modest GPR120 potency. Optimization of the "left-hand" aryl group led to compound 6, which demonstrated a GPR120 mechanism-based pharmacodynamic effect in a mouse oral glucose tolerance test (oGTT). Further optimization gave rise to the benzofuran propanoic acid series (exemplified by compound 37), which demonstrated acute mechanism-based pharmacodynamic effects. The combination of in vivo efficacy and attractive rodent pharmacodynamic profiles suggests compounds generated from this series may afford attractive candidates for the treatment of Type 2 diabetes.

Bcnu plus teniposide (vm26) as a 1st line chemotherapy for brain metastases regardless of the origin

Twenty-nine patients with brain metastases regardless of the origin were treated with the combination of 1-3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), 120 mg/m2 i.v. every six weeks, and teniposide (VM26), 100 mg/m2 i.v. on the days 1 and 2 of every three-week period. Five objective responses were obtained (17%), four of them being partial and one complete. The latter was observed in a patient suffering from breast cancer, and still remains free of the disease after three years follow-up. The median survival time for the whole group is 14.6 weeks. Twelve more patients (41%) had symptomatic improvement related to chemotherapy. The treatment was well tolerated and only mild and reversible toxicity was observed. A global 58% (17% plus 41%) symptomatic improvement was observed.

Gemcitabine (G) fixed-dose-rate infusion (FDR) plus erlotinib (E) in patients with advanced pancreatic cancer (APC)

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Background: G (30-minute infusion) plus E improves survival in patients with APC compared with G alone. In a recent phase III trial, G-FDR showed a trend to better OS compared with standard G (6.2 vs. 4.9 months, HR 0.83, p=0.04), although the study was underpowered to detect great difference in OS. Based on our previous experience with G-FDR, we decided to evaluate the combination of G-FDR plus E, after E approval for APC.

Methods: Patients with previously untreated pathologically confirmed APC, locally advanced (LAPC) or metastatic (MPC), and ECOG PS 0-2 were included. G 1500 mg/m2 was given by 150-min infusion (10 mg/m2/min) on days 1, 8, and 15 every 28 days combined with E 100 mg/day orally. Treatment modifications for G-FDR were planned according with previously Tempero's phase II trial, and as described in prescribing information for E.

Results: 62 pts were included (36M/26F), with a median age of 63 y-o (range 37-78). ECOG PS 0/1/2: 19/40/3. LAPC/MPC: 16/46. All except one had measurable disease. ORR was 13% (8 PR), 95% CI: 4.7-21.3, and there were 34 (55%) SD. Mean relative dose intensity for G was 0.76 and 0.90 for E. Main hematologic toxicities 3/4 per pt: anaemia 12/0, thrombocytopenia 7/4, neutropenia 18/7. Acneiform rash 1/2/3 occurred in 16/16/3 pts. Other relevant adverse events were (grade 2/3/4): diarrhoea 18/3/0, mucositis 5/1/0, infection 9/8/1, thrombosis 1/4/1 and vomiting 6/4/0. There were three treatment-related deaths (septic shock, cholangitis, and bilateral pulmonary embolism). Ten pts (all LAPC) received RT after ≤ 6 cycles, all with concomitant capecitabine 825 mg/m2 bid. In 4 pts salvage surgery were performed: 2 R0, 1 R1 and 1 R2. Median PFS was 4.9 months (95% CI: 3-6.7), 7.9 m for LAPC and 2.5 m for MPC (p = 0.004). Median OS was 10 months (95% CI: 7.1-12.9), 17.5 m for LAPC and 7 m for MPC (p = 0.019). OS was significantly shorter in males (p = 0.01) and in pts taking major opioids (p = 0.027). There was a trend to better OS in pts who developed skin rash grade ≥ 2 (p = 0.078).

Conclusions: In this noncomparative study, G-FDR plus E is a feasible regimen in APC with an acceptable toxicity and notable activity. G-FDR seems to increase hematologic toxicity compared with standard infusion.

No significant financial relationships to disclose.

Induction cisplatin, paclitaxel, and 5FU (PTF) before definitive local therapy for locally advanced esophageal squamous cell carcinoma (SCC)

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Background: Induction chemotherapy for locally advanced oesophageal SCC is controversial. Triple combination is under study with promising results. We analyse induction therapy with PTF before local definitive therapy in terms of response, resectability, toxicity and survival.

Methods: Pts diagnosed of locally advanced oesophageal SCC have been included. Treatment schedule: paclitaxel 175 mg/m2 and CDDP 75 mg/m2 on day 1 and 5FU 800 mg/m2/day days 1-4, every 28 days. After 2-3 cycles surgery is considered. If unresectable, radical radiotherapy (64 Gy) and concomitant carboplatin (60 mg/m2, d 1–5 during 1st, 4th and, if feasible, 7th week of RT) are administered.

Results: From May-02 to Feb-10 48 pts have been treated (44M, 4F). Age: 56,7 (32–70). PS 0-1: 8-40. Location: Upper: 14, Middle: 25, Distal: 8, Whole: 1. T2/3/4:1/26/21, N0/1: 12/36. M1a: 6. Weight loss over 10 kg: 11 pts. Cycles delivered: 140; median 3. Toxicity (episodes): Anemia 3: 1. Emesis 3: 2. Mucositis 3: 2. Asthenia 2-3: 8. Two pts died in remission (one of them with a pCR at necropsy) due to gastrostomy complications and oesophagus-tracheal fistula, treatment related. Two pts developed oesophagus-tracheal fistula as a late event after response to therapy. Response rates: CR 7 (14.6%), PR 16 (33.3%), SD 18 (37.5%), PD 7 (14.6%). Treatment after PTF: Surgery 14 pts (1 upper, 9 middle, 4 distal). One (distal) unresectable at surgery, one (middle) not resected because of liver cirrhosis, two not resected because of liver metastases, unexpected findings at surgery. pCR: 2. pPR 8 (R0: 7, R1: 1). Chemoradiation: 25, improving 2 SD to PR, 4 PR to CR and 3 SD to CR. One PR and 4 SD progressed immediately after chemoradiation. Progression: 33 (local 14, systemic 11, both 8); died: 34. Median progression free survival: 35.7 weeks (95% CI 30.2-41.2). Median overall survival: 50.7 weeks (95% CI 35.2-66.1).

Conclusions: Induction PTF has a good toxicity profile with a high response rate and disease control during therapy. Surgical rescue is possible in middle and distal tumours. Local definitive therapy with chemoradiation is the best approach for unresectable or upper third tumours.

No significant financial relationships to disclose.

Second-line chemotherapy with capecitabine (CAP) and oxaliplatin (OX) in patients with pancreatic or biliary tree adenocarcinoma (ADC)

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Background: Pancreatic and biliary tree ADC represent poor prognostic tumors. Gemcitabine is usually considered the first- line chemotherapy and after that no standard treatment has been established. CAP and OX have demonstrated some activity in metastatic (M1) and locally advanced (LA) pancreatic cancer, and the combination of these drugs confers additional benefit as well. We conducted this study in order to establish the efficacy of this schedule on pancreatic and biliary tree ADC.

Methods: Pts with M1 or LA pancreatic or biliary tree ADC with progression to one previous chemotherapy treatment were included. Performance status≤2, age≥18 years and adequate renal and hepatic function were selected. Schedule of chemotherapy: CAP 1000 mg/m2 bid on days 2 to 15 and OX 130 mg/m2 on day 1 of a 3-week cycle. RECIST criteria were used for assessment of response and NCI-CTCAE v 3.0 for toxicity.

Results: Between April 2006 and March 2010, 40 pt were included. Male/female: 29/11. Mean age: 60.7 years (37-74). Pancreatic/biliary: 23/17. PS 0/1/2: 3/27/10. LA/ M1: 1/39. Mean number of cycles: 2.50 (1-10). Disease response per pt, partial/ stable disease/progression/not evaluated: 1/9/21/9. Tumor control (partial/stable disease): 10 pt (22%). Hematologic toxicity (grade1/2/3/4) (%) per pt: neutropenia 5/2.5/7.5/0; thrombocytopenia 15/5/2.5/5; anemia 42.5/10/52.5/0. Nonhematologic toxicity (grade 1/2/3) (%) per pt: asthenia 10/45/17.5; emesis 22.5/15/2.5.; anorexia 12.5/35/7.5; diarrhea 7.5/12.5/5; neurotoxicity 42.5/17.5/2.5; hand-foot syndrome 5/2.5/2.5. One toxic death was reported. Median time to progression: 15 weeks (95% CI 6.6-23.3). Median survival time: 19 weeks (95% CI 10.4-27.5). For pts with PS0 or 1 median overall survival was 23 weeks (95% CI 6.3-39.6) and for pts with PS2 was 8 weeks (95% CI 5.3-1.6) (p 0.004).

Conclusions: Advanced pancreatic and biliar ADC have unfavorable prognosis. After first-line treatment, CAPOX shows a tolerable toxicity and some activity and it can represent an alternative on selected pretreated pts.

No significant financial relationships to disclose.