Clinical trial: levofloxacin-based quadruple therapy was inferior to traditional quadruple therapy in the treatment of resistant Helicobacter pylori infection

BACKGROUND

The efficacy of levofloxacin-based quadruple therapy in resistant Helicobacter pylori infection is not known.

AIM

To test the efficacy of levofloxacin-based quadruple therapy and traditional quadruple therapy in resistant H. pylori infection.

METHODS

One hundred and two patients with resistant H. pylori infection were randomized to 1 week of either EBAL (esomeprazole 40 mg b.d., bismuth subcitrate 240 mg b.d., amoxicillin 1 g b.d. and levofloxacin 500 mg b.d.) or EBMT (esomeprazole 40 mg b.d., bismuth subcitrate 240 mg b.d., metronidazole 400 mg t.d.s. and tetracycline 500 mg q.d.s.). (13)C-urea breath test was performed at week 12 to assess post-treatment H. pylori status.

RESULTS

In intention-to-treat analysis H. pylori eradication was achieved in 37 of 51 (73%) subjects in EBAL and 45 of 51 (88%) subjects in EBMT groups, respectively (P = 0.046). Per-protocol eradication rates of EBAL and EMBT groups were 78% and 94%, respectively (P = 0.030). The intention-to-treat eradication rate was statistically lower for EBAL than EMBT (56% vs. 90%, P = 0.013) among those who had failed more than one course of eradication therapy. Previous levofloxacin triple therapy did not affect the efficacy of either protocol significantly.

CONCLUSIONS

Levofloxacin-based quadruple therapy was inferior to traditional quadruple therapy for resistant H. pylori infection.

Leptin improves pulmonary bacterial clearance and survival in ob/ob mice during pneumococcal pneumonia

The adipocyte-derived hormone leptin is an important regulator of appetite and energy expenditure and is now appreciated for its ability to control innate and adaptive immune responses. We have reported previously that the leptin-deficient ob/ob mouse exhibited increased susceptibility to the Gram-negative bacterium Klebsiella pneumoniae. In this report we assessed the impact of chronic leptin deficiency, using ob/ob mice, on pneumococcal pneumonia and examined whether restoring circulating leptin to physiological levels in vivo could improve host defences against this pathogen. We observed that ob/ob mice, compared with wild-type (WT) animals, exhibited enhanced lethality and reduced pulmonary bacterial clearance following Streptococcus pneumoniae challenge. These impairments in host defence in ob/ob mice were associated with elevated levels of lung tumour necrosis factor (TNF)-alpha, macrophage inflammatory peptide (MIP)-2 [correction added after online publication 28 September 2007: definition of MIP corrected], prostaglandin E(2) (PGE(2)), lung neutrophil polymorphonuclear leukocyte (PMN) counts, defective alveolar macrophage (AM) phagocytosis and PMN killing of S. pneumoniae in vitro. Exogenous leptin administration to ob/ob mice in vivo improved survival and greatly improved pulmonary bacterial clearance, reduced bacteraemia, reconstituted AM phagocytosis and PMN H(2)O(2) production and killing of S. pneumoniae in vitro. Our results demonstrate, for the first time, that leptin improves pulmonary bacterial clearance and survival in ob/ob mice during pneumococcal pneumonia. Further investigations are warranted to determine whether there is a potential therapeutic role for this adipokine in immunocompromised patients.

Correlation of survival with tumor histology, age, and prognostic risk group for previously untreated patients with advanced renal cell carcinoma (adv RCC) receiving temsirolimus (TEMSR) or interferon-alpha (IFN)

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Background: Temsirolimus is a novel mTOR inhibitor and has demonstrated significantly longer overall survival (OS, P=0.0069) and progression-free survival (PFS, P=0.0001) vs IFN for patients (pts) with previously untreated adv RCC with poor-risk features (Hudes et al. ASCO 2006). Planned and post-hoc analyses were performed to assess the influence of tumor histology (clear- cell vs other), age (<65 y vs =65 y), and prognostic-risk groups (intermediate vs poor; Motzer et al. JCO 20:289) on survival in pts treated with TEMSR or IFN. Methods: Pts received IFN 3 million units [MU] subcutaneously 3x weekly, escalating to 18 MU; TEMSR 25-mg intravenous infusion weekly; or TEMSR 15-mg infusion plus IFN 6 MU. Kaplan-Meier analysis and a Cox proportional hazards model were used to analyze OS and PFS for pt subsets. Histologies were reported by investigators. Results: The proportion of pts with different histologies was balanced across the 2 arms (81% clear-cell; 13% indeterminate, 6% non-clear-cell). Of those with additional subtype data, 75% were papillary. For pts with clear-cell tumors, median OS and PFS were longer for TEMSR vs IFN with hazard ratios (HR) of 0.82 and 0.76, respectively ( Table ). For pts with other tumor histologies, median OS and PFS also were longer for TEMSR vs IFN with HR of 0.49 and 0.38, respectively. Among pts <65 y, median OS and PFS were longer for TEMSR than for IFN (OS: TEMSR [n=145] 12.0 mo; IFN [n=142] 6.9 mo; HR=0.62 [95% CI, 0.47, 0.82]; PFS: TEMSR 5.6 mo; IFN 3.1 mo; HR=0.61 [0.47, 0.79]). There was no difference in OS or PFS for pts =65 y treated with TEMSR or IFN but TEMSR had a better side effect profile than IFN. OS and PFS for pts with intermediate- or poor-risk features will be reported. Conclusions: TEMSR benefits pts with clear-cell RCC and other histologies as well as younger and older pts.

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No significant financial relationships to disclose.

A phase I/II trial of sorafenib (S) with bevacizumab (B) in metastatic renal cell cancer (mRCC) patients (Pts)

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Background: In an effort to enhance the efficacy of vascular endothelial growth factor (VEGF) pathway blockade in mRCC we initiated a Phase I-II trial of combination S and B to block VEGFR signaling and VEGF binding, as well as, platelet derived growth factor receptor β (PDGFR) signaling. Methods: Pts with measurable (RECIST) mRCC, adequate organ function, and PS 0–1 were eligible for this trial. Cohorts of 6 pts were enrolled at 3 sites to define the MTD and DLT of the combination of S and B. The schedule was B IV q 14 days and S daily with cycles of 28 days. Response and toxicity were assessed at the end of 2 cycles. Dose levels began with S at 200mg BID and B at 5 mg/kg (level 1) with the hope to reach phase II doses of both agents (S at 400mg BID and B at 10mg/kg). The MTD or the phase II dose of each agent would then be administered to up to 45 pts with mRCC, clear cell histology, and prior nephrectomy. Results: A total of 18 patients have been enrolled to date, with 15 completing their first response evaluation. Pts were median age 61 years (46–74 range); M/F: 15/3; PS: 0/1= 12/6; 17 clear cell, 1 chromophobe, 11 prior nephrectomy; 4 with prior cytokine therapy. Two pts in level 1 experienced DLT with recurrent and intolerable (grade 3) hand-foot syndrome (HFS). An additional 6 patients were treated at dose level -1 (S at 200mmg QD and B at 3mg/kg) with no DLTs. Six more pts have been treated at dose level 1 with Vit B6 at 300mg/d in an attempt to minimize HFS. Toxicity data in this cohort is incomplete. Additional toxicities among the 18 pts included grade 3 hypertension (4), grade 3 proteinuria (2), and grade 2 stomatitis (3). Responses including 4 objective PRs, and 4 pts with 20–30% regression have been seen in the 14 evaluated pts. Only 2 patients have had disease progression. Conclusions: The phase II doses for this combination have not yet been established, but will likely be lower than the full phase II doses of the individual agents. The toxicities from HFS (primarily) and hypertension and stomatitis appear to be limiting. Even at the initial low doses of S and B, significant anti-tumor activity has been observed. The completion of this phase I trial will be reported. The phase II studies in mRCC are highly anticipated. Support by phase I contract UO-1 CA099177

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Streptozotocin-induced diabetes in the rat is associated with enhanced tissue hydrogen sulfide biosynthesis

This investigation is aimed to determine whether the biosynthesis of H(2)S, an endogenous vasodilator gas, is altered in the streptozotocin-diabetic rat. Plasma H(2)S concentration as well as the activity, and expression, of H(2)S synthesizing enzymes (namely cystathionine-gamma-lyase (CSE) and cystathionine-beta-synthetase (CBS)) were measured in various tissues of non-diabetic, streptozotocin-diabetic and insulin-treated diabetic rats. H(2)S formation in pancreas and liver was increased in diabetic rats. Both CSE and CBS mRNAs were increased in liver of diabetic animals. Similarly, CBS mRNA was increased in pancreas. Insulin treatment restored the changes in H(2)S metabolism seen. The findings of this study suggest that the metabolism of H(2)S in pancreas and liver is altered in the streptozotocin-diabetic rat. This is the first study in which a derangement in H(2)S biosynthesis in diabetes has been demonstrated. H(2)S may play a part in the aetiology or development of diabetes in this animal model.