A nickel-catalysed reductive cross-coupling reaction between benzyl sulfonium salts and benzyl bromides is reported. Simple, stable and readily available sulfonium salts have shown their ability as leaving groups in cross-electrophile coupling, allowing the formation of challenging sp 3 -sp 3 carbon-carbon bonds, towards the synthesis of interesting dihydrostilbene derivatives. In addition, benzyl tosyl derivatives have been demonstrated to be suitable substrates for reductive cross-coupling by in-situ formation of the corresponding sulfonium salt.
Background
Loss of response to anti-TNF (tumor necrosis factor) therapies in inflammatory bowel disease occurs in a high proportion of patients. However, the precise incidence of dose intensification (DI) and its effectiveness remains unclear. Our aims were: 1) To evaluate the need of DI of anti-TNF therapy either by increasing the dose or decreasing doses’ interval; 2) To evaluate possible variables influencing its requirement; 3) To assess the effectiveness of empirical DI.
Methods
Bibliographical searches were performed in Pubmed, Embase, the Cochrane Library and CINAHL. Selection: prospective and retrospective studies assessing loss of response to anti-TNF therapy, considered as the need of DI, in Crohn’s disease (CD) and ulcerative colitis (UC) patients treated for at least 12 weeks with an anti-TNF drug [infliximab (IFX), adalimumab (ADA), certolizumab or golimumab]. Exclusion criteria: studies using anti-TNF as prophylaxis for postoperative recurrence in CD or those where DI was based on therapeutic drug monitoring. Data synthesis: Effectiveness by intention-to-treat (random effects model). Data were stratified by medical condition (UC vs. CD), anti-TNF drug and follow-up. Subgroup analyses were performed to explore heterogeneity.
Results
In total, 174 studies (32,031 patients) were included. The overall rate of DI requirement after 12 months follow-up was 27% (95%CI 23-31, I2=96%, 51 studies) in naïve patients and 38% (95%CI 31-46, I2=87%, 18 studies) in non-naïve patients. The rate of DI requirement was higher in patients with prior anti-TNF exposure (c²=6.5, P=0.01) and in UC patients (c²=4.7, P=0.03). The rate of DI requirement in naïve patients after 36 months follow-up was 35% (95%CI 27-43%; I2=98%; 22 studies). The overall short-term response and remission rates to empirical DI in naïve patients were 66% (95%CI 61-71%; I2=81%; 35 studies) and 48% (95%CI 35-62%; I2=97%; 27 studies), respectively. Subgroup analyses are presented in the tables.
Conclusion
Loss of response to anti-TNF agents ―and consequent DI― occur frequently in IBD (approximately in 1/4 at one year and in 1/3 at 3 years). DI requirement is higher in UC patients and in those with prior anti-TNF exposure. Empirical DI is a relatively effective therapeutic option.
Background
Loss of response to anti-TNF therapies in inflammatory bowel disease occurs in a high proportion of patients. However, the precise incidence of dose intensification (DI) and its effectiveness remain unclear. Our aims were: (1) To evaluate the need of DI of anti-TNF therapy either by increasing the dose or decreasing doses’ interval; (2) To evaluate possible variables influencing its requirement; (3) To assess the effectiveness of empirical DI.
Methods
Bibliographical searches were performed until January 2019. Selection: prospective and retrospective studies assessing the loss of response to anti-TNF therapy, considered as the need of DI, in Crohn’s disease (CD) and ulcerative colitis (UC) patients treated for at least 12 weeks with an anti-TNF drug. Exclusion criteria: Studies using anti-TNF as prophylaxis for postoperative recurrence in CD or those where DI was based on therapeutic drug monitoring. Data were analyzed by means of the inverse variance method using a random effect model and stratifying by medical baseline condition (UC vs. CD), anti-TNF drug and follow-up. Effectiveness was assessed by intention-to-treat analysis.
Results
Up to now, 107 studies (11,377 patients) were included. The overall rate of DI requirement for naïve patients after 12 and 36 months of follow-up was 35% (95% CI=26–45%, I2=95%, 15 studies) and 48% (41–55%, I2= 77%, 9 studies); respectively. Frequencies of DI requirement stratified by subgroup analysis are presented in the table (all patients being naïve except CD patients treated with adalimumab (ADA), including naïve and no naïve).
The overall short-term response and remission rates to empirical DI were 67% (95% CI: 63–72%; I2=73%; 31 studies) and 45% (95% CI: 35–55%; I2=9%; 23 studies), respectively; subgroup analyses are summarised in the table.
Conclusion
Loss of response to anti-TNF agents and consequent DI occurs frequently in both UC and CD, with an overall rate of DI requirement of 35% at one year and 48% at 3 years. Empirical DI is a relatively effective therapeutic option. Further data extraction and analysis is necessary to confirm these findings.
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