Gastrimmune-induced antigastrin-17 antibodies inhibit acid secretion in a rat fistula model

Advances in gastrointestinal pharmacotherapy

The medical management of patients with gastrointestinal diseases is advancing rapidly. At a recent symposium held during Digestive Disease Week in Chicago in May of 2005, specific attention was given to the future prospects for medical management of 3 common gastrointestinal disease areas: antisecretory therapy, chronic hepatitis C, and inflammatory bowel disease. Antisecretory approaches include drug combinations including a proton pump inhibitor, potassium competitive acid blockers, and antigastrin agents. The latter two classes are still experimental, but the former combinations have potential to enhance the highly effective agents currently available. The focus of treatment advances in chronic hepatitis C in the immediate future is the discovery of more effective treatment regimens for nonresponders to prior therapy, who are becoming the largest group of patients seeking treatment of hepatitis C. The combination of peginterferon with ribavirin results in 6%-15% sustained virologic response rates in patients who were prior nonresponders to standard interferon plus ribavirin. Newer strategies to eradicate hepatitis C virus infection using different interferons, such as interferon alfacon-1 or higher doses of peginterferon, or long-term maintenance peginterferon, are undergoing study and show promise based on data from preliminary studies. Several immunomodulators have promise in inflammatory bowel disease, although the risk-benefit ratio and costs of therapy require evaluation. Nevertheless, the success of new biologics such as anti-TNFalpha agents augurs well for effective future therapies.

New Investigational Therapies for Gastroesophageal Reflux Disease

Although PPI have revolutionized the treatment of GERD and its complications, many patients continue to have breakthrough symptoms and take antacids and H2RA. Furthermore, acid reflux actually is the innocent bystander, with few drugs available to target the true culprit, a dysfunctional LES. Future development of treatments, such as the GABA(B) agonists, which reduce TLESR, may prove an important advance in the therapy of GERD by controlling acid and nonacid reflux better. The chemical, pharmacodynamic, and clinical limitations of PPI may be addressed by the development of innovative drugs, such as the P-CAB or gastrin vaccine, to control acid secretion. Which of these drugs, if any, will be the new GERD drug for the millennium is unknown. There is no question, however, that improved drug treatments will parallel a better understanding of the complicated pathophysiology of GERD.

Review article: new pharmacological agents for the treatment of gastro-oesophageal reflux disease

Proton pump inhibitors, which act at the terminal point of acid secretion--the H+, K+-ATPase--are currently the most effective pharmacological treatments available for reflux disease. Despite the efficacy of the proton pump inhibitors, there is still potential for clinical improvement in gastro-oesophageal reflux disease pharmacotherapy. Faster onset of complete acid inhibition and improved duration of efficacy are two potential areas for improvement A number of novel pharmaceutical agents are currently undergoing clinical evaluation for the treatment of gastro-oesophageal reflux disease. These include transient lower oesophageal sphincter relaxation-reducing agents, serotonergic agents/prokinetics, potassium-competitive acid blockers, mucosal protectants, histamine H3 agonists and anti-gastrin agents. One or more of these drug groups may represent the future medical therapy for gastro-oesophageal reflux disease, should they prove effective in the clinical setting. This review summarizes the state of the art with these agents.

Therapeutic vaccination to block receptor-ligand interactions

Many chronic diseases are caused by non-physiological interactions of certain ligands with their receptors. Conventional treatment of these diseases with synthetic drugs or monoclonal antibodies (mAbs) is efficient, but problematic due to the non-compliance of patients and the risk of adverse side effects. Novel therapeutic approaches are focusing on strategies of active immunisation aimed at the induction of a humoral immune response directed against the deleterious receptor-ligand interaction. Autoantibody production has been achieved by several vaccine formulations, including conjugates of self-antigens to foreign T helper (Th) cell epitopes, virus-like particles coated with self-antigens, and naked DNA vectors. All of these approaches have the potential to be developed for clinical use if important safety issues, related to the possible long-term presence of self-reactive antibodies in the serum of vaccinated individuals and the risk of undesired T cell responses, can be properly addressed.