Gastrointestinal safety of amtolmetin guacyl in comparison with celecoxib in patients with rheumatoid arthritis Z. Jajic´, M. Malaise, K. Nekam, É. Koó, K. Dankó, M. Kovacs, C. Scarpignato1 Department for Rheumatology, Physical Medicine and Rehabilitation, Medical Faculty University of Zagreb, Referral Centre for Inflammatory Rheumatic Disease, Zagreb, Croatia; 1Laboratory of Clinical Pharmacology, School of Medicine and Dentistry, University of Parma, Parma, Italy. Multicentre Study from the Department of Rheumatology, Physical Medicine and Rehabilitation, Medical Faculty University, Zagreb (Croatia); Department of Rheumatology, University of Liege, Liege (Belgium); Department of Clinical Medicine III, Carl Gustav University, Dresden (Germany); Department of Rheumatology, Clinical Medi- cine IV, Carl-Thiem Clinic, Cotbus (Germany); Department of Rheumatology, Hospital of Horovice, Horovice (Czech Republic); Department of Rheumatology, University Hospital, Klimentskà Polyclinic, Prague (Czech Republic); Department of Allergology and Immunology and Department of Rheumatology II, Polyclinic of the Hospitaller Brothers of St. John of God in Budapest, Budapest (Hungary); Department of Internal Medicine 1, County Hospital of Zala, Zalaegerszeg (Hungary); Department of Rehabilitation, “Markusovsky” Hospital and outpatient Clinic of Vas County, Szombathely (Hungary); University of Debrecen, Medical and Health Science Centre, Institute for Internal Medicine, III Department, Division of Immunology, Debrecen (Hungary) Abstract Objective Selective inhibitors of cyclo-oxygenase-2 (COX-2) appear to be safer than conventional NSAIDs on the gastrointestinal (GI) tract. Amtolmetin guacyl (AMG), a NSAID that inhibits both COX-1 and COX-2, has an anti-inflammatory effect compara- ble to that of traditional NSAIDs, with a better GI safety profile. The primary end-point of this study was to evaluate the gas- trointestinal safety of amtolmetin guacyl in comparison with celecoxib in patients affected with rheumatoid arthritis. The assessment of efficacy was the secondary end-point. Methods This study was a 24-week, randomized, parallel group, double-blind, double dummy, multicentre trial; 235 patients were enrolled and 180 patients (85 in the AMG group and 95 in the celecoxib group) completed the study. Each patient received twice daily amtolmetin guacyl 600 mg or celecoxib 200 mg. Assessment of safety was performed by upper GI endoscopy, gastrointestinal symptoms evaluation, electrocardiography, blood and urine laboratory tests, adverse events recording. Assessment of efficacy was performed by using the American College of Rheumatology (ACR-20) responder index. Results Neither amtolmetin guacyl nor celecoxib determined a worsening of baseline gastro-duodenal endoscopy findings. The per- centage of patients with normal findings did not significantly change after treatment with both drugs, being virtually identi- cal with AMG (i.e. 75.29%) and increasing from 75.79% to 77.66% with celecoxib. Moreover an evaluation of the other safety parameters did not reveal any difference between the two treatment groups. Therapeutic efficacy was equivalent in both groups, with no statistical difference between the two drugs at all time intervals. Conclusions In patients affected with rheumatoid arthritis, AMG and celecoxib proved to be equivalent, showing comparable gastrointestinal safety and therapeutic efficacy of treatment. Key words Amtolmetin guacyl (AMG), celecoxib, NSAIDs, gastrointestinal safety, rheumatoid arthritis. Clinical and Experimental Rheumatology 2005; 23: 809-818. Safety and efficacy of amtolmetin guacyl and celecoxib / Z. Jajic´ et al. Zrinka Jajic´, MD, PhD; Michel Malaise, Introduction essentially associated with similar dam- MD, PhD; Kristof Nekam, MD, PhD; Rheumatoid arthritis is an autoimmune age. The strength of this idea is that it is Éva Koó, MD, PhD; Katalin Dankó, MD, disease characterized by chronic joint simple; there are reasonable associa- PhD, Monika Kovacs, MD; Carmelo inflammation with a fluctuating course tions between NSAID-induced reduc- Scarpignato, MD, DSc, PharmD. that can lead to progressive and des- tions in mucosal prostaglandin levels Please address correspondence and re- tructive arthropathy, followed by defor- and the damage ,and one report (13) print requests to: Prof. Zrinka Jajic´, MD, mities and disability (1, 2). Its manage- suggests that antibodies directed against Department for Rheumatology, Physical Medicine and Rehabilitation, Medical ment involves the use of new and tradi- COX cause in rabbits damage to the Faculty University of Zagreb, Referral tional disease-modifying anti-rheumat- gastrointestinal tract that is identical to Centre for Inflammatory Rheumatic ic drugs (DMARDs) (3), which can that induced by NSAIDs. Disease, Vinogradska c. 29, 10000 affect the course of the disease, and After the discovery of the two COX iso- Zagreb, Croatia. E-mail: [email protected] non-steroidal anti-inflammatory drugs forms (that is COX-1 and COX-2) com- Received in February 11, 2005; accepted (NSAIDs), which provide symptomatic pounds specifically designed to inhibit in revised form on July 14, 2005. relief by controlling pain and inflamma- COX-2, sparing COX-1 at therapeutic © Copyright CLINICAL AND EXPERIMEN- tion. Although these latter compounds doses, have been developed. Although TAL RHEUMATOLOGY 2005. represent a very effective class of drugs, increasing evidence indicates that also their use is associated with a broad COX-2 is normally expressed in the spectrum of untoward reactions in the mucosa of the digestive tract where it liver, kidney, skin and gut (4, 5); gas- plays a physiological role, assisting the trointestinal (GI) side effects are, how- housekeeping action of COX-1 in gas- ever, the most common adverse event troprotection (14, 15), the so-called encountered with this class of drugs (6- “selective COX-2 inhibitors” display a 10). GI problems encompass a wide significantly improved risk-benefit ratio range of different clinical pictures, compared with non-selective NSAIDs. spanning from mild symptoms such as Indeed, COX-1 expression represents dyspepsia, heartburn and abdominal the dominant isoform in healthy mucosa discomfort to more serious events, like (14) and PGs generated by COX-2 be- peptic ulcer and its life-threatening come important only during ulcer heal- complications, bleeding and perfora- ing (14, 15) and in the presence of Heli- tion. Indeed, gastroduodenal mucosa cobacter pylori infection (14,16). In ad- possesses an array of defensive mecha- dition, it is worth mentioning that selec- nisms and NSAIDs have a deleterious tive COX-2 inhibitors, like celecoxib effect on most of them (11). and rofecoxib, besides sparing PG syn- These drugs appear to cause gastroduo- thesis in the GI mucosa, do not display denal damage by two main mecha- any topical irritancy as they are non- nisms: a physiochemical disruption of acidic, nor do they increase gastric or the gastric mucosal barrier and a sys- intestinal permeability or cause mucosal temic inhibition of gastric mucosal pro- inflammation (17). Their failure to sig- tection, through inhibition of cyclo- nificantly affect the two basic biochem- oxygenase (prostaglandin endoperoxide ical mechanisms of NSAID-induced G/H synthase, COX) activity of the GI damage may account for their remark- mucosa. A reduced synthesis of mucus able GI tolerability. Large clinical trials and bicarbonate, an impairment of mu- have indeed demonstrated that they are cosal blood flow and an increase in acid as therapeutically effective as conven- secretion represent the main conse- tional NSAIDs (18,19), while being saf- quences of NSAID-induced prosta- er at gastroduodenal level (20,21). Not glandin (PG) deficiency (12). Addition- only have endoscopic studies shown a al mechanisms which may add to the significant reduction in the incidence of damage have been demonstrated. These gastric and duodenal ulcers (22, 23), but include the uncoupling of oxidative clinical trials have pointed out a signifi- phosphorylation, reduced mucosal cell cant reduction in peptic ulcer complica- proliferation and DNA synthesis as well tions . as neutrophil activation (12). The out- Amtolmetin guacyl (2-methoxyphenyl- standing candidate mechanism for initi- 1-methyl-5-p-methylbenzoyl-pyrrole- ating NSAID damage is their action to 2-acetamido acetate, AMG) is an inhibit cyclo-oxygenase-1 (COX-1) as NSAID (24) recently introduced into all conventional NSAIDs have this ac- the Italian market and approved for the tion (and not other agents) and all are treatment of rheumatoid arthritis, os- 810 Safety and efficacy of amtolmetin guacyl and celecoxib / Z. Jajic´ et al. teoarthritis, extra-articular rheumatism gastroprotective activity. percentage of gastrointestinal events and post-surgical pain. It affects both Taking all the above considerations in- induced by both treatments and fore- COX-1 and COX-2, the COX-2/COX- to account, this study was designed to seen dropouts. Since the number of pa- 1 selectivity ratio, evaluated in studies compare the GI safety and the clinical tients lost during the study was less using bovine aortic endothelial cells efficacy of AMG and celecoxib, a than that expected, the sample size was and LPS-stimulated macrophages, be- widely used and GI safe COX-2 selec- recalculated and the trial was stopped ing 4.4 (Vane et al., unpublished re- tive inhibitor, in patients affected by after the randomization of 235 patients sults). Like COX-2 selective com- rheumatoid