Commentary: Golimumab in Moderate-to-Severe Ulcerative Colitis.

In May 2013, golimumab (Simponi, Janssen), a new anti—tumor necrosis factor (TNF) agent, was approved by the US Food and Drug Administration (FDA) for treatment of adults with moderately to severely active ulcerative colitis. Historically, there has been a relative paucity of treatment options for ulcerative colitis as compared with Crohn’s disease. We have long had a third anti-TNF agent available for treatment of Crohn’s disease but not for ulcerative colitis. It even took a long time to formally test the first anti-TNF agent in ulcerative colitis, which finally occurred in the original ACT studies1 of infliximab (Remi-cade, Janssen); there had been many naysayers claiming that an anti-TNF agent would not work in ulcerative colitis. We used to think that ulcerative colitis was immunologically different from Crohn’s disease, which is why it was thought that a target other than TNF-α was needed to treat ulcerative colitis; we thought that ulcerative colitis and Crohn’s disease could not be immunologically identical because how else could it be explained that, at their extremes, the 2 diseases could look so different? However, we now know that these 2 diseases are very similar genetically. In fact, there is almost no genetic difference between ulcerative colitis and Crohn’s disease. Therefore, it should not be surprising that many of the treatments that work in one disease work in the other. Thus, I believe that patients should be considered responsive to anti-TNF agents until proven otherwise and that, for many patients, the issue is whether they received sufficient anti-TNF to achieve adequate trough and/or tissue levels. Infliximab was the first anti-TNF agent to be approved for treatment of ulcerative colitis and was shown to be reasonably effective for this indication. The initial studies of infliximab in ulcerative colitis were conducted in patients who were, by definition, naive to anti-TNF therapy.1 Then along came adalimumab (Humira, AbbVie), which was also shown to be reasonably effective in ulcerative colitis in clinical trials.2 The FDA has asked for more dose-finding studies to determine whether adalimumab would be more efficacious by using a higher dose in patients with ulcerative colitis. However, as we saw in many of the earlier anti-TNF studies in Crohn’s disease, once a second or third anti-TNF agent was used, the drug’s efficacy dropped off. This does not make scientific sense because if patients who had a previous response to a drug have already been preselected and are now being given the same class of drug, the population should be enriched for responders. Something else must be going on. One explanation is that patients who develop antibodies to one biologic agent will promptly develop antibodies to other biologic agents. Could it be that inhibiting TNF-α ultimately results in producing more TNF-α, and, thus, more of the second drug is needed to have a clinical effect? Accordingly, the adalimumab results3 were not quite as good as the infliximab results1 because 40% of the patients in the adalimumab clinical trial for ulcerative colitis (ULTRA) had previously been exposed to infliximab, and we know that patients previously exposed to an anti-TNF agent are not going to do as well as patients who are naive to anti-TNF agents. This is all germane to golimumab because one of the important points that readers need to keep in mind is that patients in the golimumab trial conducted by Sandborn and colleagues4 have not previously been on an anti-TNF agent. Although we should not compare study results directly between anti-TNF agents, the golimumab remission data at Week 6 and long term at Week 52 are similar to data from the adalimumab trial: golimumab has a remission rate of approximately 18% at Week 6 (compared with 6% in the placebo group),4 and adalimumab has a remission rate of 16.5% (compared with 9% in the placebo group) at Week 8.3 This is in spite of the fact that golimumab was evaluated only in patients who were naive to anti-TNF therapy (ie, a more favorable patient population). In addition, as with other anti-TNF agents, there is clearly a relationship between golimumab’s trough levels and efficacy: the higher the trough level, the better the improvement in Mayo score and the higher the rate of remission.4 Golimumab appears to be relatively comparable with adalimumab in terms of efficacy, so, in my mind, it does not matter which agent is used as second-line therapy and which agent is used as third-line therapy; having to choose between these 2 agents is a good problem to have. At present, we do not have a way to measure serum levels of golimumab, but we have learned that measuring levels is helpful in monitoring efficacy of infliximab and adalimumab. We do not yet know how best to dose escalate patients receiving golimumab. In general, we go to weekly adalimumab for patients who lose response or who have a partial response to adalimumab and low serum levels. Determining the optimal dose is an important area for future research for golimumab and anti-TNF agents in general. Ideally, we should measure drug levels to guide therapy and more effectively achieve the clinical response of mucosal healing. We still do not know the optimal serum level of anti-TNF agents for all patients; some patients appear to need much higher drug levels than others in order to have a beneficial effect. Although goli-mumab is convenient to use and well tolerated in terms of the actual injection, in certain patients, especially those with more active disease, higher doses are needed. The golimumab study4 did test 2 different doses of the drug. The lower dose appeared to be as effective as the higher dose, which must mean that there is a lot of individual variation in patients and that it is not just about giving more of the drug; it is about giving more to the right patient. Choosing the right starting dose may involve taking into account endoscopic severity, extent, and surrogate markers such as C-reactive protein and albumin. Determining the ideal dosage of golimumab will help improve treatment of patients with ulcerative colitis.