Gastroenterology and Hepatology
January 2014, Volume 10, Issue 1
Commentary
Vedolizumab: A New Mechanism of Action for the Treatment of Ulcerative Colitis
Stefan Schreiber, MD
Department of Internal Medicine I, University Hospital Schleswig-Holstein, Kiel, Germany
Significance
The study by Feagan and colleagues1 is an important contribution to the field of ulcerative colitis treatment for 3 reasons. First, it examines a biologic agent with a novel mechanism of action for use in ulcerative colitis, vedolizumab, which is an integrin antagonist that targets the gut-specific α4β7 integrin for inhibition.2,3 Currently, the biologics armamentarium for ulcerative colitis treatment consists of anti–tumor necrosis factor (anti-TNF) therapies—infliximab (Remicade, Janssen), adalimumab (Humira, AbbVie), and golimumab (Simponi, Janssen), which all deliver an anticytokine action. However, studies have shown that significant proportions of patients with ulcerative colitis do not respond or lose response to anti-TNF therapy.4,5 Thus, there is a need for alternative therapies in ulcerative colitis. The study by Feagan and colleagues1 proves through a definitive, placebo-controlled, phase 3, clinical trial that the new therapeutic option of vedolizumab is effective for treating patients who are not responding to anti-TNF therapy as well as those who are naive to anti-TNF therapy.
Second, the study by Feagan and colleagues,1 which is extensive and comprised of a large study population, reveals that, after undergoing a full year of treatment, vedolizumab has an efficacy that is very similar to that of anti-TNF therapy with an adverse-effect profile that appears to be very minimal. Having a minimal adverse-effect profile is an important feature of vedolizumab, as ulcerative colitis is a lifelong disease, and many patients with the condition are young. It appears that vedolizumab is not associated with any signs of systemic immunosuppression via its mechanism of action. Of course, the only way that we will know if this minimal adverse-effect profile will hold true in practice is through the treatment of tens of thousands of patients over time.
Third, the study by Feagan and colleagues1 used an important secondary endpoint that measured the durability of response in addition to having the primary endpoint of corticosteroid-free remission. Durable response means that, once a patient enters remission, he or she is stable enough to remain in response at all the different time points throughout the rest of the trial. Although it is still important to report how many patients achieve remission at the end of the study and how many do not, this new definition of response and remission is more meaningful for everyday clinical practice, as it reflects the way that clinicians treat patients in real life. It is most important to know if a drug can keep a patient in remission than just bring the patient to remission temporarily. Many times, patients feel well at a certain point during treatment, but then their condition worsens. The concept of durable response and remission also was explored in the development of golimumab (although using a different definition).6,7 Sharpening endpoints is the natural evolution of clinical trials.
Limitations
A useful extension of the study by Feagan and colleagues1 would be benchmarking vedolizumab against anti- TNF agents so that clinicians could see a comparative trial in which anti-TNF nonresponders are switched to vedolizumab and vice versa. The study by Feagan and colleagues1 does not provide such a comparative assessment, which would allow better positioning of the new agent in the existing therapeutic landscape. Unfortunately, this is a shortcoming of many gastroenterology trials. Most are still conceptualized in the same way that they were when the first ulcerative colitis drugs were developed. At that time, it was fine to just conduct a placebo-controlled trial because there were no other treatment options; if a study showed that a new drug worked against placebo, that was enough for doctors and patients to try it. Now, however, there are several options for treating ulcerative colitis, so it is important to compare them carefully and against each other to give each patient the best chance for achieving and staying in remission.
Future Directions
To date, there have not been any other large studies conducted on vedolizumab in ulcerative colitis to help shape its clinical use. I hope that this changes soon, but it is possible that further studies may be delayed until the drug is approved by the US Food and Drug Administration. There is still so much that we do not know about this drug that we know about anti-TNF agents. Ideally, there should be studies to explore whether early disease (ie, right after diagnosis) responds better than late disease to vedolizumab. Another area of research is the interaction between vedolizumab and coexisting therapies and whether the latter can be weaned or discontinued. We also need to determine how much the nonresponder populations overlap between vedolizumab and anti-TNF agents. For example, as with infliximab, approximately 60% of patients who take vedolizumab do not benefit from the drug in the long run. Is this 60% of vedolizumab failures the same as the 60% of infliximab failures, or are they different patient populations? Vedolizumab also needs to be examined in special populations, such as young patients and pregnant patients.
Going forward, the study by Feagan and colleagues1 suggests that vedolizumab may be the forerunner of a new drug class resulting in advances in ulcerative colitis therapy. This has been seen in drug development throughout history. The successful data from this trial may stimulate other companies to explore similar drugs in the same pathway.
Dr Schreiber has received on-spot consultancy fees from AbbVie, MSD, and Takeda/Millennium for participation in expert advisory activities.
References
1. Feagan BG, Rutgeerts P, Sands BE, et al; GEMINI 1 Study Group. Vedolizumab as induction and maintenance therapy for ulcerative colitis. N Engl J Med. 2013;369(8):699-710.
2. Barreiro O, Sanchez-Madrid F. Molecular basis of leukocyte–endothelium interactions during the inflammatory response. Rev Esp Cardiol. 2009;62(5):552-562.
3. Soler D, Chapman T, Yang LL, Wyant T, Egan R, Fedyk ER. The binding specificity and selective antagonism of vedolizumab, an anti-alpha4beta7 integrin therapeutic antibody in development for inflammatory bowel diseases. J Pharmacol Exp Ther. 2009;330(3):864-875.
4. Kornbluth A, Sachar DB; Practice Parameters Committee of the American College of Gastroenterology. Ulcerative colitis practice guidelines in adults: American College of Gastroenterology, Practice Parameters Committee. Am J Gastroenterol. 2010;105(3):501-523; quiz 524.
5. Ford AC, Sandborn WJ, Khan KJ, Hanauer SB, Talley NJ, Moayyedi P. Efficacy of biological therapies in inflammatory bowel disease: systematic review and meta-analysis. Am J Gastroenterol. 2011;106(4):644-659.
6. Sandborn WJ, Feagan BG, Marano C, et al; PURSUIT-SC Study Group. Subcutaneous golimumab induces clinical response and remission in patients with moderate-to-severe ulcerative colitis [published online June 2, 2013]. Gastroenterology. doi:10.1053/j.gastro.2013.05.048.
7. Sandborn WJ, Feagan BG, Marano C, et al; for the PURSUIT-Maintenance Study Group. Subcutaneous golimumab maintains clinical response in patients with moderate-to-severe ulcerative colitis [published online June 14, 2013]. Gastroenterology. doi:10.1053/j.gastro.2013.06.010.