Since September, I’ve been getting Remicade (infliximab) infusions every four weeks. My gastroenterologist changed my schedule from every eight weeks after my colonoscopy in August showed I was no longer in remission from Crohn’s, and the inflammation in my colon was worsening.
I started taking Remicade in April 2008 after prednisone and other medications failed. My Crohn’s became more severe, causing ulcers in my mouth that made eating painful and difficult. After I developed pyoderma gangrenosum, a skin condition that caused a nickel-sized ulcer on my lower leg, my gastroenterologist knew he would have to prescribe a more aggressive treatment.
Almost immediately after my first few Remicade infusions, the open sore on my leg healed. I went into remission about two years later.
Except for a doctor-ordered, six-month break after my liver transplant, I had infusions every six weeks. When I restarted Remicade in February 2018, my gastroenterologist increased my schedule to every eight weeks because my antirejection medication was already suppressing my immune system. Surprisingly, my Crohn’s symptoms became progressively more frequent and more severe.
When Remicade loses effectiveness
Remicade can begin to lose effectiveness for several reasons. For one, my Crohn’s could be worsening because I’ve been on Remicade for more than 12 years. My gastroenterologist warned me the medication could lose effectiveness over time.
A 2010 study of 152 pediatric Crohn’s patients found that half of them stopped responding to Remicade after five years. Several inflammatory bowel disease (IBD) patients I’ve spoken with are astounded when I tell them how long I’ve been on Remicade. Many of them had to switch to a different medication after only a few years.
Another possibility for the increased inflammation in my colon might be from stopping and restarting Remicade treatment while I was hospitalized and recovering from my liver transplant. Doctors often discourage a “medication holiday,” because it can cause IBD symptoms to return or worsen.
A 2012 study found that almost half of the patients who ceased Remicade after achieving remission relapsed within a year. However, a follow-up study found that 70.2% of those patients resumed the medication successfully.
Unfortunately, some patients no longer respond to Remicade because their symptoms become too severe or complicated. In my case, my gastroenterologist believed I might have developed antibodies, making me immune to the medication.
The science behind antibodies
The body produces antibodies in the blood to counteract an antigen. An antigen is any foreign substance, such as bacteria or a virus, that triggers an immune response. In IBD, the antigen that causes the chronic inflammation of intestinal mucosa is a cytokine called tumor necrosis factor alpha (TNF-a). Remicade suppresses the immune response generated by TNF-a, thereby reducing inflammation. In turn, the body might recognize the medication as an antigen and begin producing anti-infliximab antibodies.
To find out if I had developed antibodies, my doctor did two things. First, he increased the frequency of my infusions for four months to see if I responded to a higher dosage of the medication in my system. Next, he ordered a Prometheus Anser IFX test the week before my fourth infusion on the new dosing schedule.
The Prometheus Anser IFX test measures the number of anti-infliximab antibodies and the trough level of Remicade in the bloodstream. The trough level is the lowest volume of medication necessary to remain effective. If antibodies are present, the test calculates and reports the unaffected concentration of the medication.
Antibodies or an insufficient dosage can result in a below-normal Remicade level. To counteract and balance the antibodies, the doctor might increase the dose, frequency, or both before deciding to switch to a different medication. Increasing the dose or frequency of treatment can also restore efficacy and maintain remission.
In a small study of ulcerative colitis patients on Remicade, 16 of 24 patients who achieved remission and then relapsed were able to successfully attain remission again with intensified treatment.
If the Prometheus test reports a normal trough level of Remicade with little to no antibodies present, and the patient’s condition doesn’t stabilize or improve, then the medication is no longer therapeutic. The only recourse for the patient is to begin a new treatment.
My results and the next steps
My gastroenterology nurse called with my results in early December. I was negative for antibodies. She didn’t mention my trough level, but I’m assuming it was below or within the normal range, because my gastroenterologist wants to continue the four-week dosing schedule for now.
When I have a follow-up appointment with him next week, I’ll know for certain what my future treatment plan will be. The four-week schedule is becoming a time and financial strain, so I’m hoping we’ll discuss moving my infusions to every six weeks. However, if I don’t go back into remission with the increased frequency, I’m open to trying a new medication that might be even more convenient and less expensive.
The new year brings possibilities and renewed hope!
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