Giving Tacrolimus Another Look for Severe Colitis

The retrospective study by Zimmerman et al involved 170 pediatric patients (IFX (n = 84) and TAC (n = 86)) with acute severe colitis (ASC) form 2005 to 2017; TAC was generally used prior to 2014 and patients were more likely to be receiving 6MP as a long-term maintenance agent; the mean TAC level was 10.7 ng/mL. The mean dose of infliximab (IFX) initially was 7 mg/kg. Key findings:

  • The rate of colectomy 6 months from rescue therapy was similar whether patients received IFX or TAC (22.6% vs 26.7%, respectively, P = 0.53).
  • The mean decline in Pediatric Ulcerative Colitis Activity Index scores from admission to discharge in those treated with IFX (31.9) or TAC (29.8) was similar (P = 0.63).
  • Similar rates of adverse effects were seen. 4 patients in the TAC group experienced neurologic symptoms.
  • About half of the steroid-refractory ASC patients failing either agent as initial rescue therapy required colectomy, even if they switched to the alternative agent.
  • 17.9% of patients receiving high-dose IFX required colectomy by 6 months compared to 25% in the “typical” IFX dosing group; this was not statistically significant, likely due to limitations of sample size.

In the systematic review/meta-analysis study by Bolia et al., the authors identified 7 studies with 166 children (111 steroid-refractory, 52 steroid-dependent, 3 no steroids). The majority of cases (150/166 [90%]) were naïve to biologics. None of the participants in these studies have been treated recently (only 10 patients since 2014 and none after 2016). The two most recently published studies in 2018 and 2019 had enrollment in 2014-2016 and 2000-2012, respectively. Key findings:

  • An initial response to tacrolimus therapy was seen in 84% 
  • No difference was observed between children with high (>10 ng/mL) or low tacrolimus levels (127/150 [85%] vs 12/16 [75%], P = 0.3).
  • The pooled frequency of 1-year colectomy-free survival in children treated with initial oral tacrolimus was 64% (95% CI: 53%–75%). Twelve (7.2%) patients required cessation of therapy because of side effects.

My take: Both of these studies indicate that tacrolimus could be a useful agent for ASC and may find a role as a bridge therapy for biologic agents with slower onset of action.

Related blog posts:

NRocks Climb in Circleville, WV