Is a 6 vial induction regimen of risankizumab (generic name) over 56 days appropriate for ulcerative colitis?

Risankizumab Induction Regimen for Ulcerative Colitis

The appropriate induction regimen for risankizumab in ulcerative colitis is 1,200 mg administered intravenously at weeks 0,4, and 8, not 6 vials over 56 days. 1

Correct Dosing for Ulcerative Colitis

The FDA-approved dosing for risankizumab (Skyrizi) in ulcerative colitis follows a specific protocol:

1. Induction Phase:

   • 1,200 mg administered by intravenous infusion
   • Given at Weeks 0,4, and 8
   • Infusion should be administered over at least two hours

2. Maintenance Phase:

   • 180 mg or 360 mg administered by subcutaneous injection
   • Starting at Week 12
   • Continuing every 8 weeks thereafter
   • The lowest effective dosage should be used to maintain therapeutic response 1

Evidence Supporting This Regimen

The 2024 AGA clinical practice guideline on pharmacological management of moderate-to-severe ulcerative colitis supports the use of risankizumab, which is an interleukin-23 antagonist that selectively inhibits the p19 subunit. Clinical trials demonstrated that risankizumab was superior to placebo for induction of clinical remission, with 20.3% of patients achieving remission with the 1,200 mg dose compared to 6.2% with placebo 2, 3.

In the phase 3 clinical trials that led to FDA approval:

• Patients received 1,200 mg IV at weeks 0,4, and 8
• This dosing showed significant improvement in clinical remission rates compared to placebo
• The absolute effect was 230 more patients per 1000 achieving clinical remission 2

Why Not 6 Vials Over 56 Days?

The proposed regimen of "6 vials in a period of 56 days given every 4 weeks for a total of 3 times" is incorrect for several reasons:

1. Dose Specification: The FDA-approved dosing is specified in milligrams (1,200 mg), not in vials 1
2. Timing: While the timing (every 4 weeks for 3 doses) is correct, the total duration would be 8 weeks (0,4,8), not 56 days
3. Formulation: For ulcerative colitis induction, risankizumab must be administered intravenously, not subcutaneously 1

Clinical Implications of Correct Dosing

Using the correct dosing regimen is critical for optimal outcomes:

• Phase 3 trials showed that the 1,200 mg IV dose achieved near maximal response for all efficacy endpoints 4
• Lower doses (600 mg) showed suboptimal efficacy
• Higher doses (1,800 mg) provided little additional benefit 4

Maintenance Considerations

After completing the induction regimen, patients should transition to maintenance therapy:

• Maintenance should begin at Week 12
• Options include 180 mg or 360 mg subcutaneously every 8 weeks
• Both doses showed significant improvement in maintaining clinical remission compared to placebo (40.2% for 180 mg and 37.6% for 360 mg vs 25.1% for placebo) 3

Important Monitoring and Precautions

Before initiating risankizumab:

• Obtain liver enzymes and bilirubin levels 1
• Complete all age-appropriate vaccinations as recommended by current immunization guidelines 1
• Monitor for adverse events, though clinical trials showed favorable safety profiles with no new safety signals detected 3

Using the correct FDA-approved dosing regimen of 1,200 mg IV at weeks 0,4, and 8 is essential for achieving optimal clinical outcomes in patients with moderate-to-severe ulcerative colitis.