GENEVA — Omalizumab can be restarted successfully in patients with chronic idiopathic urticaria (CIU) who relapse upon withdrawal of treatment after being well controlled. Nearly 90% of patients regained symptom control upon retreatment after previously being well controlled and then relapsing upon discontinuation, said Charles Lynde, M.D., at the 26th European Academy of Dermatology and Venereology Congress.
Due to the intermittent nature of CIU, physicians may consider stopping omalizumab in patients who are symptom free for an extended period. The effectiveness of restarting omalizumab in patients who were initially well controlled but relapsed after omalizumab withdrawal had not been explored previously. The OPTIMA study he reported here was designed to address this question as well as to determine the relapse rate upon stopping omalizumab in patients who are well controlled. It was conducted at 35 centers across eight countries.
The OPTIMA study
Patients enrolled in OPTIMA had a diagnosis of CIU and symptoms for at least 6 months. They must have been on an approved dosage of a non-sedating H1 antihistamine for the treatment of CIU and no other treatment for at least seven consecutive days immediately prior to being randomized to omalizumab, 150 or 300 mg. A total of 314 patients were randomized in a 4:3 manner, 178 to 150 mg and 136 to 300 mg. A weekly Urticaria Activity Score (UAS7) ≥16 and an itch component of the UAS7 ≥8 during the seven days before randomization was required for entry.
The mean UAS7 score at baseline was about 30 and the mean number of prior medications used for CIU was about two in each omalizumab arm. Two-thirds had CIU for at least two years.
Of the 178 patients randomized to 150 mg of omalizumab, 27 (15.2%) were well controlled, defined as a UAS7 <6, and of these, 12 relapsed by week 20 following medication withdrawal. In the 300 mg arm, 88 (64.7%) were well controlled, and of these, there were 44 relapsers by week 20. The time to relapse was similar in both groups — 4.8 weeks in the 150-mg arm and 4.7 weeks in the 300-mg arm.
“Retreatment of previously well-controlled patients was effective with both respective dosages,” said Lynde, medical director at the Lynde Institute of Dermatology, Markham, Ontario, Canada. Seven of the 44 on 300 mg of omalizumab did not complete the second dosing period. The proportion of patients who achieved control after retreatment was 83.3% of the 12 patients in the 150-mg arm and 89.2% of the 37 remaining in the 300-mg arm.
Treatment withdrawal led to relapse, with mean UAS7 levels returning to baseline levels by 8 weeks after withdrawal. Following reinstitution of omalizumab, mean UAS7 levels declined to 3.8 (150 mg) and 2.3 (300 mg) after 12 weeks of the second dosing period.
Quality of life measures worsened considerably after drug withdrawal. The Dermatology Quality of Life Index worsened from a score of about 12 to a score of about 1 in each arm during the second dosing period, and improved to about 6 in each group during 4 weeks of follow-up.
“From this, we recommend 300 mg as probably the best dose for most patients,” Lynde said. “At some point, you probably want to see if they’ve gone into spontaneous remission, and you might decide to withdraw them but with the proviso that you talk to patients and tell them that it’s very likely they’re going to rebound after going off, but you can recapture that for them if for some reason you need to.”
Patients who choose to try withdrawal are put on a “fast track,” he said, so that they can come back to the office quickly and have treatment reinstituted if needed.