Trial Outcomes & Findings for Mepolizumab for the Treatment of Chronic Spontaneous Urticaria (NCT NCT03494881)

Last Updated: 2025-08-27

Results Overview

Study participants documented their chronic spontaneous urticaria (CSU) symptoms using a diary, daily scoring for a) the number of wheals \[none (=0 points), \<10 (=1 point), 10-50 (=2 points), or \>50 per day (=3 points)\], and b) the intensity of pruritus \[none (=0 points), mild (=1 point), moderate (=2 points), severe (=3 points)\]. The daily UAS score is summed over a week to calculate the UAS7 score (range: 0-42). Participants were considered responders if they had ≥ 95% reduction in baseline UAS7 score and non-responders if they had \<95% reduction in baseline UAS7 score.

Recruitment status

COMPLETED

Study phase

EARLY_PHASE1

Target enrollment

10 participants

Primary outcome timeframe

Baseline to 10 Weeks

Results posted on

2025-08-27

Participant Flow

Participant milestones

Participant milestones
Measure	Treatment Arm This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Overall Study STARTED	10
Overall Study COMPLETED	10
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Mepolizumab for the Treatment of Chronic Spontaneous Urticaria

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Treatment Arm n=10 Participants This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Age, Categorical <=18 years	0 Participants n=93 Participants
Age, Categorical Between 18 and 65 years	9 Participants n=93 Participants
Age, Categorical >=65 years	1 Participants n=93 Participants
Sex: Female, Male Female	8 Participants n=93 Participants
Sex: Female, Male Male	2 Participants n=93 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=93 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	10 Participants n=93 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=93 Participants
Race (NIH/OMB) Asian	1 Participants n=93 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=93 Participants
Race (NIH/OMB) Black or African American	0 Participants n=93 Participants
Race (NIH/OMB) White	9 Participants n=93 Participants
Race (NIH/OMB) More than one race	0 Participants n=93 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants
Region of Enrollment United States	10 participants n=93 Participants

PRIMARY outcome

Timeframe: Baseline to 10 Weeks

Outcome measures

Outcome measures
Measure	Treatment Arm n=10 Participants This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Reduction in Urticaria Activity Score (UAS7) Responders	3 Participants
Reduction in Urticaria Activity Score (UAS7) Non-Responders	7 Participants

SECONDARY outcome

Timeframe: Baseline to 10 weeks

Population: 10 total participants were analyzed. Those 10 participants were further broken down into the following categories non-responders (7) and responders (3), respectively.

The short form urticaria control test (S-UCT) is a more recently developed and validated outcome instrument to retrospectively assess urticaria control. The S-UCT consists of 4 questions with each question having 5 answer options scored 0-4 with low points indicating high disease activity and low disease control. The minimum and maximum S-UCT scores are 0-16 with 16 points indicating complete disease control. Participants were considered responders if they had ≥ 95% reduction in baseline S-UCT score and non-responders if they had \<95% reduction in baseline S-UCT score.

Outcome measures

Outcome measures
Measure	Treatment Arm n=10 Participants This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Change in Short Form Urticaria Control Test Score (S-UCT) Responders	12.3 score on a scale Interval 0.0 to 16.0
Change in Short Form Urticaria Control Test Score (S-UCT) Non-responders	0.71 score on a scale Interval 0.0 to 16.0

SECONDARY outcome

Timeframe: Baseline to 10 Weeks

Population: 10 total participants were analyzed. Those 10 participants were further broken down into the following categories non-responders (7) and responders (3), respectively.

The long form urticaria control test (L-UCT) is a more recently developed and validated outcome instrument to retrospectively assess urticaria control. The L-UCT consists of 8 questions with each question having 5 answer options scored 0-4 with low points indicating high disease activity and low disease control. The minimum and maximum L-UCT scores are 0-32 with 32 points indicating complete disease control. Participants were considered responders if they had ≥ 95% reduction in baseline L-UCT score and non-responders if they had \<95% reduction in baseline L-UCT score.

Outcome measures

Outcome measures
Measure	Treatment Arm n=10 Participants This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Change in Long Form Urticaria Control Test (L-UCT) Score Responders	21.3 score on a scale Interval 0.0 to 32.0
Change in Long Form Urticaria Control Test (L-UCT) Score Non-Responders	1.6 score on a scale Interval 0.0 to 32.0

SECONDARY outcome

Timeframe: Baseline to 10 weeks

Population: 10 total participants were analyzed. Those 10 participants were further broken down into the following categories non-responders (7) and responders (3), respectively.

The weekly itch severity score measures the intensity and impact of itching (pruritus). It is calculated using the pruritus score of the daily Urticaria Activity Score (UAS) score summed over a week. Scores range from 0 to 21 with higher scores indicating worse itching. Participants were considered responders if they had ≥ 95% reduction in baseline ISS score and non-responders if they had \<95% reduction in baseline ISS score.

Outcome measures

Outcome measures
Measure	Treatment Arm n=10 Participants This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
Change in Itch Severity Score (ISS) Responders	13 score on a scale Interval 0.0 to 21.0
Change in Itch Severity Score (ISS) Non-Responders	1 score on a scale Interval 0.0 to 21.0

Adverse Events

Treatment Arm

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Treatment Arm n=10 participants at risk This was an open-label pilot investigation and all study participants were assigned to active treatment. There was no placebo arm in this study. Nucala: All study participants received Nucala (2) 100mg SQ injections administered at two different anatomical sites at week zero, 2,4,6, and 8 for a total of 5 doses.
General disorders Facial Swelling	10.0% 1/10 • Number of events 1 • Adverse events were collected from baseline through end of study participation, approximately 10 weeks. This study defined an adverse event as an untoward or undesirable experience associated with the use of Mepolizumab (Nucala) in a research subject. Adverse events were collected through non-directed questioning of subjects at each follow-up visit.

Additional Information

Jason Sluzevich, M.D.

Mayo Clinic

Phone: 904-953-6192

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place