Clinical response to rhC1-INH in one out of six patients
Six patients were included in the study, four females and two males. C1-INH function and C4 levels were normal in all patients. At the start of the study, the mean age was 41 years and the median disease duration was 8 years. Frequency of AE attacks varied from 2.6 attacks to 15.8 attacks per month in the six months prior to the study. Other baseline characteristics are presented in table 1. None of the patients had been treated with long term immunosuppressive treatment (methotrexate, azathioprine, mycophenolic acid, cyclosporine), Icatibant or omalizumab before the study.
In patient 1, the attack frequency was reduced by 84% (6.3-fold) during the treatment period compared to that during the observation period (3 versus 19 attacks, respectively; Figure 1). One of the three attacks in this patient during the second treatment month occurred 7 days after the last rhC1-INH administration when the patient had missed a treatment visit. The AAS28 scores of this patient decreased 8-fold during treatment months compared to the observation period with an accumulated AAS score of 29 in the two treatment months versus 233 in the two observational months (table 2). AE related quality of life (AE-QoL) scores improved, from 26 (small effect on AE-QoL) during the observation period to 12,5 (no effect on AE-QoL) during treatment.
None of the other patients (patients 2 to 6) showed a clinical response to rhC1-INH either measured as attack frequency or accumulated AAS28 scores. No improvement of AE-QoL during treatment was observed (Supplementary table 2). Patient 3 showed a trend of a higher AAS score during the treatment period. Patients 4, 5 and 6 had lower AAS scores in the second treatment and observation periods compared to those during the first treatment and observation period.