Every-other-day interferon beta-1b versus once-weekly interferon beta-1a for multiple sclerosis (INCOMIN Trial) II: analysis of MRI responses to treatment and correlation with Nab

BACKGROUND: In RRMS, clinical exacerbations are usually associated with different types of active lesions at MRI, including: hyperintense lesions on T1-weighted post-gadolinium sequences; new hyperintense lesions or enlarging old lesions on PD/T2-weighted scans; or new hypointense lesions on T1-weighted pre-Gd sequences. OBJECTIVE/METHODS: Primary outcome was the occurrence of patients with at least one active MRI lesion of the different types indicated above during treatment with 250 microg every other day (EOD) interferon beta (IFNbeta)-1b or 30 microg once weekly (OW) IFNbeta-1a in outpatients with RRMS (INCOMIN Trial). RESULTS: The number of patients with at least one 'active' lesion, evaluated over the two-year follow-up, was significantly (P = 0.014) lower in the EOD IFNbeta-1 b arm (1 3/76, 17%) then in the OW IFNbeta-1a arm (25/73, 34%). NAb frequency over two-year follow-up was 22/65 (33.8%) in the EOD IFNbeta-1b arm and 4/62 (6.5%) in the OW IFNbeta-1a arm, significantly greater in the EOD IFNbeta-1b arm. CONCLUSIONS: The development of MRI active lesions is strongly reduced by EOD-IFNbeta-1b compared with OW-IFNbeta-1a, indicating that EOD-IFNbeta-1b is more effective than OW-IFNbeta-1a in reducing ongoing inflammation and demyelination in MS. Logistic regression showed that NAb status did not affect the risk of MRI activit

MRI activity and neutralising antibody as predictors of response to interferon beta treatment in multiple sclerosis.

Objective: To prospectively validate MRI activity and neutralising anti-interferon antibody (NAb) during the first 6 months of interferon β ;treatment as response indicators in multiple sclerosis (MS). Methods: Patients with relapsing-remitting MS were followed during the first 2 years of treatment. Neurological assessments were performed every 3 months or when a relapse was suspected. MRI scans performed at baseline and at 3, 4, 5 and 6 months after the start of treatment were assessed centrally for disease activity: new T2 or gadolinium enhancing T1 lesions. NAb were assessed using the MxA protein assay; positivity was defined as two consecutive titres ≥20 NU/ml. We evaluated the predictivity of an active scan, NAb positivity, or both, during the first 6 months of treatment, on the occurrence of clinical disease activity in the following 18 months. Results: 147 patients were assessed at 16 centres. Predictivity parameters (with confidence intervals) were as follows: active scan, sensitivity (SN) 52% (34-69%), specificity (SP) 80% (65-91%), negative predictive value (NPV) 73% (58-77%), positive predictive value (PPV) 62% (42-79%), p = 0.002; NAb positivity, SN 71% (45-88%), SP 66% (55-76%), NPV 92% (82-97%), PPV 29% (16-45%), p = 0.01; active scan and NAb positivity, SN 71% (38-91%), SP 86% (73-94%), NPV 94% (86-98%), PPV 50% (29-70%), p = 0.0003. Conclusions: MRI activity and NAb occurrence during the first 6 months of interferon β treatment were reliable predictors of long term clinical response, particularly when combined. Patients with negative predictors showed a less than 10% risk of developing clinical activity. Patients with positive predictors showed a 50% risk of further clinical activity. These patients need to be followed carefully with further MRI and NAb tests