Rituximab at lower dose for neuromyelitis optica spectrum disorder: a multicenter, open-label, self-controlled, prospective follow-up study

by Selleckchem | Nov 12 2023

Objective: To address a novel lower-dose rituximab (RTX) therapy strategy based on our clinical experience and assess its efficacy and safety in neuromyelitis optica spectrum disorder (NMOSD).

Methods: A multicenter, open-label, self-controlled, prospective follow-up study. Totally, 108 NMOSD patients were enrolled and a lower-dose RTX strategy was applied including 100 mg weekly for 3 weeks and then reinfusions every 6 months. Annualized relapse rate (ARR), the expanded disability status scale (EDSS) score and length of spinal cord lesions were included to evaluate the efficacy. Side effects were recorded to assess the safety profile.

Results: Of 108 patients, 80 (74.1%) initiated low-dose RTX therapy immediately after acute attack treatment and 33 (30.6%) initiated it after the first attack. During a median treatment period of 35.5 (22.0-48.8) months, significant decreases were observed in median ARR (1.1 [0.8-2.0] versus 0 [0-0.2], p < 0.001), EDSS score (3.5 [2.5-4.0] versus 2.0 [1.0-3.0], p < 0.001) and spinal cord lesion segments (5.0 [4.0-8.0] versus 3.0 [1.0-6.0], p < 0.001). The cumulative risk of relapses significantly decreased during the post- versus pre-RTX period (HR 0.238, 95%CI 0.160-0.356, p < 0.001) and on early therapy initiated within 24 months after disease onset versus delayed therapy (HR 0.506, 95%CI 0.258-0.994, p = 0.041). No serious side effects were recorded and all the subjects did not discontinue treatment due to RTX-related side effects.

Conclusion: Our research provided evidence supporting the lower-dose RTX strategy in treating NMOSD and reopened the issues of optimal dosage and therapy initiation timing.

Comments:

The objective, methods, results, and conclusion of the study you provided can be summarized as follows:

**Objective:**
The objective of this study was to evaluate the efficacy and safety of a novel lower-dose rituximab (RTX) therapy strategy in patients with neuromyelitis optica spectrum disorder (NMOSD), based on clinical experience.

**Methods:**
- This study was a multicenter, open-label, self-controlled, prospective follow-up study.
- A total of 108 NMOSD patients were enrolled in the study.
- The lower-dose RTX strategy involved administering 100 mg of RTX weekly for 3 weeks, followed by reinfusions every 6 months.
- The following parameters were used to evaluate the therapy's efficacy: Annualized relapse rate (ARR), the expanded disability status scale (EDSS) score, and the length of spinal cord lesions.
- Side effects were recorded to assess the safety profile of the treatment.

**Results:**
- Among the 108 patients, 80 (74.1%) started the low-dose RTX therapy immediately after acute attack treatment, while 33 (30.6%) initiated it after the first attack.
- Over a median treatment period of 35.5 months, the study observed significant improvements in several key measures:
- Median ARR decreased from 1.1 to 0 (p < 0.001).
- Median EDSS score decreased from 3.5 to 2.0 (p < 0.001).
- The length of spinal cord lesions decreased from a median of 5.0 segments to 3.0 segments (p < 0.001).
- The cumulative risk of relapses significantly decreased in the post-RTX period compared to the pre-RTX period (Hazard Ratio [HR] 0.238, 95% Confidence Interval [CI] 0.160-0.356, p < 0.001).
- Patients who initiated therapy within 24 months after disease onset had a lower risk of relapses compared to those who delayed therapy (HR 0.506, 95% CI 0.258-0.994, p = 0.041).
- No serious side effects related to RTX were recorded, and none of the subjects had to discontinue treatment due to RTX-related side effects.

**Conclusion:**
The study's findings support the use of the lower-dose RTX therapy strategy in treating NMOSD. This approach demonstrated effectiveness in reducing relapse rates, improving disability scores, and decreasing the length of spinal cord lesions. Additionally, the study suggested that initiating therapy within 24 months of disease onset may be more beneficial. Importantly, the treatment was well-tolerated, with no serious RTX-related side effects reported. This research raises questions about the optimal dosage and timing of therapy initiation for NMOSD.