OBJECTIVES:

Neuromyelitis Optica Spectrum Disorder (NMOSD) is characterized by recurrent attacks, permanent neurological damage and cumulative disability impacting health-related quality of life (HRQoL).

Due to the chronic nature of NMOSD, understanding the long-term relative effectiveness of immunotherapies is vital. We developed a model simulating long-term outcomes to evaluate the effects of inebilizumab compared with eculizumab, satralizumab and rituximab.

METHODS:

Data on time to first committee-adjudicated attack from the N-MOmentum trial with inebilizumab were used to extrapolate the risk of attack and simulate the annualized relapse rate beyond the study period. Matching adjusted indirect comparisons (MAIC) were applied to estimate the relative effects of inebilizumab vs comparators based on data from relevant clinical trials for eculizumab and satralizumab, and published patient data for rituximab. Treatment discontinuation was based on trial discontinuation rates. Following discontinuation, patients remain off treatment to isolate the effect of the drugs compared. The model simulated NMOSD-related mortality based on disease progression.

RESULTS:

Relative risks (RR) of inebilizumab vs eculizumab, satralizumab, and rituximab were estimated to 3.947, 0.666 and 0.741, respectively. However, over a lifetime, treatment with inebilizumab resulted in a life expectancy of 22.09 life years (LY), as compared to 16.67 with eculizumab, 21.44 with satralizumab and 15.63 with rituximab, corresponding to 12.57, 8.69, 11.86 and 7.87 quality-adjusted life years (QALYs) for inebilizumab, eculizumab, satralizumab and rituximab, respectively.

A sensitivity analysis using a MAIC based on time to first investigator-adjudicated attack from relevant trials largely confirmed the initial findings and suggested a smaller advantage of eculizumab over inebilizumab (RR of inebilizumab vs eculizumab, satralizumab and rituximab were 1.51, 0.49 and 0.839, respectively).

CONCLUSIONS:

The results suggest that treatment with inebilizumab is associated with an increase in LYs and QALYs compared to eculizumab, satralizumab and rituximab. Relative efficacy and discontinuation were the key drivers of the results.