Objective:

To compare incremental treatment use, myasthenia gravis (MG) exacerbations, crises, and related costs among pregnant versus non-pregnant women with generalized MG (gMG).

Background:

MG symptoms may flare up during pregnancy increasing the risk of respiratory failure and affecting pregnancy outcomes. With emerging targeted treatment options, understanding the interaction between pregnancy and gMG may help identify unmet needs and guide management decisions.

Design/Methods:

Pregnant and non-pregnant women with gMG were identified from Komodo Research Database (01/2017-09/2023). In pregnant cohort, the baseline period included 12 months pre-conception (index date), and the follow-up period included pregnancy plus 6 months post-partum. Non-pregnant cohort (random index date) was matched to pregnant cohort 10:1 based on lengths of the baseline and follow-up periods. Cohorts were weighted on baseline characteristics using entropy balancing. Treatment utilization, MG exacerbations, crises, and related costs (USD2023; per-patient-per-month) were compared during the follow-up period between weighted cohorts.

Results:

97 pregnant and 970 non-pregnant women with gMG were included. During the follow-up period, pregnant cohort had fewer days with treatment supply per month compared to non-pregnant cohort, with following mean differences (MDs): non-steroidal immunosuppressants (MD: -4.33), monoclonal antibodies (MD: -1.49), and complement-5 inhibitors (MD: -1.18; all p<0.001). While the pregnant and non-pregnant cohorts had a similar likelihood of exacerbation (odds ratio [OR]: 1.25; p=0.391), the pregnant cohort was more likely than the non-pregnant cohort to experience a crisis (OR: 3.90; p=0.027). Pregnant cohort had $3,930 lower MG-related pharmacy costs (p=0.004), but MG exacerbation- and crisis-related costs were comparable between cohorts.

Conclusions:

Results suggest unmet needs in treating gMG during pregnancy, as evidenced by significantly lower supply and costs for gMG-related treatments alongside higher likelihood of experiencing MG crisis compared to non-pregnant women. Upcoming analyses in pregnant women with and without gMG may provide additional insights into the interaction between pregnancy and gMG.