Introduction
Migraine is a debilitating primary headache disorder characterized by severe throbbing, pulsing headache, and generally associated with nausea and increased sensitivity to light and sound [
1]. It remains the second disease among the world’s causes of disability, and the first among young women, according to Global Burden of Disease 2019 data [
2]. In China, a population-based study reported that the estimated 1-year prevalence of migraine was 9.3% [
3], causing 5.5 million years lived with disability (YLDs), representing a huge health burden in China [
4].
For acute treatment of migraine, non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely used initial medications [
5], with pain freedom at 2 h occurring in 23.8–26.2% of patients [
6]. On the contrary, most international guidelines recommend triptans for the acute treatment of migraine [
7,
8], with pain freedom at 2 h ranging between 20% and 40% [
9]. A real-world study in China showed that around 55% of patients were currently experiencing at least one adverse event (AE) with their acute medication (such as gastrointestinal effects with NSAIDs) or insufficient response to their current acute medication reported by 43% of patients [
10]. Moreover, triptans are contraindicated in patients with coronary artery disease, uncontrolled hypertension, and after stroke or transient ischemic attack [
11]. The aforementioned data shows that there is a substantial unmet medical need for acute treatment of migraine in China. Since no novel acute treatment for migraine was marketed in China in the last two decades, a novel acute treatment is required as an effective therapeutic option for Chinese patients with migraine.
Lasmiditan is a selective serotonin 1F (5-HT
1F) receptor agonist (ditan), approved by the US Federal Drug Administration (FDA) for the acute treatment of migraine with or without aura in adults [
12]. Compared to triptans, 5-HT
1B/1D receptor agonists, lasmiditan has a novel mechanism of action without causing vasoconstriction [
13]. In previous phase 3 studies, lasmiditan demonstrated statistically significant superiority versus placebo for pain freedom at 2 h post-dose, as well as freedom from patients’ most bothersome symptoms (MBS) [
14,
15]. The phase 3 CENTURION study was conducted to assess the first attack efficacy and the consistency of response of lasmiditan as a treatment for acute migraine attacks [
16]. Results from the primary cohort of the CENTURION study confirmed the early and sustained efficacy of lasmiditan 100 mg and 200 mg and demonstrated consistency of response across multiple attacks [
16]. The objective of this subpopulation analysis of the CENTURION study was to demonstrate a consistent trend in the efficacy and safety of lasmiditan between the Chinese population and the primary cohort.
Discussion
Lasmiditan is a novel high-affinity, highly selective 5-HT
1F receptor agonist that acts on the trigeminal system [
13]. Unlike triptans, whose actions are mediated through the activation of 5-HT
1B receptors in cranial blood vessels with subsequent cranial vasoconstriction (and, therefore, are contraindicated in patients with cardiovascular disease) [
17], lasmiditan showed low affinity for 5-HT
1B receptors [
13]. The activation of 5-HT
1F receptor does not cause vasoconstriction [
17,
18]. Furthermore, evidence suggests that lasmiditan can alleviate migraine through 5-HT
1F agonist activity that leads to inhibition of neuropeptide and neurotransmitter release and inhibition of peripheral nervous system trigeminovascular and central nervous system pain signaling pathways [
13]. Considering that triptans were approved over 20 years ago, lasmiditan could be the first novel 5-HT
1F agonist for acute treatment of migraine in the last two decades.
As noted earlier, the CENTURION study primary cohort results demonstrated that lasmiditan was superior to placebo for all response endpoints during the first attack and consistency of response across multiple migraine attacks; these findings support that lasmiditan is an efficacious acute treatment for migraine [
16]. The current subpopulation analysis of the CENTURION study is the first analysis to investigate lasmiditan in the Chinese population which included patients from the CENTURION primary cohort and extended Chinese patients not covered by the primary publication. The current analysis reports valuable data that demonstrates the consistency with the efficacy results published previously [
16] in both single and multiple migraine attacks, with no new safety signals observed. These findings could further support the use of lasmiditan in clinical practice and resolve the unmet medical need in the acute treatment of migraine in China.
The baseline migraine characteristics of the Chinese population were generally comparable with those of the CENTURION study primary cohort. The baseline migraine attack frequency and mean MIDAS score were seemingly very close between the Chinese population and primary cohort [
16] (4.3 versus 4.9 per month, 36.4 versus 31.6, respectively), representing a similar frequency of migraine attack per month and a similar degree of migraine-related disability.
In the clinical trial setting, efficacy is measured by pain freedom at 2 h before the use of a second dose of study drug or other rescue medication [
19]. This endpoint is consistent with a patient’s treatment expectations, the clinician’s acute treatment goals, and independent of any confounding effect of rescue therapy [
19,
20]. In the Chinese population of the CENTURION study, for first migraine attack, lasmiditan at either dose (100 mg or 200 mg) showed improvement compared to placebo for pain freedom at 2 h post-dose with consistency of response as measured by pain freedom at 2 h post-dose in at least two out of three attacks. All these primary endpoints for both doses of lasmiditan in the Chinese population, except lasmiditan 100 mg for pain freedom at 2 h during first attack, reached nominal statistical significance. These results are generally consistent with the published CENTURION study primary cohort results, pain freedom at 2 h post-dose for the first attack (lasmiditan 100 mg, 25.8%; lasmiditan 200 mg, 29.3%; versus placebo, 8.4%;
P < 0.001) and in at least two out of three attacks (lasmiditan 100 mg, 14.4%; lasmiditan 200 mg, 24.4%; versus placebo, 4.3%;
P < 0.001) [
16].
The previous phase 3 trials of lasmiditan have reported therapeutic gain for pain freedom at 2 h post-dose of 10.1–12.9% for lasmiditan 100 mg and 16.9–17.5% for lasmiditan 200 mg [
14,
15]. The CENTURION study primary cohort further demonstrated the therapeutic gain for pain freedom at 2 h post-dose was 17.4% for lasmiditan 100 mg and 20.9% for lasmiditan 200 mg [
16]. Taken together, lasmiditan was reported to have generally similar therapeutic gains for pain freedom at 2 h post-dose compared to triptans (lasmiditan 100 mg, 10.1–17.4%; lasmiditan 200 mg, 16.9–20.9%; sumatriptan 50 mg, 16.9%; and sumatriptan 100 mg, 21.4%) [
6,
16]. In the Chinese population of the CENTURION study, the results of therapeutic gain for pain freedom at 2 h post-dose in lasmiditan 100 mg and 200 mg groups were 11.9% and 18.8%, respectively. Meanwhile, a numerical difference of placebo effect was observed between the Chinese population and the primary cohort of the CENTURION study (pain freedom at 2 h for the first attack in placebo group: Chinese population 13.4% [95% CI 0.08–0.22] versus primary cohort 8.4% [95% CI 0.06–0.11]). However, this is just a numerical difference between both mean values with overlapping confidence interval. The impact of placebo effect on the efficacy assessment of lasmiditan was not observed.
In addition to pain freedom, a patient values rapid and early onset of pain freedom as important aspects for acute treatment of migraine [
19]. In the Chinese population of the CENTURION study, the results showed an early onset for pain freedom as early as 1 h, which is consistent with the findings from three previous phase 3 trials [
14‐
16]. Furthermore, the CENTURION study primary cohort showed that both doses of lasmiditan exerted a late benefit with therapeutic gain of 23–28% at 4–6 h, depending on dose and time point [
16]. The results from a report that compared pain freedom at 2–8 h between lasmiditan and gepants showed similar therapeutic gains beyond 2 h across three acute treatments: lasmiditan, ubrogepant, and rimegepant [
20]. These findings of therapeutic gain for late benefit between 4 and 6 h (depending on the dose and time) with lasmiditan are further evidenced by that observed in the Chinese population of the CENTURION study (Fig.
3).
Migraine is recurrent and often lifelong, which is commonly characterized by recurring attacks that can range in severity, duration, and frequency of pain. The attack frequency generally varies among different patients, which depends on the patient’s demographic and clinical characteristics [
21]. Hence, the IHS guidelines recommend evaluating the consistency of response over multiple attacks in double-blind, placebo-controlled trials where response to at least four attacks is assessed, and at least one of the four attacks is treated with placebo in a randomized fashion. The guidelines further emphasize that testing the effect of an acute treatment on several migraine attacks may increase the discriminative power for efficacy when outcome measures are averaged across multiple attacks for each subject, provided that all analyzed subjects treat the same number of attacks [
19]. In the Chinese population of the CENTURION study, both doses of lasmiditan showed a consistent response for pain freedom and pain relief at 2 h post-dose across at least two out of three attacks and at least three out of four attacks versus placebo. These findings of consistency of response across multiple attacks are similar to those reported in the CENTURION study primary cohort [
16].
As migraine is a complex disorder with several associated symptoms, a drug effect on headache pain alone is not considered sufficient for the acute treatment of migraine. Previously, an acceptable approach to evaluate the efficacy of a drug was to demonstrate an effect on four endpoints (pain, nausea, photophobia, and phonophobia). However, per recent FDA guidance, a preferred approach aims to better align study outcomes with the symptom(s) that are of primary importance to the patient. Accordingly, a study drug should have an effect on both pain and the patient’s MBS [
22]. In accordance with the FDA guidance, the phase 3 SAMURAI and SPARTAN studies evaluated MBS as a major endpoint, and both studies demonstrated statistically significant superiority of lasmiditan compared to placebo in a proportion of patients who were free of their migraine-associated MBS [
14,
15]. Consistent findings for pain freedom from MBS were also reported in the CENTURION study primary cohort [
16]. A similar trend was observed in the Chinese population of the CENTURION study. These findings further support the use of lasmiditan for the treatment of migraine in the Chinese population.
Taken together, a similar trend was observed across multiple endpoints and the presented OR results support the statement that a similar treatment effect to that observed in the primary cohort [
16] is also demonstrated in a particular subpopulation. The results in the Chinese subpopulation showed a trend consistent with that observed in the primary cohort [
16] across all primary and secondary endpoints, as demonstrated in Fig.
2 and Supplementary Table 1.
Overall, the safety results in the Chinese population were generally consistent with those of the primary cohort [
16] with no new safety signals detected. The most commonly reported TEAE across all groups was dizziness. The incidence values of TEAEs reported in the Chinese population were generally consistent with those in the primary cohort. The common TEAEs in the Chinese population were similar to those in the CENTURION study primary cohort in type and severity [
16]. Increased risk of cardiovascular and cerebrovascular events has been reported in patients with migraine due to the vasoconstrictive effects of triptans and ergotamines [
23‐
26]. In line with the mechanism of action of lasmiditan [
13], there were no ischemic cardio-cerebrovascular events observed with either dose of lasmiditan in the Chinese population of the CENTURION study, which indicates a favorable safety profile even in patients showing safety concerns with currently available other medications.
Patients in the control group received lasmiditan 50 mg for one attack. The results showed that lasmiditan 50 mg had positive effect compared with placebo. However, the study was not powered for or designed to fully assess the efficacy of this dose, and the 50 mg data was for exploratory purposes only as a result of the limited sample size. Hence, the results for lasmiditan 50 mg dose should be interpreted with caution.
This subpopulation analysis had a few limitations. As with the primary cohort [
16], the direct comparison of TEAE findings for active treatment versus placebo across four attacks could not be evaluated because of the modified-parallel design in which lasmiditan-treated groups received lasmiditan for up to four attacks but the control group received placebo for three attacks. Secondly, on the basis of the nature of this subpopulation analysis, multiple testing control was not implemented on the tests performed.
P values less than 0.05 were considered to indicate nominal significance.