International research and advocacy for Multiple Sclerosis (MS) disease-modifying treatment (DMT) use have improved globally in recent decades. However, access, diagnosis, and financing issues persist within the Southeast Asian (SEA) region (Laurson-Doube et al., 2020; Vijayasingham and Viswanathan, 2019) which has a population of 600 million and 11 countries (Brunei, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste and Vietnam) with differing geopolitical, economic, and healthcare systems. Inequitable access to MS diagnosis, treatment, and management highlights the gap between high income countries and those within SEA, which is predominantly composed of low and middle-income countries. The lack of access to healthcare, treatment, and knowledge in MS has been attributed to the small population of MS patients, limited epidemiological research, and inadequate policy advocacy (Laurson-Doube et al., 2020; Vijayasingham and Viswanathan, 2019; Amezcua et al., 2021; Multiple Sclerosis International Federation, 2020, The Lancet Neurology, 2019). Although epidemiological modelling has shown an overall increase in MS prevalence in SEA (estimated at 5 to 9 per 100,000 population (The Lancet Neurology, 2019) or approximately 30,000 to 54,000 people in 2016), MS remains a neglected non-communicable disease. Considering the significant impact of MS on health-related quality of life and the accessibility of effective treatments (Siritho et al., 2018; Vijayasingham et al., 2017), there is a pressing need for more comprehensive strategies aimed at enhancing health utility.

The recent World Health Assembly's 10-year intersectoral global action plan to improve access to care and treatment for neurological conditions including MS (World Health Organization, 2021), provides a timely opportunity for regional discourse and action. In a noteworthy and positive development, the World Health Organisation (WHO) has, for the first time, included glatiramer acetate, cladribine, and rituximab in its Essential Medicines List (EML) for treatment of MS (World Health Organization, 2023). While these drugs represent only a small number of the effective DMTs available for MS, their inclusion sets a crucial baseline of care. The EML, which aims to improve global access to essential medicines with well-established clinical benefits, plays an important role as reference for governments and health ministries in the provision of universally accessible medicines without imposing financial burdens on low- to middle-income countries.

While previous research has explored the cost-effectiveness of DMTs in Thailand (Chanatittarat et al., 2018), barriers in the health service delivery for MS patients in the Philippines (Ignacio et al., 2020), and the challenges faced by MS patients in accessing high-cost treatments in Malaysia (Vijayasingham et al., 2017), none have thus far examined the dynamic interplay of various factors influencing access to MS treatment in this region. Importantly, studies conducted in other parts of the world such as Latin America (Rojas et al., 2021), the Middle East, and Africa (Zeineddine et al., 2023; Aderinto et al., 2023), have highlighted similar gaps in MS treatment access. Insights gleaned from such studies play a pivotal role in informing crucial implementation efforts in under-resourced regions.

In view of the opportunities presented by these recent developments, we engaged key stakeholders within the region's healthcare system to discuss the current state of access to MS treatments, the local dynamics of access, and offer potential policy directions and strategies.

The study asked the following questions: "How is access to DMTs (on-label and off-label) sought, organised, financed and used within SEA countries?" and "What are the barriers and challenges to MS management in SEA?". These broad inquiries are intended to capture the multifaceted aspects of MS care, considering the wide-ranging healthcare systems and socio-economic factors prevalent in the SEA region.