On 1st July, at the 10^th Congress of the European Academy of Neurology (EAN), during an ePresentation session sponsored by Amgen on generalized myasthenia gravis (gMG), an analysis on the role of B cells in gMG and what this entails for the future treatment landscape was displayed. The session presented clinical data on the BeatMG Study, a phase II randomized, double-blind, placebo-controlled study assessing the efficacy of rituximab in treating gMG with anti-AChR antibodies. The results of the study raise questions regarding rituximab’s position in the treatment landscape for gMG and highlight the need for all-encompassing monoclonal antibody (mAb) therapies for gMG, says GlobalData, a leading data and analytics company.

Jos Opdenakker, Pharma Analyst at GlobalData, comments: “When treating MG, physicians often prescribe acetylcholinesterase inhibitors (AChEIs) such as Mestinon (pyridostigmine). However, the majority of patients do not see an improvement in their symptoms when using AChEIs alone. The fact that AChEIs and other therapies, such as immunosuppressants or steroidal therapies, do not adequately address the underlying pathophysiology of B cell antibody production indicates there is an unmet need for mAb therapies. As a result, mAbs such as rituximab and eculizumab have also been prescribed to gMG patients.”

The session at EAN 2024 on the current treatment landscape and unmet needs of gMG presented topline data from the BeatMG study, which indicated that rituximab is not more effective than placebo and is unlikely to reduce steroid use for gMG patients with anti-AChR antibodies. However, the results of the BeatMG study contrast with rituximab’s potential in treating refractory MG and the success of rituximab in treating gMG patients with anti-MuSK antibodies.

According to GlobalData’s Pharma Intelligence Center, there is an ongoing phase III trial being conducted in China, sponsored by the Sun Yat-Sen University, which aims to assess rituximab monotherapy in the treatment of refractory MG. Furthermore, KOLs previously interviewed by GlobalData have also noted the success of rituximab in treating gMG patients with MuSK antibodies.

Opdenakker continues: “This signifies that although existing B-cell targeting mAbs have a role to play in the treatment landscape for gMG, it is not clearly defined at this time.”

GlobalData’s Pharma Intelligence Center also reveals that Amgen is currently sponsoring a clinical trial into its own B cell targeting mAb therapy, Uplizna (inebilizumab). The MINT trial, as it is known, is an ongoing, global, phase III study with an open-label period to assess the safety and efficacy of inebilizumab in treating MG. Inebilizumab’s development indicates Amgen’s focus on novel therapies that are all-encompassing in their treatment of gMG.

Opdenakker adds: “Should inebilizumab be successful in displaying efficacy over several types of gMG, then it would certainly gift it a competitive advantage over existing mAb treatments, such as rituximab, which are limited in their treatment of gMG. This would pave the way for a treatment with a more expansive label for gMG.”

Opdenakker concludes: “Considering the understanding surrounding the disease pathophysiology of gMG, we can begin to envision a future filled with novel mAb therapies that target underlying disease mechanisms, replacing treatments that are only able to suppress the disease as it manifests. Rituximab has displayed proficiency as an antibody therapy for the treatment of certain types of gMG. However, novel B-cell targeting mAbs will need to be developed to be of therapeutic benefit for all gMG patient groups.”