AANEM 2026: Promising treatment advances and innovations in neuromuscular medicine

AANEM highlights emerging clinical data in myasthenia gravis and CIPD, alongside advances in imaging, biomarkers, and disease monitoring, highlight the evolving landscape of neuromuscular care

The 2026 American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting, held September 29–October 2 in Orlando, Florida, USA, brought together emerging evidence on targeted therapies for myasthenia gravis (MG) and chronic inflammatory demyelinating polyneuropathy (CIDP), alongside developments in neuromuscular imaging, diagnosis, and disease monitoring. The Myasthenia Gravis Foundation of America (MGFA) Scientific Session, held alongside the meeting on September 29, provided additional evidence in MG.¹

Among the highlights were longer-term results with complement inhibition in generalized myasthenia gravis (gMG), findings on neonatal Fc receptor inhibition in previously underrepresented MG populations, and new analyses of treatment response in CIDP. Collectively, these results illustrated both the potential of more targeted therapies and the need for careful interpretation of open-label and interim evidence.

Plenary sessions explore the future of neuromuscular medicine

Under the theme Beyond EMG: The Future of Neuromuscular Medicine, the plenary program considered how advances in imaging, artificial intelligence (AI), and biomarkers might complement established electrodiagnostic approaches. In the Olney Lecture, Prof. Nens van Alfen (Radboud University Medical Center, Nijmegen, Netherlands) addressed AI applications in electromyography and ultrasound. Dr Matthew Birkbeck (Newcastle University, Newcastle upon Tyne, UK) presented the Lambert Lecture on motor unit imaging, while Dr Rotem Orbach (National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA) discussed the emerging use of optoacoustic imaging to assess skeletal muscle.²

Further invited presentations included Dr Karissa Gable (Duke University, Durham, NC, USA) on biomarkers in neuromuscular disease and Dr Rebecca Levy (Stanford University, Stanford, CA, USA) on three-dimensional neural organoids as models for neurogenetic disorders. Other lectures examined mitochondrial dysfunction in diabetic neuropathy, spinal and bulbar muscular atrophy biomarkers, and transcriptomic findings in amyotrophic lateral sclerosis and frontotemporal dementia. These sessions principally highlighted emerging approaches and potential clinical applications, rather than establishing new diagnostic standards.²

Longer-term gefurulimab findings suggest sustained improvements in myasthenia gravis

Results from the open-label extension of PREVAIL (NCT05556096), a phase 3 study of the investigational, once-weekly, self-administered subcutaneous complement component 5 (C5) inhibitor gefurulimab (Alexion, AstraZeneca Rare Disease, Boston, MA, USA), were presented by Dr Stojan Peric (University of Belgrade Faculty of Medicine, Belgrade, Serbia) at the MGFA Scientific Session held alongside AANEM.^3,4

Among participants who received gefurulimab during both the randomized and extension periods, least-squares mean changes from Baseline at Week 52 were −5.3 points on the Myasthenia Gravis Activities of Daily Living (MG-ADL) scale, −5.3 points on the Quantitative Myasthenia Gravis (QMG) scale, and −9.4 points on the Myasthenia Gravis Composite (MGC) scale. Those who switched from placebo to gefurulimab at Week 26 also improved, with corresponding changes of −4.9, −4.6, and −8.3 points by Week 52. No meningococcal infections were reported in the extension analysis.⁴

These observations build on the published 26-week randomized PREVAIL findings. Among 260 randomized participants, the least-squares mean change in MG-ADL score at Week 26 was −4.2 points with gefurulimab versus −2.6 with placebo (between-group difference −1.6 points; p<0.0001). Improvements in QMG and MGC scores were also reported.⁵

Efgartigimod findings extend across different myasthenia gravis populations

The phase 3 ADAPT SERON study (NCT06298552) examined intravenous efgartigimod (argenx, Amsterdam, Netherlands), a neonatal Fc receptor inhibitor, in patients with gMG without detectable acetylcholine receptor antibodies. Dr James F. Howard Jr. (University of North Carolina at Chapel Hill, Chapel Hill, NC, USA) presented the one-year results at the MGFA Scientific Session (oral presentation and poster #72). Initial ADAPT SERON results were also presented at AANEM (poster #151).^6,7

In the one-year analysis, mean MG-ADL improvements of approximately 5 points were maintained through Week 52, including clinically meaningful improvements across antibody-defined subgroups. The reported safety findings remained consistent with the established efgartigimod profile. These findings are relevant to a patient population often excluded from pivotal MG trials, although subgroup size and the open-label follow-up period should be considered when interpreting durability.⁷

For ocular MG, Dr Vern C. Juel (Duke University School of Medicine, Durham, NC, USA) presented findings from the phase 3 ADAPT OCULUS study (NCT06558279) at AANEM (poster #328). Following two additional treatment cycles beyond the placebo-controlled period, mean improvements from Baseline in the patient-reported ocular Myasthenia Gravis Impairment Index score increased in magnitude from −4.5 to −6.8 points among acetylcholine receptor antibody-positive participants and from −2.7 to −4.5 points among triple-seronegative participants.^8–10

These exploratory longer-term findings suggest that ocular symptom improvements may deepen with further treatment cycles. However, controlled and longer-term evidence will be needed to establish durability and the implications for routine ocular MG management.

Treatment outcomes and monitoring evolve in chronic inflammatory demyelinating polyneuropathy

New CIDP analyses centered on subcutaneous efgartigimod PH20, including follow-up from ADHERE (NCT04281472) and its open-label extension, ADHERE+ (NCT04280718). A published interim extension analysis led by Dr Jeffrey A. Allen (University of Minnesota, Minneapolis, MN, USA) reported maintained clinical improvements among participants receiving longer-term treatment.^11–13

An updated analysis highlighted at AANEM (poster #392) reported that approximately 40% of responding participants reached an adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability score of 0 or 1 during the extension. The company also reported follow-up extending beyond five years in some participants; however, the length of exposure and completeness of follow-up varied, so these outcomes should not be interpreted as a uniform five-year treatment effect.¹⁰

Grip strength was another focus. An AANEM post hoc analysis (poster #343) reported a 71.5% lower relative risk of grip-strength deterioration with efgartigimod PH20 (hazard ratio 0.285; p<0.001). This suggests that grip-strength measurement may complement conventional disability scales in monitoring response, but the exploratory analysis does not establish it as a replacement for established clinical outcomes.^10,14

A separate phase 4 study (NCT06637072), presented by Dr Arjun Seth (Northwestern University Feinberg School of Medicine, Chicago, IL, USA), assessed switching from intravenous immunoglobulin to subcutaneous efgartigimod one week after the final immunoglobulin dose. According to the reported results, 87% of participants remained on efgartigimod at Week 12. The small, single-group study offers preliminary evidence of the feasibility of this transition strategy, but it cannot establish comparative efficacy or longer-term outcomes.^10,15,16

Claseprubart shows an early efficacy signal in chronic inflammatory demyelinating polyneuropathy

The phase 3 CAPTIVATE study (NCT06858579) is evaluating claseprubart (Dianthus Therapeutics, New York, NY, USA), an investigational antibody that selectively inhibits activated complement component C1s. AANEM poster #149, led by Dr Allen, and an oral presentation by Prof. Richard Lewis (Cedars-Sinai Medical Center, Los Angeles, CA, USA) reported an interim responder analysis from the first 40 evaluable participants to complete the open-label Part A.^17–19

Of these participants, 30 (75%) achieved a confirmed improvement of at least 1 point on the adjusted INCAT scale. Among responders, the mean improvement in adjusted INCAT score was 1.6 points; improvements were also observed in grip strength, the Medical Research Council Sum Score, and the Inflammatory Rasch-built Overall Disability Scale. One unrelated grade 3 serious adverse event was reported, with no treatment-related serious adverse events or serious infections in this interim cohort.¹⁸

These findings support further investigation but do not establish efficacy relative to placebo. CAPTIVATE’s randomized, double-blind Part B is designed to assess time to relapse in participants who responded during Part A, and its results will be important in defining the potential clinical role of C1s inhibition.^17,18

Looking ahead

AANEM 2026 and the accompanying MGFA Scientific Session illustrated a shift toward therapies targeting specific immune pathways, alongside growing interest in more sensitive and practical methods of assessing neuromuscular disease. Longer-term MG and CIDP results offered encouraging evidence of sustained symptom control in selected study populations, while the CAPTIVATE findings provided an early signal for another complement-targeted approach.

Further randomized comparisons, longer-term safety surveillance, and validation of patient-relevant outcomes will be essential before emerging findings can be translated into broader changes in clinical practice.

References

1. American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM). 2026 Annual Meeting. 2026. Available at: www.aanem.org/meetings/annual-meeting (accessed November 3, 2026).
2. AANEM. Plenary sessions: Beyond EMG: The future of neuromuscular medicine. 2026. Available at: www.aanem.org/meetings/annual-meeting/plenary-sessions (accessed November 3, 2026).
3. ClinicalTrials.gov. A study to evaluate the efficacy and safety of gefurulimab in adults with generalized myasthenia gravis (PREVAIL). ClinicalTrials.gov Identifier: NCT05556096. Available at: clinicaltrials.gov/study/NCT05556096 (accessed November 3, 2026).
4. Peric S, Gwathmey KG, Ruck T, et al. Long-term efficacy and safety of gefurulimab in adults with generalized myasthenia gravis: Results from the open-label extension of the PREVAIL trial. Presented at: MGFA Scientific Session at the AANEM Annual Meeting, Orlando, FL, USA, September 29, 2026. Abstr #111; poster #47. Presentation details and results available in: AstraZeneca meeting announcement (accessed November 3, 2026).
5. Gwathmey KG, Saccà F, Howard JF Jr, et al. Efficacy and safety of gefurulimab in generalized myasthenia gravis: The PREVAIL phase 3 randomized clinical trial. JAMA Neurol. 2026;83:841–50. doi:10.1001/jamaneurol.2026.2333
6. ClinicalTrials.gov. A phase 3 study to evaluate the efficacy and safety of efgartigimod IV in patients with acetylcholine receptor binding antibody-seronegative generalized myasthenia gravis (ADAPT SERON). ClinicalTrials.gov Identifier: NCT06298552. Available at: clinicaltrials.gov/study/NCT06298552 (accessed November 3, 2026).
7. Howard JF Jr, Vu T, Zhao C, et al. Efficacy and safety of efgartigimod in participants with generalized myasthenia gravis who lack detectable anti-acetylcholine receptor antibodies: One-year results of ADAPT SERON. Presented at: MGFA Scientific Session at the AANEM Annual Meeting, Orlando, FL, USA, September 29, 2026. Oral presentation and poster #72. Direct conference poster (PDF)
8. ClinicalTrials.gov. A study to assess efficacy and safety of efgartigimod PH20 SC in adults with ocular myasthenia gravis (ADAPT OCULUS). ClinicalTrials.gov Identifier: NCT06558279. Available at: clinicaltrials.gov/study/NCT06558279 (accessed November 3, 2026).
9. Juel VC, Barnett-Tapia C, Meisel A, et al. Efficacy and safety of subcutaneous efgartigimod PH20 administered by prefilled syringe in adults with ocular myasthenia gravis: Interim results of ADAPT OCULUS Part A. Presented at: AANEM Annual Meeting, Orlando, FL, USA, September 29–October 2, 2026. Poster #328. AANEM 2026 congress presentations listing (accessed November 3, 2026).
10. argenx. argenx presents new data at AANEM and MGFA Scientific Session showcasing earlier and sustained treatment in MG and CIDP with VYVGART and progress across its neuromuscular pipeline [Press release]. September 29, 2026. Available at: argenx release (accessed November 3, 2026).
11. ClinicalTrials.gov. Subcutaneous efgartigimod PH20 in adults with chronic inflammatory demyelinating polyneuropathy (ADHERE). ClinicalTrials.gov Identifier: NCT04281472. Available at: clinicaltrials.gov/study/NCT04281472 (accessed November 3, 2026).
12. ClinicalTrials.gov. Long-term extension study of subcutaneous efgartigimod PH20 in chronic inflammatory demyelinating polyneuropathy (ADHERE+). ClinicalTrials.gov Identifier: NCT04280718. Available at: clinicaltrials.gov/study/NCT04280718 (accessed November 3, 2026).
13. Allen JA, Istas G, Kuwabara S, et al. Long-term safety and efficacy of efgartigimod PH20 in chronic inflammatory demyelinating polyradiculoneuropathy: ADHERE/ADHERE+ trial interim analysis. J Peripher Nerv Syst. 2026;31:e70140. doi:10.1111/jns.70140
14. Lewis RA, Eggers C, Daut R, et al. Impact of subcutaneous efgartigimod PH20 on grip strength assessment in participants with chronic inflammatory demyelinating polyradiculoneuropathy: Post hoc analysis of the ADHERE/ADHERE+ study. Presented at: AANEM Annual Meeting, Orlando, FL, USA, September 29–October 2, 2026. Poster #343. AANEM 2026 congress presentations listing (accessed November 3, 2026).
15. ClinicalTrials.gov. A study to assess adults with chronic inflammatory demyelinating polyneuropathy transitioning from intravenous immunoglobulin to efgartigimod PH20 SC. ClinicalTrials.gov Identifier: NCT06637072. Available at: clinicaltrials.gov/study/NCT06637072 (accessed November 3, 2026).
16. Seth A, Lerman A, Remmerie A, et al. Intravenous immunoglobulin to subcutaneous efgartigimod PH20 transition in chronic inflammatory demyelinating polyradiculoneuropathy: A phase 4 study in progress. Presented at: AANEM Annual Meeting, Orlando, FL, USA, September 29–October 2, 2026. Poster #128. Presentation summary (accessed November 3, 2026).
17. ClinicalTrials.gov. A study to evaluate the efficacy and safety of DNTH103 in adults with chronic inflammatory demyelinating polyneuropathy (CAPTIVATE). ClinicalTrials.gov Identifier: NCT06858579. Available at: clinicaltrials.gov/study/NCT06858579 (accessed November 3, 2026).
18. Allen JA, Querol L, Eftimov F, et al. CAPTIVATE interim analysis: A pivotal phase 3 study of claseprubart in chronic inflammatory demyelinating polyneuropathy. Presented at: AANEM Annual Meeting, Orlando, FL, USA, September 29–October 2, 2026. Poster #149. Direct conference poster (PDF)
19. Lewis R. CAPTIVATE interim analysis: A pivotal phase 3 study of claseprubart in chronic inflammatory demyelinating polyneuropathy. Presented at: AANEM Annual Meeting, Orlando, FL, USA, October 1, 2026. Oral presentation #149. Conference slides listed in the Dianthus scientific publications archive (accessed November 3, 2026).