Amylyx Nears Regulatory Run in Obesity Surgery Complication

Amylyx Pivots to New Pipeline After Relyvrio Withdrawal

Amylyx, following the market withdrawal of its ALS drug Relyvrio in March 2024 due to a Phase 3 trial failure, is strategically pivoting its pipeline. The company, which also underwent an 80% stock crash and 70% workforce reduction, is now focused on avexitide, a GLP-1 receptor antagonist acquired in July 2024. Avexitide is nearing regulatory submission for post-bariatric hypoglycemia (PBH), a rare endocrine condition affecting approximately 160,000 people in the U.S. Amylyx expects topline results from a pivotal study in Q3, with plans for an NDA submission soon after and an anticipated launch next year. The company also continues to develop AMX0114 for ALS and AMX0035 for Wolfram syndrome, reaffirming its commitment to neurodegenerative diseases.

• Amylyx experienced a significant corporate upheaval with the market withdrawal of its only approved product, Relyvrio, for ALS in March 2024. This decision followed the drug's failure to demonstrate a significant difference from placebo in the Phase 3 PHOENIX trial. The setback led to a dramatic over 80% crash in the company's stock value and a substantial 70% reduction in its workforce, necessitating a strategic re-evaluation of its operational focus and pipeline.
• The company's immediate regulatory priority is avexitide, a GLP-1 receptor antagonist acquired from Eiger BioPharmaceuticals in July 2024. This candidate targets post-bariatric hypoglycemia (PBH), a debilitating endocrine condition characterized by severe low blood sugar, affecting an estimated 160,000 individuals in the U.S. Amylyx anticipates releasing topline results from a pivotal study in the third quarter and aims to submit a New Drug Application (NDA) promptly, with a projected market launch in the coming year.
• Despite past challenges, Amylyx maintains a strong focus on addressing debilitating neurodegenerative diseases. Its pipeline includes AMX0114, an investigational antisense oligonucleotide targeting calpain-2 for ALS, which demonstrated general tolerability in its Phase 1 LUMINA trial. Additionally, the company is progressing AMX0035 (the same asset as Relyvrio) for Wolfram syndrome, having reported encouraging long-term data from a Phase 2 trial in May 2025, showing sustained stabilization or improvement in multiple disease outcomes.

Avexitide's Broader Therapeutic Potential Beyond PBH

Beyond its lead indication in post-bariatric hypoglycemia, avexitide (exendin 9-39) is being investigated in congenital hyperinsulinism (CHI), a rare pediatric disorder characterised by persistent hypoglycaemia driven by excessive insulin secretion from pancreatic β-cells. CHI arises primarily from mutations in ATP-sensitive potassium channel genes (ABCC8, KCNJ11) and manifests in focal, diffuse, and atypical histological forms, each with distinct genetic profiles that influence treatment strategy. Avexitide is positioned among a newer generation of emerging GLP-1 receptor antagonist therapies currently entering clinical evaluation for this condition.

• GLP-1 receptor antagonism as a mechanism in CHI: Avexitide's utility in CHI is predicated on its antagonism of GLP-1 receptors, which contribute to pathological insulin hypersecretion in affected patients — the same mechanistic rationale underpinning its efficacy in PBH.

• Active clinical trial status: As of 2025, avexitide is listed among emerging investigational therapies for CHI that are currently under clinical trials, alongside novel glucagon analogues, monoclonal antibodies targeting insulin receptors, and selective somatostatin receptor agonists.

• Intervention model details not yet reported: The specific trial design parameters for avexitide in CHI — including phase, dosing regimen, patient population, and primary endpoints — have not been described in the available published literature at this time.

Addressing Critical Unmet Needs in Post-Bariatric Hypoglycemia

Post-bariatric hypoglycemia (PBH) is an increasingly recognized and clinically burdensome complication, affecting up to one-third of patients following Roux-en-Y gastric bypass (RYGB), with cumulative incidence rising to 35.4% at 18 months post-surgery. Despite its prevalence, the condition remains under-diagnosed and inadequately managed, with no approved pharmacotherapy and a fragmented evidence base. There is an urgent, consensus-driven call for standardized PBH definitions, patient-centered outcome measures, and adequately powered RCTs to establish evidence-based therapeutic guidelines.

• Absence of approved pharmacotherapy and limited evidence quality: No pharmacologic agent is currently approved for PBH. Meta-analytic evidence rates the certainty of available pharmacologic data as very low, hampered by small sample sizes, heterogeneous PBH definitions, and imprecise effect estimates. Agents under evaluation — including pasireotide, anakinra, empagliflozin, GLP-1 receptor antagonists, GLP-1 receptor agonists, and stable glucagon formulations — have shown variable or inconclusive results across single-intervention studies and case reports.

• Delayed recognition and diagnostic gaps: Recognition and treatment of PBH are frequently delayed due to its rarity in the general non-diabetic adult population and a low level of clinical awareness. Non-diabetic patients presenting with unexplained postprandial hypoglycemia after bariatric surgery require evaluation of both insulin-mediated and non-insulin-mediated etiologies, including hormonal deficiencies such as adult growth hormone deficiency — a diagnostic complexity that is not yet systematically addressed in clinical workflows.

• Unmet need for standardized outcome measures and longer follow-up: Current literature lacks patient-centered outcome instruments and longitudinal data. Baseline measures of hypoglycemic event frequency, disability burden, and hypoglycemia-related worry are high among PBH patients, yet trials rarely extend beyond short-term follow-up, limiting understanding of disease trajectory and therapeutic durability.

• CGM as a first-line tool with forecasting potential still under evaluation: Unblinded continuous glucose monitoring (CGM) has demonstrated meaningful clinical impact — reducing symptom-triggered hypoglycemic events 6-fold (P = .008) and improving glucose nadir by >8 mg/dL (P = .005) — and is now considered a first-line intervention. However, CGM-guided predictive forecasting algorithms remain investigational; a 59-participant trial showed a non-significant reduction in hypoglycemia incidence (31% vs. 44%, P = 0.30), with simulations suggesting a 10 g preventive glucose dose could reduce incidence to 9%, warranting further study.

• Incomplete meal data and monitoring burden in free-living conditions: Meal information is frequently incomplete in PBH management, as manual dietary recording is burdensome and error-prone. This represents a practical unmet need, particularly for patients monitored over extended free-living periods (up to nearly 50 days), where automated or integrated meal-tracking solutions are lacking.

• Key populations being targeted: Primary focus is on non-diabetic patients post-RYGB — particularly those with younger age at surgery, female sex, early dumping syndrome, vitamin B1/B12 deficiency, and lower 120-minute glucose on preoperative OGTT, all identified as significant PBH risk factors. Additional populations include patients more than a decade post-RYGB presenting with recurrent abdominal pain and gastrointestinal symptoms, post-sleeve gastrectomy patients with recurrent postprandial hypoglycemia, and patients following upper gastrointestinal cancer or anti-reflux surgery. Notably, having type 2 diabetes, higher baseline HbA1c, and longer diabetes duration are identified as protective factors, distinguishing this population from typical diabetic hypoglycemia cohorts.

• Behavioral and digital intervention gap: The HypoPals digital behavioral intervention — comprising hypoglycemia symptom detection training and psychoeducation targeting unhelpful hypoglycemia beliefs — demonstrated strong feasibility in a 52-week pilot (n = 40; 98% retention; 88% found it at least somewhat helpful; no intervention-related adverse events). This signals an unmet need for structured behavioral support programs in PBH, an area largely absent from current management frameworks.

Amylyx's Strategic Pivot: A New Chapter Post-Relyvrio

The pharmaceutical landscape for neurodegenerative diseases, particularly amyotrophic lateral sclerosis (ALS), remains one of the most challenging and high-risk areas for drug development. Amylyx's recent decision to withdraw AMX0035 (Relyvrio) from the market, following a failed Phase 3 trial, starkly illustrates these difficulties. Relyvrio's journey, from a conditional approval based on a small Phase 2 study to its eventual withdrawal, highlights the critical importance of robust confirmatory data, especially for drugs targeting fatal conditions with limited treatment options. Studies indicated that while the Phase 2 trial showed a slower functional decline, secondary outcomes were not significantly different, and real-world use revealed high discontinuation rates primarily due to gastrointestinal side effects and taste issues. The subsequent negative Phase 3 results underscored the limitations of early approvals and the need for definitive efficacy evidence.

In response to this significant setback, Amylyx is executing a strategic pivot, shifting its immediate focus to avexitide, a GLP-1 receptor antagonist for post-bariatric hypoglycemia (PBH). This move into a rare endocrine condition, with an anticipated regulatory submission and launch next year, represents a calculated effort to de-risk the company's pipeline and establish a more stable commercial foundation. While this strategy offers a potential pathway to market in a less competitive therapeutic area, the efficacy and safety profile of avexitide for PBH are not detailed in the existing literature, meaning its success hinges entirely on the upcoming pivotal study results.

Despite the pivot, Amylyx maintains its commitment to neurodegenerative diseases, continuing development of AMX0114 for ALS and AMX0035 for Wolfram syndrome. However, this continued investment in a high-risk area, following the Relyvrio experience, means the company still faces significant development hurdles. The prior controversial approval and subsequent withdrawal of AMX0035 could also cast a long shadow, potentially impacting future regulatory interactions and market perception of new assets. This strategic reorientation by Amylyx reflects a broader industry trend where companies, facing setbacks in challenging disease areas, seek to diversify their portfolios into indications with clearer regulatory pathways and potentially higher probabilities of success.