Early initiation of riluzole may improve absolute survival in amyotrophic lateral sclerosis

Identification and characterization of novel ERBB4 variant associated with sporadic amyotrophic lateral sclerosis (ALS)

Amyotrophic Lateral Sclerosis (ALS) is the most common type of motor neuron disease characterized by progressive motor neuron degeneration in brain and spinal cord. Most cases are sporadic in ALS and 5-10% of cases are familiar. >50 genes are known to be associated with ALS and one of them is ERBB4. In this paper, we report the case of a 53-year-old ALS patient with progressive muscle weakness and fasciculation, but he had no cognitive decline. We performed the next generation sequencing (NGS) and in silico analysis, it predicted a highly pathogenic variant, c.2116 A > G, p.Asn706Asp (N706D) in the ERBB4 gene. The amino acid residue is highly conserved among species. ERBB4 is a member of the ERBB family of receptor tyrosine kinases. ERBB4 has multiple tyrosine phosphorylation sites, including an autophosphorylation site at tyrosine 1284 residue. Autophosphorylation of ERBB4 promotes biological activity and it associated with NRG-1/ERBB4 pathway. It is already known that tyrosine 128 phosphorylation of ERBB4 is decreased in patients who have ALS-associated ERBB4 mutations. We generated ERBB4 N706D construct using site-directed mutagenesis and checked the phosphorylation level of ERBB4 N706D in NSC-34 cells. We found that the phosphorylation of ERBB4 N706D was decreased compared to ERBB4 wild-type, indicating a loss of function mutation in ERBB4. We report a novel variant in ERBB4 gene leading to ALS through dysfunction of ERBB4.

Adherence to riluzole therapy in patients with amyotrophic lateral sclerosis in three Italian regions-The CAESAR study

PURPOSE

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease. Riluzole may increase survival and delay the need for mechanical ventilation. The CAESAR project ('Comparative evaluation of the efficacy and safety of drugs used in rare neuromuscular and neurodegenerative diseases', FV AIFA project 2012-2013-2014) involves evaluating prescribing patterns, and analysing effectiveness and comparative safety of drugs, in patients with neurodegenerative diseases. The aim of this study is to evaluate adherence to riluzole in patients with ALS during the first year of use, identifying adherence clusters.

METHODS

A retrospective cohort study was conducted using administrative data from Latium, Tuscany, and Umbria. We identified subjects with a new diagnosis of ALS between 2014 and 2019, with the first dispensation of riluzole within 180 days of diagnosis. We considered a two-year look-back period for the characterization of patients, and we followed them from the date of first dispensing of riluzole for 1 year. We calculated 12 monthly adherence measures, through a modified version of the Medication Possession Ratio, estimating drug coverage with Defined Daily Dose. Adherence trajectories were identified using a three-step method: (1) calculation of statistical measures; (2) principal component analysis; (3) cluster analysis. Patient characteristics at baseline and during follow-up were described and compared between adherence groups identified.

RESULTS

We included 264 ALS patients as new users of riluzole in Latium, 344 in Tuscany, and 63 in Umbria. We observed a higher frequency of males (56.2%) and a mean age of 67.4 (standard deviation, SD, 10.4) in the overall population. We identified two clusters in all regions: one more numerous, including adherent patients (60%, 74%, 88%, respectively), and another one including patients who discontinued therapy (40%, 26%, 12%, respectively). In Tuscany patients discontinuing riluzole more frequently died (28.6% vs. 15.4%, p-value <0.01). Additionally, low-adherers had a higher frequency of central nervous system disorders (69.0% vs. 52.5%, p-value 0.01), and a greater use of non-pharmacological treatments (p-values ≤0.01 for invasive ventilation and tracheostomy). We did not observe any differences in Lazio, whereas in Umbria we observed a higher use of drugs for dementia-related psychiatric problems among low-adherers (57.1% vs. 7.8%, respectively, p-value <0.01), although with small numbers.

CONCLUSION

Most ALS patients who start riluzole adhere to therapy during the first year. Patients who discontinue therapy early show greater fragility and mortality.

A randomized, double-blind, placebo-controlled phase 2 study to assess safety, tolerability, and efficacy of RT001 in patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

RT001 is a deuterated synthetic homologue of linoleic acid, which makes membrane polyunsaturated fatty acids resistant to lipid peroxidation, a process involved in motor neuron degeneration in amyotrophic lateral sclerosis (ALS).

METHODS

We conducted a randomized, multicenter, placebo-controlled clinical trial. Patients with ALS were randomly allocated to receive either RT001 or placebo for 24 weeks. After the double-blind period, all patients received RT001 during an open-label phase for 24 weeks. The primary outcome measures were safety and tolerability. Key efficacy outcomes included the ALS Functional Rating Scale (ALSFRS-R), percent predicted slow vital capacity, and plasma neurofilament light chain concentration.

RESULTS

In total, 43 patients (RT001 = 21; placebo = 22) were randomized. RT001 was well tolerated; one patient required dose reduction due to adverse events (AEs). Numerically, there were more AEs in the RT001 group compared to the placebo group (71% versus 55%, p = 0.35), with gastrointestinal symptoms being the most common (43% in RT001, 27% in placebo, p = 0.35). Two patients in the RT001 group experienced a serious AE, though unrelated to treatment. The least-squares mean difference in ALSFRS-R total score at week 24 of treatment was 1.90 (95% confidence interval = -1.39 to 5.19) in favor of RT001 (p = 0.25). The directions of other efficacy outcomes favored RT001 compared to placebo, although no inferential statistics were performed.

CONCLUSIONS

Initial data indicate that RT001 is safe and well tolerated. Given the exploratory nature of the study, a larger clinical trial is required to evaluate its efficacy.