Triheptanoin Did Not Show Benefit versus Placebo for the Treatment of Paroxysmal Movement Disorders in Glut1 Deficiency Syndrome: Results of a Randomized Phase 3 Study.

BACKGROUND: Paroxysmal movement disorders are common in Glut1 deficiency syndrome (Glut1DS). Not all patients respond to or tolerate ketogenic diets. OBJECTIVES: The objective was to evaluate the effectiveness and safety of triheptanoin in reducing the frequency of disabling movement disorders in patients with Glut1DS not receiving a ketogenic diet. METHODS: UX007G-CL301 was a randomized, double-blind, placebo-controlled, phase 3 crossover study. After a 6-week run-in, eligible patients were randomized 1:1 to the first sequence (triheptanoin/placebo or placebo/triheptanoin) titration plus maintenance, followed by washout and the opposite sequence titration plus maintenance. The placebo (safflower oil) matched the appearance, taste, and smell of triheptanoin. Open-label triheptanoin was administered in the extension. The frequency of disabling paroxysmal movement disorder events per 4 weeks (recorded by diary during maintenance; primary endpoint) was assessed by Wilcoxon rank-sum test. RESULTS: Forty-three patients (children, n = 16; adults, n = 27) were randomized and treated. There was no difference between triheptanoin and placebo in the mean (interquartile range) number of disabling paroxysmal movement disorder events (14.3 [4.7-38.3] vs. 11.8; [3.2-28.7]; Hodges-Lehmann estimated median difference: 1.46; 95% confidence interval, -1.12 to 4.36; P = 0.2684). Treatment-emergent adverse events were mild/moderate in severity and included diarrhea, vomiting, upper abdominal pain, headache, and nausea. Two patients discontinued the study because of non-serious adverse events that were predominantly gastrointestinal. The study was closed early during the open-label extension because of lack of effectiveness. Seven patients continued to receive triheptanoin compassionately. CONCLUSION: There were no significant differences between the triheptanoin and placebo groups in the frequency of disabling movement disorder events during the double-blind maintenance period. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

A randomized, double-blind trial of triheptanoin for drug-resistant epilepsy in glucose transporter 1 deficiency syndrome.

OBJECTIVE: This study was undertaken to evaluate efficacy and long-term safety of triheptanoin in patients >1 year old, not on a ketogenic diet, with drug-resistant seizures associated with glucose transporter 1 deficiency syndrome (Glut1DS). METHODS: UX007G-CL201 was a randomized, double-blind, placebo-controlled trial. Following a 6-week baseline period, eligible patients were randomized 3:1 to triheptanoin or placebo. Dosing was titrated to 35% of total daily calories over 2 weeks. After an 8-week placebo-controlled period, all patients received open-label triheptanoin through Week 52. RESULTS: The study included 36 patients (15 children, 13 adolescents, eight adults). A median 12.6% reduction in overall seizure frequency was observed in the triheptanoin arm relative to baseline, and a 13.5% difference was observed relative to placebo (p = .58). In patients with absence seizures only (n = 9), a median 62.2% reduction in seizure frequency was observed in the triheptanoin arm relative to baseline. Only one patient with absence seizures only was present in the control group, preventing comparison. No statistically significant differences in seizure frequency were observed. Common treatment-emergent adverse events included diarrhea, vomiting, abdominal pain, and nausea, mostly mild or moderate in severity. No serious adverse events were considered to be treatment related. One patient discontinued due to status epilepticus. SIGNIFICANCE: Triheptanoin did not significantly reduce seizure frequency in patients with Glut1DS not on the ketogenic diet. Treatment was associated with mild to moderate gastrointestinal treatment-related events; most resolved following dose reduction or interruption and/or medication for treatment. Triheptanoin was not associated with any long-term safety concerns when administered at dose levels up to 35% of total daily caloric intake for up to 1 year.

Results from a 3-year Non-interventional, Observational Disease Monitoring Program in Adults with GNE Myopathy.

BACKGROUND: GNE myopathy is a rare, autosomal recessive, muscle disease caused by mutations in GNE and is characterized by rimmed vacuoles on muscle biopsy and progressive distal to proximal muscle weakness. OBJECTIVE: Investigate the clinical presentation and progression of GNE myopathy. METHODS: The GNE Myopathy Disease Monitoring Program was an international, prospective, observational study in subjects with GNE myopathy. Muscle strength was assessed with hand-held dynamometry (HHD), with upper extremity (UE) and lower extremity (LE) composite scores reflecting upper and lower extremity muscle groups, respectively. The GNE myopathy-Functional Activity Scale (GNEM-FAS) was used to further assess impairment in mobility, upper extremity function, and self-care. RESULTS: Eighty-seven of 101 enrolled subjects completed the trial until study closure by the sponsor; 60 completed 36 months. Mean (SD) HHD UE composite score decreased from 34.3 kg (32.0) at baseline to 29.4 kg (32.6) kg at month 36 (LS mean change [95%CI]: -3.8 kg [-5.9, -1.7]; P = 0.0005). Mean (SD) HHD LE composite score decreased from 32.0 kg (34.1) at baseline to 25.5 kg (31.2) at month 36 (LS mean change [95%CI]: -4.9 [-7.7, -2.2]; P = 0.0005). GNEM-FAS scores were more severe at baseline in subjects who walked <200 meters versus ≥200 meters in 6 minutes; in both groups, GNEM-FAS total, mobility, UE, and self-care scores decreased from baseline through month 36. CONCLUSIONS: These findings demonstrate progressive decline in muscle strength in GNE myopathy and provide insight into the appropriate tools to detect clinically meaningful changes in future GNE myopathy interventional trials.

Retrospective chart review of urinary glycosaminoglycan excretion and long-term clinical outcomes of enzyme replacement therapy in patients with mucopolysaccharidoses.

BACKGROUND: Mucopolysaccharidoses (MPS) are a group of rare, inherited metabolic diseases that result from a deficiency in one of several lysosomal enzymes essential for stepwise glycosaminoglycan (GAG) degradation, leading to GAG accumulation and widespread cellular pathology and clinical disease. Although disease presentation is heterogeneous, the clinical hallmarks are largely comparable across several MPS subtypes. Extensive data have shown that the level of urinary GAG (uGAG) excretion above normal is strongly correlated with disease severity and clinical outcomes in MPS diseases. Thus, change in uGAG excretion may have significant value as a potential primary endpoint in clinical trials of MPS diseases that are too rare to study using traditional clinical endpoints. METHODS: A retrospective medical chart review was undertaken of patients with MPS I, II, and VI who had been treated long term with enzyme replacement therapy (ERT). The relationship between uGAG reduction and clinical outcomes relevant to the major clinical manifestations of these MPS diseases was evaluated. A multi-domain responder index (MDRI) score was calculated, measuring the following 4 domains: 6-min walk test, pulmonary function, growth rate, and Clinician Global Impression of Change. For each domain, a minimal important difference (MID) was defined based on published information of these outcome measures in MPS and other diseases. RESULTS: Of the 50 patients evaluated, 18 (36%) had MPS I, 23 (46%) had MPS II, and 9 (18%) had MPS VI. Forty-two were clinical practice patients and 8 had participated in clinical trials. Across all MPS subtypes, the mean (± SD) uGAG level at baseline was 66.0 ± 51.5 mg/mmol creatinine (n = 48) and there was a mean reduction of 54.6% following ERT. Analysis of the MDRI score based on the MID defined for each domain showed a greater magnitude of improvement in patients with increased uGAG reduction when compared with those patients with lower uGAG reduction for all assessed uGAG thresholds, and a trend toward a higher likelihood of positive mean MDRI score in patients with a uGAG reduction ≥40%. CONCLUSIONS: In this retrospective study, uGAG reduction was associated with long-term clinical outcomes as assessed by a number of approaches, supporting the use of uGAG reduction as a biomarker primary endpoint.

A phase 3 randomized study evaluating sialic acid extended-release for GNE myopathy.

OBJECTIVE: To investigate the efficacy and safety of aceneuramic acid extended-release (Ace-ER), a treatment intended to replace deficient sialic acid, in patients with GNE myopathy. METHODS: UX001-CL301 was a phase 3, double-blind, placebo-controlled, randomized, international study evaluating the efficacy and safety of Ace-ER in patients with GNE myopathy. Participants who could walk ≥200 meters in a 6-minute walk test at screening were randomized 1:1, and stratified by sex, to receive Ace-ER 6 g/d or placebo for 48 weeks and assessed every 8 weeks. The primary endpoint was change in muscle strength over 48 weeks measured by upper extremity composite (UEC) score. Key secondary endpoints included change in lower extremity composite (LEC) score, knee extensor strength, and GNE myopathy-Functional Activity Scale (GNEM-FAS) mobility domain score. Safety assessments included adverse events (AEs), vital signs, and clinical laboratory results. RESULTS: Eighty-nine patients were randomized (Ace-ER n = 45; placebo n = 44). Change from baseline to week 48 for UEC score between treatments did not differ (least square mean [LSM] Ace-ER -2.25 kg vs placebo -2.99 kg; LSM difference confidence interval [CI] 0.74 [-1.61 to 3.09]; p = 0.5387). At week 48, there was no significant difference between treatments for the change in key secondary endpoints: LEC LSM difference (CI) -1.49 (-5.83 to 2.86); knee extension strength -0.40 (-2.38 to 1.58); and GNEM-FAS mobility domain score -0.72 (-2.01 to 0.57). Gastrointestinal events were the most common AEs. CONCLUSIONS: Ace-ER was not superior to placebo in improving muscle strength and function in patients with GNE myopathy. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with GNE myopathy, Ace-ER does not improve muscle strength compared to placebo.

Aceneuramic Acid Extended Release Administration Maintains Upper Limb Muscle Strength in a 48-week Study of Subjects with GNE Myopathy: Results from a Phase 2, Randomized, Controlled Study.

BACKGROUND: GNE Myopathy (GNEM) is a progressive adult-onset myopathy likely caused by deficiency of sialic acid (SA) biosynthesis. OBJECTIVE: Evaluate the safety and efficacy of SA (delivered by aceneuramic acid extended-release [Ace-ER]) as treatment for GNEM. METHODS: A Phase 2, randomized, double-blind, placebo-controlled study evaluating Ace-ER 3 g/day or 6 g/day versus placebo was conducted in GNEM subjects (n = 47). After the first 24 weeks, placebo subjects crossed over to 3 g/day or 6 g/day for 24 additional weeks (dose pre-assigned during initial randomization). Assessments included serum SA, muscle strength by dynamometry, functional assessments, clinician- and patient-reported outcomes, and safety. RESULTS: Dose-dependent increases in serum SA levels were observed. Supplementation with Ace-ER resulted in maintenance of muscle strength in an upper extremity composite (UEC) score at 6 g/day compared with placebo at Week 24 (LS mean difference +2.33 kg, p = 0.040), and larger in a pre-specified subgroup able to walk ≥200 m at Screening (+3.10 kg, p = 0.040). After cross-over, a combined 6 g/day group showed significantly better UEC strength than a combined 3 g/day group (+3.46 kg, p = 0.0031). A similar dose-dependent response was demonstrated within the lower extremity composite score, but was not significant (+1.06 kg, p = 0.61). The GNEM-Functional Activity Scale demonstrated a trend improvement in UE function and mobility in a combined 6 g/day group compared with a combined 3 g/day group. Patients receiving Ace-ER tablets had predominantly mild-to-moderate AEs and no serious adverse events. CONCLUSIONS: This is the first clinical study to provide evidence that supplementation with SA delivered by Ace-ER may stabilize muscle strength in individuals with GNEM and initiating treatment earlier in the disease course may lead to better outcomes.

Pralatrexate is an effective treatment for relapsed or refractory transformed mycosis fungoides: a subgroup efficacy analysis from the PROPEL study.

UNLABELLED: Transformed mycosis fungoides (tMF) is an aggressive disease with a median survival of 12-24 months. In this retrospective analysis of 12 patients with tMF, treatment with pralatrexate resulted in an objective response of 25% per independent central review and 58% per investigator assessment. Pralatrexate was well tolerated, with no toxicity-related discontinuations, which makes this an additional option for tMF treatment. BACKGROUND: Transformed mycosis fungoides (tMF) is an aggressive disease, with poor prognosis and a median survival of 24 months. PATIENTS AND METHODS: In the Pralatrexate in Patients With Relapsed or Refractory Peripheral T-cell Lymphoma (PROPEL) study, 12 patients with tMF were treated with a median of 10 pralatrexate doses (starting dose of 30 mg/m(2)) administered weekly for 6 weeks in a 7-week cycle. The median number of prior systemic therapies was 3. RESULTS: This retrospective analysis showed that the objective response rate in this subgroup was 25% (n = 3) per independent central review and 58% (n = 7) per investigator assessment, with this discrepancy likely attributed to challenges with photodocumentation of cutaneous lesions. The median duration of response and the median progression-free survival were 2.2 and 1.7 months, respectively, per central review, whereas median duration of response was 4.4 months, and median progression-free survival was 5.3 months per investigator assessment. Median survival was 13 months. Grade 1-3 mucositis was reported in 7 (58%) patients. Grade 4 adverse events were fatigue (n = 1) and thrombocytopenia (n = 1). Pralatrexate was well tolerated, with no toxicity-related discontinuations. CONCLUSIONS: Based on these results, pralatrexate may be a treatment option for patients with relapsed or refractory tMF.

Randomized phase 2b study of pralatrexate versus erlotinib in patients with stage IIIB/IV non-small-cell lung cancer (NSCLC) after failure of prior platinum-based therapy.

INTRODUCTION: Pralatrexate, a folate analogue targeting dihydrofolate reductase, has antitumor activity in non-small-cell lung cancer (NSCLC). This randomized phase 2b trial was designed to further evaluate pralatrexate activity in NSCLC by estimating overall survival (OS) relative to erlotinib in patients with relapsed/refractory disease. METHODS: In 43 centers across 6 countries, patients were randomized 1:1 to receive intravenous pralatrexate 190 mg/m on days 1 and 15 of a 28-day cycle, or oral erlotinib 150 mg/day. The primary objective was to estimate OS in all patients and prespecified subgroups using relative comparisons of hazard ratios (HRs). Secondary endpoints included progression-free survival, response rate, and safety. Key eligibility criteria included: (1) ≥1 prior platinum-based therapy, (2) Eastern Cooperative Oncology Group performance status of 0 to 1, and 3) a smoking history of 100 cigarettes or more. RESULTS: A total of 201 patients were randomized. A trend toward improvement in OS favoring pralatrexate was observed with an HR of 0.84 (95% confidence interval: 0.61-1.14) in the intent-to-treat population. This favorable survival result was seen in most prespecified subgroups for pralatrexate. The largest reduction in the risk of death was observed in patients with nonsquamous cell carcinoma (n = 107; HR = 0.65; 95% confidence interval: 0.42-1.0). The most common grade 3 to 4 adverse event in the pralatrexate arm was mucositis (23%). Discontinuation of pralatrexate for any grade of mucositis was 21%. CONCLUSIONS: Pralatrexate demonstrated a trend toward improved survival relative to erlotinib in patients with advanced NSCLC. Future studies should include a mucositis management plan to improve tolerability and maximize treatment benefit.

Identification of an active, well-tolerated dose of pralatrexate in patients with relapsed or refractory cutaneous T-cell lymphoma.

Systemic treatment for cutaneous T-cell lymphoma (CTCL) involves the use of less aggressive, well-tolerated therapies. Pralatrexate is a novel antifolate with high affinity for reduced folate carrier-1. A dose de-escalation strategy identified recommended pralatrexate dosing for patients with CTCL that demonstrated high activity, good rates of disease control, and an acceptable toxicity profile for continuous long-term dosing. Eligibility included mycosis fungoides, Sézary syndrome, or primary cutaneous anaplastic large cell lymphoma, with disease progression after ≥ 1 prior systemic therapy. The starting dose and schedule was 30 mg/m(2)/wk intravenously for 3 of 4 (3/4) weeks. Subsequent starting doses were 20, 15, and 10 mg/m(2)/wk for 3/4 or 2 of 3 (2/3) weeks. Response was evaluated by the modified severity-weighted adjustment tool. Fifty-four patients were treated. The recommended regimen was identified as 15 mg/m(2)/wk for 3/4 weeks and was explored in the expansion cohort. In 29 patients treated overall with the recommended dosing regimen, the median number of prior systemic therapies was 4. Pralatrexate was administered for a median of 4 cycles; response rate was 45%. The most common grade 3 adverse event (AE) was mucositis (17%); the only grade 4 AE was leukopenia (3%). Pralatrexate 15 mg/m(2)/wk for 3/4 weeks shows high activity with acceptable toxicity in patients with relapsed/refractory CTCL.

Assessment of futility in clinical trials.

The term 'futility' is used to refer to the inability of a clinical trial to achieve its objectives. In particular, stopping a clinical trial when the interim results suggest that it is unlikely to achieve statistical significance can save resources that could be used on more promising research. There are various approaches that have been proposed to assess futility, including stochastic curtailment, predictive power, predictive probability, and group sequential methods. In this paper, we describe and contrast these approaches, and discuss several issues associated with futility analyses, such as ethical considerations, whether or not type I error can or should be reclaimed, one-sided vs two-sided futility rules, and the impact of futility analyses on power.