Mucopolysaccharidoses (MPSs) are characterized by deficient activity of lysosomal hydrolase enzymes, leading to progressive accumulation of glycosaminoglycans. These glycosaminoglycans can be assayed in biofluids as potential markers of disease severity and response to disease-modifying therapies. This study sought to calculate control reference intervals in a largely pediatric population for key MPS biomarkers: heparan sulfate (HS) and dermatan sulfate (DS) in cerebrospinal fluid (CSF) and urine, and CSF monosialic gangliosides GM2 and GM3. We also explored the effect of age on biomarker levels. Biomarker levels were measured using liquid chromatography-tandem mass spectrometry in CSF and urine samples from pediatric and young adult donors and were compared with baseline CSF and urine biomarker levels from an ongoing Phase 1/2 study of children with MPS II. Age-specific reference intervals were estimated for CSF HS, DS, and GM2, and for urine HS, DS, and the sum of HS and DS, after observing that levels of these markers decreased with age. CSF GM3 levels were not found to be age dependent, therefore a single reference interval was estimated for the reference population. In patients with MPS II, levels of HS and DS, respectively, were 6- and 7-fold higher in CSF, and 13- and 30-fold higher in urine than the upper reference interval limits. Establishing age-specific reference intervals will help to optimize biomarker use in clinical studies.
BACKGROUND:Tividenofusp alfa, comprising iduronate-2-sulfatase fused to an engineered transferrin receptor-binding Fc domain, has been developed to treat neurologic and peripheral manifestations of mucopolysaccharidosis type II (MPS II), a rare lysosomal disorder causing progressive multisystem and neurologic decline. METHODS:We conducted a phase 1-2, open-label study in which male participants up to 18 years of age with MPS II received weekly intravenous tividenofusp alfa for 24 weeks, followed by an 80-week safety extension and a 157-week open-label extension. The primary objective was to evaluate the safety of tividenofusp alfa. Secondary objectives were to evaluate central nervous system and peripheral effects as assessed by cerebrospinal fluid (CSF) and urinary heparan sulfate levels, adaptive behavior (as assessed with the Vineland Adaptive Behavior Scales), and liver volume. RESULTS:A total of 47 male participants were enrolled. At the 24-week primary analysis, all 47 participants reported at least one adverse event that emerged during the treatment period, most commonly infusion-related reactions. Pyrexia, urticaria, and vomiting were the most frequently reported symptoms of infusion-related reactions, occurring in more than 40% of the participants, despite routine premedication. Three participants had serious treatment-related adverse events; all continued to receive treatment. CSF and urinary heparan sulfate levels appeared to be reduced from baseline by 91% and 88%, respectively. Across all study periods, adverse events remained common. Reductions in heparan sulfate levels appeared to be maintained through week 153, adaptive behavior stabilized or improved, and liver volumes normalized or remained normal. CONCLUSIONS:In participants with MPS II, tividenofusp alfa treatment was commonly associated with adverse events. Heparan sulfate, the primary substrate that accumulates in the CSF and urine in persons with MPS II, appeared to decrease to levels within the range of unaffected children. A randomized trial is ongoing to further evaluate these effects. (Funded by Denali Therapeutics; ClinicalTrials.gov number, NCT04251026; EudraCT number, 2019-004909-27.).
Disentangling the effects of disease activity associated with focal inflammation, e.g., as characterized by relapses, and other pathophysiological processes leading to disability progression in multiple sclerosis (MS) is of central importance. This is because it will provide an enhanced understanding of the pathology of MS, and may have implications for treating patients. Recently, this endeavor has lead researchers to characterize progression independent of relapse activity (PIRA), which has been defined as a counterfactual outcome representing disability progression without relapses. To date, several methods based on data pre-processing have been proposed to characterize PIRA, e.g., censoring onset of disability progression at onset of relapses. However, these methods can be subject to severe bias if relapse-progression confounders are present and lead to highly imprecise inference if most of the data is unused. In this article, we perform simulations to demonstrate that, unlike these methods, the parametric g-computation formula can provide unbiased inference on PIRA in the presence of relapse-progression confounders. Additionally, we utilize new results on the g-computation formula to estimate treatment effects that provide complementary information, and require less extrapolation to be estimated than the treatment effect on PIRA. Finally, we apply our proposed methodology to two phase 3 studies of MS to highlight the benefits and additional insights that it generates over standard methods.
Background Clinical trials comparing the efficacy of ocrelizumab (OCR) with other disease-modifying therapies (DMTs) other than interferon (IFN) β-1a in relapsing multiple sclerosis (RMS) are lacking. Objectives To compare the treatment effect of OCR vs six DMTs’ (IFN β-1a, glatiramer acetate, fingolimod, dimethyl fumarate, teriflunomide, natalizumab) treatment pathways used in clinical practice by combining clinical trial and real-world data. Methods Patient-level data from OPERA trials and open-label extension phase, and from the German NeuroTransData (NTD) MS registry, were used to build 1:1 propensity score-matched (PSM) cohorts controlling for seven baseline covariates, including brain imaging activity. Efficacy outcomes were time to first relapse and time to 24-week confirmed disability progression over 5.5 years of follow-up. Intention-to-treat analysis using all outcome data irrespective of treatment switch was applied. Results The analyses included 611 OPERA patients and 7141 NTD patients. We built 12 paired-matched cohorts (six for each outcome, two for each DMT) to compare efficacy of OCR in OPERA with each DMT treatment pathway in NTD. Post-matching, baseline covariates and PS were well balanced (standardized mean difference <.2 for all cohorts). Over 5.5 years, patients treated with OCR showed a statistically significant reduction in the risk of relapse (hazard ratios [HRs] .30 to .54) and disability progression (HRs .51 to .67) compared with all index therapies and their treatment switching pathways in NTD. Treatment switch and/or discontinuation occurred frequently in NTD cohorts. Conclusion OCR demonstrates superiority in controlling relapses and disability progression in RMS compared with real-world treatment pathways over a 5.5-year period. These analyses suggest that high-efficacy DMTs and high treatment persistence are critical to achieve greatest clinical benefit in RMS. Registration OPERA I (NCT01247324), OPERA II (NCT01412333)
BackgroundNeurofilament light chain (NfL), a neuronal cytoskeletal protein that is released upon neuroaxonal injury, is associated with multiple sclerosis (MS) relapsing activity and has demonstrated some prognostic ability for future relapse-related disease progression, yet its value in assessing non-relapsing disease progression remains unclear.MethodsWe examined baseline and longitudinal blood NfL levels in 1421 persons with relapsing MS (RMS) and 596 persons with primary progressive MS (PPMS) from the pivotal ocrelizumab MS trials. NfL treatment-response and risk for disease worsening (including disability progression into the open-label extension period and slowly expanding lesions [SELs] on brain MRI) at baseline and following treatment with ocrelizumab were evaluated using time-to-event analysis and linear regression models.FindingsIn persons from the RMS control arms without acute disease activity and in the entire PPMS control arm, higher baseline NfL was prognostic for greater whole brain and thalamic atrophy, greater volume expansion of SELs, and clinical progression. Ocrelizumab reduced NfL levels vs. controls in persons with RMS and those with PPMS, and abrogated the prognostic value of baseline NfL on disability progression. Following effective suppression of relapse activity by ocrelizumab, NfL levels at weeks 24 and 48 were significantly associated with long-term risk for disability progression, including up to 9 years of observation in RMS and PPMS.InterpretationHighly elevated NfL from acute MS disease activity may mask a more subtle NfL abnormality that reflects underlying non-relapsing progressive biology. Ocrelizumab significantly reduced NfL levels, consistent with its effects on acute disease activity and disability progression. Persistently elevated NfL levels, observed in a subgroup of persons under ocrelizumab treatment, demonstrate potential clinical utility as a predictive biomarker of increased risk for clinical progression. Suppression of relapsing biology with high-efficacy immunotherapy provides a window into the relationship between NfL levels and future non-relapsing progression.FundingF. Hoffmann-La Roche Ltd.
Background and Objectives Ocrelizumab improved clinical and MRI measures of disease activity and progression in three phase 3 multiple sclerosis (MS) studies. Post hoc analyses demonstrated a correlation between the ocrelizumab serum concentration and the degree of blood B-cell depletion, and body weight was identified as the most influential covariate on ocrelizumab pharmacokinetics. The magnitude of ocrelizumab treatment benefit on disability progression was greater in lighter vs heavier patients. These observations suggest that higher ocrelizumab serum levels provide more complete B-cell depletion and a greater delay in disability progression. The current post hoc analyses assessed population exposure–efficacy/safety relationships of ocrelizumab in patients with relapsing and primary progressive MS. Methods Patients in OPERA I/II and ORATORIO were grouped in exposure quartiles based on their observed individual serum ocrelizumab level over the treatment period. Exposure–response relationships were analyzed for clinical efficacy (24-week confirmed disability progression (CDP), annualized relapse rate [ARR], and MRI outcomes) and adverse events. Results Ocrelizumab reduced new MRI lesion counts to nearly undetectable levels in patients with relapsing or primary progressive MS across all exposure subgroups, and reduced ARR in patients with relapsing MS to very low levels (0.13–0.18). A consistent trend of higher ocrelizumab exposure leading to lower rates of CDP was seen (0%–25% [lowest] to 75%–100% [highest] quartile hazard ratios and 95% confidence intervals; relapsing MS: 0.70 [0.41–1.19], 0.85 [0.52–1.39], 0.47 [0.25–0.87], and 0.34 [0.17–0.70] vs interferon β-1a; primary progressive MS: 0.88 [0.59–1.30], 0.86 [0.60–1.25], 0.77 [0.52–1.14], and 0.55 [0.36–0.83] vs placebo). Infusion-related reactions, serious adverse events, and serious infections were similar across exposure subgroups. Discussion The almost complete reduction of ARR and MRI activity already evident in the lowest quartile, and across all ocrelizumab-exposure groups, suggests a ceiling effect. A consistent trend of higher ocrelizumab exposure leading to greater reduction in risk of CDP was observed, particularly in the relapsing MS trials, and was not associated with a higher rate of adverse events. Higher ocrelizumab exposure may provide improved control of disability progression by reducing disease activity below that detectable by ARR and MRI, and/or by attenuating other B-cell–related pathologies responsible for tissue damage. Classification of Evidence This analysis provides Class III evidence that higher ocrelizumab serum levels are related to greater reduction in risk of disability progression in patients with multiple sclerosis. The study is rated Class III because of the initial treatment randomization disclosure that occurred after inclusion in the open-label extension. Trial Registration Information ClinicalTrials.gov Identifier: NCT01247324 (OPERA I), NCT01412333 (OPERA II), and NCT01194570 (ORATORIO).
In clinical development, it is useful to characterize the causal relationship between individual drug concentrations and clinical outcomes in large phase III trials of new therapeutic agents because it can provide insights on whether increasing the currently administered drug dose may lead to better outcomes. However, estimating causal effects of drug concentration is complicated by the fact that drug concentration is a continuous measure and it is usually influenced by patient-level prognostic characteristics such as body weight and sex. In this article, we compare two approaches to estimate causal effects of continuous point exposures on time-to-event outcomes: (a) outcome regression (OR) and (b) weighting. In particular, we make the first direct comparison of the balancing weights, inverse probability weighting and OR methods for estimating the effects of continuous exposures on time-to-event outcomes in simulations and demonstrate that these methods can exhibit markedly different behaviours that subsequently lead to a change in the conclusions. To improve weighted exposure effect estimators, we also propose a new simple-to-apply diagnostic to detect when such estimators might be subject to severe bias, and demonstrate its effectiveness in simulations. Finally, we apply these methods to an example of multiple sclerosis drug development by providing causal effect estimates of average ocrelizumab concentrations on time-to-event disability progression outcomes.
Supplementary Table S2 from Association of DNA Methylation of Phosphoserine Aminotransferase with Response to Endocrine Therapy in Patients with Recurrent Breast Cancer
Chronotropic incompetence, measured by the percentage (%) of heart rate (HR) reserve achieved (%HR reserve), abnormal HR recovery, reduced exercise capacity (EC), and myocardial perfusion single-photon emission computerized tomography (SPECT MPS) abnormalities are known predictors of all-cause mortality (ACM) and cardiac death (CD). The aim of this study was to determine if EC, %HR reserve, and HR recovery add incremental value to MPS in the prediction of ACM and CD. A total of 11,218 patients without valvular disease and not on β blockers underwent symptom-limited exercise MPS. %HR reserve was (peak HR − rest HR)/(220 − age − rest HR) × 100, with %HR reserve <80 defined as low. HR recovery was peak HR − recovery HR. An HR recovery <22 beats/min at 2 minutes after peak exercise was considered abnormal. Poor EC was defined as exercise duration ≤6 minutes (7 metabolic equivalents). Summed stress scores (SSSs) were calculated using a 20-segment, 5-point MPS model. Statistical analysis was performed using Cox regression models. There were 445 deaths (148 CD) during a mean follow-up of 3.2 ± 2.5 years. In multivariate analysis, the independent predictors of ACM were age, χ2 = 154.81; EC, χ2 = 74.00; SSS, χ2 = 32.99; %HR reserve, χ2 = 24.74; abnormal electrocardiogram at rest, χ2 = 23.13; HR recovery, χ2 = 18.45; diabetes, χ2 = 17.75; and previous coronary artery disease, χ2 = 11.85 (p ≤0.0006). The independent predictors of CD were SSS, χ2 = 54.25; EC, χ2 = 49.34; age, χ2 = 46.45; abnormal electrocardiogram at rest, χ2 = 30.60; previous coronary artery disease, χ2 = 20.69; Duke treadmill score, χ2 = 19.50; %HR reserve, χ2 = 11.43; diabetes, χ2 = 10.23 (all p ≤0.0014); and HR recovery, χ2 = 5.30 (p = 0.0214). The exercise variables showed increases in Harrell's C static and net improvement reclassification, with EC showing the strongest incremental improvement in predicting ACM and CD (respective C-index 76.5% and 83.3% and net reclassification index 0.3201 and 0.4996). In conclusion, EC, %HR reserve, and HR recovery are independent predictors of ACM and CD and add incremental prognostic value to extent and severity of MPS.
Supplementary Table S3 from Identification and Validation of Colorectal Neoplasia–Specific Methylation Markers for Accurate Classification of Disease
Supplementary Table S2 from Identification and Validation of Colorectal Neoplasia–Specific Methylation Markers for Accurate Classification of Disease
Supplementary Table S1 from Association of DNA Methylation of Phosphoserine Aminotransferase with Response to Endocrine Therapy in Patients with Recurrent Breast Cancer
Supplementary Table S1 from Identification and Validation of Colorectal Neoplasia–Specific Methylation Markers for Accurate Classification of Disease
Supplementary Table S4 from Identification and Validation of Colorectal Neoplasia–Specific Methylation Markers for Accurate Classification of Disease
Background: The current standard endpoint to assess disability accumulation in multiple sclerosis (MS) clinical trials is the time to the first confirmed disability progression, which excludes subsequent progression events. Including recurrent progression events may permit a more comprehensive assessment of treatment effects on disability progression. Objective: To propose a definition of recurrent disability progression events and to compare time-to-first and recurrent event analysis. Methods: Recurrent disability progression events were defined by expanding the recommended first event definition. Marginal recurrent event methods (negative binomial model, Lin–Wei–Yang–Ying model) were compared with Cox regression in data from three randomized controlled trials in relapsing multiple sclerosis (RMS) and primary progressive multiple sclerosis (PPMS), and in simulated randomized controlled trial data. Results: The recurrent event analyses included a substantially larger number of progression events compared with the time-to-first-event analyses (+7.5% and +9.9% in the RMS trials and +22.7% in the PPMS trial). The increase in the number of events resulted in more precise treatment effect estimates and a corresponding gain in statistical power. Conclusion: Our results support the use of recurrent event data analysis, especially in progressive MS trials, to improve estimates of treatment effects, increase statistical power, and better capture the clinically meaningful long-term disability progression experience.