Access to clinically indicated genetic tests for pediatric patients with Medicaid: Evidence from outpatient genetics clinics in Texas

PurposeLittle is known about how Medicaid coverage policies affect access to genetic tests for pediatric patients. Building upon and extending a previous analysis of prior authorization requests (PARs), we describe expected coverage of genetic tests submitted to Texas Medicaid and the PAR and diagnostic outcomes of those tests.MethodsWe retrospectively reviewed genetic tests ordered at 3 pediatric outpatient genetics clinics in Texas. We compared Current Procedural Terminology (CPT) codes with the Texas Medicaid fee-for-service schedule (FFSS) to determine whether tests were expected to be covered by Medicaid. We assessed completion and diagnostic yield of commonly ordered tests.ResultsAmong the 3388 total tests submitted to Texas Medicaid, 68.9% (n = 2336) used at least 1 CPT code that was not on the FFSS and 80.7% (n = 2735) received a favorable PAR outcome. Of the tests with a CPT code not on the FFSS, 60.0% (n = 1400) received a favorable PAR outcome and were completed and 20.5% (n = 287) were diagnostic. The diagnostic yield of all tests with a favorable PAR outcome that were completed was 18.7% (n = 380/2029).ConclusionMost PARs submitted to Texas Medicaid used a CPT code for which reimbursement from Texas Medicaid was not guaranteed. The frequency with which clinically indicated genetic tests were not listed on the Texas Medicaid FFSS suggests misalignment between genetic testing needs and coverage policies. Our findings can inform updates to Medicaid policies to reduce coverage uncertainty and expand access to genetic tests with high diagnostic utility.     

Missense variants in RPH3A cause defects in excitatory synaptic function and are associated with a clinically variable neurodevelopmental disorder

PurposeRPH3A encodes a protein involved in the stabilization of GluN2A subunit of N-methyl-D-aspartate (NMDA)-type glutamate receptors at the cell surface, forming a complex essential for synaptic plasticity and cognition. We investigated the effect of variants in RPH3A in patients with neurodevelopmental disorders.MethodsBy using trio-based exome sequencing, GeneMatcher, and screening of 100,000 Genomes Project data, we identified 6 heterozygous variants in RPH3A. In silico and in vitro models, including rat hippocampal neuronal cultures, have been used to characterize the effect of the variants.ResultsFour cases had a neurodevelopmental disorder with untreatable epileptic seizures [p.(Gln73His)dn; p.(Arg209Lys); p.(Thr450Ser)dn; p.(Gln508His)], and 2 cases [p.(Arg235Ser); p.(Asn618Ser)dn] showed high-functioning autism spectrum disorder. Using neuronal cultures, we demonstrated that p.(Thr450Ser) and p.(Asn618Ser) reduce the synaptic localization of GluN2A; p.(Thr450Ser) also increased the surface levels of GluN2A. Electrophysiological recordings showed increased GluN2A-dependent NMDA ionotropic glutamate receptor currents for both variants and alteration of postsynaptic calcium levels. Finally, expression of the Rph3A^Thr450Ser variant in neurons affected dendritic spine morphology.ConclusionOverall, we provide evidence that missense gain-of-function variants in RPH3A increase GluN2A-containing NMDA ionotropic glutamate receptors at extrasynaptic sites, altering synaptic function and leading to a clinically variable neurodevelopmental presentation ranging from untreatable epilepsy to autism spectrum disorder.     

Genotype-phenotype correlations in RHOBTB2-associated neurodevelopmental disorders

PurposeMissense variants clustering in the BTB domain region of RHOBTB2 cause a developmental and epileptic encephalopathy with early-onset seizures and severe intellectual disability.MethodsBy international collaboration, we assembled individuals with pathogenic RHOBTB2 variants and a variable spectrum of neurodevelopmental disorders. By western blotting, we investigated the consequences of missense variants in vitro.ResultsIn accordance with previous observations, de novo heterozygous missense variants in the BTB domain region led to a severe developmental and epileptic encephalopathy in 16 individuals. Now, we also identified de novo missense variants in the GTPase domain in 6 individuals with apparently more variable neurodevelopmental phenotypes with or without epilepsy. In contrast to variants in the BTB domain region, variants in the GTPase domain do not impair proteasomal degradation of RHOBTB2 in vitro, indicating different functional consequences. Furthermore, we observed biallelic splice-site and truncating variants in 9 families with variable neurodevelopmental phenotypes, indicating that complete loss of RHOBTB2 is pathogenic as well.ConclusionBy identifying genotype-phenotype correlations regarding location and consequences of de novo missense variants in RHOBTB2 and by identifying biallelic truncating variants, we further delineate and expand the molecular and clinical spectrum of RHOBTB2-related phenotypes, including both autosomal dominant and recessive neurodevelopmental disorders.     

Methodology of clinical trials for rare diseases

Evidence from clinical trials, ideally using randomisation and allocation concealment, is essential for informing clinical decisions regarding the benefits and harms of treatments for patients. Where diseases are rare, such as in paediatric rheumatic diseases, patient recruitment into clinical trials can be a major obstacle, leading to an absence of evidence and patients receiving treatments based on anecdotal evidence. There are numerous trial designs and modifications that can be made to improve efficiency and maximise what little data may be available in a rare disease clinical trial. These are discussed and illustrated with examples from paediatric rheumatology. Regulatory incentives and support from research networks have helped to deliver these trials, but more can be done to continue this important research.     

Physicians’ comprehension of the German Patients’ Rights Act: A cross-sectional study

ObjectiveThe German Patients' Rights Act (PRA), promulgated on February 25, 2013, was created to enhance transparency of patients' rights. This prospective study aimed to objectively measure physicians' comprehension of the PRA.MethodsWe generated a controlled study design, developing a questionnaire consisting of six case scenarios with 4–7 dichotomous items each. The survey concluded with seven 5-point-Likert scale questions, dealing with the PRA’s effects. Physicians teaching at the Westfälische Wilhelms-Universität (WWU) Münster served as the intervention group, and medical students from WWU Münster at the beginning of their clinical education formed the control group. Physicians were surveyed in November 2015; students were surveyed in February 2016.ResultsA total 56 completed surveys of physicians and 134 of students were analyzed. Of a total 33 points, on average physicians answered 21.04 (95% confidence interval (CI) 20.43–21.64) items correctly, a significantly higher result than students' 19.74 (95% CI 19.31–20.17) points (p < 0.001; Hedges' g = 0.53). Estimations of the PRA’s effects were ambiguous. Students agreed with the PRA’s supporting effect more often than physicians (p < 0.001) whereas physicians felt increased uncertainty arising from the PRA.ConclusionComprehension of the PRA increases significantly over the course of medical work experience; however, this comprehension is limited among medical experts. The PRA leads to ambiguity and uncertainty in the medical decision-making process.     

Immuno-pharmacodynamics for evaluating mechanism of action and developing immunotherapy combinations

Immunotherapy has become a major modality of cancer treatment, with multiple new classes of immunotherapeutics recently entering the clinic and obtaining market approval from regulatory agencies. While the promise of these therapies is great, so is the number of possible combinations not only with each other but also with small molecule therapeutics. Furthermore, the observation of unusual dose-response relationships suggests a critical dependency of drug effectiveness on the dosage regimen (dose and schedule). Clinical pharmacodynamic (PD) biomarkers will be useful endpoints for confirming drug mechanism of action, evaluating combination therapies for synergy or antagonism, and identifying optimal dosage regimens. In contrast to conventional PD in which drug action occurs entirely within a single target cell (ie, is self-contained within the malignant cell), immunotherapy involves a complex mechanism of action with sequential steps that propagate through multiple cell types, both normal and malignant. Its intercellular pharmacology begins with molecular target engagement either on an immune effector cell or a malignant cell, followed by stimulatory biochemical and biological signals in immune effector cells, and then finally ends with activation of cell death mechanisms in malignant cells lying within a certain distance from the activated effector cells (immune cell–tumor cell proximity). Evaluating such “trans-cellular pharmacology,” in which different steps of drug action are distributed across multiple cell types, requires novel microscopy and image analysis tools capable of quantifying PD-biomarker responses, mapping the responses onto the cellular geography of the tumor using phenotypic biomarkers to identify specific cell types, and finally analyzing the spatial relationships between biomarkers in the context of each cell’s biological role. We have termed this form of nearest neighbor image analysis of drug action “proximity PD microscopy,” to indicate the importance of the location of the PD-biomarker response within the cellular landscape of a tumor specimen. We discuss herein the major modes of immunotherapy, and lay out a blueprint for using PD assessment to optimize dosage regimens of single agents and guide development of combination immunotherapy regimens, using PD1/PD-L1 immune checkpoint inhibition as a case study.     

放疗联合免疫检查点抑制剂治疗肿瘤的应用基础

免疫检查点抑制剂单药有效率不足30%。放疗可以促进机体的抗肿瘤免疫应答,通过协同效应或互补机制增进免疫检查点抑制剂的疗效。笔者就放疗联合免疫检查点治疗的应用基础及面临的问题进行深入阐述。     

A prospective study on the neurological complications of breast cancer and its treatment: Updated analysis three years after cancer diagnosis

ObjectivesTo quantify the prevalence of neurological complications among breast cancer patients at one and three years after diagnosis, and to identify factors associated with neuropathic pain (NP) and chemotherapy-induced peripheral neuropathy (CIPN).Material and methodsProspective cohort study including 475 patients with newly diagnosed breast cancer, recruited among those proposed for surgical treatment (Portuguese Institute of Oncology, Porto). Patients underwent a neurological evaluation and had their cognitive function assesses with the Montreal Cognitive Assessment, before treatment and at one and three years after enrollment. We estimated the prevalence of each neurological complication, and odds ratios (OR), adjusted for socio-demographic and clinical characteristics, to identify factors associated with NP and CIPN.ResultsMore than half of the patients [54.7%, 95% confidence interval (95%CI): 50.2–59.2] presented at least one neurological complication, at one or at three years after cancer diagnosis. Between the first and the third year of follow-up, there was an increase in the prevalence of NP (from 21.1% to 23.6%), cognitive impairment (from 7.2% to 8.2%), cerebrovascular disease (from 0.6% to 1.5%) and brain metastasis (from 0.0% to 0.6%). The prevalence of CIPN decreased from 14.1% to 12.6%. Axillary lymph node dissection was associated with NP at one year (OR = 2.75, 95%CI: 1.34–5.63) and chemotherapy with NP at three years (OR = 2.10, 95%CI: 1.20–3.67). Taxane-based chemotherapy was strongly associated with prevalence of CIPN at one and three years.ConclusionNeurological complications are frequent even three years after cancer diagnosis and NP remained the major contributor to the burden of these conditions among survivors.