Prognostic indicators of disease progression in Duchenne muscular dystrophy: A literature review and evidence synthesis.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a rare, severely debilitating, and fatal neuromuscular disease characterized by progressive muscle degeneration. Like in many orphan diseases, randomized controlled trials are uncommon in DMD, resulting in the need to indirectly compare treatment effects, for example by pooling individual patient-level data from multiple sources. However, to derive reliable estimates, it is necessary to ensure that the samples considered are comparable with respect to factors significantly affecting the clinical progression of the disease. To help inform such analyses, the objective of this study was to review and synthesise published evidence of prognostic indicators of disease progression in DMD. We searched MEDLINE (via Ovid), Embase (via Ovid) and the Cochrane Library (via Wiley) for records published from inception up until April 23 2021, reporting evidence of prognostic indicators of disease progression in DMD. Risk of bias was established with the grading system of the Centre for Evidence-Based Medicine (CEBM). RESULTS: Our search included 135 studies involving 25,610 patients from 18 countries across six continents (Africa, Asia, Australia, Europe, North America and South America). We identified a total of 23 prognostic indicators of disease progression in DMD, namely age at diagnosis, age at onset of symptoms, ataluren treatment, ATL1102, BMI, cardiac medication, DMD genetic modifiers, DMD mutation type, drisapersen, edasalonexent, eteplirsen, glucocorticoid exposure, height, idebenone, lower limb surgery, orthoses, oxandrolone, spinal surgery, TAS-205, vamorolone, vitlolarsen, ventilation support, and weight. Of these, cardiac medication, DMD genetic modifiers, DMD mutation type, and glucocorticoid exposure were designated core prognostic indicators, each supported by a high level of evidence and significantly affecting a wide range of clinical outcomes. CONCLUSION: This study provides a current summary of prognostic indicators of disease progression in DMD, which will help inform the design of comparative analyses and future data collection initiatives in this patient population.

Exploring the Burden of X-Linked Hypophosphataemia: An Opportunistic Qualitative Study of Patient Statements Generated During a Technology Appraisal.

INTRODUCTION: Capturing the patient experience of living with a rare disease such as X-linked hypophosphataemia (XLH) is critical for a holistic understanding of the burden of a disease. The complexity of the disease coupled with the limited population makes elicitation of the patient burden methodologically challenging. This study used qualitative information direct from patient and caregiver statements to assess the burden of XLH. METHODS: A thematic analysis was conducted on statements received during a National Institute for Health and Care Excellence (NICE) online public open consultation from 15 June to 6 July 2018. Researchers and clinical experts generated themes and codes based on expected aspects of XLH burden. Statements were independently coded by two reviewers, adding additional codes as required, and analysed by frequency and co-reporting across age groups. RESULTS: The majority of responses were submitted from UK-based patients with some from the USA and Australia, and the statements related to children, adolescents and adults. The findings suggest that the greatest burden experienced by children is associated with conventional therapy, co-reported with dosing regimen, adherence, distress and pain. During adolescence, the burden becomes increasingly complex and multi-factorial, with an increasing psychological burden. In adults, conventional therapy co-reported with bone deformity and orthopaedic surgery, as well as pain, mobility, fatigue and dental problems, featured highly. DISCUSSION: Whilst our study was opportunistic in nature, it has highlighted the clear and distinctive evolution of the burden of XLH, transitioning from being therapy-oriented in childhood to multi-factorial in adolescence, and finally to adulthood with its high impact on need for other interventions, function and mobility. This qualitative thematic analysis enhances the understanding of the symptom and treatment burden of XLH.

α5ß1 integrin recycling promotes Arp2/3-independent cancer cell invasion via the formin FHOD3.

Invasive migration in 3D extracellular matrix (ECM) is crucial to cancer metastasis, yet little is known of the molecular mechanisms that drive reorganization of the cytoskeleton as cancer cells disseminate in vivo. 2D Rac-driven lamellipodial migration is well understood, but how these features apply to 3D migration is not clear. We find that lamellipodia-like protrusions and retrograde actin flow are indeed observed in cells moving in 3D ECM. However, Rab-coupling protein (RCP)-driven endocytic recycling of α5ß1 integrin enhances invasive migration of cancer cells into fibronectin-rich 3D ECM, driven by RhoA and filopodial spike-based protrusions, not lamellipodia. Furthermore, we show that actin spike protrusions are Arp2/3-independent. Dynamic actin spike assembly in cells invading in vitro and in vivo is regulated by Formin homology-2 domain containing 3 (FHOD3), which is activated by RhoA/ROCK, establishing a novel mechanism through which the RCP-α5ß1 pathway reprograms the actin cytoskeleton to promote invasive migration and local invasion in vivo.