Browsing by Author "Horslen, Simon"

Now showing 1 - 10 of 10
  • Thumbnail Image
    Item
    Colorectal Dysplasia and Cancer in Pediatric-Onset Ulcerative Colitis Associated With Primary Sclerosing Cholangitis
    (Elsevier, 2021) El-Matary, Wael; Guthery, Stephen L.; Amir, Achiya Z.; DiGuglielmo, Matthew; Draijer, Laura G.; Furuya, Katryn N.; Gupta, Nitika; Hochberg, Jessica T.; Horslen, Simon; Kerkar, Nanda; Koot, Bart G. P.; Laborda, Trevor J.; Loomes, Kathleen M.; Mack, Cara; Martinez, Mercedes; Miethke, Alexander; Miloh, Tamir; Mogul, Douglas; Mohammed, Saeed; Moroz, Stacy; Ovchinsky, Nadia; Perito, Emily R.; Rao, Girish; Ricciuto, Amanda; Sathya, Pushpa; Schwarz, Kathleen B.; Shah, Uzma; Singh, Ruchi; Soufi, Nisreen; Valentino, Pamela L.; Zizzo, Andréanne; Deneau, Mark R.; Pediatrics, School of Medicine
    Inflammatory bowel disease (IBD), especially when associated with primary sclerosing cholangitis (PSC), is a risk factor for developing colorectal cancer (CRC). We aimed to determine the incidence of CRC in a large cohort of pediatric-onset PSC-ulcerative colitis (UC) patients.
  • Thumbnail Image
    Item
    Evaluation of the child with suspected mitochondrial liver disease
    (Wiley, 2013) Molleston, Jean P.; Sokol, Ronald J.; Karnsakul, Wikrom; Miethke, Alexander; Horslen, Simon; Magee, John C.; Romero, René; Squires, Robert H.; Van Hove, Johan L. K.; Childhood Liver Disease Research and Education Network (ChiLDREN); Pediatrics, School of Medicine
  • Thumbnail Image
    Item
    Impact of Genotype, Serum Bile Acids, and Surgical Biliary Diversion on Native Liver Survival in FIC1 Deficiency
    (Wolters Kluwer, 2021-08) van Wessel, Daan B.E.; Thompson, Richard J.; Gonzales, Emmanuel; Jankowska, Irena; Shneider, Benjamin L.; Sokal, Etienne; Grammatikopoulos, Tassos; Kadaristiana, Agustina; Jacquemin, Emmanuel; Spraul, Anne; Lipiński, Patryk; Czubkowski, Piotr; Rock, Nathalie; Shagrani, Mohammad; Broering, Dieter; Algoufi, Talal; Mazhar, Nejat; Nicastro, Emanuele; Kelly, Deirdre; Nebbia, Gabriella; Arnell, Henrik; Fischler, Björn; Hulscher, Jan B.F.; Serranti, Daniele; Arikan, Cigdem; Debray, Dominique; Lacaille, Florence; Goncalves, Cristina; Hierro, Loreto; Muñoz Bartolo, Gema; Mozer-Glassberg, Yael; Azaz, Amer; Brecelj, Jernej; Dezsőfi, Antal; Calvo, Pier Luigi; Krebs-Schmitt, Dorothee; Hartleif, Steffen; van der Woerd, Wendy L.; Wang, Jian-She; Li, Li-ting; Durmaz, Özlem; Kerkar, Nanda; Hørby Jørgensen, Marianne; Fischer, Ryan; Jimenez-Rivera, Carolina; Alam, Seema; Cananzi, Mara; Laverdure, Noémie; Targa Ferreira, Cristina; Ordonez, Felipe; Wang, Heng; Sency, Valerie; Kim, Kyung Mo; Chen, Huey-Ling; Carvalho, Elisa; Fabre, Alexandre; Bernabeu, Jesus Quintero; Alonso, Estella M.; Sokol, Ronald J.; Suchy, Frederick J.; Loomes, Kathleen M.; McKiernan, Patrick J.; Rosenthal, Philip; Turmelle, Yumirle; Rao, Girish S.; Horslen, Simon; Kamath, Binita M.; Rogalidou, Maria; Karnsakul, Wikrom W.; Hansen, Bettina; Verkade, Henkjan J.; Pediatrics, School of Medicine
    Background and aims: Mutations in ATPase phospholipid transporting 8B1 (ATP8B1) can lead to familial intrahepatic cholestasis type 1 (FIC1) deficiency, or progressive familial intrahepatic cholestasis type 1. The rarity of FIC1 deficiency has largely prevented a detailed analysis of its natural history, effects of predicted protein truncating mutations (PPTMs), and possible associations of serum bile acid (sBA) concentrations and surgical biliary diversion (SBD) with long-term outcome. We aimed to provide insights by using the largest genetically defined cohort of patients with FIC1 deficiency to date. Approach and results: This multicenter, combined retrospective and prospective study included 130 patients with compound heterozygous or homozygous predicted pathogenic ATP8B1 variants. Patients were categorized according to the number of PPTMs (i.e., splice site, frameshift due to deletion or insertion, nonsense, duplication), FIC1-A (n = 67; no PPTMs), FIC1-B (n = 29; one PPTM), or FIC1-C (n = 34; two PPTMs). Survival analysis showed an overall native liver survival (NLS) of 44% at age 18 years. NLS was comparable among FIC1-A, FIC1-B, and FIC1-C (% NLS at age 10 years: 67%, 41%, and 59%, respectively; P = 0.12), despite FIC1-C undergoing SBD less often (% SBD at age 10 years: 65%, 57%, and 45%, respectively; P = 0.03). sBAs at presentation were negatively associated with NLS (NLS at age 10 years, sBAs < 194 µmol/L: 49% vs. sBAs ≥ 194 µmol/L: 15%; P = 0.03). SBD decreased sBAs (230 [125-282] to 74 [11-177] μmol/L; P = 0.005). SBD (HR 0.55, 95% CI 0.28-1.03, P = 0.06) and post-SBD sBA concentrations < 65 μmol/L (P = 0.05) tended to be associated with improved NLS. Conclusions: Less than half of patients with FIC1 deficiency reach adulthood with native liver. The number of PPTMs did not associate with the natural history or prognosis of FIC1 deficiency. sBA concentrations at initial presentation and after SBD provide limited prognostic information on long-term NLS.
  • Thumbnail Image
    Item
    Oral Vancomycin, Ursodeoxycholic Acid, or No Therapy for Pediatric Primary Sclerosing Cholangitis: A Matched Analysis
    (Wolters Kluwer, 2021) Deneau, Mark R.; Mack, Cara; Mogul, Douglas; Perito, Emily R.; Valentino, Pamela L.; Amir, Achiya Z.; DiGuglielmo, Matthew; Draijer, Laura G.; El-Matary, Wael; Furuya, Katryn N.; Gupta, Nitika; Hochberg, Jessica T.; Horslen, Simon; Jensen, M. Kyle; Jonas, Maureen M.; Kerkar, Nanda; Koot, Bart G. P.; Laborda, Trevor J.; Lee, Christine K.; Loomes, Kathleen M.; Martinez, Mercedes; Miethke, Alexander; Miloh, Tamir; Mohammad, Saeed; Ovchinsky, Nadia; Rao, Girish; Ricciuto, Amanda; Sathya, Pushpa; Schwarz, Kathleen B.; Shah, Uzma; Singh, Ruchi; Vitola, Bernadette; Zizzo, Andréanne; Guthery, Stephen L.; Pediatrics, School of Medicine
    Background and aims: Many children with primary sclerosing cholangitis (PSC) receive oral vancomycin therapy (OVT) or ursodeoxycholic acid (UDCA). There is a paucity of data on whether these medications improve outcomes. Approach and results: We analyzed retrospective data from the Pediatric PSC Consortium. Children treated with OVT were matched 1:1:1 to those treated with UDCA or managed with observation (no treatment) based on the closest propensity score, ensuring similar baseline characteristics. Two hundred sixty-four patients (88 each with OVT, UDCA, or observation) had matching propensity scores and were similar in demographics, phenotype, immunosuppression, baseline biochemistry, and hepatic fibrosis. After 1 year in an intention-to-treat analysis, all outcome metrics were similar regardless of treatment group. In OVT, UDCA, and untreated groups, respectively: Gamma-glutamyltransferase normalized in 53%, 49%, and 52% (P = not significant [NS]), liver fibrosis stage was improved in 20%, 13%, and 18% and worsened in 11%, 29%, and 18% (P = NS), and the 5-year probability of liver transplant listing was 21%, 10%, and 12% (P = NS). Favorable outcome was associated with having a mild phenotype of PSC and minimal hepatic fibrosis. Conclusions: We presented the largest-ever description of outcomes on OVT in PSC and compared them to carefully matched patients on UDCA or no therapy. Neither OVT nor UDCA showed improvement in outcomes compared to a strategy of observation. Patients progressed to end-stage liver disease at similar rates. Spontaneous normalization of biochemistry is common in children receiving no therapy, particularly in the majority of children with a mild phenotype and an early stage of disease. Placebo-controlled treatment trials are needed to identify effective treatments for pediatric PSC.
  • Thumbnail Image
    Item
    Outcomes from a 12-Week, Open-Label, Multicenter Clinical Trial of Teduglutide in Pediatric Short Bowel Syndrome
    (Elsevier, 2017-02) Carter, Beth A.; Cohran, Valeria C.; Cole, Conrad R.; Corkins, Mark R.; Dimmitt, Reed A.; Duggan, Christopher; Hill, Susan; Horslen, Simon; Lim, Joel D.; Mercer, David F.; Merritt, Russell J.; Nichol, Peter F.; Sigurdsson, Luther; Teitelbaum, Daniel H.; Thompson, John; Vanderpool, Charles; Vaughan, Juliana F.; Li, Benjamin; Youssef, Nader N.; Venick, Robert S.; Venick, Robert S.; Kocoshis, Samuel A.; Department of Pediatrics, School of Medicine
    Objective To determine safety and pharmacodynamics/efficacy of teduglutide in children with intestinal failure associated with short bowel syndrome (SBS-IF). Study design This 12-week, open-label study enrolled patients aged 1-17 years with SBS-IF who required parenteral nutrition (PN) and showed minimal or no advance in enteral nutrition (EN) feeds. Patients enrolled sequentially into 3 teduglutide cohorts (0.0125 mg/kg/d [n = 8], 0.025 mg/kg/d [n = 14], 0.05 mg/kg/d [n = 15]) or received standard of care (SOC, n = 5). Descriptive summary statistics were used. Results All patients experienced ≥1 treatment-emergent adverse event; most were mild or moderate. No serious teduglutide-related treatment-emergent adverse events occurred. Between baseline and week 12, prescribed PN volume and calories (kcal/kg/d) changed by a median of −41% and −45%, respectively, with 0.025 mg/kg/d teduglutide and by −25% and −52% with 0.05 mg/kg/d teduglutide. In contrast, PN volume and calories changed by 0% and −6%, respectively, with 0.0125 mg/kg/d teduglutide and by 0% and −1% with SOC. Per patient diary data, EN volume increased by a median of 22%, 32%, and 40% in the 0.0125, 0.025, and 0.05 mg/kg/d cohorts, respectively, and by 11% with SOC. Four patients achieved independence from PN, 3 in the 0.05 mg/kg/d cohort and 1 in the 0.025 mg/kg/d cohort. Study limitations included its short-term, open-label design, and small sample size. Conclusions Teduglutide was well tolerated in pediatric patients with SBS-IF. Teduglutide 0.025 or 0.05 mg/kg/d was associated with trends toward reductions in PN requirements and advancements in EN feeding in children with SBS-IF.
  • Thumbnail Image
    Item
    Recurrence of Primary Sclerosing Cholangitis After Liver Transplant in Children: An International Observational Study
    (Wolters Kluwer, 2021) Martinez, Mercedes; Perito, Emily R.; Valentino, Pamela; Mack, Cara L.; Aumar, Madeleine; Broderick, Annemarie; Draijer, Laura G.; Fagundes, Eleonora D. T.; Furuya, Katryn N.; Gupta, Nitika; Horslen, Simon; Jonas, Maureen M.; Kamath, Binita M.; Kerkar, Nanda; Kim, Kyung Mo; Kolho, Kaija-Leena; Koot, Bart G. P.; Laborda, Trevor J.; Lee, Christine K.; Loomes, Kathleen M.; Miloh, Tamir; Mogul, Douglas; Mohammed, Saeed; Ovchinsky, Nadia; Rao, Girish; Ricciuto, Amanda; Rodrigues Ferreira, Alexandre; Schwarz, Kathleen B.; Smolka, Vratislav; Tanaka, Atsushi; Tessier, Mary E. M.; Venkat, Venna L.; Vitola, Bernadette E.; Woynarowski, Marek; Zerofsky, Melissa; Deneau, Mark R.; Pediatrics, School of Medicine
    Background and aims: Recurrent primary sclerosing cholangitis (rPSC) following liver transplant (LT) has a negative impact on graft and patient survival; little is known about risk factors for rPSC or disease course in children. Approach and results: We retrospectively evaluated risk factors for rPSC in 140 children from the Pediatric PSC Consortium, a multicenter international registry. Recipients underwent LT for PSC and had >90 days of follow-up. The primary outcome, rPSC, was defined using Graziadei criteria. Median follow-up after LT was 3 years (interquartile range 1.1-6.1). rPSC occurred in 36 children, representing 10% and 27% of the subjects at 2 years and 5 years following LT, respectively. Subjects with rPSC were younger at LT (12.9 vs. 16.2 years), had faster progression from PSC diagnosis to LT (2.5 vs. 4.1 years), and had higher alanine aminotransferase (112 vs. 66 IU/L) at LT (all P < 0.01). Inflammatory bowel disease was more prevalent in the rPSC group (86% vs. 66%; P = 0.025). After LT, rPSC subjects had more episodes of biopsy-proved acute rejection (mean 3 vs. 1; P < 0.001), and higher prevalence of steroid-refractory rejection (41% vs. 20%; P = 0.04). In those with rPSC, 43% developed complications of portal hypertension, were relisted for LT, or died within 2 years of the diagnosis. Mortality was higher in the rPSC group (11.1% vs. 2.9%; P = 0.05). Conclusions: The incidence of rPSC in this cohort was higher than previously reported, and was associated with increased morbidity and mortality. Patients with rPSC appeared to have a more aggressive, immune-reactive phenotype. These findings underscore the need to understand the immune mechanisms of rPSC, to lay the foundation for developing new therapies and improve outcomes in this challenging population.
  • Thumbnail Image
    Item
    Risk of variceal hemorrhage and pretransplant mortality in children with biliary atresia
    (Wiley, 2022) Bass, Lee M.; Ye, Wen; Hawthorne, Kieran; Leung, Daniel H.; Murray, Karen F.; Molleston, Jean P.; Romero, Rene; Karpen, Saul; Rosenthal, Philip; Loomes, Kathleen M.; Wang, Kasper S.; Squires, Robert H.; Miethke, Alexander; Ng, Vicky L.; Horslen, Simon; Jensen, M. Kyle; Sokol, Ronald J.; Magee, John C.; Shneider, Benjamin L.; ChiLDReN; Pediatrics, School of Medicine
    Background and aims: The natural history of gastroesophageal variceal hemorrhage (VH) in biliary atresia (BA) is not well characterized. We analyzed risk factors, incidence, and outcomes of VH in a longitudinal multicenter study. Approach and results: Participants enrolled in either an incident (Prospective Database of Infants with Cholestasis [PROBE]) or prevalent (Biliary Atresia Study of Infants and Children [BASIC]) cohort of BA were included. Variceal hemorrhage (VH) was defined based on gastrointestinal bleeding in the presence of varices accompanied by endoscopic or nontransplant surgical intervention. Cumulative incidence of VH and transplant-free survival was compared based on features of portal hypertension (e.g., splenomegaly, thrombocytopenia) and clinical parameters at baseline in each cohort (PROBE: 1.5 to 4.5 months after hepatoportoenterostomy [HPE]; BASIC: at enrollment > 3 years of age). Analyses were conducted on 869 children with BA enrolled between June 2004 and December 2020 (521 in PROBE [262 (51%) with a functioning HPE] and 348 in BASIC). The overall incidence of first observed VH at 5 years was 9.4% (95% CI: 7.0-12.4) in PROBE and 8.0% (5.2-11.5) in BASIC. Features of portal hypertension, platelet count, total bilirubin, aspartate aminotransferase (AST), albumin, and AST-to-platelet ratio index at baseline were associated with an increased risk of subsequent VH in both cohorts. Transplant-free survival at 5 years was 45.1% (40.5-49.6) in PROBE and 79.2% (74.1-83.4) in BASIC. Two (2.5%) of 80 participants who had VH died, whereas 10 (12.5%) underwent transplant within 6 weeks of VH. Conclusions: The low risk of VH and associated mortality in children with BA needs to be considered in decisions related to screening for varices and primary prophylaxis of VH.
  • Thumbnail Image
    Item
    Safety Findings in Pediatric Patients During Long-Term Treatment With Teduglutide for Short-Bowel Syndrome–Associated Intestinal Failure: Pooled Analysis of 4 Clinical Studies
    (Wiley, 2021-09) Hill, Susan; Carter, Beth A.; Cohran, Valeria; Horslen, Simon; Kaufman, Stuart S.; Kocoshis, Samuel A.; Mercer, David F.; Merritt, Russell J.; Pakarinen, Mikko P.; Protheroe, Susan; Thompson, John F.; Vanderpool, Charles P. B.; Venick, Robert S.; Wales, Paul W.; Smith, Sharon E.; Yoon, MinJung; Grimm, Andrew A.; Pediatrics, School of Medicine
    Background This analysis assessed combined safety data from 4 clinical studies of teduglutide in pediatric patients with short-bowel syndrome–associated intestinal failure (SBS–IF). Methods Safety data from teduglutide-treated patients in 4 clinical trials were pooled. The completed 12-week and 24-week phase 3 core studies (NCT01952080/EudraCT 2013-004588-30 and NCT02682381/EudraCT 2015-002252-27) enrolled children aged 1–17 years with SBS–IF. Patients could elect to enroll in ongoing open-label extensions (NCT02949362/EudraCT 2016-000863-17 and NCT02954458/EudraCT 2016-000849-30). Interim data from ongoing studies were included. Results Safety data are reported for 89 pediatric patients treated with teduglutide for a median (range) of 51.7 (5.0–94.7) weeks. Adverse events (AEs) were reported in all patients; the most common were vomiting (51.7%), pyrexia (43.8%), upper respiratory tract infection (41.6%), and cough (33.7%). Thirty-five patients (39.3%) had AEs considered related to teduglutide treatment; abdominal pain and vomiting were most frequent (5.6% each). Three serious AEs in 3 patients (3.4%) were considered related to teduglutide treatment: ileus, d-lactic acidosis, and gastrointestinal obstruction due to hard stools. All 3 events resolved. One cecal polyp was detected, which was not biopsied or found on repeat colonoscopy. No cases of neoplasia occurred. Conclusion Based on integrated data from 4 clinical studies, including long-term follow-up for ≤161 weeks, teduglutide had a safety profile consistent with the individual core pediatric studies and as expected for pediatric patients with SBS–IF who never received teduglutide. The most frequent AEs reflected treatment with teduglutide, complications of the underlying disease, and typical childhood illnesses.
  • Thumbnail Image
    Item
    Serum bile acids as a prognostic biomarker in biliary atresia following Kasai portoenterostomy
    (Wolters Kluwer, 2023) Harpavat, Sanjiv; Hawthorne, Kieran; Setchell, Kenneth D. R.; Narvaez Rivas, Monica; Henn, Lisa; Beil, Charlotte A.; Karpen, Saul J.; Ng, Vicky L.; Alonso, Estella M.; Bezerra, Jorge A.; Guthery, Stephen L.; Horslen, Simon; Loomes, Kathy M.; McKiernan, Patrick; Magee, John C.; Merion, Robert M.; Molleston, Jean P.; Rosenthal, Philip; Thompson, Richard J.; Wang, Kasper S.; Sokol, Ronald J.; Shneider, Benjamin L.; Childhood Liver Disease Research Network (ChiLDReN); Pediatrics, School of Medicine
    Background and aims: In biliary atresia, serum bilirubin is commonly used to predict outcomes after Kasai portoenterostomy (KP). Infants with persistently high levels invariably need liver transplant, but those achieving normalized levels have a less certain disease course. We hypothesized that serum bile acid levels could help predict outcomes in the latter group. Approach and results: Participants with biliary atresia from the Childhood Liver Disease Research Network were included if they had normalized bilirubin levels 6 months after KP and stored serum samples from the 6-month post-KP clinic visit ( n = 137). Bile acids were measured from the stored serum samples and used to divide participants into ≤40 μmol/L ( n = 43) or >40 μmol/L ( n = 94) groups. At 2 years of age, the ≤40 μmol/L compared with >40 μmol/L group had significantly lower total bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, bile acids, and spleen size, as well as significantly higher albumin and platelet counts. Furthermore, during 734 person-years of follow-up, those in the ≤40 μmol/L group were significantly less likely to develop splenomegaly, ascites, gastrointestinal bleeding, or clinically evident portal hypertension. The ≤40 μmol/L group had a 10-year cumulative incidence of liver transplant/death of 8.5% (95% CI: 1.1%-26.1%), compared with 42.9% (95% CI: 28.6%-56.4%) for the >40 μmol/L group ( p = 0.001). Conclusions: Serum bile acid levels may be a useful prognostic biomarker for infants achieving normalized bilirubin levels after KP.
  • Thumbnail Image
    Item
    The Sclerosing Cholangitis Outcomes in Pediatrics (SCOPE) Index: A Prognostic Tool for Children
    (Wolters Kluwer, 2021) Deneau, Mark R.; Mack, Cara; Perito, Emily R.; Ricciuto, Amanda; Valentino, Pamela L.; Amin, Mansi; Amir, Achiya Z.; Aumar, Madeleine; Auth, Marcus; Broderick, Annemarie; DiGuglielmo, Matthew; Draijer, Laura G.; Druve Tavares Fagundes, Eleonora; El-Matary, Wael; Ferrari, Federica; Furuya, Katryn N.; Gupta, Nitika; Hochberg, Jessica T.; Homan, Matjaz; Horslen, Simon; Iorio, Raffaele; Jensen, M. Kyle; Jonas, Maureen M.; Kamath, Binita M.; Kerkar, Nanda; Kim, Kyung Mo; Kolho, Kaija-Leena; Koot, Bart G. P.; Laborda, Trevor J.; Lee, Christine K.; Loomes, Kathleen M.; Martinez, Mercedes; Miethke, Alexander; Miloh, Tamir; Mogul, Douglas; Mohammad, Saeed; Mohan, Parvathi; Moroz, Stacy; Ovchinsky, Nadia; Palle, Sirish; Papadopoulou, Alexandra; Rao, Girish; Rodrigues Ferreira, Alexandre; Sathya, Pushpa; Schwarz, Kathleen B.; Shah, Uzma; Shteyer, Eyal; Singh, Ruchi; Smolka, Vratislav; Soufi, Nisreen; Tanaka, Atsushi; Varier, Raghu; Vitola, Bernadette; Woynarowski, Marek; Zerofsky, Melissa; Zizzo, Andréanne; Guthery, Stephen L.; Pediatrics, School of Medicine
    Background and aims: Disease progression in children with primary sclerosing cholangitis (PSC) is variable. Prognostic and risk-stratification tools exist for adult-onset PSC, but not for children. We aimed to create a tool that accounts for the biochemical and phenotypic features and early disease stage of pediatric PSC. Approach and results: We used retrospective data from the Pediatric PSC Consortium. The training cohort contained 1,012 patients from 40 centers. We generated a multivariate risk index (Sclerosing Cholangitis Outcomes in Pediatrics [SCOPE] index) that contained total bilirubin, albumin, platelet count, gamma glutamyltransferase, and cholangiography to predict a primary outcome of liver transplantation or death (TD) and a broader secondary outcome that included portal hypertensive, biliary, and cancer complications termed hepatobiliary complications (HBCs). The model stratified patients as low, medium, or high risk based on progression to TD at rates of <1%, 3%, and 9% annually and to HBCs at rates of 2%, 6%, and 13% annually, respectively (P < 0.001). C-statistics to discriminate outcomes at 1 and 5 years were 0.95 and 0.82 for TD and 0.80 and 0.76 for HBCs, respectively. Baseline hepatic fibrosis stage was worse with increasing risk score, with extensive fibrosis in 8% of the lowest versus 100% with the highest risk index (P < 0.001). The model was validated in 240 children from 11 additional centers and performed well. Conclusions: The SCOPE index is a pediatric-specific prognostic tool for PSC. It uses routinely obtained, objective data to predict a complicated clinical course. It correlates strongly with biopsy-proven liver fibrosis. SCOPE can be used with families for shared decision making on clinical care based on a patient's individual risk, and to account for variable disease progression when designing future clinical trials.