Al-Samkari, Hanny

Abstract Hereditary hemorrhagic telangiectasia (HHT), an autosomal dominant vasculopathy affecting 1 in 5000 individuals, is the second most common inherited bleeding disorder worldwide. Despite this prevalence, comprehensive data on disease manifestations and complications remain limited. To address this gap, the US Congress allocated funding leading to the Comprehensive HHT Outcomes Registry of the United States (CHORUS), a prospective, 15-center longitudinal registry enrolling unselected patients with confirmed HHT. In this initial report, we describe findings from the first 600 participants, with a median age of 53 (range, 0-88) years and 60% female. Despite most participants developing typical HHT manifestations by age 13 years, the majority (63%) were not diagnosed until mid-to-late adulthood. Recurrent spontaneous epistaxis occurred in 95% of participants, chronic gastrointestinal bleeding in 30%, and heavy menstrual bleeding in 35% of postmenarche females, together resulting in moderate-to-severe mucosal bleeding in 76%. Iron deficiency and/or anemia were diagnosed in 68%, with 41% requiring IV iron and 25% requiring red cell transfusions. Serious complications of solid-organ arteriovenous malformations were frequent, including intracranial hemorrhage (3%), pulmonary hemorrhage (2%), venous thromboembolism (7%), arterial thromboembolism (11%), heart failure (7%), and pulmonary hypertension (7%). These data from CHORUS, the first national US registry of its kind, provide reliable, real-world estimates of the incidence, prevalence, and severity of numerous HHT manifestations and complications. HHT has a high burden of moderate-to-severe bleeding, anemia, thrombosis, and major neurologic and cardiopulmonary complications. There is a mean interval between first symptoms and diagnosis of >2 decades, during which substantial, serious, and preventable HHT morbidity, including early intracranial hemorrhage, may occur. This trial was registered at clinicaltrials.gov as NCT06259292.

Abstract Hereditary hemorrhagic telangiectasia (HHT) results in recurrent severe epistaxis, chronic gastrointestinal bleeding, and other morbid manifestations. Pomalidomide was recently demonstrated to be efficacious for bleeding in HHT in the landmark PATH-HHT trial. Given that the vascular remodeling that results in bleeding improvement may require several months, characteristics associated with treatment response would be invaluable to plan treatment. Using data from PATH-HHT (NCT03910244), we identified characteristics associated with change from baseline in Epistaxis Severity Score (ESS; a well-validated 10-point HHT bleeding scale and the trial’s primary end point) using multivariable-adjusted repeated-measures models. Characteristics associated with a better response to pomalidomide at weeks 16 to 24 of the trial included a higher (more severe) baseline ESS (change from baseline, −0.76 [95% confidence interval (CI), −0.99 to −0.54] points per 1-point higher baseline score, P< .001) and concomitant antifibrinolytic therapy (−0.73 [95% CI, −1.48 to 0.01] vs no therapy, P = .05). Characteristics associated with a less robust response were older age (0.29 [95% CI, 0.05-0.53] per 10 years older, P = .02) and underlying ACVRL1 germ line mutation (0.62 [95% CI, −0.04 to 1.27] vs ENG, SMAD4, or mutation not known, P = .06]. Characteristics notably associated with placebo response (placebo effect) were patient-reported outcome measures, such that those experiencing more severe disease at baseline had less placebo effect. In conclusion, several baseline patient and disease characteristics were associated with pomalidomide response, findings that may help guide patient selection for the use of pomalidomide in HHT. This trial was registered at www.Clinicaltrials.gov as NCT03910244.

Abstract Hereditary hemorrhagic telangiectasia (HHT) causes severe recurrent epistaxis, chronic gastrointestinal bleeding, solid organ arteriovenous malformations, and significant anemia. Although it is the second most common inherited bleeding disorder worldwide, no approved therapies exist. The multicenter, US randomized, controlled PATH-HHT trial demonstrated efficacy of short-term pomalidomide treatment of epistaxis in HHT. However, questions regarding long-term safety, effectiveness, and utility for HHT-associated gastrointestinal bleeding remain. The PATH-HHT ATLAS (after trial longitudinal assessment study) was a multicenter US longitudinal observational study evaluating patients enrolled in PATH-HHT who continued pomalidomide after PATH-HHT through a poststudy drug access program, with ongoing close monitoring per PATH-HHT protocol and as mandated by the US Food and Drug Administration. Sixty-two patients treated with pomalidomide for HHT for up to 4.4 years were included. Significant, durable improvements in mean epistaxis severity score (5.55 points [baseline] to 2.80 points [month 12]; P< .0001) and mean hematologic support score (9.11 red cell unit equivalents [RUEs] during 6 months pretreatment to 5.73 RUEs [months 7-12]; P = .0056) were observed. Pomalidomide was less effective for gastrointestinal bleeding than for epistaxis, particularly in patients with high red blood cell transfusion requirements. Thirty-one patients (50%) underwent dose reduction from 4 mg daily, primarily due to neutropenia, but most maintained effectiveness at 2 or 3 mg daily. Over 105.2 patient-years of pomalidomide treatment, 0 patients developed peripheral neuropathy, 1 developed venous thromboembolism, and 5 developed serious infections. In conclusion, pomalidomide was effective for HHT-associated epistaxis over extended durations, albeit with nontrivial potential toxicities, and may be considered for certain patients with HHT. This trial was registered at www.clinicaltrials.gov as NCT07018401.

Abstract Immune checkpoint inhibitor–associated immune thrombocytopenia (ICI-ITP) has been described in case reports and small case series, but comprehensive data on its incidence, risk factors, clinical features, treatment, and outcomes are lacking. We reviewed medical records of all adults initiating ICI therapy between 2016 and 2023 at 29 US hospitals across 7 major cancer centers to identify patients with ICI-ITP. Multivariable logistic regression was used to identify risk factors, and Cox modeling was performed to assess the association between ICI-ITP, its severity, and mortality. Among 86 467 patients, ICI-ITP occurred in 214 (0.25%). Independent risk factors included lower baseline platelet count, combination ICI therapy, stage IV cancer, and additional immune-related adverse events. ICI-ITP occurred at a median of 8 weeks (interquartile range [IQR], 4-18) after ICI initiation, with a median nadir platelet count of 41 × 109/L (IQR, 17 × 109/L to 64 × 109/L). Patients were treated with glucocorticoids (n = 106 [49.5%]), immune globulin (n = 39 [18.2%]), and thrombopoietin receptor agonists (n = 29 [13.6%]). Recovery occurred in 161 patients (75.2%) at a median of 2.3 weeks (IQR, 1.0-5.3). Of 76 patients rechallenged with ICIs, 23 (30.3%) developed recurrent ICI-ITP. ICI-ITP and its severity were associated with higher all-cause mortality, with a nearly threefold increase in risk among patients with severe ICI-ITP than those without ICI-ITP (adjusted hazard ratio, 2.96 [95% confidence interval, 2.14-4.08]). These findings establish ICI-ITP as a rare but clinically significant complication of ICI therapy, provide, to our knowledge, the first large-scale description of its risk factors and clinical course, and underscore the importance of timely recognition and management.

ABSTRACT Hereditary hemorrhagic telangiectasia (HHT, Osler‐Weber‐Rendu disease) is the second most common inherited bleeding disorder worldwide, affecting approximately 1 in 5000 people. Development of disease‐modifying and efficacious hemostatic agents to treat HHT has finally begun after decades without such medical therapies. However, the lack of consensus on standardized severity definitions, outcome criteria, and terminology remains a major obstacle to clinical investigation and therapeutic development in HHT. Additionally, with the ongoing repurposing of antiangiogenic agents and emerging development of novel HHT‐specific therapies, comparative clinical trials are expected in the future. Therefore, to end the problematic heterogeneity hindering these efforts, the Global Research and Medical Advisory Board (GRMAB) of the Cure HHT Foundation, an international group of recognized HHT experts, convened a conference of expert HHT clinician‐investigators from within GRMAB as well as invited external experts in HHT and bleeding disorders generally, patients with HHT, and patient advocates to define standard terminology and definitions for outcomes and severity classification for bleeding and anemia in HHT. These criteria and definitions should be adopted by regulators, investigators, and the pharmaceutical industry in the development and performance of interventional clinical trials and cohort studies to allow improved comparability between clinical trials, facilitate communication between clinicians and investigators, improve therapeutic guideline development, and provide a standardized framework for regulatory agencies. Search Strategy and Selection Criteria Evidence for this report was systematically identified and evaluated utilizing two search strategies in Ovid MEDLINE, described in full detail in the Appendix, pp.4–13. The searches were conducted on January 7, 2025. The titles and abstracts of each record were reviewed, and the inclusion criteria were applied to all search results to identify full text articles to be retrieved for further review. All retrieved full texts were then reviewed to reach a final determination if a study met the inclusion criteria. Included references were then compiled into evidence tables, which were then utilized by the International Consensus Report Working Group throughout the development of report recommendations.

AbstractIntroductionSystemic bevacizumab is a novel targeted therapy for severe epistaxis and chronic gastrointestinal bleeding in hereditary haemorrhagic telangiectasia (HHT), but published data are very limited.AimWe conducted a survey‐based study to characterize current treatment practices and physician‐reported safety and effectiveness of systemic bevacizumab for bleeding in (HHT).MethodsA 27‐item survey was sent to physician centre directors of 31 International HHT Centers of Excellence.ResultsResponse rate was 84%. Approximately half of centres had treated >10 HHT patients with systemic bevacizumab for chronic bleeding for a total of 291 patients treated. All centres utilize a 5 mg/kg dose for induction treatment and most administer six doses (range, 4‐8) every 2 weeks. However, maintenance regimens varied considerably between centres. Bevacizumab was highly effective, with 86% reporting significant (>50%) improvement in GI bleeding and/or epistaxis and haemoglobin rise in most patients treated with bevacizumab; 52% reported haemoglobin normalization in most patients. All centres reported adverse event rates <30% and two‐thirds of centres reported adverse event rates <10%. Discontinuation for adverse events or inefficacy was rare. Bleeding severity thresholds for initiation of bevacizumab were highly variable, and it is typically administered by haematologists (76% of centres). Two‐thirds of centres reported obtaining insurance approval for bevacizumab for most or all patients but 48% reported difficulty in obtaining coverage.ConclusionSystemic bevacizumab is widely used to treat bleeding in HHT with excellent physician‐reported effectiveness and safety. There is considerable variation in maintenance treatment practices and thresholds for initiation of bevacizumab among HHT centres.

SummaryThrombocytopenic patients requiring invasive surgery have few options to improve their platelet count preoperatively. This is a single‐centre, retrospective review of thrombocytopenic patients receiving the thrombopoietin receptor agonist romiplostim perioperatively to allow for surgical interventions. Patient characteristics, romiplostim use, and surgical and safety outcomes (bleeding, thrombosis, transfusions) were collected and analysed. Forty‐seven patients underwent 51 surgical procedures (ranging from total hip arthroplasty to open cardiac surgery) with romiplostim support. Thrombocytopenia aetiologies included immune thrombocytopenia, chronic liver disease, haematological malignancy, drug‐related thrombocytopenia, and hereditary thrombocytopenia. Median (range) platelet counts improved, from 47 × 109/l (9–120 × 109/l) at romiplostim initiation to 164 × 109/l (28–603 × 109/l) at the time of surgery (P < 0·0001). A dose of 3 μg/kg per week for 2 doses increased the platelet count to >100 × 109/l in 79% of patients within 14 days. In 96% of cases, surgery proceeded on schedule without delay or cancellation. Four patients had bleeding events unrelated to thrombocytopenia and 1 patient developed deep venous thrombosis. Six patients required red cell transfusion and 3 patients required platelet transfusion perioperatively. In conclusion, romiplostim was effective in increasing platelet counts to allow surgery to proceed safely and on schedule. Bleeding and thromboembolic events were within acceptable limits for this surgical population.