Sickle-Cell Disease in Greece: Patient Reported Outcomes Related to Clinical Complications, Treatment Choices and Attitudes, Beliefs and Trends Affecting Potential Participation in Clinical Trials - a Greek National Multicentric Study
Authors: Delicou Sophia , Diamantidis Michael D. , Manganas Konstantinos , Eftychiadis Eftychios , Pantelidou Despoina , Kourakli Alexandra , Vlachaki Efthymia , Evliati Loukia , Lafiatis Ioannis , Klironomos Evangelos , Kyriakopoulou Dimitra , Xydaki Aikaterini , Bartzi Vassiliki , Papadopoulou Despoina , Lazaris Vasileios , Apostolou Chrysoula , Kattamis Antonis , Symeonidis Argiris 
Published: November 2019

Background: Sickle cell disease (SCD) is an autosomal recessive disorder caused by a point mutation in the β-globin chain of hemoglobin that forms hemoglobin S. It is clinically characterized by complicated episodes of veno-occlusive crises (VOC), emergency room (ER) visits and uncomplicated inpatient admissions.

Aim: We investigated the clinical complications and treatment choices of a large cohort of Greek SCD patients, representative of the whole country. Most importantly, this study aimed to assess patients' attitudes and beliefs regarding their enrollment in clinical trials testing new drugs. We examined the factors influencing such a participation.

Patients and Methods: A total of 254 patients from 10 Thalassemia and Sickle Cell Departments across Greece (110 men/144 women), aged 18 - over 65, 210 (82.7%) with β-thalassemia/sickle cell trait and 44 (17.3%) with homozygous SCD participated in the study. The participants had variable educational and socioeconomic background. They all answered an anonymous self-report questionnaire during their medical evaluations between November 2018 and May 2019, including their demographic and clinical characteristics, their current treatment and their opinion regarding a possible participation in a clinical trial for SCD. Descriptive statistical analysis using calculated scale variables and Chi-square test were performed.

Results: All participants completed the survey. During the previous year, 64 patients (25.3%) had no admissions for VOC, 128 (50.6%) had 1-5, whereas 21 (8.3%) had 5-10 and 40 (15.8%) more than 10. Except for acute pain crises, the most frequent complications were chronic pain (59%), liver/spleen dysfunction (32.4%), infectious episodes (29.5%), iron overload (23.8%) and pulmonary hypertension (20.1%). In addition to hematological care, patients seeked medical attention from expert physicians for disease complications; 77.6% of the patients reported that they yearly visited a cardiologist, 42.4% an ophthalmologist, 31.9% an orthopedic, 28.4% a pneumonologist, 28.9% a hepatologist, 12.6% an urologist, 14% a nephrologist, 11.9% an infectious disease doctor, 10.1% a pain management specialist and 8.1% a neurologist. The therapeutic approaches included daily folic acid supplementation (86.1%), vaccines (68.3%), hydroxyurea (66.3%), antibiotics (57.1%), simple pain moderators (52.4%), opioids (48.8%) and iron chelators (30.2%). Previous experience in clinical trials was reported by only 17 patients (6.9%). Regarding the patients' attitudes towards a probable clinical trial, 41.3% were positive to try new therapies, 28.3% negative and 30.4% neutral. 67.2% were satisfied with their current treatment, without excluding a potential participation in clinical trials; such treatment satisfaction correlated significantly with older age, lower income and secondary hemochromatosis under chelation treatment (p<0.05). 40% reported that they had been waiting for years for a new treatment, but 43.2% strongly denied becoming an experimental mouse model, whereas 47.3% mentioned that they would trust their doctors' advice correlating positively with male gender and higher income (p<0.05). Lower educational status, prior intake of hydroxyurea and residence/origin in the capital in contrast to the countryside (chi-square, p<0.05) significantly correlated with a potential clinical trial participation. Internet and television information motivated patients to seek more details from their doctor.

Concerning the factors rated as the most important for a potential participation in a clinical trial, 7 out of 10 patients of our cohort considered of utmost equal importance the effectiveness of a probable treatment and the relative toxicity.

Conclusions: Most SCD patients have chronic complications and visit specialized physicians. Since the participation of larger number of patients in clinical trials is essential for the application of novel drugs, the most important factors of our cohort are the effectiveness of a probable treatment and the relative toxicity, along with the trust to the doctor. These factors are crucial, influencing patients' decision. Even though a proportion of our patients remain skeptical towards clinical trials, an increasing number is willing to participate, which correlates positively with residence in the capital, lower educational status and prior intake of hydroxyurea.

Disclosures

Kattamis: Apopharma: Honoraria; Vertex: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ionis: Membership on an entity's Board of Directors or advisory committees; ViFOR: Membership on an entity's Board of Directors or advisory committees; Novartis Oncology: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Symeonidis:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; MSD: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tekeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding.