Among children and adults with sickle cell anemia, the median number of pain crises over 48 weeks was lower among those who received oral therapy with l-glutamine, administered alone or with hydroxyurea, than among those who received placebo, with or without hydroxyurea. (Funded by Emmaus Medical; ClinicalTrials.gov number, NCT01179217 .).

Background The NHLBI-sponsored Sickle Cell Disease Clinical Research Network (SCDCRN) conducted a multi-center, acute intervention randomized clinical trial of two methods of Patient Controlled Analgesia for acute pain. This trial was terminated early due to low enrollment. We analyzed the perceived barriers and recruitment difficulties as reported by the coordinators and principal investigators. Methods Participating sites completed a missed eligibility log of subjects admitted in pain crisis throughout the study and a survey at the end of the trial. The survey covered site-specific factors, policies, and procedures in study implementation, recruitment strategies, and eligibility factors. The New England Research Institutes (NERI) collected de-identified surveys from 31 respondents at 29 of 31 participating sites. Results From December 2009 to June 2010, 1116 patient encounters for SCD and pain occurred at participating institutions: 38 subjects were enrolled (14 pediatric and 24 adults) and 34 completed the trial, below the projected 278 subjects. Fourteen sites enrolled subjects and seventeen did not. Recruitment barriers included insufficient staff, subject ineligibility or in too much pain to consent, competing protocols, and concerns regarding pain control. Recruitment methods were referrals from urgent care, SCD clinics and in house databases. No use of media or outside physicians was reported. Conclusion We identified multiple barriers to patient accrual including short duration of enrollment period, protocol design, complex dosing schedule, requirement for staff availability during week-end and after hours, multiple departments’ involvement, protocol acceptance, eligibility criteria, competing protocols, and limited staff. Each of these areas should be targeted for intervention in order to plan and conduct successful future clinical trials.

Background: Sickle cell disease (SCD) is characterized by continuous oxidative stress through various mechanisms contributing to the pathophysiology and clinical course of sickle cell crises (SCC) and organ damage. L-glutamine is a precursor for the synthesis of essential metabolic redox cofactors including Nicotinamide Adenine Dinucleotide (NAD). Early studies have demonstrated that altered erythrocyte NAD redox potential was improved by oral L-glutamine therapy, suggesting that higher L-glutamine utilization in SCD exceeded de novo synthesis and its depletion played a role in oxidative stress. A Phase 2 study of Pharmaceutical Grade L-glutamine (L-glutamine) versus placebo showed promising results on clinical endpoints. In a Phase 3 study with 230 SCD patients, randomized 2:1 to L-glutamine or placebo, the median number of SCCs was 25% lower for L-glutamine than placebo (L-glutamine 3.0 vs. placebo 4.0). An analysis of SCC events showed significant differences between groups (p < 0.01). Categories for pre-specified subgroups for Age, Gender and Hydroxyurea (HU) use were defined in the statistical plan. HU use was also a randomization stratification factor since HU is the only FDA-approved drug for SCD treatment. Examination of the HU subgroup for differences in L-glutamine effect across categories (HU vs. no HU) was appropriate since approximately 66% of patients remained on HU throughout the Phase 3 study. To investigate the subgroup treatment effect size, treatment by subgroup interaction and consistency of the primary endpoint across the categories of the subgroups, an examination was performed following the guidelines for reporting subgroup analysis. Methods: The Negative Binomial Regression (NBR) model was utilized to generate an estimate of treatment effect and treatment by subgroup interactions of the three pre-specified subgroups. SCC events are most accurately described as counts and NBR is specifically intended for modeling count variables, usually for over-dispersed counts as seen in SCD studies. Rates of SCC for each treatment arm in a subgroup (Rate L-glutamine per 48 weeks / Rate placebo per 48 weeks) provide rate ratios, and an estimate of effect size, with 95% confidence intervals. A rate ratio <1.0 favored L-glutamine. Tests for treatment by subgroup interactions were conducted simultaneously. A significant interaction could be seen if the treatment is better than placebo for one category and worse than placebo for the other. Predefined categories for subgroups with corresponding sample sizes were as follows: Age: 5 - 18 years (n = 118) and ≥ 18 years (n = 111); Gender: Females (n = 124) and Males (n = 105). HU use before and during study: Yes (n = 153) and No (n = 76). Data for this Phase 3 subgroup report were obtained from an integrated dataset and the NBR model with treatment, subgroup, region and HU use as main effects and a treatment by subgroup interaction term was run with log (time on study) as an offset. Results: Age Subgroup:Both the 5 - 18 years and the > 18 years groups had a lower rate of SCCs per 48 weeks in the L-glutamine arm relative to placebo. The rate ratio was 0.93 [0.67 - 1.29] for the 5 - 18 years group and 0.64 [0.45 - 0.89] in the > 18 years group. There was no treatment by Age Group interaction (p = 0.118). Gender Subgroup: Both the Female and the Male groups had a lower rate of SCCs per 48 weeks in the L-glutamine treatment arm. The rate ratio was 0.81 [0.59 -1.12] for the Female group and 0.73 [0.51 - 1.05] for the Male group, indicating consistent treatment effects across genders. There was no treatment by Gender interaction (p = 0.683). Hydroxyurea Use Subgroup: Both HU groups had a lower rate of SCCs per 48 weeks in the L-glutamine arm. The treatment effects were consistent across groups, with a rate ratio of 0.78 [0.51 - 1.20] for the group without HU use and 0.77 [0.58 - 1.03] for the group with HU use. There was no treatment by HU use interaction (p = 0.961). See Figure 1 for a graphic example. Conclusion: For the Age and Gender subgroups, both categories in each subgroup benefited from L-glutamine but to varying degrees noted by the difference in rate ratios. For the HU use subgroup, both categories (on HU and not on HU) benefited from L-glutamine similarly. Lack of interactions in all subgroups indicated that regardless of category within a subgroup, treatment effect by Pharmaceutical Grade L-glutamine was beneficial. Figure 1 Hydroxyurea Use Subgroup Analysis Figure 1. Hydroxyurea Use Subgroup Analysis Disclosures Niihara: Emmaus Medical, Inc.: Employment, Equity Ownership. Viswanathan:Novartis: Speakers Bureau. Razon:Emmaus Medical, Inc.: Employment. Tran:Emmaus Medical, Inc.: Employment, Equity Ownership. Stark:Emmaus Medical, Inc.: Employment, Equity Ownership.

Background: Sickle cell patients produce more reactive oxygen species (ROS) than healthy individuals, leading to increased cell membrane damage. Theoretically, reducing ROS formation would preserve red cell membranes of sickle cell patients. Vitamin C is a powerful anti-oxidant capable of inhibiting ROS formation in a variety of situations, by functioning as an electron donor to reduce molecular oxygen. This study aimed to determine whether Vitamin C reduced ROS formation in sickle red cells. Methods: 27 homozygous (HbSS) patients were recruited from the outpatient clinics of Lagos University Teaching Hospital, Nigeria, and annex at the Sickle Cell Foundation, Lagos, Nigeria. Demographic information and EDTA patient blood samples were collected. The test group were red cells preincubated in 80uM and 100uM Vitamin C concentrations before stressing with tertbutylhydroperoxide. These were compared to stressed matched controls preincubated in phosphate buffered saline. Cell staining was done with CellRox Orange followed by flow cytometry to quantify ROS. Results: ROS count for Vitamin C pre-treated red cells was significantly lower than matched controls (p<0.001). Average ROS count for 80uM test samples was 27.5/ul (95% CI, 17.5 to 72.5) and for 100uM 3.9/ul (95% CI, 1.9 to 5.9). Male gender was significantly associated with elevated baseline ROS count (p=0.03). Conclusion: Vitamin C reduced ROS formation in HbSS cells. Future studies should focus on a role for Vitamin C as a safe, cheap addition to maintenance therapy of sickle cell patients.

Objective: Despite the low prevalence (0.008%) of adrenal insufficiency (AI) in the general population, this disorder was recently diagnosed in a substantial number of sickle cell disease (SCD) patients at our hospital. The main objective of this study was to assess the prevalence of AI in SCD patients. Methods: All adult patients admitted to the Department of Medicine at Interfaith Medical Center from October 2010 to November 2011 were eligible for this retrospective study. Medical records of adult SCD patients hospitalized for painful crisis and who had undergone cosyntropin testing were reviewed. Adult non-SCD patients hospitalized for painful crisis and who had undergone cosyntropin testing served as controls. The result of the cosyntropin test was the primary outcome. The prevalence of positive cosyntropin tests was compared between the 2 groups by using Student?s t-test, and odds ratios. Results: 62 adult SCD patients were enrolled in the study. 15 underwent cosyntropin testing and 12 (19.4%) of these patients were found to have AI. AI was also diagnosed in 1 of 1?340 non-SCD patients. The odds ratio for AI in SCD to non-SCD patients [(12/62)/(1?340)] was 259. The odds ratio for the prevalence of AI in SCD patients in our study (19.4%) vs. the general population (approximately 0.008%) was 2?375. Conclusion: AI occurred in 19.4% of SCD patients included in this study. These patients thus have a 2?375-fold higher risk of developing AI than the general population, and a 259-fold greater risk of developing AI than do hospitalized non-SCD patients.