Deokumar Srivastava

Adenovirus-Associated Virus Vector-Mediated Gene Transfer in Hemophilia B

BACKGROUND Hemophilia B, an X-linked disorder, is ideally suited for gene therapy. We investigated the use of a new gene therapy in patients with the disorder. METHODS We infused a single dose of a serotype-8-pseudotyped, self-complementary adenovirus-associated virus (AAV) vector expressing a codon-optimized human factor IX (FIX) transgene (scAAV2/8-LP1-hFIXco) in a peripheral vein in six patients with severe hemophilia B (FIX activity, <1% of normal values). Study participants were enrolled sequentially in one of three cohorts (given a high, intermediate, or low dose of vector), with two participants in each group. Vector was administered without immunosuppressive therapy, and participants were followed for 6 to 16 months. RESULTS AAV-mediated expression of FIX at 2 to 11% of normal levels was observed in all participants. Four of the six discontinued FIX prophylaxis and remained free of spontaneous hemorrhage; in the other two, the interval between prophylactic injections was increased. Of the two participants who received the high dose of vector, one had a transient, asymptomatic elevation of serum aminotransferase levels, which was associated with the detection of AAV8-capsid-specific T cells in the peripheral blood; the other had a slight increase in liver-enzyme levels, the cause of which was less clear. Each of these two participants received a short course of glucocorticoid therapy, which rapidly normalized aminotransferase levels and maintained FIX levels in the range of 3 to 11% of normal values. CONCLUSIONS Peripheral-vein infusion of scAAV2/8-LP1-hFIXco resulted in FIX transgene expression at levels sufficient to improve the bleeding phenotype, with few side effects. Although immune-mediated clearance of AAV-transduced hepatocytes remains a concern, this process may be controlled with a short course of glucocorticoids without loss of transgene expression. (Funded by the Medical Research Council and others; ClinicalTrials.gov number, NCT00979238.).

Long-Term Safety and Efficacy of Factor IX Gene Therapy in Hemophilia B

BACKGROUND In patients with severe hemophilia B, gene therapy that is mediated by a novel self-complementary adeno-associated virus serotype 8 (AAV8) vector has been shown to raise factor IX levels for periods of up to 16 months. We wanted to determine the durability of transgene expression, the vector dose-response relationship, and the level of persistent or late toxicity. METHODS We evaluated the stability of transgene expression and long-term safety in 10 patients with severe hemophilia B: 6 patients who had been enrolled in an initial phase 1 dose-escalation trial, with 2 patients each receiving a low, intermediate, or high dose, and 4 additional patients who received the high dose (2×10(12) vector genomes per kilogram of body weight). The patients subsequently underwent extensive clinical and laboratory monitoring. RESULTS A single intravenous infusion of vector in all 10 patients with severe hemophilia B resulted in a dose-dependent increase in circulating factor IX to a level that was 1 to 6% of the normal value over a median period of 3.2 years, with observation ongoing. In the high-dose group, a consistent increase in the factor IX level to a mean (±SD) of 5.1±1.7% was observed in all 6 patients, which resulted in a reduction of more than 90% in both bleeding episodes and the use of prophylactic factor IX concentrate. A transient increase in the mean alanine aminotransferase level to 86 IU per liter (range, 36 to 202) occurred between week 7 and week 10 in 4 of the 6 patients in the high-dose group but resolved over a median of 5 days (range, 2 to 35) after prednisolone treatment. CONCLUSIONS In 10 patients with severe hemophilia B, the infusion of a single dose of AAV8 vector resulted in long-term therapeutic factor IX expression associated with clinical improvement. With a follow-up period of up to 3 years, no late toxic effects from the therapy were reported. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT00979238.).

Screening Adult Survivors of Childhood Cancer for Cardiomyopathy: Comparison of Echocardiography and Cardiac Magnetic Resonance Imaging

PURPOSE To compare two-dimensional (2D) echocardiography, the current method of screening for treatment-related cardiomyopathy recommended by the Childrens Oncology Group Guidelines, to cardiac magnetic resonance (CMR) imaging, the reference standard for left ventricular (LV) function. PATIENTS AND METHODS Cross-sectional, contemporaneous evaluation of LV structure and function by 2D and three-dimensional (3D) echocardiography and CMR imaging in 114 adult survivors of childhood cancer currently median age 39 years (range, 22 to 53 years) exposed to anthracycline chemotherapy and/or chest-directed radiation therapy. RESULTS In this survivor population, 14% (n = 16) had an ejection fraction (EF) less than 50% by CMR. Survivors previously undiagnosed with cardiotoxicity (n = 108) had a high prevalence of EF (32%) and cardiac mass (48%) that were more than two standard deviations below the mean of normative CMR data. 2D echocardiography overestimated the mean EF of this population by 5%. Compared with CMR, 2D echocardiography (biplane method) had a sensitivity of 25% and a false-negative rate of 75% for detection of EF less than 50%, although 3D echocardiography had 53% and 47%, respectively. Twelve survivors (11%) had an EF less than 50% by CMR but were misclassified as ≥ 50% (range, 50% to 68%) by 2D echocardiography (biplane method). Detection of cardiomyopathy was improved (sensitivity, 75%) by using a higher 2D echocardiography cutoff (EF < 60%) to detect an EF less than 50% by the reference standard CMR. CONCLUSION CMR identified a high prevalence of cardiomyopathy among adult survivors previously undiagnosed with cardiac disease. 2D echocardiography demonstrated limited screening performance. In this high-risk population, survivors with an EF 50% to 59% by 2D echocardiography should be considered for comprehensive cardiac assessment, which may include CMR.

Survival and long-term health and cognitive outcomes after low-grade glioma

Long-term morbidity for children with low-grade glioma (LGG) requires exposure-specific characterization. Overall survival (OS) and progression-free survival (PFS) were estimated for 361 children diagnosed with LGG between 1985 and 2007 at a single institution. Five-year survivors (n = 240) received risk-based clinical assessment. Cumulative incidence of late effects 15 years from diagnosis were estimated. Risk factors for adverse health were identified using Fine and Grays approach to Coxs proportional hazards model, accounting for death as a competing risk. OS at 15 years was 86% (95% confidence interval [CI] 82%-90%), and PFS was 55% (95% CI 51%-58%). Among the 240 5-year survivors, the 5-, 10-, and 15-year cumulative incidence of adverse outcomes included blindness: 10%, 13%, and 18%, respectively; hearing loss: 8%, 14%, and 22%; obesity/overweight: 18%, 35%, and 53%; hyperinsulinism: 1%, 5%, and 24%; growth hormone deficiency: 13%, 27%, and 29%;thyroid hormone deficiency: 16%, 28%, and 33%; and adrenocorticotropic hormone (ACTH) deficiency: 12%, 22%, and 26%. Multivariable models demonstrated radiation therapy to be a significant independent predictor of hearing loss, growth hormone deficiency, abnormal thyroid function, and ACTH deficiency. Diencephalic location was a statistically significant independent risk factor for blindness, growth hormone deficiency, abnormal thyroid function, and ACTH deficiency. Among the 182 5-year survivors assessed for intellectual function, 34% had an intelligence quotient (IQ) below average (<85), associated with younger age at diagnosis, epilepsy, and shunt placement. Survivors of childhood LGG experience substantial long-term adverse effects that continue to increase well beyond the 5-year survival time point.

Occurrence of Multiple Subsequent Neoplasms in Long-Term Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study

PURPOSE Childhood cancer survivors experience an increased incidence of subsequent neoplasms (SNs). Those surviving the first SN (SN1) remain at risk to develop multiple SNs. Because SNs are a common cause of late morbidity and mortality, characterization of rates of multiple SNs is needed. PATIENTS AND METHODS In a total of 14,358 5-year survivors of childhood cancer diagnosed between 1970 and 1986, analyses were carried out among 1,382 survivors with an SN1. Cumulative incidence of second subsequent neoplasm (SN2), either malignant or benign, was calculated. RESULTS A total of 1,382 survivors (9.6%) developed SN1, of whom 386 (27.9%) developed SN2. Of those with SN2, 153 (39.6%) developed more than two SNs. Cumulative incidence of SN2 was 46.9% (95% CI, 41.6% to 52.2%) at 20 years after SN1. The cumulative incidence of SN2 among radiation-exposed survivors was 41.3% (95% CI, 37.2% to 45.4%) at 15 years compared with 25.7% (95% CI, 16.5% to 34.9%) for those not treated with radiation. Radiation-exposed survivors who developed an SN1 of nonmelanoma skin cancer (NMSC) had a cumulative incidence of subsequent malignant neoplasm (SMN; ie, malignancies excluding NMSC) of 20.3% (95% CI, 13.0% to 27.6%) at 15 years compared with only 10.7% (95% CI, 7.2% to 14.2%) for those who were exposed to radiation and whose SN1 was an invasive SMN (excluding NMSC). CONCLUSION Multiple SNs are common among aging survivors of childhood cancer. SN1 of NMSC identifies a population at high risk for invasive SMN. Survivors not exposed to radiation who develop multiple SNs represent a population of interest for studying genetic susceptibility to neoplasia.

Metabolic syndrome and cardiovascular risk among long‐term survivors of acute lymphoblastic leukaemia ‐ From the St. Jude Lifetime Cohort

Adult survivors of childhood acute lymphoblastic leukaemia (ALL) have a four‐fold excess risk of mortality from cardiovascular disease. This cardiovascular risk has not been fully characterized. ALL survivors [n = 784, median age 31·7 years (18·9–59·1)] in the St. Jude Lifetime Cohort Study underwent evaluation for cardiovascular risk and metabolic syndrome (MetS) according to National Cholesterol Education Program – Adult Treatment Panel III criteria. Comparisons were made to 777 age‐, sex‐, and race‐matched controls from the National Health and Nutrition Examination Survey (NHANES). MetS was identified in 259 survivors (33·6%) and associated with older age in 5‐year increments (relative risk [RR] 1·13, 95% confidence interval [CI] 1·06–1·19) and prior cranial radiotherapy (CRT) (with craniospinal radiation: RR 1·88, 95%CI 1·32–2·67; without: RR 1·67, 95%CI 1·26–2·23). Measures of obesity were highly prevalent among female survivors and CRT recipients. Compared to NHANES controls, ALL survivors had a higher risk of MetS (RR 1·43, 95%CI 1·22–1·69), hypertension (RR 2·43, 95%CI 2·06–2·86), low high‐density lipoprotein (RR 1·40, 95%CI 1·23–1·59), obesity (RR 1·47, 95%CI 1·29–1·68) and insulin resistance (1·64, 95%CI 1·44–1·86). This large study of clinically evaluated ALL survivors identified a high prevalence of MetS, obesity and cardiovascular risk, particularly in CRT recipients, underscoring the need for screening and aggressive reduction of modifiable risks.

Cumulative alkylating agent exposure and semen parameters in adult survivors of childhood cancer: a report from the St Jude Lifetime Cohort Study

BACKGROUND Few data define the dose-specific relation between alkylating agent exposure and semen variables in adult survivors of childhood cancer. We undertook this study to test the hypothesis that increased exposure to alkylating agents would be associated with decreased sperm concentration in a cohort of adult male survivors of childhood cancer who were not exposed to radiation therapy for their childhood cancer. METHODS We did semen analysis on 214 adult male survivors of childhood cancer (median age 7·7 years [range 0·01-20·3] at diagnosis, 29·0 years [18·4-56·1] at assessment, and a median of 21·0 years [10·5-41·6] since diagnosis) who had received alkylating agent chemotherapy but no radiation therapy. Alkylating agent exposure was estimated using the cyclophosphamide equivalent dose (CED). Odds ratios (ORs) and 95% CIs for oligospermia (sperm concentration >0 and <15 million per mL) and azoospermia were calculated with logistic regression modelling. FINDINGS Azoospermia was noted in 53 (25%) of 214 participants, oligospermia in 59 (28%), and normospermia (sperm concentration ≥15 million per mL) in 102 (48%) participants. 31 (89%) of 35 participants who received CED less than 4000 mg/m(2) were normospermic. CED was negatively correlated with sperm concentration (correlation coefficient=-0·37, p<0·0001). Mean CED was 10 830 mg/m(2) (SD 7274) in patients with azoospermia, 8480 mg/m(2) (4264) in patients with oligospermia, and 6626 mg/m(2) (3576) in patients with normospermia. In multivariable analysis, CED was significantly associated with an increased risk per 1000 mg/m(2) CED for azoospermia (OR 1·22, 95% CI 1·11-1·34), and for oligospermia (1·14, 1·04-1·25), but age at diagnosis and age at assessment were not. INTERPRETATION Impaired spermatogenesis was unlikely when the CED was less than 4000 mg/m(2). Although sperm concentration decreases with increasing CED, there was substantial overlap of CED associated with normospermia, oligospermia, and azoospermia. These data can inform pretreatment patient counselling and use of fertility preservation services. FUNDING US National Cancer Institute, American Lebanese Syrian Associated Charities.

Secondary Colorectal Carcinoma After Childhood Cancer

PURPOSE Colorectal carcinoma (CRC) has been described as a subsequent malignant neoplasm (SMN), although little is known about associated risk factors. We aimed to quantify the long-term risk of secondary CRC and identify treatment-related risk factors. PATIENTS AND METHODS In this nested case-control study, 19 cases of adenocarcinoma of the colon or rectum were identified from 13,048 oncology patients treated for childhood cancer at St Jude Childrens Research Hospital. Group 1 controls (n = 148) were matched for age at primary malignancy and follow-up interval. Group 2 controls (n = 72) were matched on primary diagnosis in addition to group 1 criteria. Exact conditional logistic regression was performed to calculate odds ratios (ORs) for chemotherapy and radiation exposure. RESULTS Forty-year cumulative incidence of secondary CRC was 1.4%. Standardized incidence ratio was 10.9 (95% CI, 6.6 to 17.0) compared with that in the general US population. Secondary CRC was more likely in an irradiated segment of the colon (group 1 OR, 7.7; P = .001; group 2 OR, 15.4; P = .002). Risk increased by 70% with each 10-Gy increase in radiation dose. Increasing radiation volume increased risk (group 1 OR, 1.5; P < .001; group 2 OR, 1.8; P < .001). Alkylating agent exposure was associated with an 8.8-fold increased risk of secondary CRC (P = .03). CONCLUSION In matched analyses, radiation and alkylator exposure are associated with secondary CRC. This risk is proportional to dose and volume of radiation. Surveillance should be initiated at a young age among survivors receiving high-risk exposures.

Bone mineral density among long-term survivors of childhood acute lymphoblastic leukemia: Results from the St. Jude Lifetime Cohort Study

The prevalence of low bone mineral density (BMD) in adult survivors of childhood acute lymphoblastic leukemia (ALL), and the degree of recovery or decline, are not well elucidated.

Temporal Trends in Cause-Specific Late Mortality Among 5-Year Survivors of Childhood Cancer

PURPOSE Five-year survival rates for childhood cancer have improved over the past four decades. However, it is unknown whether changes in primary cancer therapy have improved rates of long-term (> 5 years from diagnosis) durable remissions and reduced treatment-related deaths. We investigated changes in patterns of late mortality over time and cause-specific attribution of late-mortality among 5-year survivors. PATIENTS AND METHODS Using data from the Surveillance, Epidemiology and End Results (SEER) population-based registry, we assessed all-cause and cause-specific (recurrence/progression of primary disease, external cause, and nonrecurrence/nonexternal cause) late mortality during four consecutive time periods from 1974 through 2000 among 26,643 5-year survivors of childhood cancer. RESULTS All-cause late mortality improved during more recent eras, dropping from 7.1% (95% CI, 6.4% to 7.8%) among children diagnosed during 1974 to 1980 to 3.9% (95% CI, 3.3% to 4.4%) among children diagnosed during 1995 to 2000 (P < .001), largely because of reduced mortality from recurrence or progression. While there was no significant reduction in mortality attributable to other health conditions (including treatment-related health conditions), analysis controlling for demographic characteristics identified a trend toward reduced risk during more recent eras (P = .007). Disparity by race/ethnicity was identified, with higher mortality among non-Hispanic blacks than among non-Hispanic whites for all-cause and nonrecurrence/nonexternal -cause late mortality. CONCLUSION While overall patterns of mortality from other health conditions do not differ over time, adjustment for demographic characteristics provides evidence that risk of treatment-related mortality may be lower in more recent eras. Disparities in health care utilization among survivors should be explored.