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Burkitt lymphoma (BL) accounts for most pediatric non-Hodgkin lymphomas, being less common but significantly more lethal when diagnosed in adults. Much of the knowledge of the genetics of BL thus far has originated from the study of pediatric BL (pBL), leaving its relationship to adult BL (aBL) and other adult lymphomas not fully explored. We sought to more thoroughly identify the somatic changes that underlie lymphomagenesis in aBL and any molecular features that associate with clinical disparities within and between pBL and aBL. Through comprehensive whole-genome sequencing of 230 BL and 295 diffuse large B-cell lymphoma (DLBCL) tumors, we identified additional significantly mutated genes, including more genetic features that associate with tumor Epstein-Barr virus status, and unraveled new distinct subgroupings within BL and DLBCL with 3 predominantly comprising BLs: DGG-BL (DDX3X, GNA13, and GNAI2), IC-BL (ID3 and CCND3), and Q53-BL (quiet TP53). Each BL subgroup is characterized by combinations of common driver and noncoding mutations caused by aberrant somatic hypermutation. The largest subgroups of BL cases, IC-BL and DGG-BL, are further characterized by distinct biological and gene expression differences. IC-BL and DGG-BL and their prototypical genetic features (ID3 and TP53) had significant associations with patient outcomes that were different among aBL and pBL cohorts. These findings highlight shared pathogenesis between aBL and pBL, and establish genetic subtypes within BL that serve to delineate tumors with distinct molecular features, providing a new framework for epidemiologic, diagnostic, and therapeutic strategies.

Burkitt lymphoma (BL) accounts for the majority of pediatric non-Hodgkin lymphomas (NHL) and is relatively rare but significantly more lethal when diagnosed in adults. The global incidence is highest in Sub-Saharan Africa, where Epstein-Barr virus (EBV) positivity is observed in 95% of all tumors. Both pediatric (pBL) and adult (aBL) cases are known to share some driver mutations, for example MYC translocations, which are seen in > 90% of cases. Sequencing efforts have identified many common somatic alterations that cooperate with MYC in lymphomagenesis with approximately 30 significantly mutated genes (SMG) reported thus far. Recent analyses revealed non-coding mutation patterns in pBL that were attributed to aberrant somatic hypermutation (aSHM). We sought to identify genomic and molecular features that may explain clinical disparities within and between aBL and pBL in an effort to delineate BL subtypes that may allow for the stratification of patients with shared pathobiology. Through comprehensive sequencing of BL genomes, we found additional SMGs, including more genetic features that associate with tumor EBV status, and established three new genetic subgroups that span pBL and aBL. Direct comparisons between pBL and aBL revealed only marginal differences and the mutational profiles were consistently better explained by EBV status. Using an unsupervised clustering approach to identify subgroupings within BL and diffuse large B-cell lymphoma (DLBCL), we have defined three genetic subgroups that predominantly comprise BL tumors. Akin to the recently defined DLBCL subgroups, each BL subgroup is characterized by combinations of common driver mutations and non-coding mutations caused by aSHM. Two of these subgroups and their prototypical genetic features (ID3 and TP53) had significant associations with patient outcomes that were different among the aBL and pBL cohorts. These findings highlight not only a shared pathogenesis between aBL and pBL, but also establish genetic subtypes within BL that serve to delineate tumors with distinct molecular features, providing a new framework for epidemiological studies, and diagnostic and therapeutic strategies.

Introduction: Burkitt lymphoma (BL) accounts for approximately 50% of all pediatric non-Hodgkin lymphomas compared to 1-2% in adults. Adult BL (aBL) remains a poorly understood entity and its relationship to pediatric BL (pBL) and to DLBCL has not been fully elucidated. The variable treatment outcomes between these entities necessitate a more thorough understanding of the genetic and molecular features underlying their biology to enable better prognostication and more effective treatments. We sought to comprehensively determine genetic features shared with DLBCL and those that are unique to BL, to further delineate genetic subgroupings within each entity. Methods: Samples for this study were collected through the Burkitt Lymphoma Genome Sequencing Project (BLGSP). We sequenced the tumor genomes of 139 pBL and 92 aBL, consisting of both EBV-positive (EBV+) and EBV-negative (EBV-) BLs, and compared these to the genomes of 252 DLBCL patients. All cases were analyzed for simple somatic mutations (SSM), recurrent copy number variations (CNV), structural variations (SV), aberrant somatic hypermutation (aSHM), and SSM hotspots. Mutations were used as features for the identification of genetic subgroups using non-negative matrix factorization (NMF) clustering. Results: Clustering of BL and DLBCL revealed six distinct genetic subgroups (Figure 1) with three primarily representing DLBCLs (DLBCL-1, DLBCL-2, and DLBCL-3) and three predominantly comprising BLs (M53-BL, IC-BL, and DGG-BL). The DLBCL-predominant subgroups partially overlapped with those previously described and resembled features of EZB and ST2-like subgroups. The frequency of aBLs within these subgroups was higher than that of pBL patients (p=0.0005). The new cluster M53-BL consists of both pBL (9/27) and aBL (13/27) samples and is characterized by the highest prevalence of mutations in TP53 accompanied by the paucity of other driver mutations but without the aneuploidy associated with the A53 subgroup described in DLBCL. Enrichment of EBV- samples in this cluster further corroborate our previous findings of TP53 mutations being associated with EBV- BL. IC-BL is characterized by mutations in ID3, CCND3, and SMARCA4. In contrast, DGG-BL, where 65% of the cluster consisted of EBV+ BL samples, had mutations in DDX3X, GNA13, and GNAI2. Using a linear model, we compared the rates of aSHM in BL genomes from all clusters and identified the DLBCL-3 cluster to harbor the highest aSHM rates at common sites while the M53-BL cluster harbored the lowest rates. To further establish the biological basis of unique clusters within BL, we conducted differential gene expression analyses between the two major BL genetic subgroups, DGG-BL and IC-BL. We identified a total of 86 differentially expressed genes between the two clusters (p.adj < 0.01 and |log2foldChange| > 1). Among the genes with the strongest differential expression were IRF4, SERPINA9, and TNFRSF13B. Each of these are notable as their expression is a component of the DLBCL cell-of-origin and double-hit signature classifiers. Further, we found IRF4 expression to be one of the strongest predictors of cluster membership, with high IRF4 expression associated with IC-BL membership. Using TP53 and ID3 mutations as a proxy for M53-BL and IC-BL clusters in aBL, we found mutations in TP53 to be associated with significantly inferior progression free survival (PFS) at 2 year follow up, while mutations in ID3 were associated with overall better PFS at 2 year follow up. Conclusion: This work identifies novel genetic subgroups within BL with characteristic genetic and gene expression differences and some bearing relationship to DLBCL subgroups. The three subgroups with predominantly BL samples (DGG-BL, IC-BL, and M53-BL) each comprised a mixture of aBL and pBL samples, confirming similar molecular features in these entities. The IC-BL cluster is associated with mutations in ID3 and CCND3, high IRF4 expression, and ID3 mutated cases exhibited significantly better outcomes. M53-BL is associated with TP53 mutations and inferior PFS in aBL, representing a subset of patients to be considered for novel treatment approaches. These findings highlight shared pathogenesis between aBL and pBL and establish genetic subtypes within BL that delineate cases with distinct molecular and clinical features. This provides a new framework for new diagnostic and therapeutic strategies. Figure 1 Figure 1. Disclosures Abramson: Seagen Inc.: Research Funding; Allogene Therapeutics: Consultancy; Astra-Zeneca: Consultancy; Incyte Corporation: Consultancy; BeiGene: Consultancy; Kymera: Consultancy; Kite Pharma: Consultancy; Novartis: Consultancy; Bluebird Bio: Consultancy; C4 Therapeutics: Consultancy; Morphosys: Consultancy; Genmab: Consultancy; EMD Serono: Consultancy; Bristol-Myers Squibb Company: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy; Genentech: Consultancy. Bartlett: Pharmacyclics: Research Funding; Millennium: Research Funding; Merck: Research Funding; Kite, a Gilead Company: Research Funding; Janssen: Research Funding; Genentech: Research Funding; Forty Seven: Research Funding; Celgene: Research Funding; Bristol Myers Squibb: Research Funding; Autolus: Research Funding; Seagen: Consultancy, Research Funding; Roche/Genentech: Consultancy; ADC Therapeutics: Consultancy, Research Funding. Casper: EUSA Pharma: Consultancy. Gerrie: Roche: Research Funding; AbbVie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Astrazeneca: Honoraria, Research Funding; Sandoz: Honoraria. Grande: Sage Bionetworks: Current Employment. Mullighan: Illumina: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; AbbVie: Research Funding; Amgen: Current equity holder in publicly-traded company. Noy: Epizyme: Consultancy; Rafael Parhma: Research Funding; Morphosys: Consultancy; Targeted Oncology: Consultancy; Medscape: Consultancy; Pharmacyclics: Consultancy, Research Funding; Janssen: Consultancy, Honoraria. Scott: NanoString Technologies: Patents & Royalties: Patent describing measuring the proliferation signature in MCL using gene expression profiling.; AstraZeneca: Consultancy; Abbvie: Consultancy; Celgene: Consultancy; Incyte: Consultancy; Janssen: Consultancy, Research Funding; Rich/Genentech: Research Funding; BC Cancer: Patents & Royalties: Patent describing assigning DLBCL COO by gene expression profiling--licensed to NanoString Technologies. Patent describing measuring the proliferation signature in MCL using gene expression profiling. . Morin: Foundation for Burkitt Lymphoma Research: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Epizyme: Patents & Royalties.

Although generally curable with intensive chemotherapy in resource-rich settings, Burkitt lymphoma (BL) remains a deadly disease in older patients and in sub-Saharan Africa. Epstein-Barr virus (EBV) positivity is a feature in more than 90% of cases in malaria-endemic regions, and up to 30% elsewhere. However, the molecular features of BL have not been comprehensively evaluated when taking into account tumor EBV status or geographic origin. Through an integrative analysis of whole-genome and transcriptome data, we show a striking genome-wide increase in aberrant somatic hypermutation in EBV-positive tumors, supporting a link between EBV and activation-induced cytidine deaminase (AICDA) activity. In addition to identifying novel candidate BL genes such as SIN3A, USP7, and CHD8, we demonstrate that EBV-positive tumors had significantly fewer driver mutations, especially among genes with roles in apoptosis. We also found immunoglobulin variable region genes that were disproportionally used to encode clonal B-cell receptors (BCRs) in the tumors. These include IGHV4-34, known to produce autoreactive antibodies, and IGKV3-20, a feature described in other B-cell malignancies but not yet in BL. Our results suggest that tumor EBV status defines a specific BL phenotype irrespective of geographic origin, with particular molecular properties and distinct pathogenic mechanisms. The novel mutation patterns identified here imply rational use of DNA-damaging chemotherapy in some patients with BL and targeted agents such as the CDK4/6 inhibitor palbociclib in others, whereas the importance of BCR signaling in BL strengthens the potential benefit of inhibitors for PI3K, Syk, and Src family kinases among these patients.

Introduction: Burkitt Lymphoma (BL) is an aggressive B-cell lymphoma with a translocation involving MYC and immunoglobulin(Ig) loci. It is most common in children, but also affects adults, and occurs in sporadic, endemic and HIV-associated forms. The Epstein-Barr virus (EBV)-associated endemic subtype is the most common pediatric cancer in equatorial Africa, but also occurs in other parts of the world, for example in the rain forest of Brazil. Intensive chemotherapy is effective, but the associated toxicity requires supportive care that is not readily available in resource-poor regions. Previously published molecular characterization of small numbers of tumors indicated that the mutation profiles of endemic and sporadic cases are similar, but not identical. One goal of the BLGSP is to conduct comprehensive molecular characterization of BL by sequencing DNA and RNA from a large BL cohort - including endemic, sporadic, pediatric and adult cases - in order to define the genetic and phenotypic features that drive these cancers. These data will be analyzed with an intent toward developing new therapeutic strategies that can be deployed worldwide. Methods: The goal is to collect 160 BL cases, of which 50% will be endemic, 38% sporadic (pediatric and adult) and 12% from HIV+ patients. For the discovery phase, each tumor requires case-matching normal DNA as well as treatment, outcome and other clinical information. The optimal source of tumor DNA and RNA is from frozen tissue with at least 50% tumor nuclei, but FFPE immobilization is also accepted. Accrual locations include Africa, Brazil, Europe and the US. The BLGSP has developed extensive standard operating procedures for tissue collection, pathology review and tissue processing to reduce the variation associated with these parameters in the interpretation of the results (see https://ocg.cancer.gov/programs/cgci/projects/burkitt-lymphoma). The project also established procedures that allow sharing of all clinical and sample information through the National Cancer Institute Genomic Data Commons (https://gdc.cancer.gov). Molecular characterization includes whole genome sequencing of tumor and normal DNA (80X and 40X coverage, respectively), RNA-sequencing (RNA-seq) and micro-RNA sequencing. These data will enable the BLGSP to identify chromosomal rearrangements, chromosomal copy number alternations, somatic mutations (single nucleotide, insertions, deletions), viral insertions, expression signatures, viral expressions and miRNA regulation of transcripts. Results: To date we have accrued 80 cases of BL of which 75% passed diagnostic pathology review. There was an additional 25% attrition at the tissue processing stage, either due to low quality nucleic acids or low percent tumor nuclei. We have completed sequencing for 45 cases, all but one of which have a MYC translocation involving one of the 3 Ig loci; one case has a MYC rearrangement by FISH analysis that is being characterized further. We have identified recurrent mutations in ID3, DDX3X, ARID1A, FOXO1, TP53, SMARCA4 and other genes. Most mutations are supported by the RNA-seq data, which is also useful in defining the pattern of EBV genome transcription. Preliminary unsupervised hierarchical clustering and principal component analysis of gene expression data defined sample clusters that do not correspond to mutation status or EBV infection, warranting further investigation. Some genes accumulated somatic mutations in a BL subtype-specific fashion. Discussion: BLGSP is an ongoing international collaborative project that will provide a comprehensive molecular portrait of BL subtypes when completed, with the potential to suggest new molecular targets for therapy that can eventually lead to effective treatments that are less toxic than the current regimens. Disclosures Casper: Janssen: Consultancy, Research Funding; Roche: Consultancy, Other: Travel, Accommodation, Expenses; TempTime: Consultancy, Other: Travel, Accommodation, Expenses; Up to Date: Patents & Royalties; GSK: Other: Travel, Accommodation, Expenses. Abramson:Kite Pharma: Consultancy; Abbvie: Consultancy; Seattle Genetics: Consultancy; Gilead: Consultancy. Noy:Pharmacyclics, LLC, an AbbVie Company: Other: travel, accommodations, expenses, Research Funding.

Two hundred eighty-six patients with mild to moderate hypertension who had untreated diastolic blood pressure while seated of 95 to 115 mm Hg were randomized to receive placebo or once-daily doses of 2.5, 5, or 10 mg of the dihydropyridine calcium channel blocker felodipine extended release (ER). Blood pressure was measured 24 hours after dosing (at trough). Mean reductions in diastolic blood pressure after 8 weeks of double-blind treatment were significantly greater in each of the ER felodipine treatment groups (2.5, 5, and 10 mg ER felodipine: -7.8, -9.5, and -11.3 mm Hg, respectively) than in the placebo group (-5.3 mm Hg). The effect was dose dependent for both diastolic and systolic blood pressure. Moreover, much of the peak antihypertensive effect was still present at trough, confirming the 24-hour efficacy of the drug. Felodipine was well tolerated.

The Consumer Use Study of OTC Mevacor evaluated the ability of subjects to self-manage high levels of low-density lipoprotein (LDL) cholesterol by using a multifaceted cholesterol self-management program (the Mevacor Over-the-Counter Self-Management System; MOTC-SMS). This 26-week all-comers multicenter observational study was conducted in naturalistic storefront settings that used the fully functional MOTC-SMS to guide subjects' behavior. Of 3,316 subjects who evaluated the product (evaluators), 1,061 took >or=1 20-mg tablet of Mevacor OTC (users). Eighty-four percent of evaluators made appropriate initial use decisions. Most users demonstrated acceptable ongoing use behavior regarding treatment to goal, compliance/persistence, changes in health status, dietary patterns, and exercise habits. Throughout the study, 23 users (2%) demonstrated behavior that created the potential for suboptimal safety. After 26 weeks, median levels of LDL cholesterol were reduced by 25% among users who fasted. Of the 878 users who completed the study lipid test, 548 (62%) achieved the LDL cholesterol target goal (

Eight patients with essential hypertension completed a double-blind, randomly allocated crossover comparison of either 5 or 10 mg enalapril maleate, 50 mg hydrochlorothiazide, or their combination administered once daily during sequential two-week periods. Blood pressure, pulse rate, plasma renin activity, angiotensin-converting enzyme activity, plasma aldosterone concentration, and urinary electrolytes were monitored for 24 hours after placebo and on days 1 and 14 of each treatment period. After two weeks of each treatment, only the combination of enalapril and hydrochlorothiazide significantly lowered the mean seated diastolic blood pressure (SDBP). Likewise, SDBP control (less than or equal to 90 mm Hg) was achieved only after combination therapy; six of the eight patients were controlled by the combination for up to 24 hours. The initial SDBP response to combination therapy differed with the sequence of drug addition; however, by day 14 the responses were comparable, regardless of whether hydrochlorothiazide or enalapril was first given. Mean converting enzyme activity was suppressed by enalapril in all patients, though it did not always correlate with changes in SDBP or plasma aldosterone. Mean plasma renin activity increased, but the increase was significant only on the combination. There were no serious adverse effects.

The effects of the new nonsulfhydryl-containing oral converting-enzyme inhibitor MK-521 on blood pressure, heart rate, angiotensin-converting enzyme activity, plasma renin activity and plasma aldosterone concentration were assessed in 10 hypertensive patients. After a 2-week no-treatment period, patients received placebo and then 14 days each: MK-521 20 mg once daily, hydrochlorothiazide 50 mg once daily and the latter 2 in combination. During the last day of each treatment, the mean (+/- standard deviation) time-averaged (1- to 12-hour) standing diastolic blood pressure decreased from 106 +/- 8 (placebo) to 95 +/- 10 mm Hg with MK-521, 95 +/- 13 mm Hg with hydrochlorothiazide (p less than 0.05 vs placebo) and 88 +/- 11 mm Hg with the combination (p less than 0.05 vs all other treatments). The antihypertensive effect of MK-521 was maintained 24 hours after dosing. Heart rate did not change significantly after MK-521 treatment. MK-521 caused a marked suppression of converting enzyme activity for over 24 hours; plasma renin activity increased significantly after each active treatment and MK-521 significantly decreased the hydrochlorothiazide-induced elevation of plasma aldosterone concentration. In this short-term trial, MK-521 was well tolerated.

The effects of enalapril alone and in combination with the cyclooxygenase inhibitors sulindac and indomethacin on blood pressure (BP), plasma aldosterone, renin activity and converting enzyme activity were evaluated in 29 patients with mild to moderate essential hypertension, 26 of whom had low plasma renin activity. Patients were randomly assigned to one of three treatment groups. All patients underwent a 4-week placebo phase (phase I), then received enalapril (20 mg BID) for 4 weeks (phase II). In phase III, group I (n = 10) continued on enalapril alone; group II (n = 9) received sulindac 200 mg BID plus enalapril, and group III (n = 10) received indomethacin 50 mg BID plus enalapril, all for 4 weeks. Enalapril lowered BP significantly (mean supine BP 149/100 in phase I vs. 134/90 in phase II, p < 0.05) without inhibiting aldosterone production. The BP effect was not blunted by concomitant administration of sulindac or indomethacin. Enalapril lowered converting enzyme activity to 25% to 30% of baseline and tended to increase renin activity. In the 10 patients who received indomethacin (group III), the effects of enalapril alone and enalapril plus indomethacin on urinary excretion of 6-keto prostaglandin Flα (PGFlα), a stable metabolite of prostacyclin (PGI2), were examined. Enalapril increased urinary 6-keto PGFlα in group III from 118 ± 23 to 194 ± 38 ng/g creatinine (p < 0.05), while addition of indomethacin reduced 6-keto PGFlα to basal levels (138 ± 26 ng/g creatinine). There was no significant correlation between the fall in blood pressure and the increase in 6-keto PGFlα excretion in enalapril-treated patients. These data indicate that the antihypertensive effect of enalapril in essential hypertension occurs in the absence of an active renin-angiotensin system and is associated with increased excretion of 6-keto PGFlα but is not blunted by cyclooxygenase inhibitors. These findings indicate (1) enalapril administration is associated with enhanced prostacyclin production in this patient group but (2) the antihypertensive action of enalapril is not crtically dependent on prostacyclin, since blockade of prostacyclin production with a cyclooxygenase inhibitor does not blunt the antihypertensive effect of the drug.

Cyclobenzaprine hydrochloride was administered to healthy volunteers as a 10 mg oral tablet, 10 mg and 20 mg intramuscular injections, and a 10 mg intravenous injection. Urinary excretion and plasma level data for cyclobenzaprine together provide evidence for route dependent biotransformation. Urinary excretion of total cyclobenzaprine (unchanged plus the glucuronide conjugate) was greater for the oral treatment than for the parenteral treatments (i.m. and i.v.). Area under the plasma concentration-time curve for unchanged cyclobenzaprine, however, was less for the oral treatment than for the parenteral treatments. Based on area calculations, the bioavailability of the 10 mg oral tablet, 10 mg i.m. and 20 mg i.m. injection was 0.33, 0.76, and 0.56, respectively, when compared to the 10 mg i.v. injection of cyclobenzaprine hydrochloride. The four treatments were well tolerated and no clinically adverse effects were observed.

Enalapril, an orally-active, long-acting, nonsulphydryl angiotensin-converting enzyme (ACE) inhibitor, is extensively hydrolysed in vivo to enalaprilat, its bioactive form. Bioactivation probably occurs in the liver. Metabolism beyond activation to enalaprilat is not observed in man. Administration with food does not affect the bioavailability of enalapril; excretion of enalapril and enalaprilat is primarily renal. Peak serum enalaprilat concentrations are reached 4 hours post-dose, and the profile is polyphasic with a prolonged terminal half-life (greater than 30 hours) due to the binding of enalaprilat to ACE. Steady-state is achieved by the fourth daily dose, with no evidence of accumulation. The effective accumulation half-life following multiple dosing is 11 hours. Higher serum concentrations and delayed urinary excretion occur in patients with severe renal insufficiency. Enalapril reduces blood pressure in hypertensive patients by decreasing systemic vascular resistance. The blood pressure reduction is not accompanied by an increase in heart rate. Furthermore, cardiac output is slightly increased and cardiovascular reflexes are not impaired. Once- and twice-daily dosage regimens reduce blood pressure to a similar extent. Enalapril increases renal blood flow and decreases renal vascular resistance. Enalapril also augments the glomerular filtration rate in patients with a glomerular filtration rate less than 80 ml/min. Enalapril reduces left ventricular mass, and does not affect cardiac function or myocardial perfusion during exercise. There is no rebound hypertension after enalapril therapy is stopped. Enalapril does not produce hypokalaemia, hyperglycaemia, hyperuricaemia or hypercholesterolaemia. When combined with hydrochlorothiazide, enalapril attenuates the undesirable diuretic-induced metabolic changes. Therapeutic doses of enalapril do not affect serum prolactin and plasma cortisol in healthy volunteers or T3, rT3, T4 and TSH in hypertensive patients. Enalapril has natriuretic and uricosuric properties. The antihypertensive effect of enalapril is potentiated by hydrochlorothiazide, timolol and methyldopa, but unaffected by indomethacin and sulindac. No interactions occur between enalapril and frusemide, hydrochlorothiazide, digoxin and warfarin. The bioavailability of enalapril is slightly reduced when propranolol is coadministered, but this does not appear to be of any clinical significance. Enalapril increases cardiac output and stroke volume and decreases pulmonary capillary wedge pressure in patients with congestive heart failure refractory to conventional treatment with digitalis and diuretics.(ABSTRACT TRUNCATED AT 400 WORDS)

The safety profiles of the angiotensin converting enzyme inhibitors, captopril and enalapril, are the focus of this review. Adverse effects are reviewed as those associated with sulfhydryl compounds and as those considered class-specific adverse effects of angiotensin converting enzyme inhibitors. Specifically discussed are the incidences of the adverse effects of rash, taste disturbance, neutropenia, and proteinuria, which are characteristic of compounds containing sulfhydryl moieties, such as captopril. It is concluded from the review of these safety data that enalapril is well tolerated, has few class-specific adverse effects, and may offer a potential advantage over captopril by having fewer sulfhydryl-related adverse effects.

The oral dose response and time course of action of indacrinone was compared with that of furosemide in six healthy men on a sodium and potassium-controlled diet. The single doses were 5, 10, 20, 40, and 80 mg indacrinone and 20, 40, and 80 mg furosemide. Diuretic, natriuretic, and kaliuretic effects revealed that indacrinone was more potent, had a longer duration of action, and induced a greater sodium for equivalent potassium loss during its period of peak activity than furosemide. During the 8 hr after drug, all doses of indacrinone decreased serum uric acid levels and increased uric acid clearance while furosemide generally increased serum uric acid and decreased uric acid clearance. After 24 hr, serum uric acid and uric acid clearance were the same for the two drugs. A rise in plasma renin activity was observed 2 hr after an 80-mg dose of furosemide but not after indacrinone.

The contribution of the adrenal glands to the pressor and nerve tissue necrotic responses that follow acute paralyzing spinal cord injury was determined in cats by total adrenal gland removal. The study suggests that either epinephrine or endogenous steroids may exert posttraumatic protective influences on the cord since after adrenalectomy, both the systematic pressor response and local hemorrhagic necrosis are significantly increased.

Enalapril maleate is an investigational oral prodrug whose hydrolyzed diacid metabolite is a potent angiotensin-converting enzyme inhibitor. Fourteen patients with mild to moderate hypertension were evaluated after receiving placebo, and two weeks of treatment with each of the following: enalapril maleate (20 mg b.i.d.), hydrochlorothiazide (25 mg b.i.d.), and the two in combination. In comparison to placebo, the magnitudes of the blood pressure reduction after enalapril and hydrochlorothiazide alone were comparable. The reduction in blood pressure following enalapril was evident throughout the 12-hour dosing interval. The combination of enalapril and hydrochlorothiazide resulted in a marked further reduction in blood pressure that was greater than that predicted from the responses to the individual drugs (P less than 0.05). Biochemical parameters confirmed inhibition of angiotensin-converting enzyme during enalapril treatment; serum angiotensin-converting enzyme activity proved an excellent monitor of compliance. Enalapril was generally well tolerated. Adverse effects included symptomatic hypotension in three patients when enalapril was first added to hydrochlorothiazide and hyperesthesia of the oral mucosa without a loss of taste in one patient on enalapril. Enalapril maleate alone and especially in combination with hydrochlorothiazide appears to be an effective, well-tolerated converting enzyme inhibitor with at least a 12-hour duration of action.

To determine the influence of systemic arterial blood pressure upon the pathogenesis of spinal cord injury, we eliminated the increase in systemic blood pressure normally observed after trauma to the spinal cord with the ganglionic blocker chlorisondamine. Blockade of the pressure response did not influence the development of hemorrhagic necrosis in the spinal cord. We conclude that the transient pressure response accompanying spinal cord injury is probably not a major factor in the pathogenesis of hemorrhagic necrosis at the site of the spinal cord injury.

Overall, the worldwide experience on enalapril to date is very encouraging. The drug produces good to excellent responses in 54 to 66 percent of patients with essential hypertension and is at least as effective as either diuretics or beta blockers. The effects of enalapril compared with those of diuretics confirm that patients more dependent upon the renin-angiotensin system respond better. When hydrochlorothiazide is administered concomitantly with enalapril, almost all patients respond, with good long-term maintenance. In patients with severe hypertension, Blocadren or Aldomet may be added in addition to hydrochlorothiazide and will produce additional benefit. Enalapril attenuates the adverse metabolic effects of hydrochlorothiazide, particularly hypokalemia. Overall, although the efficacy of enalapril and that of captopril are similar, enalapril is better tolerated and does not appear to be associated with any significant occurrence of captopril-type side effects, particularly the skin rash and loss of taste. As expected, enalapril and other converting enzyme inhibitors may be associated with azotemia in patients with bilateral renovascular hypertension.

In a randomized, two-period crossover study in 12 normal volunteers, serum and urine concentrations of the angiotensin-converting enzyme inhibitor enalapril and its active metabolite enalaprilat were determined following administration of a single 40-mg tablet of enalapril maleate administered both in the fasting state and with a standard breakfast. A 7-d interval separated the two treatment periods. Area under the serum concentration-time curves for enalaprilat and urinary recoveries for enalaprilat and total drug did not differ significantly between the fed and fasted conditions. The mean observed maximum serum concentration of enalaprilat was slightly higher for the fasting treatment, but the time to peak concentration was almost identical for the two treatments. Enalapril maleate is unlike the prototype angiotensin-converting enzyme inhibitor captopril in that a standard meal does not appear to influence absorption of this new drug.

Indacrinone, a racemic mixture, is a loop-blocking diuretic with effects on uric acid elimination that differ from those of furosemide. A series of studies in healthy men was undertaken to characterize the pharmacologic activity of the positive (+) and negative (–) enantiomers (E) of indacrinone and its (–) p-OH metabolite, (–) MET. All subjects were on sodium- and potassium-controlled diet; each experiment was similar in design and included placebo and positive controls. Oral (–)E and (–)MET exerted dose-related natriuretic and diuretic effects; intravenous doses of (–)E were more effective than (–)MET. The effects of (–)E and (–)MET on serum uric acid were the same as those reported with indacrinone. After (–)E, both (–)E and generated (–)MET appeared to contribute to the natriuresis. (+)E induced dose-related decreases in serum uric acid up to 24 hr after dosage; at the higher doses of (+)E, the hypouricemic effects were of the order of those after 500 mg of probenecid. Thus, indacrinone is a novel loop diuretic with enantiomers and a (–)MET, each of which has a different pharmacologic profile. Clinical Pharmacology and Therapeutics (1981) 29, 798–807; doi:10.1038/clpt.1981.114

Indacrinone is an investigational loop-acting diuretic. To evaluate the natriuretic and uricosuric effects of varying ratios of its enantiomers, 10 healthy men, on a controlled Na+ (100 mEq) and K+ (80 mEq) diet, participated in a double-blind, randomized, balanced incomplete block, multiple-dose (one week) study of a fixed daily dose (10 mg) of (-) enantiomer combined with increasing doses (40, 90 and 140 mg) of (+) enantiomer versus 50 mg hydrochlorothiazide and placebo. On day 1, mean 24-h urinary Na+ increased (p less than 0.01) comparably (approximately 285 mEq) after each enantiomer combination and hydrochlorothiazide; however, the enantiomer combinations had marked uricosuric and hypouricemic effects that were enhanced with increased (+) enantiomer doses. By day 7, while enantiomer combinations and hydrochlorothiazide demonstrated comparable natriuretic activity, mean serum uric acid levels (mg/dl), in comparison to placebo, were increased (p less than 0.05) with hydrochlorothiazide but progressively decreased with increases in (+) enantiomer. Thus varying the ratio [(+, uricosuric): (-, natriuretic)] of the enantiomers of indacrinone caused natriuresis similar to hydrochlorothiazide, but had an opposite effect on serum uric acid.