A Phase 2 Randomized, Double-Blind, Placebo-Controlled Trial of the Monoclonal Antibody MHAA4549A in Patients With Acute Uncomplicated Influenza A Infection.

BACKGROUND: MHAA4549A, a human monoclonal antibody targeting the influenza A hemagglutinin stalk, neutralizes influenza A virus in animal and human volunteer challenge studies. We investigated the safety and tolerability, efficacy, and pharmacokinetics of MHAA4549A in outpatients with acute, uncomplicated influenza A infection. METHODS: This was a phase 2, randomized, double-blind, placebo-controlled trial of single intravenous (IV) doses of 3600 mg or 8400 mg of MHAA4549A or IV placebo in adult outpatients testing positive for influenza A. Patients were enrolled across 35 sites in 6 countries. Randomization and dosing occurred within ≤72 hours of symptom onset; the study duration was 14 weeks. The primary end point was the nature and frequency of adverse events (AEs). Secondary end points included median time to alleviation of all influenza symptoms, effects on nasopharyngeal viral load and duration of viral shedding, and MHAA4549A serum pharmacokinetics. RESULTS: Of 125 randomized patients, 124 received study treatment, with 99 confirmed positive for influenza A by central testing. The frequency of AEs between the MHAA4549A and placebo groups was similar; nausea was most common (8 patients; 6.5%). MHAA4549A serum exposure was confirmed in all MHAA4549A-treated patients and was dose-proportional. No hospitalizations or deaths occurred. Between the MHAA4549A and placebo groups, no statistically significant differences occurred in the median time to alleviation of all symptoms, nasopharyngeal viral load, or duration of viral shedding. CONCLUSIONS: While MHAA4549A was safe and well tolerated with confirmed exposure, the antibody did not improve clinical outcomes in patients with acute uncomplicated influenza A infection.

Pharmacokinetics of the Monoclonal Antibody MHAA4549A Administered in Combination With Oseltamivir in Patients Hospitalized With Severe Influenza A Infection.

MHAA4549A is a human anti-influenza A monoclonal antibody developed to treat influenza A. We report MHAA4549A serum, nasopharyngeal, and tracheal aspirate pharmacokinetics from a phase 2b study in hospitalized patients with severe influenza A. Patients were randomized 1:1:1 into 3 groups receiving single intravenous doses of 3600 mg (n = 55) or 8400 mg (n = 47) MHAA4549A or placebo (n = 56). Patients also received oral oseltamivir twice daily for ≥5 days. Serum, nasopharyngeal, and tracheal aspirate pharmacokinetic samples were collected on days 1-60 from MHAA4549A-treated groups. Day 5 plasma samples from all groups were collected for assessing the pharmacokinetics of oseltamivir and its active metabolite, oseltamivir carboxylate. Noncompartmental pharmacokinetic analysis was performed using Phoenix WinNonlin. Data were collected during a preplanned interim analysis that became final when the trial terminated because of a lack of efficacy. Serum MHAA4549A concentrations were dose-proportional and biphasic. Mean MHAA4549A clearance was 288-350 mL/day, and mean half-life was 17.8-19.0 days. Nasopharyngeal MHAA4549A concentrations were non-dose-proportional. We detected MHAA4549A in tracheal aspirate samples, but intersubject variability was high. MHAA4549A serum and nasopharyngeal exposures were confirmed in all MHAA4549A-treated patients. Serum MHAA4549A had faster clearance and a shorter half-life in influenza A-infected patients compared with healthy subjects. MHAA4549A detection in tracheal aspirate samples indicated exposure in the lower respiratory tract. Oseltamivir and oseltamivir carboxylate exposures were similar between MHAA4549A-treated and placebo groups, suggesting a lack of MHAA4549A interference with oseltamivir pharmacokinetics.

A Phase 2 Randomized, Double-Blind, Placebo-Controlled Trial of MHAA4549A, a Monoclonal Antibody, plus Oseltamivir in Patients Hospitalized with Severe Influenza A Virus Infection.

For patients hospitalized with severe influenza A virus infection, morbidity and mortality remain high. MHAA4549A, a human monoclonal antibody targeting the influenza A virus hemagglutinin stalk, has demonstrated pharmacological activity in animal studies and in a human influenza A challenge study. We evaluated the safety and efficacy of MHAA4549A plus oseltamivir against influenza A virus infection in hospitalized patients. The CRANE trial was a phase 2b randomized, double-blind, placebo-controlled study of single intravenous (i.v.) doses of placebo, 3,600 mg MHAA4549A, or 8,400 mg MHAA4549A each combined with oral oseltamivir (+OTV) in patients hospitalized with severe influenza A virus infection. Patients, enrolled across 68 clinical sites in 18 countries, were randomized 1:1:1. The primary outcome was the median time to normalization of respiratory function, defined as the time to removal of supplemental oxygen support to maintain a stable oxygen saturation (SpO2) of ≥95%. Safety, pharmacokinetics, and effects on influenza viral load were also assessed. One hundred sixty-six patients were randomized and analyzed during a preplanned interim analysis. Compared to placebo+OTV, MHAA4549A+OTV did not significantly reduce the time to normalization of respiratory function (placebo+OTV, 4.28 days; 3,600 mg MHAA4549A+OTV, 2.78 days; 8,400 mg MHAA4549A+OTV, 2.65 days), nor did it improve other secondary clinical outcomes. Adverse event frequency was balanced across cohorts. MHAA4549A+OTV did not further reduce viral load versus placebo+OTV. In hospitalized patients with influenza A virus infection, MHAA4549A did not improve clinical outcomes over OTV alone. Variability in patient removal from oxygen supplementation limited the utility of the primary endpoint. Validated endpoints are needed to assess novel treatments for severe influenza A virus infection. (This study has been registered at ClinicalTrials.gov under registration no. NCT02293863.).

A Phase 1, Randomized, Single-Ascending-Dose Study To Investigate the Safety, Tolerability, and Pharmacokinetics of DSTA4637S, an Anti-Staphylococcus aureus Thiomab Antibody-Antibiotic Conjugate, in Healthy Volunteers.

Staphylococcus aureus causes serious bacterial infections with high morbidity and mortality, necessitating the discovery of new antibiotics. DSTA4637S is a novel antibody-antibiotic conjugate designed to target intracellular S. aureus that is not adequately eliminated by current standard-of-care antibiotics. DSTA4637S is composed of an anti-S. aureus Thiomab human immunoglobulin G1 (IgG1) monoclonal antibody linked to a novel rifamycin-class antibiotic (4-dimethylaminopiperidino-hydroxybenzoxazino rifamycin [dmDNA31]) via a protease-cleavable linker. Phagocytic cells ingest DSTA4637S-bound S. aureus, and intracellular cathepsins cleave the linker, releasing dmDNA31and killing intracellular S. aureus This first-in-human, randomized, double-blind, placebo-controlled, single-ascending-dose phase 1 trial analyzed the safety, pharmacokinetics, and immunogenicity of DSTA4637S in healthy volunteers. Thirty healthy male and female volunteers, 18-65 years old, were randomized into five cohorts receiving single intravenous (i.v.) doses of 5, 15, 50, 100, and 150 mg/kg of DSTA4637S or placebo (4 active:2 placebo). Subjects were followed for 85 days after dosing. No subject withdrew from the study, and no serious or severe adverse events occurred. One moderate infusion-related reaction (150 mg/kg DSTA4637S) occurred. No clinically meaningful or dose-related changes in laboratory parameters or vital signs occurred. Pharmacokinetics of plasma DSTA4637S conjugate and serum DSTA4637S total antibody were dose proportional. Systemic exposure of unconjugated dmDNA31 was low. No DSTA4637S-induced anti-drug antibody responses were observed. DSTA4637S was generally safe and well tolerated as a single i.v. dose in healthy volunteers. DSTA4637S has a favorable safety and pharmacokinetic profile that supports future development as a novel therapeutic for S. aureus infections. (This study has been registered at ClinicalTrials.gov under identifier NCT02596399.).

Correlation of Cytomegalovirus (CMV) Disease Severity and Mortality With CMV Viral Burden in CMV-Seropositive Donor and CMV-Seronegative Solid Organ Transplant Recipients.

BACKGROUND: The rate of cytomegalovirus (CMV) viral load increase and peak viral loads are associated with CMV disease in kidney and liver transplant recipients, but relationships to disease severity or mortality have not been shown. METHODS: Using stored serial serum specimens from renal (n = 59) and liver (n = 35) transplant recipients (D+R-; CMV-seropositive donors, CMV-seronegative recipients) from 2 prospective, randomized, controlled, interventional prophylaxis trials of CMV immune globulin (CMVIG), CMV viral load was measured using the COBAS quantitative polymerase chain reaction assay and the World Health Organization CMV standard. Patients with severe CMV-associated disease were classified according to trial definitions. Pairwise comparisons of mean viral load among deceased, surviving diseased, and nondiseased patients were analyzed by 2-way analysis of variance. To determine if viral load could predict mortality, receiver operating characteristic (ROC) curves were constructed using area under the curve (AUC) of the viral load and peak viral concentration (Vmax). RESULTS: Viral load (mean log10 [AUC], peak viral load [Vmax]) for patients with severe CMV disease was significantly higher compared with nondiseased patients (P < .001). Similarly, higher viral burden was significantly associated with mortality (P < .001). Viral load AUC and Vmax AUROCs for predicting mortality were 0.796 and 0.824, respectively, for renal patients, and 0.769 and 0.807, respectively, for liver patients. CONCLUSIONS: Using specimens from studies preceding the antiviral prophylaxis era, CMV viral load was associated with severe CMV disease and death, supporting CMV viral load quantification as a proxy for CMV disease severity and disease-associated mortality end points in solid organ transplantation.

Pharmacokinetics and Exposure-Response Analysis of RG7667, a Combination of Two Anticytomegalovirus Monoclonal Antibodies, in a Phase 2a Randomized Trial To Prevent Cytomegalovirus Infection in High-Risk Kidney Transplant Recipients.

RG7667, a novel combination of two anticytomegalovirus (anti-CMV) monoclonal IgG1 antibodies (MCMV5322A and MCMV3068A), was designed to block CMV entry into host cells. It was developed as a potential therapy for preventing CMV infection and disease in transplant recipients. RG7667 was assessed for preventing CMV infection in a phase 2a trial with CMV-seronegative recipients of kidney transplants from CMV-seropositive donors. The patients received 4 intravenous doses of RG7667 (10 mg/kg of body weight of each antibody, n = 60) or placebo (n = 60) at the time of the transplant and at 1, 4, and 8 weeks after the transplant. Serum samples were collected for pharmacokinetic (PK) analysis and antidrug antibody (ADA) evaluation. To guide future dose selection, the relationships between RG7667 exposure and pharmacological activity were evaluated. MCMV5322A and MCMV3068A exposures were confirmed in all RG7667-treated patients. Mean clearances for MCMV5322A and MCMV3068A were 2.97 and 2.65 ml/day/kg, respectively, and the terminal half-lives of MCMV5322A and MCMV3068A were 26.9 and 27.4 days, respectively. The ADA incidence was low and was not associated with lower drug exposure. Patients with RG7667 or component antibody exposures greater than the respective median values had a lower incidence of viremia at 12 weeks and 24 weeks after transplantation and a longer delayed time to detectable CMV viremia than patients with exposures less than the median values. MCMV5322A and MCMV3068A exhibited expected IgG1 PK profiles in high-risk kidney transplant recipients, consistent with the earlier PK behavior of RG7667 in healthy subjects. Higher drug exposure was associated with better anti-CMV pharmacological activity. (This study has been registered at ClinicalTrials.gov under identifier NCT01753167.).

Pharmacokinetics of MHAA4549A, an Anti-Influenza A Monoclonal Antibody, in Healthy Subjects Challenged with Influenza A Virus in a Phase IIa Randomized Trial.

BACKGROUND AND OBJECTIVES: MHAA4549A, a human anti-influenza immunoglobulin (Ig) G1 monoclonal antibody, is being developed to treat patients hospitalized for influenza A infection. This study examined the pharmacokinetics (PKs) of MHAA4549A in a phase IIa, randomized, double-blind, dose-ranging trial in healthy volunteers challenged with influenza A virus. METHODS: Serum PK data were collected from 60 subjects in three single-dose groups (400, 1200, or 3600 mg) who received MHAA4549A intravenously 24-36 h after inoculation with the influenza A virus. Nasopharyngeal swab MHAA4549A concentration data were collected on days 1-8, and all subjects, including the placebo group, received 75 mg oseltamivir twice daily from days 7 to 11. Plasma samples were collected 4 h postdose on day 8 for oseltamivir and its active metabolite oseltamivir carboxylate (OC) (all subjects, n = 100), including subjects treated with oseltamivir alone and placebo. Noncompartmental analysis was performed for both nasal and serum PKs. RESULTS: MHAA4549A showed dose-proportional serum PKs with a long terminal half-life (approximately 21.9-24.6 days) and slow clearance (approximately 152-240 mL/day); however, nasopharyngeal swab PKs were not dose proportional. No differences in mean plasma concentrations of oseltamivir and OC at 4 h postdose on day 8 were observed between the MHAA4549A treatment and placebo groups. No subjects who received MHAA4549A developed anti-drug antibodies. CONCLUSION: MHAA4549A serum PKs were consistent with that of a human IgG1antibody without known endogenous targets. MHAA4549A showed nonlinear PKs in nasopharyngeal swab samples, which will guide future dose selection to achieve the high drug concentrations needed at the site of action for efficacy. These data demonstrate no PK interactions between MHAA4549A and oseltamivir, and support flat dosing. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01980966.

Phase 2 Randomized Trial of the Safety and Efficacy of MHAA4549A, a Broadly Neutralizing Monoclonal Antibody, in a Human Influenza A Virus Challenge Model.

MHAA4549A, a human monoclonal antibody targeting the hemagglutinin stalk region of influenza A virus (IAV), is being developed as a therapeutic for patients hospitalized with severe IAV infection. The safety and efficacy of MHAA4549A were assessed in a randomized, double-blind, placebo-controlled, dose-ranging study in a human IAV challenge model. One hundred healthy volunteers were inoculated with A/Wisconsin/67/2005 (H3N2) IAV and, 24 to 36 h later, administered a single intravenous dose of either placebo, MHAA4549A (400, 1,200, or 3,600 mg), or a standard oral dose of oseltamivir. Subjects were assessed for safety, pharmacokinetics (PK), and immunogenicity. The intent-to-treat-infected (ITTI) population was assessed for changes in viral load, influenza symptoms, and inflammatory biomarkers. MHAA4549A was well tolerated in all IAV challenge subjects. The 3,600-mg dose of MHAA4549A significantly reduced the viral burden relative to that of the placebo as determined by the area under the curve (AUC) of nasopharyngeal virus infection, quantified using quantitative PCR (98%) and 50% tissue culture infective dose (TCID50) (100%) assays. Peak viral load, duration of viral shedding, influenza symptom scores, mucus weight, and inflammatory biomarkers were also reduced. Serum PK was linear with a half-life of ∼23 days. No MHAA4549A-treated subjects developed anti-drug antibodies. In conclusion, MHAA4549A was well tolerated and demonstrated statistically significant and substantial antiviral activity in an IAV challenge model. (This study has been registered at ClinicalTrials.gov under identifier NCT01980966.).

A Phase 1, Randomized, Double-Blind, Placebo-Controlled, Single-Ascending-Dose Study To Investigate the Safety, Tolerability, and Pharmacokinetics of an Anti-Influenza B Virus Monoclonal Antibody, MHAB5553A, in Healthy Volunteers.

Influenza B can cause significant morbidity and mortality. MHAB5553A, a human monoclonal immunoglobulin G1 (IgG1) antibody that binds to a highly conserved region of the hemagglutinin protein of influenza B virus, is being examined as a novel therapeutic for the treatment of influenza B patients with severe disease. This phase 1, randomized, double-blind, placebo-controlled, single-ascending-dose study was conducted to assess the safety, tolerability, and pharmacokinetics (PK) of MHAB5553A. Twenty-six healthy male and female volunteers of >18 years of age were randomized into five cohorts receiving a single intravenous (i.v.) dose of 120, 1,200, 3,600, 8,400, or 10,800 mg MHAB5553A or placebo (four active:one placebo, except for the 120-mg cohort [4:2]). Subjects were followed for 120 days after dosing. No subject discontinued the study, no dose-limiting adverse events or serious adverse events were reported, and a maximum tolerated dose (MTD) was not defined. The most commonly reported adverse events were cold symptoms and headache; most were mild and occurred at a similar rate across all cohorts. MHAB5553A showed no relevant time- or dose-related changes in laboratory values or vital signs compared to the placebo. The observed serum PK was linear and generally dose proportional, and the observed nasal PK was nonlinear and generally non-dose proportional. MHAB5553A is generally well tolerated in healthy volunteers up to at least a single i.v. dose of 10,800 mg and demonstrated linear serum PK consistent with those of a human IgG1 antibody lacking known endogenous targets in humans. (This study has been registered at ClinicalTrials.gov under registration no. NCT02528903.).

Phase 2 Randomized, Double-Blind, Placebo-Controlled Trial of RG7667, a Combination Monoclonal Antibody, for Prevention of Cytomegalovirus Infection in High-Risk Kidney Transplant Recipients.

Cytomegalovirus (CMV) infection is a significant complication after kidney transplantation. We examined the ability of RG7667, a combination of two monoclonal antibodies, to prevent CMV infection in high-risk kidney transplant recipients in a randomized, double-blind, placebo-controlled trial. CMV-seronegative recipients of a kidney transplant from a CMV-seropositive donor (D+R-) were randomized to receive RG7667 (n = 60) or placebo (n = 60) at the time of transplant and 1, 4, and 8 weeks posttransplant. Patients were monitored for CMV viremia every 1 to 2 weeks posttransplant for 24 weeks. Patients who had seroconverted (D+R+) or withdrawn before dosing were excluded from the analysis (n = 4). CMV viremia occurred in 27 of 59 (45.8%) patients receiving RG7667 and 35 of 57 (61.4%) patients receiving placebo (stratum-adjusted difference, 15.3%; P = 0.100) within 12 weeks posttransplant and in 30 of 59 (50.8%) patients receiving RG7667 and 40 of 57 (70.2%) patients receiving placebo (stratum-adjusted difference, 19.3%; P = 0.040) within 24 weeks posttransplant. Median time to CMV viremia was 139 days in patients receiving RG7667 compared to 46 days in patients receiving placebo (hazard ratio, 0.53; P = 0.009). CMV disease was less common in the RG7667 than placebo group (3.4% versus 15.8%; P = 0.030). Adverse events were generally balanced between treatment groups. In high-risk kidney transplant recipients, RG7667 was well tolerated, numerically reduced the incidence of CMV infection within 12 and 24 weeks posttransplant, delayed time to CMV viremia, and was associated with less CMV disease than the placebo. (This study has been registered at ClinicalTrials.gov under registration no. NCT01753167.).

Two Phase 1, Randomized, Double-Blind, Placebo-Controlled, Single-Ascending-Dose Studies To Investigate the Safety, Tolerability, and Pharmacokinetics of an Anti-Influenza A Virus Monoclonal Antibody, MHAA4549A, in Healthy Volunteers.

Hospitalized patients with severe influenza are at significant risk for morbidity and mortality. MHAA4549A is a human monoclonal immunoglobulin (Ig) G1 antibody that binds to a highly conserved stalk region of the influenza A virus hemagglutinin protein and neutralizes all tested seasonal human influenza A virus strains. Two phase 1 trials examined the safety, tolerability, and pharmacokinetics of MHAA4549A in healthy volunteers. Both single ascending-dose trials were randomized, double blinded, and placebo controlled. Trial 1 randomized 21 healthy adults into four cohorts receiving a single intravenous dose of 1.5, 5, 15, or 45 mg/kg MHAA4549A or placebo. Trial 2 randomized 14 healthy adults into two cohorts receiving a single intravenous fixed dose of 8,400 mg or 10,800 mg of MHAA4549A or placebo. Subjects were followed for 120 days after dosing. No subject was discontinued in either trial, and no serious adverse events were reported. The most common adverse event in both studies was mild headache (trial 1, 4/16 subjects receiving MHAA4549A and 1/5 receiving placebo; trial 2, 4/8 subjects receiving MHAA4549A and 2/6 receiving placebo). MHAA4549A produced no relevant time- or dose-related changes in laboratory values or vital signs compared to those with placebo. No subjects developed an antitherapeutic antibody response following MHAA4549A administration. MHAA4549A showed linear serum pharmacokinetics, with a mean half-life of 22.5 to 23.7 days. MHAA4549A is safe and well tolerated in healthy volunteers up to a single intravenous dose of 10,800 mg and demonstrates linear serum pharmacokinetics consistent with those of a human IgG1 antibody lacking known endogenous targets in humans. (These trials have been registered at ClinicalTrials.gov under registration no. NCT01877785 and NCT02284607).

Phase 1 Randomized, Double-Blind, Placebo-Controlled Study of RG7667, an Anticytomegalovirus Combination Monoclonal Antibody Therapy, in Healthy Adults.

Cytomegalovirus can cause debilitating and life-threatening disease in newborns infected in utero and immunocompromised individuals, including transplant recipients. RG7667 is a unique combination of two monoclonal antibodies that binds glycoprotein complexes on the surface of cytomegalovirus and inhibits its entry into host cells. A phase 1 first-in-human, randomized, double-blind, placebo-controlled, dose-escalation study of RG7667 given intravenously was conducted in 181 healthy adults. The study involved a single ascending dose stage (1, 3, 5, and 10 mg/kg each antibody; n = 21), a multiple ascending dose stage (5 and 10 mg/kg each antibody monthly for 3 doses; n = 10), and a multiple dose expansion stage (10 mg/kg each antibody monthly for 3 doses; n = 150). Subjects were followed for 85 to 141 days to evaluate safety, tolerability, pharmacokinetics, and immunogenicity. Most adverse events were mild, and the incidence of adverse events was similar among the RG7667 and placebo groups. RG7667 had dose-proportional pharmacokinetics in all three dosing stages, a mean terminal half-life of 20 to 30 days, and an overall pharmacokinetic profile consistent with that of a human monoclonal antibody that lacks endogenous host targets. The proportion of subjects developing an antitherapeutic antibody response was not higher in the RG7667 group than in the placebo group. In summary, single and multiple doses of RG7667 were found to be safe and well-tolerated in healthy adults and had a favorable pharmacokinetic and immunogenicity profile. This study supports further development of RG7667 as a therapy for the prevention and treatment of cytomegalovirus infection in susceptible populations. (This study has been registered at ClinicalTrials.gov under registration no. NCT01496755.).

Randomized study of danoprevir/ritonavir-based therapy for HCV genotype 1 patients with prior partial or null responses to peginterferon/ribavirin.

BACKGROUND & AIMS: Chronic hepatitis C treatment for prior non-responders to peginterferon (PegIFN)/ribavirin remains suboptimal. The MATTERHORN study evaluated regimens containing ritonavir-boosted danoprevir (danoprevir/r) in prior PegIFN alfa/ribavirin non-responders. METHODS: Prior partial responders (N=152) were randomized to 24 weeks of twice-daily danoprevir/r 100/100mg, mericitabine 1000 mg and ribavirin 1000/1200 mg (IFN-free); danoprevir/r plus PegIFN alfa-2a/ribavirin (triple); or danoprevir/r, mericitabine and PegIFN alfa-2a/ribavirin (Quad). Prior null responders (N=229) were randomized to 24 weeks of IFN-free therapy, or quad alone (Quad 24) or quad plus 24-weeks of PegIFN alfa-2a/ribavirin (Quad 48). The primary endpoint was sustained virological response (HCV RNA <25 IU/ml) 24 weeks after end-of-treatment (SVR24). Due to high relapse rates, genotype (G) 1a patients in IFN-free arms were offered additional PegIFN alfa-2a/ribavirin. RESULTS: Among prior partial responders, SVR24 rates were 46.2%, 51.0%, and 86.0%, in the IFN-free, Triple and Quad arms, respectively; among prior null responders, SVR24 rates were 45.5%, 80.5%, and 83.8% respectively. Relapse rates were lower and SVR24 rates higher in G1b-infected than G1a-infected patients. SVR24 rates in G1a and G1b patients randomized to Quad were 75.0% and 96.2%, respectively, in the partial Quad arm, and 68.1% and 100%, respectively, in the null Quad 24 arm. Treatment failure was associated with resistance to danoprevir, but not to mericitabine, and was more common in G1a infected patients. Treatment was well-tolerated. CONCLUSIONS: Danoprevir/r, mericitabine plus PegIFN alfa-2a/ribavirin was well-tolerated and produced high overall SVR24 rates in prior partial and null responders to PegIFN alfa/ribavirin. In contrast, IFN-free regimens were associated with unacceptably high relapse rates.

Pre-ART levels of inflammation and coagulation markers are strong predictors of death in a South African cohort with advanced HIV disease.

BACKGROUND: Levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and D-dimer predict mortality in HIV patients on antiretroviral therapy (ART) with relatively preserved CD4+ T cell counts. We hypothesized that elevated pre-ART levels of these markers among patients with advanced HIV would be associated with an increased risk of death following the initiation of ART. METHODS: Pre-ART plasma from patients with advanced HIV in South Africa was used to measure hsCRP, IL-6 and D-dimer. Using a nested case-control study design, the biomarkers were measured for 187 deaths and two controls matched on age, sex, clinical site, follow-up time and CD4+ cell counts. Odds ratios were estimated using conditional logistic regression. In addition, for a random sample of 100 patients, biomarkers were measured at baseline and 6 months following randomization to determine whether ART altered their levels. RESULTS: Median baseline biomarkers levels for cases and controls, respectively, were 11.25 vs. 3.6 mg/L for hsCRP, 1.41 vs. 0.98 mg/L for D-dimer, and 9.02 vs. 4.20 pg/mL for IL-6 (all p<0.0001). Adjusted odds ratios for the highest versus lowest quartile of baseline biomarker levels were 3.5 (95% CI: 1.9-6.7) for hsCRP, 2.6 (95%CI 1.4-4.9) for D-dimer, and 3.8 (95% CI: 1.8-7.8) for IL-6. These associations were stronger for deaths that occurred more proximal to the biomarker measurements. Levels of D-dimer and IL-6, but not hsCRP, were significantly lower at month 6 after commencing ART compared to baseline (p<0.0001). CONCLUSIONS: Among patients with advanced HIV disease, elevated pre-ART levels of hsCRP, IL-6 and D-dimer are strongly associated with early mortality after commencing ART. Elevated levels of inflammatory and coagulation biomarkers may identify patients who may benefit from aggressive clinical monitoring after commencing ART. Further investigation of strategies to reduce biomarkers of inflammation and coagulation in patients with advanced HIV disease is warranted. TRIAL REGISTRATION: Parent study: ClinicalTrials.gov NCT00342355.

What are biomarkers?

PURPOSE OF REVIEW: This article provides working definitions and a conceptual framework to understand the roles of biomarkers in clinical research. RECENT FINDINGS: The definitions of the terms discussed in this article--medical signs, symptoms, biomarkers, surrogate endpoints, clinical endpoints, validation--are still under discussion, as are their relationships to each other, but broad consensus has developed in the past decade and a half about the necessity of distinguishing between, in particular, surrogate and clinical endpoints. SUMMARY: This article outlines the major definitions of the key terms in this field and considers select cases in which misunderstandings about the terms led to flawed research conclusions.

Interferon-alpha produces significant decreases in HIV load.

A randomized, controlled clinical trial was started in the pre-HAART era to compare the efficacy of zidovudine (AZT) and interferon-alpha (IFN-alpha) either alone or in combination to reduce HIV viremia, maintain CD4(+) cell count, and decrease time to AIDS progression and death. The purpose of the current study was to compare the effects of AZT and IFN on HIV load using modern technology. One hundred and eighty patients with CD4(+) counts above 500 cells/mm(3) were randomized to receive AZT alone, IFN-alpha alone, or AZT and IFN-alpha in combination. CD4(+) cell count and HIV load at baseline and at the last follow-up visit were compared, and time to AIDS or death was calculated by treatment group. At a mean follow-up of 45 weeks, the mean change in log HIV RNA was -0.06 for the AZT alone group, -0.47 for the AZT plus IFN-alpha group (P = 0.01 versus AZT group), and -0.35 for the IFN-alpha alone group (P = 0.02 versus AZT group). There was no significant difference among groups in change in total CD4(+) count or in time to AIDS or death. Since treatment with IFN-alpha produces significant decreases in HIV load, additional studies of IFN-alpha as part of a combination regimen are warranted.

Effects of intermittent IL-2 alone or with peri-cycle antiretroviral therapy in early HIV infection: the STALWART study.

BACKGROUND: The Study of Aldesleukin with and without antiretroviral therapy (STALWART) evaluated whether intermittent interleukin-2 (IL-2) alone or with antiretroviral therapy (ART) around IL-2 cycles increased CD4(+) counts compared to no therapy. METHODOLOGY: Participants not on continuous ART with > or = 300 CD4(+) cells/mm(3) were randomized to: no treatment; IL-2 for 5 consecutive days every 8 weeks for 3 cycles; or the same IL-2 regimen with 10 days of ART administered around each IL-2 cycle. CD4(+) counts, HIV RNA, and HIV progression events were collected monthly. PRINCIPAL FINDINGS: A total of 267 participants were randomized. At week 32, the mean CD4(+) count was 134 cells greater in the IL-2 alone group (p<0.001), and 133 cells greater in the IL-2 plus ART group (p<0.001) compared to the no therapy group. Twelve participants in the IL-2 groups compared to 1 participant in the group assigned to no therapy experienced an opportunistic event or died (HR 5.84, CI: 0.59 to 43.57; p = 0.009). CONCLUSIONS: IL-2 alone or with peri-cycle HAART increases CD4(+) counts but was associated with a greater number of opportunistic events or deaths compared to no therapy. These results call into question the immunoprotective significance of IL-2-induced CD4(+) cells. TRIAL REGISTRATION: ClinicalTrials.gov NCT00110812.

CD4 T cell survival after intermittent interleukin-2 therapy is predictive of an increase in the CD4 T cell count of HIV-infected patients.

Administration of interleukin (IL)-2 to human immunodeficiency virus (HIV)-infected patients leads to significant increases in CD4 T cell counts. We previously have shown that IL-2 induces increased proliferation and survival of CD4 T cells. Deuterium labeling studies were undertaken to study the relationship between IL-2-induced increases in the CD4 T cell count and the effects of IL-2 on cell proliferation and survival. A strong inverse correlation was noted between the rate of decay of the label in CD4 cells and increases in CD4 cell counts (R =or- 0.67; P<.001). This correlation was not seen with the level of proliferating cells. Although the CD4 cell count at baseline and the number of CD4 cells expressing CD25 were also predictive of increases in the CD4 cell count, the rate of decay remained the most statistically significant predictor in multivariate regression models. Thus, an increase in the survival of CD4 T cells appears to be the critical mechanism leading to sustained increases in the CD4 cell counts of HIV-infected patients receiving intermittent IL-2 therapy.