Effectiveness of Elbasvir and Grazoprevir Combination, With or Without Ribavirin, for Treatment-Experienced Patients With Chronic Hepatitis C Infection

BACKGROUND & AIMS

Patients infected with hepatitis C virus (HCV) genotype 1, 4, or 6, with or without cirrhosis, previously treated with peg-interferon and ribavirin, are a challenge to treat. We performed a phase 3 randomized controlled open-label trial to assess the effects of 12 or 16 weeks of treatment with once-daily elbasvir (an HCV NS5A inhibitor, 50 mg) and grazoprevir (an HCV NS3/4A protease inhibitor, 100 mg), in a fixed-dose combination tablet, with or without twice-daily ribavirin, in this patient population.

METHODS

We analyzed data from 420 patients (35% with cirrhosis, 64% with a null or partial response to peg-interferon and ribavirin) who were randomly assigned (1:1:1:1) to groups given elbasvir and grazoprevir once daily, with or without twice-daily ribavirin, for 12 or 16 weeks, at 65 study centers in 15 countries in Europe, Asia, and Central and North America. Randomization was stratified by cirrhosis status and type of peg-interferon and ribavirin treatment failure. HCV RNA was measured using COBAS TaqMan v2.0. The primary end point was HCV RNA <15 IU/mL, 12 weeks after completion of treatment (SVR12). We aimed to determine whether the proportion of patients achieving an SVR12 in any group was greater than the reference rate (58%).

RESULTS

With 12 weeks of treatment, an SVR12 was achieved by 92.4% of patients given elbasvir and grazoprevir and 94.2% of patients given elbasvir and grazoprevir with ribavirin. With 16 weeks of treatment, an SVR12 was achieved by 92.4% of patients given elbasvir and grazoprevir and 98.1% of patients given elbasvir and grazoprevir with ribavirin. Among patients treated for 12 weeks without ribavirin, virologic failure occurred in 6.8%, 0%, and 12.5% of patients with HCV genotype 1a, 1b, or 4 infection, respectively. Among patients given elbasvir and grazoprevir for 12 weeks, virologic failure occurred in 0% of patients infected with HCV genotypes 1 and 4 who relapsed after completing peg-interferon and ribavirin, and 7.5% infected with HCV genotypes 1 and 4, respectively, with a null or partial response to peg-interferon and ribavirin. Among patients treated for 16 weeks who received ribavirin, there were no incidences of virologic failure. Common adverse events were fatigue (23.1%), headache (19.8%), and nausea (11.0%).

CONCLUSIONS

The combination tablet of elbasvir and grazoprevir, with or without ribavirin, was highly efficacious in inducing an SVR12 in patients with HCV genotype 1, 4, or 6 infection failed by previous treatment with peg-interferon and ribavirin, including patients with cirrhosis and/or a prior null response. The treatment was generally well tolerated. ClinicalTrials.gov Number: NCT02105701.

Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures

Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0-110mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6-111μg/100cm(2), typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22-7.8μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals.

Cleaning-induced arsenic mobilization and chromium oxidation from CCA-wood deck: Potential risk to children

Concern about children's exposure to arsenic (As) from wood treated with chromated-copper-arsenate (CCA) led to its withdrawal from residential use in 2004. However, due to its effectiveness, millions of American homes still have CCA-wood decks on which children play. This study evaluated the effects of three deck-cleaning methods on formation of dislodgeable As and hexavalent chromium (CrVI) on CCA-wood surfaces and in leachate. Initial wipes from CCA-wood wetted with water showed 3-4 times more dislodgeable As than on dry wood. After cleaning with a bleach solution, 9.8-40.3μg/100cm(2) of CrVI was found on the wood surface, with up to 170μg/L CrVI in the leachate. Depending on the cleaning method, 699-2473mg of As would be released into the environment from cleaning a 18.6-m(2)-deck. Estimated As doses in children aged 1-6 after 1h of playing on a wet CCA-wood deck were 0.25-0.41μg/kg. This is the first study to identify increased dislodgeable As on wet CCA-wood and to evaluate dislodgeable CrVI after bleach application. Our data suggest that As and CrVI in 25-year old CCA-wood still show exposure risks for children and potential for soil contamination.

The combination of MK-5172, peginterferon, and ribavirin is effective in treatment-naive patients with hepatitis C virus genotype 1 infection without cirrhosis

BACKGROUND & AIMS

MK-5172 is an inhibitor of the hepatitis C virus (HCV) nonstructural protein 3/4A protease; MK-5172 is taken once daily and has a higher potency and barrier to resistance than licensed protease inhibitors. We investigated the efficacy and tolerability of MK-5172 with peginterferon and ribavirin (PR) in treatment-naive patients with chronic HCV genotype 1 infection without cirrhosis.

METHODS

We performed a multicenter, double-blind, randomized, active-controlled, dose-ranging, response-guided therapy study. A total of 332 patients received MK-5172 (100, 200, 400, or 800 mg) once daily for 12 weeks in combination with PR. Patients in the MK-5172 groups received PR for an additional 12 or 36 weeks, based on response at week 4. Patients in the control group (n = 66) received a combination of boceprevir and PR, dosed in accordance with boceprevir's US product circular.

RESULTS

At 24 weeks after the end of therapy, sustained virologic responses were achieved in 89%, 93%, 91%, and 86% of the patients in the groups given the combination of PR and MK-5172 (100, 200, 400, or 800 mg), respectively, vs 61% of controls. In the MK-5172 group receiving 100 mg, 91% of patients had undetectable levels of HCV RNA at week 4 and qualified for the short duration of therapy. The combination of MK-5172 and PR generally was well tolerated. Transient increases in transaminase levels were noted in the MK-5172 groups given 400 and 800 mg, at higher frequencies than in the MK-5172 groups given 100 or 200 mg, or control groups.

CONCLUSIONS

Once-daily MK-5172 (100 mg) with PR for 24 or 48 weeks was highly effective and well tolerated among treatment-naive patients with HCV genotype 1 infection without cirrhosis. Studies are underway to evaluate interferon-free MK-5172-based regimens. ClinicalTrials.gov number: NCT01353911.

Abstract P4-11-04: A Structured Genetic Risk Evaluation and Testing Program in the Community Oncology Practice Increases Identification of Individuals at Risk for BRCA Mutations

Background: Genetic risk assessment is an important component of the care of the community oncology breast cancer patient. However, identification of at-risk patients is largely an ad-hoc process and practices lack a systematic approach to genetic risk evaluation. The US Oncology Network Genetic Risk Evaluation and Testing (USON GREAT) Program provides a structured approach to implementation of genetic risk evaluation, testing, and triage for appropriate intervention.

Methods: In 2009, our multi-disciplinary community oncology practice implemented the USON GREAT Program. The practice's program has a single dedicated nurse practitioner and physician lead, trained in part through a core educational curriculum and utilizing US Oncology Network-wide genetics resources (web-based MD, midlevel, and genetic counselor conferencing; discussion Portal; published guidelines and office procedures). NCCN guidelines were used to guide testing recommendations. Sequential risk evaluations were documented prospectively. We retrospectively analyzed how evaluation patterns changed over a 4 year time period. We also sought to capture descriptive characteristics of the evaluated population.

Results: Overall, between 2008 and 2011, our practice evaluated 1018 patients at potential risk for a BRCA mutation (mut), based on personal history of breast cancer under age 50; ovarian, fallopian or peritoneal cancer; known family history of malignancy; or known BRCA mutation in the family.

Safety, tolerability and immunogenicity of VAQTA given concomitantly versus nonconcomitantly with other pediatric vaccines in healthy 12-month-old children

BACKGROUND

The objective of this study is to assess whether hepatitis A vaccine is immunogenic and well tolerated when administered to 12-month-old children alone or concomitantly with other routinely administered pediatric vaccines.

METHODS

Six hundred seventeen healthy 12-month-old children were randomized to receive dose 1 of hepatitis A vaccine given alone or concomitantly with measles-mumps-rubella vaccine and varicella vaccine and dose 2 of hepatitis A vaccine given alone or concomitantly with diphtheria-tetanus-acellular pertussis vaccine and optionally with oral or inactivated poliovirus vaccine. Participants were followed for clinical adverse experiences and serologic responses to all vaccine antigens. Antibody responses were compared with historical controls for some indices.

RESULTS

The safety profile was generally comparable whether hepatitis A vaccine was administered alone or concomitantly with other vaccines. When administered alone, the hepatitis A seropositivity rate was 98.3% and 100% for dose 1 and dose 2, respectively, and after dose 2 was similar to historical rates and the geometric mean titers were similar between initially seropositive and initially seronegative subjects (6207 and 6810 mIU/mL, respectively). After concomitant administration with hepatitis A vaccine, antibody responses to measles, mumps, rubella, diphtheria, tetanus and filamentous hemagglutinin (98.8%, 99.6%, 100%, 98.6%, 100% and 83.3%, respectively) were similar to historical controls and response to poliovirus was demonstrated, but immune responses to varicella zoster virus (79%) and pertussis toxoid (76%) were inferior to historical controls.

CONCLUSIONS

Hepatitis A vaccine is highly immunogenic and generally well tolerated when administered to healthy children as young as 12 months of age regardless of initial hepatitis A serostatus and can be administered concomitantly with measles-mumps-rubella vaccine and oral or inactivated poliovirus vaccine.

Immunizing children to protect against the increasing risk of hepatitis A in adolescents and young adults in South Korea

We evaluated the CR326F strain (VAQTA) derived hepatitis A vaccine in Korean children and adolescents >2 years of age to consider a future immunization program. In our study, the pediatric two-dose regimen of VAQTA was found to be generally well tolerated and resulted in 100% (95% CI 94.8, 100.0) seroconversion after 2 doses. Immunizing children with the HAV vaccine routinely should be considered in South Korea, particularly in areas where recent outbreaks have occurred.

Field performance of VAQTA (inactivated, purified hepatitis a vaccine) in Chinese children in Jiangsu

In Jiangsu, 30% of children between the ages of 5 and 8 years test seropositive for hepatitis A. The safety, tolerability, and immunogenicity of a 2-dose regimen (0, 6 months) of VAQTA (0.5 ml of 25U) administered IM in 50 healthy children aged 5 to 8 years without prior serological screening was evaluated. Blood samples were collected prior to the first dose and after each additional dose of VAQTA to determine the initial anti-HAV serostatus and response rates to the vaccine. Twelve children (24%) were initially seropositive and 38 (76%) were initially seronegative. Four weeks after the primary dose of VAQTA, 34 of the 38 subjects (89.5%, 95% CI 75 to 97) were anti-HAV seropositive. The geometric mean titer was 33.1 mIU/ml (95% CI 22.4 to 49.0). After the booster dose at 6 months, all the subjects were seropositive (37/37), giving a seroconversion of 100% (95% CI: 90, 100). The geometric mean titer was 7585.8 mIU/ml (95% CI: 5623.4 to 10,471.3). Adverse experiences were generally mild and transient. Results of this study are consistent with results from a previous double-blind randomized trial of this vaccine and confirm that VAQTA is highly immunogenic, and generally well-tolerated.

Monotherapy for fever and neutropenia in cancer patients: a randomized comparison of ceftazidime versus imipenem

PURPOSE

To compare the efficacy of ceftazidime and imipenem monotherapy for fever and neutropenia, and to determine whether fewer antimicrobial modifications (additions or changes) are required by the broader-spectrum agent, imipenem.

PATIENTS AND METHODS

Adult and pediatric patients undergoing chemotherapy for solid tumors, leukemias, or lymphomas were randomized to receive open-label ceftazidime or imipenem on presentation with fever and neutropenia. Success with or without modifications of the initial antibiotic was defined as survival through neutropenia; failure was death due to infection. Comparisons were based on numbers of modifications made to each monotherapy during the course of neutropenia, in patients stratified as having unexplained fever or a documented infection.

RESULTS

Among 204 ceftazidime and 195 imipenem recipients, the overall success rate with or without modification was more than 98%, regardless of initial antibiotic regimen. Modifications occurred in half of all episodes, primarily in patients with documented infections on either monotherapy. Antianaerobic agents were more frequently added to ceftazidime (P < .001), but addition of other antibiotics, including vancomycin and aminoglycosides, was similar between the two monotherapy groups. Imipenem therapy was associated with significantly greater toxicity, manifested by Clostridium difficile-associated diarrhea and by nausea and vomiting, which required discontinuation of imipenem in 10% of recipients.

CONCLUSION

Ceftazidime and imipenem are both effective in the management of fever and chemotherapy-related neutropenia, provided that modifications are made in response to clinical and microbiologic data that emerge during the course of neutropenia. Imipenem, despite its broader antimicrobial spectrum, does not significantly decrease the overall need for antibiotic modifications and is more often complicated by gastrointestinal toxicity.

A prospective randomized trial comparing the infectious and noninfectious complications of an externalized catheter versus a subcutaneously implanted device in cancer patients

PURPOSE

To compare the frequency of infectious episodes or other problems occurring with an externalized catheter (Hickman) versus a subcutaneously implanted device (Port-a-Cath, Pharmacia, Piscataway, NJ) in cancer patients, we performed a prospective, randomized study in 100 cancer patients (age range, 5 to 74 years).

PATIENTS AND METHODS

Patients who were chemotherapy candidates and required an indwelling catheter were monitored prospectively and evaluated during the 180 days after the insertion of the catheter and again at time of study closure. The frequency of catheter use, reason for access, and any problems that might have been related to catheter use were noted. All data were collected prospectively and included the patient's age, sex, underlying malignancy, temperature, and leukocyte and absolute granulocyte counts at the time of catheter insertion and when complications occurred. The time to and reason for removal of the catheter, as well as any intercurrent infectious or mechanical problems, were also determined.

RESULTS

Most of the infections that occurred were caused by gram-positive organisms, especially staphylococci or streptococci. A total of 22 complications (11 in each group) resulted in removal of the central line. Only one infection in the Hickman catheter group and four in the Port-a-Cath group led to removal of the central line. All other infectious episodes were successfully treated without removal of the catheters. The mean device life was 230 days for the Hickman catheter and 318 days for the Port-a-Cath (not significant).

CONCLUSION

There were no differences between the two study groups regarding incidence of documented infections or mechanical or thrombotic complications.

Clinical pharmacology of 2',3'-dideoxyinosine in human immunodeficiency virus-infected children

The pharmacokinetics of intravenous and oral 2',3'-dideoxyinosine (ddI) and the relationships between pharmacokinetic parameters and measures of response were studied in 48 human immunodeficiency virus-infected children. Disappearance of ddI from plasma after the intravenous dose was rapid and biexponential, with half-lives of 12 min and 1.0 h and a total clearance of 510 +/- 180 ml/min/m2. After oral administration, ddI absorption was limited and variable (mean bioavailability, 19% +/- 17%). A plasma ddI concentration-response relationship was observed for both decline in viral p24 antigen levels and improvement in intelligence quotient score. A limited sampling model was developed that accurately predicts the area under the ddI plasma concentration-time curve from one to three plasma samples. Although this pharmacokinetic study was done in children, the results also have relevance to adults and suggest that individualization of dose and schedule through therapeutic drug monitoring may be necessary to achieve optimal response.

Empiric therapy with amphotericin B in febrile granulocytopenic patients

The early diagnosis of invasive fungal infection in granulocytopenic patients remains unreliable. Granulocytopenic patients who are persistently or recurrently febrile despite therapy with appropriate antibacterial agents are at high risk for the development of such infection. Two randomized clinical trials demonstrated that the empiric administration of amphotericin B to persistently or recurrently febrile granulocytopenic patients decreased the frequency, morbidity, and mortality of invasive fungal infection; these effects were especially marked in profoundly granulocytopenic patients who were not receiving antifungal prophylaxis. Current studies continue to indicate that prompt empiric administration of amphotericin B to persistently or recurrently febrile granulocytopenic patients ensures earlier treatment of deep mycoses. The roles of newer antifungal triazole compounds and of liposomal and lipid complexes of amphotericin B in empiric antifungal therapy must be investigated further in thoughtfully designed, randomized clinical trials.

Amphotericin B vs high-dose ketoconazole for empirical antifungal therapy among febrile, granulocytopenic cancer patients. A prospective, randomized study

We compared high-dose ketoconazole (800 mg/kg per day, orally) with amphotericin B (0.5 mg/kg per day, intravenously) for empirical antifungal therapy in a prospective, randomized study of persistently or recurrently febrile granulocytopenic cancer patients. Among 97 patients eligible for empirical antifungal therapy, 20 (21%) of these patients were ineligible for randomization to ketoconazole treatment because of their inability to tolerate oral medications. Among 72 patients eligible for randomization, 64 were assessable (32 in each arm of the study). Five of six patients with proved fungal infections who were randomized to receive ketoconazole treatment required crossover to amphotericin B treatment because of progressive infection. The conditions of three of these five patients improved after receiving amphotericin B. The frequency of transaminase elevation was higher in those receiving ketoconazole, while the frequency of azotemia was higher in those receiving amphotericin B. Bioavailability of ketoconazole was unpredictable. Amphotericin B remains the drug of choice for empirical antifungal therapy in granulocytopenic patients; whereas, lack of a parenteral formulation, ineffectiveness against proved mycoses, and unreliable bioavailability preclude high-dose ketoconazole from being an appropriate compound for this purpose.

Dideoxyinosine in children with symptomatic human immunodeficiency virus infection

BACKGROUND

2',3'-Dideoxyinosine (ddl) is a dideoxynucleoside with potent activity in vitro against the human immunodeficiency virus (HIV). In initial clinical trials in adults, ddl showed evidence of antiretroviral activity with little hematologic toxicity.

METHODS

We conducted a phase I-II study in 43 children with symptomatic (CDC class P-2) HIV infection. Of these children, 16 (median age, 10 years) had previously received zidovudine, and 27 (median age, 2.6 years) had not. ddl was administered orally in three divided doses totalling 60, 120, 180, 360, or 540 mg per square meter of body-surface area per day for 24 weeks. Eight of the 43 patients did not complete 24 weeks of ddl: 6 died, 1 was withdrawn because of progressive disease, and the other because of toxicity.

RESULTS

After oral administration, ddl was rapidly absorbed, although its bioavailability varied greatly among patients. Pancreatitis developed in two children, one receiving ddl at each of the two highest doses. The median CD4 cell count in 38 patients with paired counts increased from 0.218 x 10(9) per liter (218 per cubic millimeter) at base line to 0.327 x 10(9) per liter (327 per cubic millimeter) after 20 to 24 weeks (P = 0.001). Those with CD4 cell counts above 0.1 x 10(9) per liter (100 per cubic millimeter) at base line were significantly more likely to improve in this respect. The median levels of p24 antigen (in 27 patients with detectable levels at entry) declined from 272 pg per milliliter at base line to 77 pg per milliliter at 20 to 24 weeks (P = 0.005). The plasma concentration of ddl correlated significantly with both the degree of decline in the p24 antigen and the degree of improvement in IQ score. Improvement in clinical and immunologic measures occurred in both the previously untreated patients and in those who had been treated with zidovudine.

CONCLUSIONS

Dideoxyinosine was well tolerated and showed promising antiretroviral activity in HIV-infected children. The correlation between the clinical response and the plasma concentration of ddl indicates that bioavailability is an important consideration in the use of ddl to treat HIV infection and that individualized pharmacokinetic monitoring and dose adjustment may be important for optimal activity.

A randomized trial of open lung biopsy versus empiric antimicrobial therapy in cancer patients with diffuse pulmonary infiltrates

Twenty-four cancer patients with diffuse interstitial pneumonitis (DIP) were randomized to undergo an open lung biopsy (OLB) within 8 hours of presentation (12 patients) or to receive empiric antimicrobial therapy (ET) with trimethoprim-sulfamethoxazole (TMP-SMX) erythromycin for a minimum of 4 days (12 patients). Patients whose condition deteriorated underwent an OLB on day 4. Eight of 12 patients (67%) having OLB survived versus 10 of 12 (83%) receiving ET (P = .64). Morbidity occurred in nine of 12 (75%) having OLB versus eight of 12 (67%) receiving ET (P = 1.0). Concurrently, there were 14 additional cancer patients with DIP who were not randomized (nine refused, three had a coagulopathy contraindicating surgery, two were excluded by primary care physicians) and who were comparable demographically to the randomized group. Two received OLB and 12 ET. Combining the randomized and nonrandomized groups, eight of 14 (57%) having an initial OLB survived versus 18 of 24 (75%) of ET-treated patients (P2 = .19). Results of the OLB were seven Pneumocystis carinii pneumonia (PCP), five nonspecific pneumonitis (NSP), one cytomegalovirus, and one lymphoma. Results of OLB led to discontinuation of antibiotics in three patients. Of the 24 ET patients, eight failed to improve by day 4 and had an OLB. Results were two NSP, two PCP, two cancer, one blastomycosis, and one Candida pneumonia. Complications were seen in 10 of 14 (72%) initial OLB patients versus 14 of 24 (58%) patients on the ET arm (P = .65). When the complication rate between patients receiving only empiric antibiotics was compared with all patients having an OLB (initially or on day 4), the difference was greater in patients undergoing OLB (37% v 72%, respectively) (P2 = .14). ET with TMP-SMX plus erythromycin and broad spectrum antibiotics in granulocytopenic patients appeared to be as successful and potentially less toxic than an OLB in this study. Although the number of patients in this study was small, these data suggest that a trial of empiric antibiotic management may be reasonable in cancer patients presenting with DIP, especially if they are nonneutropenic.

Gram-positive infections and the use of vancomycin in 550 episodes of fever and neutropenia

STUDY OBJECTIVE

To determine the appropriate role for vancomycin in neutropenic patients with cancer. To review the incidence, types, and outcome of gram-positive infections in a series of neutropenic patients with cancer.

DESIGN

Retrospective review.

SETTING

Inpatient units of the Medical and Pediatric Oncology Branches of the National Cancer Institute.

PATIENTS

Five hundred and fifty consecutive episodes of fever and neutropenia in patients with cancer randomized prospectively on another study to receive either ceftazidime alone or combination antibiotics for initial empirical therapy.

INTERVENTION

Intravenous vancomycin (dosage adjusted by serum levels).

MEASUREMENTS AND MAIN RESULTS

Gram-positive organisms were the commonest of the bacterial pathogens isolated (63%). Of the 53 gram-positive organisms accounting for primary infections (isolated at initial presentation), there were 36 staphylococcal isolates (19 coagulase-negative and 17 coagulase-positive), 13 streptococcal isolates (8 non-group D and 5 group D), and 4 polymicrobial isolates. Of the 22 secondary gram-positive infections (occurring after institution of initial antibiotics), there were 10 streptococcal isolates (9 group D and 1 non-group D), 7 staphylococcal isolates (6 coagulase-negative and 1 coagulase-positive), and 5 polymicrobial isolates. Vancomycin was used to treat 26 of the 53 primary infections, but was begun only after knowledge of the isolate in 25. Vancomycin was used to treat 17 of the 22 secondary infections, and begun only after knowledge of the isolate in 14. This approach resulted in no treatment failures for the primary infections, and a single microbiological failure for the secondary infections. There was a tendency towards a greater proportion of secondary gram-positive infections in the monotherapy group compared to the combination therapy group (16 of 282 compared with 6 of 268 respectively, P2 = 0.04 by the chi-squared test); but all were treated successfully.

CONCLUSION

Vancomycin need not be included in routine empirical therapy for febrile neutropenic patients, but should be added when clinical or microbiological data suggest the need.

Clinical features and therapeutic interventions in 17 cases of Bacillus bacteremia in an immunosuppressed patient population

We retrospectively examined episodes of Bacillus bacteremia at a hospital with a large proportion of immunosuppressed patients. Seventeen episodes in 9.5 years met our case definition: two of two bottles of one blood culture or one of two bottles of two or more separately obtained blood cultures drawn on the same date. During the same period, there were 59 additional episodes in which a single blood culture had only one of two bottles positive for Bacillus species. Only 2 of 59 such episodes resulted in recurrent bacteremia (3%), as compared with 5 of 17 episodes meeting our case definition (29%) (P = 0.004). In four of five episodes complicated by recurrent bacteremia and in which appropriate antibiotics were used, a Hickman-Broviac catheter was in place and was not removed. We suggest that our case definition permits the differentiation of infection from contamination based on outcome and that patients with Bacillus bacteremia have chronic venous catheters removed as well as receive antibiotic treatment.

A randomized trial comparing ceftazidime alone with combination antibiotic therapy in cancer patients with fever and neutropenia

To assess the efficacy of single-agent therapy relative to standard combination antibiotic therapy for the initial management of fever and neutropenia in cancer patients, we conducted a randomized trial comparing ceftazidime alone with a combination of cephalothin, gentamicin, and carbenicillin. Of 550 evaluable episodes of fever and neutropenia, 282 were treated with ceftazidime alone and 268 with the combination. All episodes were evaluated for responses at 72 hours after the start of treatment and at resolution of the neutropenia. Of the patients with unexplained fever who were given ceftazidime alone, 99 percent were alive at 72 hours and 98 percent were alive when the neutropenia resolved, as compared with 100 percent and 98 percent, respectively, of those given combination therapy. Of the patients with documented infection who were given ceftazidime alone, 98 percent were alive at 72 hours and 89 percent when the neutropenia resolved, as compared with 98 percent and 91 percent, respectively, of those given combination therapy. The majority of episodes of documented infection in both treatment groups necessitated additional antimicrobial treatment or other modifications of the initial regimen, as compared with only 22 percent of the episodes of unexplained fever. We conclude that initial single-agent therapy with certain beta-lactam antibiotics is a safe alternative to standard combination antibiotic therapy, although patients with documented infection or protracted neutropenia are likely to require additional or modified treatment.

Approaching the controversies in antibacterial management of cancer patients

The principles for management of infectious complications in cancer patients are continuing to evolve. The critical element includes the prompt institution of broad-spectrum antibiotic(s) empirically when granulocytopenic patients become febrile and continuation and modification of the regimen in patients with persistent fever and granulocytopenia. The view is presented that antibiotics provide systemic prophylaxis as well as therapy in persistently granulocytopenic patients and that they should be continued until all signs of infection have cleared or the granulocyte count has recovered. Such aggressive therapy, supplemented by continued evaluation and monitoring of the patient, can significantly reduce infection-relation morbidity and mortality.