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Hereditary angioedema (HAE) is an autosomal dominant disorder characterized by recurrent episodes of swelling of the skin, larynx, gastrointestinal tract, genitals, and extremities that can be disruptive to patient quality of life. Dysregulation of plasma kallikrein activity leads to increased production and accumulation of bradykinin in HAE and causes attacks of angioedema. Plasma kallikrein is a serine protease essential for the formation of bradykinin. Berotralstat is a potent, highly selective, orally bioavailable small-molecule plasma kallikrein inhibitor that has been approved to prevent attacks of HAE in adults and children 12 years of age and older. Population pharmacokinetic (PK) analyses were conducted to describe the PK of berotralstat (BCX7353; Orladeyo ™ ) and to evaluate the covariates that may explain variability in PK. The PK of berotralstat were characterized by population PK modeling of data from 13 clinical studies and a total of 771 healthy subjects and patients with HAE. The PK profile was well described by a three-compartment model with first-order absorption including an absorption lag time and linear elimination. Among the covariates tested, the effects of bilirubin and food were found not to be clinically significant and were removed from the model. Covariate analysis indicated significant effects of dose on bioavailability and weight on berotralstat clearance and volume. Despite the covariate effect of weight, simulations in adolescents and adults who were underweight, low weight, and overweight demonstrated similar predicted exposures to those observed at therapeutic doses in a clinical trial. Therefore, no dose adjustment is required in these HAE patient subpopulations., (© 2022 BioCryst Pharmaceuticals, Inc. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Galidesivir (BCX4430) is an adenosine nucleoside analog broadly active in cell culture against multiple RNA virus families, and active in animal models of viral diseases associated with Ebola, Marburg, yellow fever, Zika, and Rift Valley fever. Current studies demonstrated the pharmacokinetics and safety of the first-in-human evaluations of galidesivir as intramuscular (IM) and intravenous (IV) formulations. Two double-blind, placebo-controlled, dose-ranging studies were conducted enrolling 126 healthy subjects. Study 1 evaluated the safety and tolerability of IM galidesivir over single day dosing, single day dosing ± lidocaine, and 7-day dosing with lidocaine. Study 2 evaluated the safety and tolerability of single ascending doses of IV galidesivir. Safety and tolerability were evaluated via clinical and laboratory monitoring. The plasma concentration-time profile of galidesivir at doses 0.3 to 10 mg/kg IM was characterized by rapid absorption, an initial rapid distribution and clearance phase, and an extended terminal elimination phase. The initial rapid distribution and extended terminal elimination were mimicked in the profile of galidesivir at doses 5 to 20 mg/kg IV. No fatal events or related serious adverse events were reported. No clinically significant dose-related trends in laboratory values, vital signs, electrocardiograms, or echocardiograms were noted. Galidesivir was safe and generally well tolerated., (© 2022, The American College of Clinical Pharmacology.)

Background: Berotralstat (BCX7353) is an oral, once-daily inhibitor of plasma kallikrein in development for the prophylaxis of hereditary angioedema (HAE) attacks., Objective: Our aim was to determine the efficacy, safety, and tolerability of berotralstat in patients with HAE over a 24-week treatment period (the phase 3 APeX-2 trial)., Methods: APeX-2 was a double-blind, parallel-group study that randomized patients at 40 sites in 11 countries 1:1:1 to receive once-daily berotralstat in a dose of 110 mg or 150 mg or placebo (Clinicaltrials.gov identifier NCT03485911). Patients aged 12 years or older with HAE due to C1 inhibitor deficiency and at least 2 investigator-confirmed HAE attacks in the first 56 days of a prospective run-in period were eligible. The primary efficacy end point was the rate of investigator-confirmed HAE attacks during the 24-week treatment period., Results: A total of 121 patients were randomized; 120 of them received at least 1 dose of the study drug (n = 41, 40, and 39 in the 110-mg dose of berotralstat, 150-mg of dose berotralstat, and placebo groups, respectively). Berotralstat demonstrated a significant reduction in attack rate at both 110 mg (1.65 attacks per month; P = .024) and 150 mg (1.31 attacks per month; P < .001) relative to placebo (2.35 attacks per month). The most frequent treatment-emergent adverse events that occurred more with berotralstat than with placebo were abdominal pain, vomiting, diarrhea, and back pain. No drug-related serious treatment-emergent adverse events occurred., Conclusion: Both the 110-mg and 150-mg doses of berotralstat reduced HAE attack rates compared with placebo and were safe and generally well tolerated. The most favorable benefit-to-risk profile was observed at a dose of 150 mg per day., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Berotralstat (BCX7353) is an oral, once-daily inhibitor of plasma kallikrein recently approved for prevention of angioedema attacks in adults and adolescents with hereditary angioedema (HAE). The objective of this report is to summarize results from an interim analysis of an ongoing long-term safety study of berotralstat in patients with HAE., Methods: APeX-S is an ongoing, phase 2, open-label study conducted in 22 countries (ClinicalTrials.gov, NCT03472040). Eligible patients with a clinical diagnosis of HAE due to C1 inhibitor deficiency (HAE-C1-INH) were centrally allocated to receive berotralstat 150 or 110 mg once daily. The primary objective was to determine long-term safety and the secondary objective was to evaluate effectiveness., Results: Enrolled patients (N = 227) received berotralstat 150 mg (n = 127) or 110 mg (n = 100) once daily. The median (range) duration of exposure was 342 (11-540) and 307 (14-429) days for the 150-mg and 110-mg groups, respectively. Treatment-emergent adverse events (TEAEs) occurred in 91% (n = 206) of patients. The most common TEAEs across treatment groups were upper respiratory tract infection (n = 91, 40%), abdominal pain (n = 57, 25%), headache (n = 40, 18%), and diarrhea (n = 31, 14%) and were mostly mild to moderate. Fifty percent (n = 113) of patients had at least one drug-related adverse event (AE; 150 mg, n = 57 [45%]; 110 mg, n = 56 [56%]), and discontinuations due to AEs occurred in 19 (8%) patients (150 mg, n = 13 [10%]; 110 mg, n = 6 [6%]). Three (1.3%) patients experienced a drug-related serious TEAE. Among patients who received berotralstat through 48 weeks (150 mg, n = 73; 110 mg, n = 30), median HAE attack rates were low in month 1 (150 mg, 1.0 attacks/month; 110 mg, 0.5 attacks/month) and remained low through 12 months (0 attacks/month in both dose groups). Mean HAE attack rates followed a similar trend, and no evidence for patient tolerance to berotralstat emerged. In both dose groups, angioedema quality of life scores showed clinically meaningful changes from baseline., Conclusions: In this analysis, both berotralstat doses, 150  and 110 mg once daily, were generally well tolerated. Effectiveness results support the durability and robustness of berotralstat as prophylactic therapy in patients with HAE., Trial Registration: The study is registered with ClinicalTrials.gov (NCT03472040)., (© 2021 The Authors. Clinical and Translational Allergy published by John Wiley and Sons Ltd on behalf of European Academy of Allergy and Clinical Immunology.)

Background: Berotralstat (BCX7353) is a recently approved, oral, once-daily kallikrein inhibitor for hereditary angioedema (HAE) prophylaxis. In the APeX-2 trial, berotralstat reduced HAE attack rates over 24 weeks, with a favorable safety and tolerability profile., Objective: Evaluate berotralstat safety, tolerability, and effectiveness over 48 weeks., Methods: APeX-2 is a phase 3, parallel-group, multicenter trial (NCT03485911) in patients with HAE due to C1 esterase inhibitor deficiency. Part 1 was double-blind and placebo-controlled, with patients randomized to 24 weeks of berotralstat 150 mg, 110 mg, or placebo. In part 2, patients continued berotralstat the same dose or, if initially randomized to placebo, were rerandomized to berotralstat 150 mg or 110 mg through weeks 24 to 48. The primary end point was safety and tolerability., Results: One hundred eight patients received 1 or more doses of berotralstat in part 2. Treatment-emergent adverse events (TEAEs) occurred in 30 of 39 patients (77%) in the placebo group during part 1, and 25 of 34 patients (74%) re-randomized from placebo to berotralstat 110 mg or 150 mg in part 2, with drug-related TEAEs in 13 of 39 (33%), and 11 of 34 (32%) in the same groups. Most TEAEs were mild or moderate, with no serious drug-related TEAEs. The most common TEAEs were upper respiratory tract infections, abdominal pain, diarrhea, and vomiting. Mean (±standard error of the mean) monthly attack rates at baseline and week 48 were 3.06 (±0.25) and 1.06 (±0.25) in the berotralstat 150mg 48-week group and 2.97 (±0.21) and 1.35 (±0.33) in the berotralstat 110mg 48-week group., Conclusions: The safety, tolerability, and effectiveness of berotralstat were maintained over 48 weeks of treatment., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: With no approved treatments in Japan for the prevention of hereditary angioedema (HAE) attacks, there is a significant unmet need for long-term prophylactic therapies for Japanese patients with HAE. Berotralstat (BCX7353) is an oral, once-daily, highly selective inhibitor of plasma kallikrein in development for prophylaxis of angioedema attacks in HAE patients., Methods: APeX-J is a phase 3, randomized, double-blind, placebo-controlled, parallel-group, 3-part trial conducted in Japan (University Hospital Medical Information Network identifier, UMIN000034869; ClinicalTrials.gov identifier, NCT03873116). Patients with a clinical diagnosis of type 1 or 2 HAE underwent a prospective run-in period of 56 days to determine eligibility, allowing enrollment of those with ≥2 expert-confirmed angioedema attacks. Patients were randomly assigned (1:1:1) and stratified by baseline attack rate (≥2 vs. <2 expert-confirmed attacks/month between screening and randomization) to receive once-daily berotralstat 110 mg, berotralstat 150 mg, or placebo. The primary endpoint was the rate of expert-confirmed angioedema attacks during dosing in the 24-week treatment period., Results: Nineteen patients were randomized to receive once-daily berotralstat 110 mg (n = 6), berotralstat 150 mg (n = 7), or placebo (n = 6). Treatment with berotralstat 150 mg significantly reduced HAE attacks relative to placebo (1.11 vs. 2.18 attacks/month, p = .003). The most frequently reported treatment-emergent adverse events (TEAEs) in berotralstat-treated patients (n = 13) were nasopharyngitis (n = 4, 31%), abdominal pain, cough, diarrhea, and pyrexia (n = 2 each, 15%)., Conclusions: Orally administered, once-daily berotralstat 150 mg significantly reduced the frequency of HAE attacks and was safe and well tolerated, supporting its use as a prophylactic therapy in patients with type 1 or 2 HAE in Japan., (© 2020 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Zika virus infection in humans has been associated with serious reproductive and neurological complications. At present, no protective antiviral drug treatment is available. Here, we describe the testing and evaluation of the antiviral drug, galidesivir, against Zika virus infection in rhesus macaques. We conducted four preclinical studies in rhesus macaques to assess the safety, antiviral efficacy, and dosing strategies for galidesivir (BCX4430) against Zika virus infection. We treated 70 rhesus macaques infected by various routes with the Puerto Rico or Thai Zika virus isolates. We evaluated galidesivir administered as early as 90 min and as late as 72 hours after subcutaneous Zika virus infection and as late as 5 days after intravaginal infection. We evaluated the efficacy of a range of galidesivir doses with endpoints including Zika virus RNA in plasma, saliva, urine, and cerebrospinal fluid. Galidesivir dosing in rhesus macaques was safe and offered postexposure protection against Zika virus infection. Galidesivir exhibited favorable pharmacokinetics with no observed teratogenic effects in rats or rabbits at any dose tested. The antiviral efficacy of galidesivir observed in the blood and central nervous system of infected animals warrants continued evaluation of this compound for the treatment of flaviviral infections., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Background: Effective inhibition of plasma kallikrein may have significant benefits for patients with hereditary angioedema due to deficiency of C1 inhibitor (C1-INH-HAE) by reducing the frequency of angioedema attacks. Avoralstat is a small molecule inhibitor of plasma kallikrein. This study (OPuS-2) evaluated the efficacy and safety of prophylactic avoralstat 300 or 500 mg compared with placebo., Methods: OPuS-2 was a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Subjects were administered avoralstat 300 mg, avoralstat 500 mg, or placebo orally 3 times per day for 12 weeks. The primary efficacy endpoint was the angioedema attack rate based on adjudicator-confirmed attacks., Results: A total of 110 subjects were randomized and dosed. The least squares (LS) mean attack rates per week were 0.589, 0.675, and 0.593 for subjects receiving avoralstat 500 mg, avoralstat 300 mg, and placebo, respectively. Overall, 1 subject in each of the avoralstat groups and no subjects in the placebo group were attack-free during the 84-day treatment period. The LS mean duration of all confirmed attacks was 25.4, 29.4, and 31.4 hours for the avoralstat 500 mg, avoralstat 300 mg, and placebo groups, respectively. Using the Angioedema Quality of Life Questionnaire (AE-QoL), improved QoL was observed for the avoralstat 500 mg group compared with placebo. Avoralstat was generally safe and well tolerated., Conclusions: Although this study did not demonstrate efficacy of avoralstat in preventing angioedema attacks in C1-INH-HAE, it provided evidence of shortened angioedema episodes and improved QoL in the avoralstat 500 mg treatment group compared with placebo., (© 2018 The Authors. Allergy Published by John Wiley & Sons Ltd.)

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen endemic to sub-Saharan Africa and the Arabian Peninsula. There are no approved antiviral therapies or vaccines available to treat or prevent severe disease associated with RVFV infection in humans. The adenosine analog, galidesivir (BCX4430), is a broad-spectrum antiviral drug candidate with in vitro antiviral potency (EC 50 of less than 50 μM) in more than 20 different viruses across eight different virus families. Here we report on the activity of galidesivir in the hamster model of peracute RVFV infection. Intramuscular and intraperitoneal treatments effectively limited systemic RVFV (strain ZH501) infection as demonstrated by significantly improved survival outcomes and the absence of infectious virus in the spleen and the majority of the serum, brain, and liver samples collected from infected animals. Our findings support the further development of galidesivir as an antiviral therapy for use in treating severe RVFV infection, and possibly other related phleboviral diseases., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Zika virus (ZIKV) is currently undergoing pandemic emergence. While disease is typically subclinical, severe neurologic manifestations in fetuses and newborns after congenital infection underscore an urgent need for antiviral interventions. The adenosine analog BCX4430 has broad-spectrum activity against a wide range of RNA viruses, including potent in vivo activity against yellow fever, Marburg and Ebola viruses. We tested this compound against African and Asian lineage ZIKV in cytopathic effect inhibition and virus yield reduction assays in various cell lines. To further evaluate the efficacy in a relevant animal model, we developed a mouse model of severe ZIKV infection, which recapitulates various human disease manifestations including peripheral virus replication, conjunctivitis, encephalitis and myelitis. Time-course quantification of viral RNA accumulation demonstrated robust viral replication in several relevant tissues, including high and persistent viral loads observed in the brain and testis. The presence of viral RNA in various tissues was confirmed by an infectious culture assay as well as immunohistochemical staining of tissue sections. Treatment of ZIKV-infected mice with BCX4430 significantly improved outcome even when treatment was initiated during the peak of viremia. The demonstration of potent activity of BCX4430 against ZIKV in a lethal mouse model warrant its continued clinical development., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Avoralstat is a potent small-molecule oral plasma kallikrein inhibitor under development for treatment of hereditary angioedema (HAE). This first-in-human study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of avoralstat., Methods: This double-blind, placebo-controlled, ascending-dose cohort trial evaluated avoralstat single doses of 50, 125, 250, 500, and 1000 mg and multiple doses up to 2400 mg daily (100, 200, 400, and 800 mg every 8 h [q8 h] up to 7 days)., Results: Avoralstat (n = 71) was generally well tolerated with no signals for a safety concern; there were no serious adverse events (AEs) or discontinuations due to AEs, and compared to placebo (n = 18), no notable difference in AEs. Four moderate severity AEs were reported in two subjects; syncope after a single 250 mg dose (one subject) and abdominal pain, back pain, and eczema after multiple doses of 800 mg avoralstat (one subject). For multiple-dose cohorts, the incidence of gastrointestinal AEs was highest at the 2400 mg/day dose. Elimination of avoralstat was bi-exponential with a terminal half-life of 12-31 h. Inhibition of plasma kallikrein was observed at all doses, and the degree of inhibition was highly correlated with avoralstat concentrations (R = 0.93). Mean avoralstat concentrations at doses ≥400 mg q8 h met or exceeded plasma kallikrein EC 50 values throughout the dosing interval., Conclusion: Avoralstat was well tolerated, and drug exposure was sufficient to meet target levels for inhibition of plasma kallikrein. Based on these results, the 400 mg q8 h dose was selected for further evaluation in patients with HAE., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The adenosine nucleoside analog BCX4430 is a direct-acting antiviral drug under investigation for the treatment of serious and life-threatening infections from highly pathogenic viruses, such as the Ebola virus. Cellular kinases phosphorylate BCX4430 to a triphosphate that mimics ATP; viral RNA polymerases incorporate the drug's monophosphate nucleotide into the growing RNA chain, causing premature chain termination. BCX4430 is active in vitro against many RNA viral pathogens, including the filoviruses and emerging infectious agents such as MERS-CoV and SARS-CoV. In vivo, BCX4430 is active after intramuscular, intraperitoneal, and oral administration in a variety of experimental infections. In nonclinical studies involving lethal infections with Ebola virus, Marburg virus, Rift Valley fever virus, and Yellow Fever virus, BCX4430 has demonstrated pronounced efficacy. In experiments conducted in several models, both a reduction in the viral load and an improvement in survival were found to be related to the dose of BCX4430. A Phase 1 clinical trial of intramuscular administration of BCX4430 in healthy subjects is currently ongoing., (Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. All rights reserved.)

Background: Current influenza treatment options include oral or inhaled antiviral agents. There is an unmet need for parenteral antiviral treatments., Methods: Peramivir, a parenteral influenza neuraminidase inhibitor (NAI), was administered by single-dose intramuscular (IM) injection in two placebo-controlled studies in adult outpatients with acute, uncomplicated influenza during two consecutive influenza seasons., Results: In a Phase II study, peramivir treatment significantly shortened duration of fever and reduced viral load in nasopharyngeal secretions. A subsequent Phase III study was not fully enrolled; however, in both studies, the magnitude of the treatment effect favouring peramivir was consistent with that reported for other NAIs. A post-hoc analysis was conducted by integrating efficacy and safety results of 427 subjects from both studies. The median time to alleviation of symptoms (TTAS) in subjects receiving peramivir 300 mg (113.2 h) was shorter than for placebo (134.8 h; P=0.161 adjusted for smoking behaviour, influenza season and virus type; unadjusted P=0.047). The median time to resolution of fever was reduced by 24 h after treatment with peramivir 300 mg compared with placebo (P=0.004). The proportion of subjects shedding influenza virus was significantly decreased over 48 h following peramivir treatment (P=0.009). Detection of post-treatment viruses with decreased susceptibility to NAIs was uncommon. Peramivir was generally safe and well-tolerated with types and rates of adverse event similar to placebo., Conclusions: The results of these studies are consistent with previous reports of peramivir administered by intravenous infusion, and demonstrate a positive risk-benefit profile for peramivir in patients with acute uncomplicated influenza.

Background: Seasonal influenza causes >200 000 annual hospitalizations in the United States. Current antiviral treatment options are limited to oral or inhaled agents. There is an urgent unmet need for intravenous antiviral treatments., Methods: Patients hospitalized with suspected influenza were randomized to 5-day treatment with intravenous peramivir (600 mg once daily) or placebo; all received the institution's standard of care (SOC) treatment. Time to clinical resolution and change in viral shedding in nasopharyngeal specimens were the primary and key secondary end points., Results: Influenza infection was confirmed in 338 of 405 enrolled patients. At the time of a preplanned interim analysis, the primary efficacy analysis population comprised 121 patients who did not receive a concurrent neuraminidase inhibitor as part of the SOC. The median (95% confidence interval) time to clinical resolution was 42.5 (34.0-57.9) hours for peramivir versus 49.5 (40.0-61.9) hours for placebo (P = .97). A larger treatment effect was observed in patients with history of symptoms <48 hours or admitted to an intensive care unit. Greater reductions in viral shedding, based on median tissue culture infective dose, were observed in patients who received peramivir than in placebo recipients, although this difference was not statistically significant. The incidence and severity of adverse events and laboratory abnormalities were similar between the 2 treatment groups. The study was terminated for futility after a preplanned interim analysis., Conclusions: A significant clinical benefit was not demonstrated for peramivir plus SOC compared with placebo plus SOC. Peramivir was generally safe and well tolerated. These findings highlight the challenges in designing studies to evaluate influenza antiviral agents in a hospitalized setting. Clinical Trials Registration. NCT00958776., (© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

No effective antiviral therapies are currently available to treat disease after infection with yellow fever virus (YFV). A Syrian golden hamster model of yellow fever (YF) was used to characterize the effect of treatment with BCX4430, a novel adenosine nucleoside analog. Significant improvement in survival was observed after treatment with BCX4430 at 4 mg/kg of body weight per day dosed intraperitoneally (i.p.) twice daily (BID). Treatment with BCX4430 at 12.5 mg/kg/day administered i.p. BID for 7 days offered complete protection from mortality and also resulted in significant improvement of other YF disease parameters, including weight loss, serum alanine aminotransferase levels (6 days postinfection [dpi]), and viremia (4 dpi). In uninfected hamsters, BCX4430 at 200 mg/kg/day administered i.p. BID for 7 days was well tolerated and did not result in mortality or weight loss, suggesting a potentially wide therapeutic index. Treatment with BCX4430 at 12 mg/kg/day i.p. remained effective when administered once daily and for only 4 days. Moreover, BCX4430 dosed at 200 mg/kg/day i.p. BID for 7 days effectively treated YF, even when treatment was delayed up to 4 days after virus challenge, corresponding with peak viral titers in the liver and serum. BCX4430 treatment did not preclude a protective antibody response, as higher neutralizing antibody (nAb) concentrations corresponded with increasing delays of treatment initiation, and greater nAb responses resulted in the protection of animals from a secondary challenge with YFV. In summary, BCX4430 is highly active in a hamster model of YF, even when treatment is initiated at the peak of viral replication., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Filoviruses are emerging pathogens and causative agents of viral haemorrhagic fever. Case fatality rates of filovirus disease outbreaks are among the highest reported for any human pathogen, exceeding 90% (ref. 1). Licensed therapeutic or vaccine products are not available to treat filovirus diseases. Candidate therapeutics previously shown to be efficacious in non-human primate disease models are based on virus-specific designs and have limited broad-spectrum antiviral potential. Here we show that BCX4430, a novel synthetic adenosine analogue, inhibits infection of distinct filoviruses in human cells. Biochemical, reporter-based and primer-extension assays indicate that BCX4430 inhibits viral RNA polymerase function, acting as a non-obligate RNA chain terminator. Post-exposure intramuscular administration of BCX4430 protects against Ebola virus and Marburg virus disease in rodent models. Most importantly, BCX4430 completely protects cynomolgus macaques from Marburg virus infection when administered as late as 48 hours after infection. In addition, BCX4430 exhibits broad-spectrum antiviral activity against numerous viruses, including bunyaviruses, arenaviruses, paramyxoviruses, coronaviruses and flaviviruses. This is the first report, to our knowledge, of non-human primate protection from filovirus disease by a synthetic drug-like small molecule. We provide additional pharmacological characterizations supporting the potential development of BCX4430 as a countermeasure against human filovirus diseases and other viral diseases representing major public health threats.

Background: Influenza causes over 200,000 hospitalizations a year in the United States, but few antiviral treatment studies have focused on patients hospitalized with influenza. This open-label, randomized study was initiated during the 2009 H1N1 pandemic to help assess the antiviral activity, safety and tolerability of 5-10 days treatment with two different dosing regimens of the intravenous neuraminidase inhibitor, peramivir, in hospitalized subjects with influenza., Methods: Quantitative virology was done on nasopharyngeal swab specimens from subjects ≥6 years of age to measure change from baseline in tissue culture infective dose (primary end point) and quantitative viral RNA levels by real-time PCR. Clinical end points included time to clinical resolution, a composite end point of four vital signs and oxygen saturation., Results: A total of 234 hospitalized patients were randomized to peramivir 300 mg twice daily or 600 mg once daily; 127 had laboratory confirmed influenza. In those with detectable virus at baseline, viral titres declined without differences between regimens. There were no significant differences in clinical or virological end points between treatment arms, and apparent differences were explained by baseline disease severity differences in the groups. Peramivir was generally safe and well tolerated for treated patients hospitalized with pandemic influenza with outcomes similar to those described in the literature., Conclusions: This open-label trial of intravenous peramivir in subjects hospitalized predominantly with 2009 influenza A (H1N1) demonstrated that once- or twice-daily administration was associated with decreases in viral shedding and clinical improvement. ClinicalTrials.gov number NCT00957996.

Analysis of a US hospitalization database demonstrated that more influenza patients were hospitalized and the age distribution of hospitalizations was younger during the 2009 (H1N1) influenza A pandemic compared with the three previous influenza seasons. The duration of hospital stay remained stable in all four seasons. A higher proportion of patients was treated with antivirals (P < 0·0001), comprised almost entirely of neuraminidase inhibitors, and the proportion was highest in those with influenza confirmed by diagnostic testing (P < 0·0001). Approximately one-third remained untreated. Young children had the lowest rate of neuraminidase-inhibitor treatment during the 2009 pandemic (P < 0·05)., (© 2011 Blackwell Publishing Ltd.)

The 2009 H1N1 influenza pandemic prompted the US Food and Drug Administration (FDA) to issue an emergency use authorization (EUA) for the intravenous antiviral peramivir, an unapproved neuraminidase inhibitor (NAI) currently under development. Peramivir use was limited to patients for whom other NAI therapy had failed or in whom oral or inhalational drug absorption was believed to be unreliable. This introduced a patient selection bias that precluded safety and efficacy assessment. Despite the challenges and risks, there was a compelling public health need for an intravenous agent during the 2009 H1N1 pandemic.

Prostate cancer has become the most common cancer among American men and is second only to lung cancer as a cause of male cancer-related death. Several treatment options exist for different stages of prostate cancer including observation, prostatectomy, radiation therapy, chemotherapy, and hormone therapy. Hormone therapy has evolved from the use of estrogens to gonadotropin-releasing hormone (GnRH) agonists and recently, investigational GnRH antagonists. GnRH receptor agonists such as leuprolide, bruserelin and goserelin have been used for the treatment of prostate cancer. These agonists eventually cause the inhibition of lutenizing hormone production, which in turn causes a suppression of testosterone and dihydrotestosterone, on which continued growth of prostate cancer cells depend. Several comparative studies of leuprorelin administered as daily injections or monthly depot injections have been reported. Disease progression was prevented in more than 72% of men administered daily leuprorelin, and in 82% to 89% of those receiving monthly depots. Another synthetic GnRH analog, goserelin, has been studied in a similar population of men with daily injections producing partial responses in 60% to 80% of men with previously untreated prostate cancer. Abarelix, a peptide antagonist of GnRH receptor, is also being studied for the treatment of prostate cancer. The discovery and development of GnRH antagonists may provide an important advance for patients with prostate cancer. Clearly the studies described herein, as well as many others, outline an exciting era of research to define the optimal use of hormonal therapy in prostate cancer.

A single injection of > or =10 microg/kg PEG-rHuMGDF in mice causes a dose-dependent increase in circulating platelets beginning on day 3 and peaking on days 5-6. The mean platelet volume and platelet distribution width at doses > or =100 microg/kg initially increase in a dose-dependent fashion and later decrease. However, the mean platelet volume does not change when platelets are incubated with PEG-rHuMGDF in vitro. The number of marrow megakaryocytes increases in a dose-dependent fashion as early as day 1 and peaks on day 3. Marrow megakaryocyte colony-forming units (CFU-Meg) do not increase on days 1-3 at a dose of 100 microg/kg (a dose that increases platelet numbers two- to threefold and may be clinically relevant), but the relative frequency of high ploidy megakaryocytes and the proportion of large marrow megakaryocytes (29-50 microm in diameter) increases. After a dose of 1,000 microg/kg the percentage of megakaryocytes in mitosis peaks at 24-48 hours and the percentage of megakaryocytes incorporating BrdU is maximal at 48 hours, the relatively delayed peak of BrdU incorporation most likely representing endomitosis. The relative frequency of type II and III megakaryocytes peaks on days 3 and 4, respectively. Pharmacokinetic analysis of PEG-rHuMGDF shows peak serum concentrations at 2-4 hours and a terminal half-life of 11.4+/-2.5 hours. A single injection of PEG-rHuMGDF ameliorates carboplatin-induced megakaryocytopenia and thrombocytopenia in a dose-response dependent fashion. In conclusion, a single injection of PEG-rHuMGDF increases megakaryocyte and platelet production in normal and myelo-suppressed mice.

Purpose: To determine the safety and efficacy of multiple cycles of dose-intensive, nonablative chemotherapy in women with poor-prognosis breast cancer., Patients and Methods: Women with stage II breast cancer and 10 or more involved nodes or four or more involved nodes and estrogen receptor-negative tumors and women with stage III disease received three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2, with progenitor cell and filgrastim support every 28 days (n = 79) or 21 days (n = 20). Patients were reviewed at least twice yearly thereafter. Twenty-six patients had bone marrow and apheresis collections assessed for the presence of micrometastatic tumor cells., Results: Ninety-nine women (median age, 43 years; range, 24 to 60 years) were treated. Ninety-two completed all three cycles of chemotherapy. The major toxicity was severe, reversible myelosuppression that was more prolonged with successive cycles, and this did not differ between patients given treatment every 28 days and those treated every 21 days. Febrile neutropenia occurred in 176 (61%) of 287 cycles. Severe mucositis (grade 3 or 4) occurred in 23% of cycles but tended to be short-lived and was reversible. The cardiac ejection fraction fell by a median of 4% during treatment, and three patients developed evidence of cardiac failure after chemotherapy. Two patients (2%) died of acute toxicity. Three of 26 patients had evidence of circulating micrometastatic tumor cells. The actuarial distant disease-free and overall survival rates at 60-month follow-up were 64% (95% confidence interval [CI], 53% to 75%) and 67% (95% CI, 56% to 78%), respectively., Conclusion: Multiple cycles of dose-intensive, nonablative chemotherapy is a feasible and safe approach. Disease control and survival are similar to those in other studies of myeloablative chemotherapy in poor-prognosis breast cancer. The regimen is being evaluated in a randomized trial of the International Breast Cancer Study Group.

This clinical trial was designed to explore dose escalation of carboplatin and cyclophosphamide when supported with filgrastim. Twenty-seven patients who had advanced solid tumors received up to six cycles of treatment; a total of 92 cycles of chemotherapy were delivered. Two control groups received standard-dose carboplatin (300 mg/m2) and cyclophosphamide (600 mg/m2), with and without filgrastim. Subsequently, the doses of both carboplatin and cyclophosphamide were increased simultaneously by 50% of the standard dose in sequential cohorts. Doses of up to 2.5 times the standard dose were explored. A final dose of carboplatin, 600 mg/m2, and cyclophosphamide, 1,500 mg/m2, was tested in 4 patients. The duration of neutropenia was brief, even at the highest dose levels. The mean duration of grade 3 or 4 neutropenia was 5.8 days at standard dose without filgrastim and 5.4 days at 2.5 times standard dose with filgrastim. More severe neutropenia was more prolonged at higher doses but remained brief in duration. The mean duration of neutropenia of less than 100 x 10(6)/l was 0.4 days at standard dose without filgrastim and 1.3 days at 2.5 times standard dose. There was no evidence of cumulative neutropenia over repeated cycles of treatment. In contrast, thrombocytopenia was both dose limiting and cumulative. The mean duration of grade 3 or 4 thrombocytopenia was 1.6 days at standard dose and 9.6 days at 2.5 times standard dose. An average of 2.3 platelet transfusions per cycle of treatment was required at the highest dose. Thrombocytopenia was worse with repetitive cycles of therapy. The mean duration of grade 3 or 4 thrombocytopenia was 2.2 days after the first cycle of chemotherapy and 7.8 days after cycle four. The maximum tolerated dose, as defined prospectively, was not reached but further dose escalation was not thought to be warranted because of the severity of thrombocytopenia. When supported with filgrastim, carboplatin and cyclophosphamide can be administered safely with substantially increased dose and acceptable toxicity.

Purpose: To assess the mobilization potential and safety of recombinant human stem-cell factor (SCF) when coadministered with filgrastim to untreated women with poor-prognosis breast cancer., Patients and Methods: Eligible women had breast cancer with 10 or more positive axillary nodes, or estrogen receptor-negative tumor with 4 positive nodes, or stage III disease. Patients were randomized to receive SCF plus filgrastim or filgrastim alone. Filgrastim 12 microg/kg daily was administered for 6 days by continuous subcutaneous infusion. SCF was administered by daily subcutaneous injection at 5, 10, or 15 microg/kg concurrent with filgrastim for 7 days, or 10 microg/kg daily starting 3 days before filgrastim for a total of 10 days (SCF pretreatment). Apheresis was performed on days 5, 6, and 7 of filgrastim administration. Patients then had three cycles of epirubicin 200 mg/m2 and cyclophosphamide 4 g/m2 every 28 days, each supported by one third of the apheresis product., Results: Sixty-two women were treated. Greater yields occurred in patients who received SCF 10 microg/kg daily plus filgastim than those who received filgrastim alone (P=.013 for CD34+ cells; P=.07 for granulocyte-macrophage colony-forming cells [GM-CFCs]). The difference was more marked with SCF-pretreatment than concurrent SCF. Fewer aphereses were required to reach the predetermined target of peripheral-blood progenitor/stem cells (PBPCs) in women who received SCF. SCF was generally well tolerated. Hematologic recovery was rapid after each of the three cycles of chemotherapy. There was no difference in recovery between the different treatment groups., Conclusion: Mobilization of PBPCs by filgrastim is significantly enhanced by coadministration of SCF, and commencing SCF before filgrastim can optimize this effect. SCF has the potential to reduce the number of aphereses required to collect a target number of PBPCs.

Administration of hematopoietic growth factors is being used increasingly to obtain populations of blood progenitor/stem cells (PBPC) for clinical transplantation. Here we examined the effect of combining stem cell factor (SCF ) and granulocyte colony-stimulating factor (G-CSF ) versus G-CSF alone in a randomized clinical study involving 62 women with early-stage breast cancer. In the first patient cohorts, escalating doses of SCF were administered for 7 days with concurrent G-CSF administration. At baseline, levels of progenitor cells in the bone marrow or blood were comparable in the different patient groups. As with administration of G-CSF alone, the combination of SCF plus G-CSF did not alter the wide variation in levels of PBPC observed between individuals and did not alter the selective nature of PBPC release, with preferential release of day-14 granulocyte-macrophage colony-stimulating factor (GM-CFC) versus day-7 GM-CFC. However, SCF acted to sustain the levels of PBPC after cessation of growth factor treatment; levels of PBPC were elevated 100-fold at later timepoints compared with G-CSF alone. In addition, the maximum levels of PBPC observed were increased approximately fivefold at day 5 of growth-factor administration. The increased levels of PBPC resulted in significantly increased levels of PBPC obtained by leukapheresis. In a subsequent patient cohort, 3-days pretreatment with SCF was introduced and followed by 7 days concurrent SCF plus G-CSF. The 3-days pretreatment with SCF resulted in an earlier wave of PBPC release in response to commencement of G-CSF. In addition, maximum PBPC levels in blood and PBPC yield in leukapheresis products were further increased. Unexpectedly however, SCF pretreatment resulted in progenitor cells with enhanced self-generation potential. Recloning assays documented the ability of approximately 30% of primary granulocyte-macrophage (GM) colonies from control cell populations to generate secondary GM colonies (n = 1,106 primary colonies examined). In contrast approximately 90% of GM colonies from PBPC after SCF pretreatment generated secondary clones and 65% generated secondary colonies. The action of SCF was not explicable in terms of altered SCF, GM-CSF, or G-CSF responsiveness, but SCF pretreatment was associated with maximum serum SCF levels at the time G-CSF was commenced. These results show that PBPC populations mobilized by different growth factor regimens can differ in their functional properties and caution against solely considering number of harvested progenitor cells without regard to their function.

The safety and optimal dose and schedule of stem cell factor (SCF) administered in combination with filgrastim for the mobilization of peripheral blood progenitor cells (PBPCs) was determined in 215 patients with high-risk breast cancer. Patients received either filgrastim alone (10 microg/kg/d for 7 days) or the combination of 10 microg/kg/d filgrastim and 5 to 30 microg/kg/d SCF for either 7, 10, or 13 days. SCF patients were premedicated with antiallergy prophylaxis. Leukapheresis was performed on the final 3 days of cytokine therapy and, after high-dose chemotherapy and infusion of PBPCs, patients received 10 microg/kg/d filgrastim until absolute neutrophil count recovery. The median number of CD34+ cells collected was greater for patients receiving the combination of filgrastim and SCF, at doses greater than 10 microg/kg/d, than for those receiving filgrastim alone (7.7 v 3.2 x 10(6)/kg, P < .05). There were significantly (P < .05) more CD34+ cells harvested for the 20 microg/kg/d SCF (median, 7.9 x 10(6)/kg) and 25 microg/kg/d SCF (median, 13.6 x 10(6)/kg) 7-day combination groups than for the filgrastim alone patients (median, 3.2 x 10(6)/kg). The duration of administration of SCF and filgrastim (7, 10, or 13 days) did not significantly affect CD34+ cell yield. Treatment groups mobilized with filgrastim alone or with the cytokine combination had similar hematopoietic engraftment and overall survival after PBPC infusion. In conclusion, the results of this study indicate that SCF therapy enhances CD34+ cell yield and is associated with manageable levels of toxicity when combined with filgrastim for PBPC mobilization. The combination of 20 microg/kg/d SCF and 10 microg/kg/d filgrastim with daily apheresis beginning on day 5 was selected as the optimal dose and schedule for the mobilization of PBPCs.

Mpl ligand is the hematopoietic growth factor responsible for regulating the production of platelets. Since its discovery just 3 years ago, it has provided both unique insights into megakaryocytopoiesis and the means to stimulate platelet production in numerous clinical situations. In animals deficient in Mpl ligand, the number of megakaryocytes and platelets decreases by more than 80%. In addition to having an effect on the megakaryocyte lineage, Mpl ligand supports the growth of stem cells, multipotential cells, and erythroid precursors. The endogenous Mpl ligand, thrombopoietin, is produced in the liver and kidneys, and circulating levels appear to be regulated primarily by the mass of platelets and megakaryocytes, which bind and catabolize Mpl ligand. The clinical utility of recombinant Mpl ligands is currently under intense investigation. Early results have demonstrated a marked stimulation of megakaryocyte and platelet production with no apparent adverse effects. In patients with cancer who are treated with chemotherapy, the duration of thrombocytopenia was shorter in patients treated with Mpl ligand than in those receiving placebo. The eventual role of Mpl ligand in clinical practice will be determined by the results of many ongoing clinical studies.

The most important physiological regulator of megakaryocytopoiesis is the ligand for the c-mpl receptor (thrombopoietin/megakaryocyte growth and development factor, MGDF). We examined the effect of pegylated-recombinant human MGDF (PEG-rHuMGDF): patients received PEG-rHuMGDF at doses of 0.03, 0.1, 0.3 or 1.0 microg/kg/d or placebo for 10d maximum in a double-blinded randomized study. There was a dose-dependent elevation in circulating platelet counts but no alteration in erythrocyte or total leucocyte counts. The number of bone marrow megakaryocytes was increased approximately 2-fold. The frequency of bone marrow progenitor cells was not altered. In contrast, both to the bone marrow results and to published pre-clinical data, there was a dose-dependent mobilization into the blood of progenitor cells of multiple cell lineages. Increased levels of Meg-CFC (maximum increase 30-fold), day 7 and day 14 GM-CFC and BFU-E were demonstrated at doses of 0.3 and 1.0 microg/kg/d PEG-rHuMGDF. At 0.1 microg/kg/d, mobilization of Meg-CFC alone occurred in two-thirds of patients. Maximum blood levels of progenitor cells occurred at day 12. Thus, administration of PEG-rHuMGDF to humans resulted in mobilization of progenitor cells of multiple lineages despite its 'lineage-specific' activity on mature cell development.

The present study shows that recombinant human megakaryocyte growth and development factor (r-HuMGDF) behaves both as a megakaryocyte colony stimulating factor and as a differentiation factor in human progenitor cell cultures. Megakaryocyte colony formation induced with r-HuMGDF is synergistically affected by stem cell factor but not by interleukin 3. Megakaryocytes stimulated with r-HuMGDF demonstrate progressive cytoplasmic and nuclear maturation. Measurable levels of megakaryocyte growth and development factor in serum from patients undergoing myeloablative therapy and transplantation are shown to be elaborated in response to thrombocytopenic stress. These data support the concept that megakaryocyte growth and development factor is a physiologically regulated cytokine that is capable of supporting several aspects of megakaryopoiesis.

Autologous bone marrow transplantation, although successful, is limited in the rate of hematopoietic recovery achieved. Myeloablative chemotherapy results in prolonged pancytopenia with standard autologous bone marrow support. High-dose myelosuppressive chemotherapy results in severe but short-term pancytopenia, and hematopoietic recovery is routine without cellular support. Cellular support becomes necessary when multiple-cycle, severely myelosuppressive regimens are used because of the cumulative stem cell damage and unacceptably long duration of severe pancytopenia. Peripheral blood progenitor cells (PBPCs) may be used as cellular support, and colony-stimulating factors with or without chemotherapy are currently the most potent available PBPC-mobilizing tools. Filgrastim (rmethG-CSF) has been shown to enhance the number of PBPCs for harvest in both cancer patients and normal donors. When Filgrastim is used in conjunction with chemotherapy, there appears to be greater PBPC mobilization, which seems to be dependent on dose and schedule of chemotherapy as well as the type of chemotherapeutic agent used. Platelet recovery has been shown to be more rapid when PBPCs are used compared with historical controls given autologous bone marrow infusions. It may be concluded that PBPC transplantation is useful supportive care following myeloablative chemotherapy.

Objective: To determine if filgrastim (recombinant human methionyl granulocyte colony-stimulating factor) used in addition to standard inpatient antibiotic therapy accelerated recovery from infection associated with chemotherapy-induced neutropenia., Design: Randomized, double-blind, placebo-controlled trial., Setting: Hematology and oncology wards of four teaching hospitals., Patients: 218 patients with cancer who had fever (temperature > 38.2 degrees C) and neutropenia (neutrophil count < 1.0 x 10(9)/L) after chemotherapy., Intervention: Patients were randomly assigned to receive filgrastim (12 micrograms/kg of body weight per day) (n = 109) or placebo (n = 107) beginning within 12 hours of empiric therapy with tobramycin and piperacillin. Patients received treatment and remained in the study until the neutrophil count was greater than 0.5 x 10(9)/L and until 4 days without fever (temperature < 37.5 degrees C) had elapsed., Measurements: Days of neutropenia and fever and days in the study (hospitalization); time to resolution of fever and febrile neutropenia; and frequency of the use of alternative antibiotics., Results: Compared with placebo, filgrastim reduced the median number of days of neutropenia (3.0 compared with 4.0 days of a neutrophil count of < 0.5 x 10(9)/L; P = 0.005) and the time to resolution of febrile neutropenia (5.0 compared with 6.0 days; P = 0.01) but not days of fever (3.0 days for both groups). The frequency of the use of alternative antibiotics was similar in the two groups (46% compared with 41%; P = 0.48). The median number of days patients were hospitalized while on study was the same (8.0 days; P = 0.09); however, filgrastim decreased the risk for prolonged hospitalization (> 11 days, 4th quartile) by half (relative risk, 2.1 [95% CI, 1.1 to 4.1]; P = 0.02). In exploratory subset analyses, filgrastim appeared to provide the greatest benefit in patients with documented infection and in patients presenting with neutrophil counts of less than 0.1 x 10(9)/L., Conclusions: Filgrastim treatment used with antibiotics at the onset of febrile neutropenia in patients with cancer who have received chemotherapy accelerated neutrophil recovery and shortened the duration of febrile neutropenia.

We retrospectively reviewed the regimen-related toxicity associated with busulphan (1 mg/kg orally QID days -7 to -4) and cyclophosphamide (60 mg/kg IV days -3 and -2) (Bu/Cy) chemotherapy in 69 consecutive patients who underwent autologous bone marrow transplantation (ABMT). Twenty-four patients received bone marrow (BM) alone, 22 received BM plus post-transplant granulocyte-colony stimulating factor (G-CSF) and 23 received peripheral blood progenitor cells (PBPC) +/- BM plus post-transplant G-CSF. Toxicity was scored using the criteria of Bearman. Grade II and III toxicities included mucosa (38%), liver (8%), central nervous system (5%), kidney (5%), heart (3%), pericardium (2%), bladder (2%) and lung (2%). There were five treatment related deaths (7%) from pneumonitis (2) and veno-occlusive disease, pulmonary hemorrhage and sepsis (1 each). Post-transplant G-CSF (+/- PBPC) resulted in a trend (p = 0.07) towards a reduction in post-transplant stomatitis, but did not impact on the already low incidence of other organ toxicities. As Bu/Cy for ABMT is associated with minimal non-hemopoietic toxicity, the addition of other cytotoxic agents is justified in an attempt to augment the anti-tumour effect of this conditioning regimen.

The hemopoietic growth factor filgrastim (r-metHu G-CSF) stimulates granulopoiesis after autologous BMT and can also be used as a peripheral blood progenitor cell (PBPC)-mobilizing agent. Rapid platelet recovery follows the addition of filgrastim-mobilized PBPC to autologous BMT. We have now studied 29 adults with malignant lymphoma, Hodgkin's disease or ALL to assess the ability of filgrastim-mobilized PBPC to rapidly and durably restore hemopoiesis without bone marrow (BM) infusion. Patients with a high yield of PBPC from three leukaphereses, defined as > 30 x 10(4)/kg GM-CFC, were eligible for PBPC transplant without BM. Patients with a low yield of GM-CFC received both PBPC and BM infusion. After filgrastim therapy 12 or 24 micrograms/kg/day by continuous sc infusion for 6 or 7 days, a high yield was obtained in 11 of 29 patients. Kinetics of recovery of both the platelet and neutrophil counts were more rapid in the high yield group than in the low yield group. The platelet count recovered to > 20 x 10(9)/l at a median of 9 days, to > 50 x 10(9)/l at 11 days and the neutrophil count to > 0.5 x 10(9)/l at 9 days in the high yield group compared with 12 days, 37 days and 10 days, respectively, in the low yield group (p = 0.028, p < 0.001 and p = 0.027). Fewer platelet transfusions were required in the high yield group (median 11 vs 29.5 units, p = 0.021).(ABSTRACT TRUNCATED AT 250 WORDS)

Nucleoside transporter expression has been linked to proliferation in a variety of haemopoietic cell types. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was given for 72 h before commencing chemotherapy in 15 patients with relapsed or refractory acute myeloid leukaemia (AML) and in 11 patients serial bone marrows were taken for measurement of [3H]thymidine labelling index, Ki-67 positivity and maximal binding of 5-(SAENTA-x8)-fluorescein, a flow cytometry ligand which enumerates nucleoside transporter sites. GM-CSF caused proliferation of marrow myeloblasts in eight of 11 patients, while in three patients there was no change in proliferative indices. The expression of nucleoside transporters increased up to 4-fold in the myeloblasts from the patients showing a proliferative response to GM-CSF but there was no increase in transporters on the myeloblasts from the three non-responding patients. A close correlation was found between the fold increase in nucleoside transporter expression and the fold increase in labelling index of marrow myeloblasts (r = 0.86, n = 9, p < 0.01). In one patient with acute megakaryoblastic leukemia, GM-CSF caused parallel increases in labelling index, Ki-67 positivity and numbers of nucleoside transporters on peripheral blood blast cells. Thus induction of proliferation by cytokine increases the expression of nucleoside transporters on leukaemic myeloblasts studied in serial samples from the same source (bone marrow or blood). The suitability of 5-(SAENTA-x8)-fluorescein for two colour flow cytometric analysis allows the rapid enumeration of nucleoside transporters in the myeloblast compartment of heterogeneous marrow samples.

Four patients with acute myeloid leukaemia relapsed within 6 months of allogeneic BMT. Three patients were treated with cytosine arabinoside and amsacrine while the fourth received no chemotherapy. All patients received infusions of leucocytes obtained by repeated leukapheresis from the original bone marrow donor. Three patients developed GVHD requiring immunosuppressive therapy. One of these achieved a complete remission which has been sustained for more than 1 year with 100% donor haematopoiesis. The other patients died with persistent leukaemia 45-134 days after the infusions of donor cells. We conclude that the addition of marrow donor leucocytes to salvage chemotherapy may produce durable remissions in patients with acute myeloid leukaemia relapsing after BMT and that this may be due to a graft-versus-leukaemia effect.

Eleven patients with primary cerebral lymphoma were treated at a single institution over a 5 year period. Patient characteristics were typical of this rare disease. One patient died prior to receiving treatment and of the remaining 10, all received cranial irradiation and in addition, five received systemic cyclophosphamide, adriamycin, vincristine and prednisolone (CHOP) chemotherapy. Of the six patients who are alive and disease-free, five received the combined modality therapy. The median survival for those patients receiving cranial irradiation alone was 18 months and for the combined modalities was 25+ months. Combination systemic chemotherapy, in addition to cerebral irradiation, may convey a survival benefit in patients with primary cerebral lymphoma but this requires further investigation with multicentre, prospective randomized trials.

The haematopoietic growth factor (HGF), granulocyte colony stimulating factor (G-CSF; filgrastim) substantially shortens the period of severe neutropenia that follows high-dose chemotherapy and autologous bone marrow infusion by stimulating granulopoiesis. Filgrastim also increases numbers of circulating progenitor cells. We have studied the ability of filgrastim to mobilise peripheral blood progenitor cells (PBPC) and assessed their efficacy when infused after chemotherapy on recovery of neutrophil and platelet counts. Seventeen patients with non-myeloid malignant disorders received filgrastim (12 micrograms/kg daily for six days) by continuous subcutaneous infusion. Numbers of granulocyte-macrophage progenitors in peripheral blood increased a median of 58-fold over pretreatment values, and numbers of erythroid progenitors increased a median of 24-fold. Three leukapheresis procedures collected a mean total of 33 (SEM 5.7) x 10(4) granulocyte-macrophage progenitors per kg body weight. After high-dose chemotherapy in 14 of the patients (busulphan and cyclophosphamide), these cells were used to augment autologous bone marrow rescue and post-transplant filgrastim treatment. Platelet recovery was significantly faster in these patients than in controls who received the same treatment apart from the infusion of peripheral blood progenitors; the platelet count reached 50 x 10(9)/L a median of 15 days after infusion of haematopoietic cells in the study patients compared with 39 days in controls (p = 0.0006). The accelerated neutrophil recovery associated with filgrastim treatment after chemotherapy was maintained. Subsequently, 10 patients received filgrastim-mobilised PBPC without marrow after high-dose chemotherapy. The rate of platelet and neutrophil recovery in these patients was at least equal to that observed in the patients receiving PBPC and bone marrow.(ABSTRACT TRUNCATED AT 250 WORDS)