A multinational, phase 2, randomised, adaptive protocol to evaluate immunogenicity and reactogenicity of different COVID-19 vaccines in adults ≥75 already vaccinated against SARS-CoV-2 (EU-COVAT-1-AGED): a trial conducted within the VACCELERATE network

Background

In the ongoing COVID-19 pandemic, advanced age is a risk factor for a severe clinical course of SARS-CoV-2 infection. Thus, older people may benefit in particular from booster doses with potent vaccines and research should focus on optimal vaccination schedules. In addition to each individual’s medical history, immunosenescence warrants further research in this population. This study investigates vaccine-induced immune response over 1 year.

Methods/design

EU-COVAT-1-AGED is a randomised controlled, adaptive, multicentre phase II protocol evaluating different booster strategies in individuals aged ≥75 years (n=600) already vaccinated against SARS-CoV-2. The initial protocol foresaw a 3rd vaccination (1st booster) as study intervention. The present modified Part B of this trial foresees testing of mRNA-1273 (Spikevax®) vs. BNT162b2 (Comirnaty®) as 4th vaccination dose (2nd booster) for comparative assessment of their immunogenicity and safety against SARS-CoV-2 wild-type and variants. The primary endpoint of the trial is to assess the rate of 2-fold antibody titre increase 14 days after vaccination measured by quantitative enzyme-linked immunosorbent assay (Anti-RBD-ELISA) against wild-type virus. Secondary endpoints include the changes in neutralising antibody titres (Virus Neutralisation Assay) against wild-type as well as against Variants of Concern (VOC) at 14 days and up to 12 months. T cell response measured by qPCR will be performed in subgroups at 14 days as exploratory endpoint. Biobanking samples are being collected for neutralising antibody titres against potential future VOC. Furthermore, potential correlates between humoral immune response, T cell response and neutralising capacity will be assessed.

The primary endpoint analysis will be triggered as soon as for all patients the primary endpoint (14 days after the 4th vaccination dose) has been observed.

Discussion

The EU-COVAT-1-AGED trial Part B compares immunogenicity and safety of mRNA-1273 (Spikevax®) and BNT162b2 (Comirnaty®) as 4th SARS-CoV-2 vaccine dose in adults ≥75 years of age. The findings of this trial have the potential to optimise the COVID-19 vaccination strategy for this at-risk population.

Trial registration

ClinicalTrials.govNCT05160766. Registered on 16 December 2021.

Protocol version: V06_0: 27 July 2022

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06791-y.

Anti-cancer drug combinations approved by US FDA from 2011 to 2021: main design features of clinical trials and role of pharmacokinetics

During the last decade, the treatment for many cancer indications has evolved due to intensive clinical research into anti-tumor agents' combination. In most instances, new combination treatments consist of an add-on to the standard of care (SOC), which then demonstrate a substantial gain in efficacy and no detrimental effect in tolerability. In the era of targeted therapies, for which maximum tolerated dose (MTD)-based dosing strategies are no longer applicable, early stage studies exploring new combinations are often conducted in the population of interest, expediting the collection of preliminary safety data, to be promptly expanded to collect preliminary efficacy data. Nevertheless, rule-based dose-finding studies are still a prevailing approach for early stage cancer, especially for chemotherapy (CT)-containing combinations. Pharmacokinetic (PK) assessments play a key role throughout the clinical development of drug combinations, informing potential PK interactions. But most importantly, they allow the development of innovative exposure-response (E-R) models aimed at exploring the contribution of each agent to the overall effect of the combination therapy. This review identifies 81 new drug combinations approved by the United States Food and Drug Administration (FDA) for hemato-oncology during the 2011-2021 period and summarizes the main design features of clinical trials and the role of PK assessments.

Immunogenic dynamics and SARS-CoV-2 variant neutralisation of the heterologous ChAdOx1-S/BNT162b2 vaccination: Secondary analysis of the randomised CombiVacS study

BACKGROUND

The CombiVacS study was designed to assess immunogenicity and reactogenicity of the heterologous ChAdOx1-S/BNT162b2 combination, and 14-day results showed a strong immune response. The present secondary analysis addresses the evolution of humoral and cellular response up to day 180.

METHODS

Between April 24 and 30, 2021, 676 adults primed with ChAdOx1-S were enrolled in five hospitals in Spain, and randomised to receive BNT162b2 as second dose (interventional group [IG]) or no vaccine (control group [CG]). Individuals from CG received BNT162b2 as second dose and also on day 28, as planned based on favourable results on day 14. Humoral immunogenicity, measured by immunoassay for SARS-CoV-2 receptor binding domain (RBD), antibody functionality using pseudovirus neutralisation assays for the reference (G614), Alpha, Beta, Delta, and Omicron variants, as well as cellular immune response using interferon-γ and IL-2 immunoassays were assessed at day 28 after BNT162b2 in both groups, at day 90 (planned only in the interventional group) and at day 180 (laboratory data cut-off on Nov 19, 2021). This study was registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739).

FINDINGS

In this secondary analysis, 664 individuals (441 from IG and 223 from CG) were included. At day 28 post vaccine, geometric mean titres (GMT) of RBD antibodies were 5616·91 BAU/mL (95% CI 5296·49-5956·71) in the IG and 7298·22 BAU/mL (6739·41-7903·37) in the CG (p < 0·0001). RBD antibodies titres decreased at day 180 (1142·0 BAU/mL [1048·69-1243·62] and 1836·4 BAU/mL [1621·62-2079·62] in the IG and CG, respectively; p < 0·0001). Neutralising antibodies also waned from day 28 to day 180 in both the IG (1429·01 [1220·37-1673·33] and 198·72 [161·54-244·47], respectively) and the CG (1503·28 [1210·71-1866·54] and 295·57 [209·84-416·33], respectively). The lowest variant-specific response was observed against Omicron-and Beta variants, with low proportion of individuals exhibiting specific neutralising antibody titres (NT50) >1:100 at day 180 (19% and 22%, respectively).

INTERPRETATION

Titres of RBD antibodies decay over time, similar to homologous regimes. Our findings suggested that delaying administration of the second dose did not have a detrimental effect after vaccination and may have improved the response obtained. Lower neutralisation was observed against Omicron and Beta variants at day 180.

FUNDING

Funded by Instituto de Salud Carlos III (ISCIII).

Identification and validation of clinical phenotypes with prognostic implications in patients admitted to hospital with COVID-19: a multicentre cohort study

BACKGROUND

The clinical presentation of COVID-19 in patients admitted to hospital is heterogeneous. We aimed to determine whether clinical phenotypes of patients with COVID-19 can be derived from clinical data, to assess the reproducibility of these phenotypes and correlation with prognosis, and to derive and validate a simplified probabilistic model for phenotype assignment. Phenotype identification was not primarily intended as a predictive tool for mortality.

METHODS

In this study, we used data from two cohorts: the COVID-19@Spain cohort, a retrospective cohort including 4035 consecutive adult patients admitted to 127 hospitals in Spain with COVID-19 between Feb 2 and March 17, 2020, and the COVID-19@HULP cohort, including 2226 consecutive adult patients admitted to a teaching hospital in Madrid between Feb 25 and April 19, 2020. The COVID-19@Spain cohort was divided into a derivation cohort, comprising 2667 randomly selected patients, and an internal validation cohort, comprising the remaining 1368 patients. The COVID-19@HULP cohort was used as an external validation cohort. A probabilistic model for phenotype assignment was derived in the derivation cohort using multinomial logistic regression and validated in the internal validation cohort. The model was also applied to the external validation cohort. 30-day mortality and other prognostic variables were assessed in the derived phenotypes and in the phenotypes assigned by the probabilistic model.

FINDINGS

Three distinct phenotypes were derived in the derivation cohort (n=2667)-phenotype A (516 [19%] patients), phenotype B (1955 [73%]) and phenotype C (196 [7%])-and reproduced in the internal validation cohort (n=1368)-phenotype A (233 [17%] patients), phenotype B (1019 [74%]), and phenotype C (116 [8%]). Patients with phenotype A were younger, were less frequently male, had mild viral symptoms, and had normal inflammatory parameters. Patients with phenotype B included more patients with obesity, lymphocytopenia, and moderately elevated inflammatory parameters. Patients with phenotype C included older patients with more comorbidities and even higher inflammatory parameters than phenotype B. We developed a simplified probabilistic model (validated in the internal validation cohort) for phenotype assignment, including 16 variables. In the derivation cohort, 30-day mortality rates were 2·5% (95% CI 1·4-4·3) for patients with phenotype A, 30·5% (28·5-32·6) for patients with phenotype B, and 60·7% (53·7-67·2) for patients with phenotype C (log-rank test p<0·0001). The predicted phenotypes in the internal validation cohort and external validation cohort showed similar mortality rates to the assigned phenotypes (internal validation cohort: 5·3% [95% CI 3·4-8·1] for phenotype A, 31·3% [28·5-34·2] for phenotype B, and 59·5% [48·8-69·3] for phenotype C; external validation cohort: 3·7% [2·0-6·4] for phenotype A, 23·7% [21·8-25·7] for phenotype B, and 51·4% [41·9-60·7] for phenotype C).

INTERPRETATION

Patients admitted to hospital with COVID-19 can be classified into three phenotypes that correlate with mortality. We developed and validated a simplified tool for the probabilistic assignment of patients into phenotypes. These results might help to better classify patients for clinical management, but the pathophysiological mechanisms of the phenotypes must be investigated.

FUNDING

Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation, and Fundación SEIMC/GeSIDA.

Effectiveness of immunosuppression minimisation, conversion or withdrawal strategies in paediatric solid organ and haematopoietic stem cell transplantation: a protocol of a systematic review and meta-analysis

INTRODUCTION

Paediatric transplantation is the only curative therapeutic procedure for several end-stage rare diseases affecting different organs and body systems, causing altogether great impact in European children's health and quality of life. Transplanted children shift their primary disease to a chronic condition of immunosuppression to avoid rejection. Longer life expectancy in children poses a greater risk of prolonged and severe side effects related to long-term immunosuppressive (IS) disabilities and secondary cancer susceptibility. The goal remains to find the best combination of IS agents that optimises allograft survival by preventing acute rejection while limiting drug toxicities. This systematic review will aim to determine the optimal IS strategy within the so-called minimisation, conversion or withdrawal strategies.

METHODS AND ANALYSIS

We will search the following databases with no language restrictions: Cochrane Central Register of Controlled Trials in the Cochrane Library, OvidSP Medline and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily; OvidSP Embase Classic+Embase; Ebsco CINAHL Plus, complete database; WHO International Clinical Trials Registry Platform search portal. We will include controlled and uncontrolled clinical trials along with any prospective or retrospective study that includes a universal cohort (all participants from a centre/region/city over a certain period). Cases series and cross-sectional studies are excluded. Two review authors will independently assess the trial eligibility, risk of bias and extract appropriate data points. The outcomes included in this review are: patient survival, acute graft rejection, chronic graft rejection, diabetes, graft function, graft loss, chronic graft versus host disease, acute graft versus host disease, surgical complications, infusion complications, post-transplant lymphoproliferative disease, liver function, renal function, cognition, depression, health-related quality of life, hospitalisation, high blood pressure, low blood pressure, cancer-other, cancer-skin, cardiovascular disease, bacterial infection, Epstein-Barr infection, cytomegalovirus infection, other viral infections and growth.

Randomised multicentre clinical trial to evaluate voriconazole pre-emptive genotyping strategy in patients with risk of aspergillosis: vorigenipharm study protocol

INTRODUCTION

Invasive aspergillosis is the most important cause of morbidity and mortality in patients with haematological diseases. At present, voriconazole is the first-line treatment for invasive fungal disease. The pharmacokinetic interindividual variability of voriconazole depends on genetic factors. CYP450 is involved in 70%-75% of total metabolism of voriconazole, mainly CYP3A4 and CYP2C19, with the remaining 25%-30% of metabolism conducted by monooxygenase flavins. CYP2C19 single nucleotide polymorphisms could explain 50%-55% of variability in voriconazole metabolism.

MATERIALS AND METHODS

The main objective is to compare efficiency of pre-emptive voriconazole genotyping with routine practice. The primary outcome is serum voriconazole on the fifth day within the therapeutic range. The secondary outcome is the combined variables of therapeutic failure and adverse events within 90 days of first administration, associated with voriconazole. A total of 146 patients at risk of invasive aspergillosis who will potentially receive voriconazole will be recruited, and CYP2C19 will be genotyped. If the patient ultimately receives voriconazole, they will be randomised (1:1 experimental/control). In the experimental arm, patients will receive a dose according to a pharmacogenetic algorithm, including CYP2C19 genotype and clinical and demographic information. In the control arm, patients will receive a dose according to clinical practice guidelines. In addition, a Spanish National Healthcare System (NHS) point-of-view cost-effectiveness evaluation will be performed. Direct cost calculations for each arm will be performed.

CONCLUSION

This trial will provide information about the viability and cost-effectiveness of the implementation of a pre-emptive voriconazole genotyping strategy in the Spanish NHS.

ETHICS AND DISSEMINATION

A Spanish version of this protocol has been evaluated and approved by the La Paz University Hospital Ethics Committee and the Spanish Agency of Medicines and Medical Devices. Trial results will be submitted for publication in an open peer-reviewed medical speciality-specific publication.

TRIAL REGISTRATION NUMBER

Eudra-CT: 2019-000376-41 and NCT04238884; Pre-results.

Effects of aripiprazole on pupillometric parameters related to pharmacokinetics and pharmacogenetics after single oral administration to healthy subjects

BACKGROUND

Pupillometry is used for the detection of autonomic dysfunction related to numerous diseases and drug administration. Genetic variants in cytochrome P450 ( CYP2D6, CYP3A4), dopamine receptor ( DRD2, DRD3), serotonin receptor ( HTR2A, HTR2C) and ATP-binding cassette subfamily B ( ABCB1) genes were previously associated with aripiprazole response.

AIMS

Our aim was to evaluate if aripiprazole affects pupil contraction and its relationship with pharmacokinetics and pharmacogenetics.

METHODS

Thirty-two healthy volunteers receiving a 10 mg single oral dose of aripiprazole were genotyped for 15 polymorphisms in ABCB1, CYP2D6, DRD2, DRD3, HTR2A and HTR2C genes by reverse transcription polymerase chain reaction. Aripiprazole and dehydro-aripiprazole plasma concentrations were measured by high-performance liquid chromatography tandem mass spectrometry. Pupil examination was performed by automated pupillometry.

RESULTS

Aripiprazole caused pupil constriction and reached the peak value at C_max. HTR2A rs6313 T allele carriers and HTR2C rs3813929 C/T subjects showed higher maximum constriction velocity and maximum pupil diameter. Besides, Gly/Gly homozygotes for DRD3 rs6280 showed significantly lower maximum constriction velocity values. A/G heterozygotes for DRD2 rs6277 showed higher total time taken by the pupil to recover 75% of the initial resting size values. CYP2D6 intermediate metabolisers showed higher area under the curve, C_max and T_1/2 than extensive metabolisers. ABCB1 G2677T/A A/A homozygotes had greater T_1/2 in comparison with C/C homozygotes. ABCB1 C3435T T allele carriers and C1236T C/T subjects showed greater area under the curve than C/C homozygotes.

CONCLUSIONS

Aripiprazole affects pupil contraction, which could be a secondary effect through dopamine and serotonin receptors. Pupillometry could be a useful tool to assess autonomic nervous system activity during antipsychotic treatment.

Phase I trial in advanced refractory solid tumors of the new drug first-in-class PDM08

e13085

Background: PDM08 is a new active compound with antitumor activity in different cancer models. It is a synthetic derivative of the pyroglutamic acid. The lack of direct effect on tumour cells and antitumor activity in immunodeficient models indicates an immune response mediated mechanism. Toxicology and pharmacology preclinical studies showed a favourable safety profile, confirmed by a single-dose placebo controlled healthy volunteer phase I trial. Methods: A single institution open label phase I study was designed (NCT01380249). PDM08 was administered twice a week for four-week cycles. Initially an accelerate escalation phase was chosen with cohorts of 2 patients who after completing the safety period (2 weeks after last dose) had the possibility of escalate to the next dose level if no grade ≥ 2 toxicity and no progressive disease was observed. After 4 cohorts without meaningful toxicity, this design was amended to open new dose levels after a two-week period of treatment completed by the last patient of the cohort if no grade ≥ 2 toxicity was found. The trial was approved by the Ethics Committee and the Spanish Drug Agency. Extensive pharmacokinetic (PK) and pharmacodynamic (PD) data including serum cytokines, lymphoid subpopulations and immunoglobulins are collected. Preliminary efficacy was evaluated by PET-CT. Results: Since July 2011, 10 patients (pts) were recruited into 6 different dose levels (2pts were escalated) ranged from 0.560 mg to 14 mg. Pt characteristics were: female-male ratio 1:1. Median age: 67 (47-76). ECOG 0: 6 pts. 8 pts had colorectal cancer, 1 lung adenocarcinoma and 1 ovarian carcinoma. Median of previous treatments was 3 ranged 2 to 5. 3 pts presented G1 headache. No Dose Limiting Toxicities were found. Preliminary outcome data showed: best response stable disease for 4 patients, 2 of them being stable for 12 weeks. After 40 target lesions evaluated by PET-CT 6 (15%) showed a reduction in the maximum Standard Uptake Value (SUV) of 18-FDG. Conclusions: PDM08 is the first compound of a new class of drugs that can be dose-escalated safely in an accelerated manner and has promising activity. Last patient will be included in March 2012 so final data for toxicity, PK, PD and efficacy will be provided at the meeting.

Genetic polymorphisms of CYP1A2, CYP3A4, CYP3A5, pregnane/steroid X receptor and constitutive androstane receptor in 207 healthy Spanish volunteers

BACKGROUND

Variability of cytochrome P450 (CYP) in humans is largely related to the pharmacological and toxicological effects of drugs and chemicals. Identification of single nucleotide polymorphisms (SNPs) could be important for knowing their involvement in many drugs metabolism. The goal of this study was to analyze the genotype frequency of 10 SNPs related to mirtazapine metabolism [CYP3A4*17, CYP3A4*18, CYP3A5*3A, CYP1A2*1F, pregnane/steroid X receptor (PXR) (rs3814055, rs38114057, rs3814058) and constitutive androstane receptor (CAR) (rs4073054, rs2307424, rs2502815)].

METHODS

The study was carried out in 207 healthy Spanish volunteers that had participated in phase I clinical trials. Other studies were performed: Hardy-Weinberg equilibrium, haplotype estimation and linkage disequilibrium.

RESULTS

No mutation related to CYP3A4*17 and CYP3A4*18 was found. Therefore, we analyzed data for the other eight SNPs. Allele frequencies were in equilibrium with the Hardy-Weinberg equation. Six haplotypes were determined for three PXR SNPs, and four for CAR SNPs. Tests for linkage disequilibrium showed a high association between PXR (rs38114057) and PXR (rs3814058) (p= 0.001), and between the three CAR SNPs (p=0.001), which could be useful for identification of tag SNPs.

CONCLUSIONS

In the present study, the genotype frequencies of some SNPs related to mirtazapine metabolism in Spaniards were analyzed and showed that our study population is representative of HapMap European population. The results obtained could be analyzed with pharmacokinetic parameters of mirtazapine to elucidate the genotype-phenotype relationship, the involvement of these SNPs in metabolic reactions, drug interactions, and prediction of treatment response.

In vitro analysis of synergism and antagonism of different nucleoside/nucleotide analogue combinations on the inhibition of human immunodeficiency virus type 1 replication

In this study we have developed an in vitro system to evaluate the combined effect of two NRTIs on HIV replication and to assess their antagonism or synergy. Synergy or antagonism effect was determined in peripheral blood mononuclear cells (PBMCs) to approach a more physiological model than T-cell lines. PBMCs were infected with a full-length HIV-1 clone carrying the luciferase gene as a reporter. The following combinations were investigated: zidovudine+stavudine (ZDV + d4T), lamivudine + abacavir (3TC + ABC), lamivudine + didanosine (3TC + ddI), lamivudine + stavudine (3TC + d4T), tenofovir + stavudine (TDF + d4T), tenofovir + didanosine (TDF + ddI), tenofovir + abacavir (TDF + ABC), tenofovir + lamivudine (TDF + 3TC), tenofovir + zidovudine (TDF + ZDV), stavudine + didanosine (d4T + ddI), zidovudine + lamivudine (ZDV + 3TC), abacavir + didanosine (ABC + ddI), zidovudine + didanosine (ZDV + ddI), and abacavir + stavudine (ABC + d4T). The effect of combining two drugs was evaluated with a quantitative method based on the median-effect principle of Chou and Talalay. A synergistic effect was observed with combinations containing TDF and ZDV or d4T, d4T and ddI and ZDV plus 3TC. In contrast, combinations including TDF + ddI, 3TC + ddI, ABC + ddI, and ZDV + ddI showed an antagonistic effect on the inhibition of viral replication at all levels of inhibition tested. Lower antagonistic effect was also found in drug combinations that included 3TC + ABC, 3TC + TDF, 3TC + d4T, and TDF + ABC. In conclusion, the method developed allows to measure in vitro the effect of different combinations of two NRTIs on HIV replication. The results suggest that combined therapy including TDF with thymidine analogues may be considered for future therapeutic options in contrast to clearly antagonistic combinations such us TDF plus ddI or 3TC plus ddI, that would explain virological failure in clinical studies when these combinations were used.

Sublingual administration of tacrolimus in a renal transplant patient

Tacrolimus is used in renal and other organ transplantations for immunossupression therapy. Bioavailability of enterally administered tacrolimus is poor, and further reduced by gastrointestinal failure or enteral nutrition. In these situations, intravenous administration is necessary to prevent treatment failure. However, intravenous administration should be done in a continuous manner and it has been implicated in anaphylaxis, torsades de pointes, cardiac arrhythmia and other serious adverse events. Also it is more expensive than other routes of administration. Sublingual administration of tacrolimus has been used in some cases, and literature reports show that it provides therapeutic tacrolimus levels in lung and liver transplant recipients. Here, we report a first case of sublingual administration of tacrolimus in kidney transplantation.

Effect of the hematocrit and its correction on the relationship between blood tacrolimus concentrations obtained using the microparticle enzyme immunoassay (MEIA) and enzyme multiplied immunoassay technique (EMIT)

The Abbott microparticle enzyme immunoassay (MEIA) and the Dade Behring enzyme multiplied immunoassay technique (EMIT) are the most frequently used methods in the therapeutic drug monitoring of tacrolimus; however, a hematocrit-dependent interference for the MEIA has been described. In 244 whole blood samples from patients with liver (n=152) and kidney (n=92) transplants, the MEIA/EMIT ratio presented a highly significant negative correlation with the hematocrit (r = -0.482, p < 0.001). On distributing the samples into three groups with a hematocrit of less than 30%, 30-40%, and higher than 40%, different regression equations were found between the results of MEIA and EMIT and demonstrate the different effect of the hematocrit on both immunoassays. Correcting the MEIA results by calculation for a hematocrit of less than 30% and higher than 40% (Hermida et al. Clin Lab 2005; 51: 43-45) led to a regression with EMIT that was similar to that found between MEIA and EMIT for the group of samples with a hematocrit of 30-40%. Furthermore, the corrected MEIA/EMIT ratio had a poor correlation with the hematocrit (r = 0.149, p < 0.05). In 95 samples with a hematocrit of less than 25% (n=73) and higher than 40% (n=22) we also determined the tacrolimus levels using the modified MEIA method to correct hematocrit interference, as proposed by Tomita et al. (Ther Drug Monit 2005; 27: 94-97). In the samples with a hematocrit of less than 25%, correcting the MEIA results by calculation produced results that were similar and had a high correlation coefficient (r = 0.954, p < 0.001) to those of the modified MEIA method, whose application as a routine practice is more expensive and laborious. Calculation of the corrected MEIA values in anemic patients may be useful for the therapeutic monitoring of tacrolimus.

Epileptic seizures caused by low valproic acid levels from an interaction with meropenem

A 55-year-old woman was diagnosed with pneumonia and was treated with meropenem; 5 days later she developed epileptic seizures. She had been treated with valproic acid for 16 years to control her epileptic seizures. Her serum valproic acid concentration was low during treatment with meropenem than previously recorded despite an increase of valproic dose. As soon as administration of meropenem was withdrawn, valproic acid concentration increased to previous levels and her seizures stopped. Meropenem decreases valproic acid concentration, and may promote the development of epileptic seizures in previously controlled epileptic patients. The acute lowering of serum valproate produced by meropenem probably precludes their concomitant use.

Lopinavir/ritonavir as single-drug therapy for maintenance of HIV-1 viral suppression: 48-week results of a randomized, controlled, open-label, proof-of-concept pilot clinical trial (OK Study)

OBJECTIVE

This study evaluated maintenance with lopinavir/ritonavir monotherapy vs. continuing lopinavir/ritonavir and 2 nucleosides in HIV-infected patients with suppressed HIV replication.

DESIGN

Randomized, controlled, open-label, multicenter, pilot clinical trial.

METHODS

Adult patients were eligible if they had no history of virologic failure while receiving a protease inhibitor, were receiving 2 nucleosides + lopinavir/ritonavir (400/100 mg b.i.d.) for >1 month and had maintained serum HIV RNA <50 copies/mL for >6 months prior to enrollment.

RESULTS

Forty-two patients were randomly assigned 1:1 to continue or stop the nucleosides. At baseline there were no significant differences between groups in median CD4 cells/muL (baseline or nadir), pre-HAART (highly active antiretroviral therapy) HIV log10 viremia, or time with HIV RNA <50 copies/mL prior to enrollment. After 48 weeks of follow-up, percentage of patients remaining at <50 HIV RNA copies/mL (intention to treat, M = F) was 81% for the monotherapy group (95% CI: 64% to 98%) vs. 95% for the triple-therapy group (95% CI: 86% to 100%); P = 0.34. Patients in whom monotherapy failed had significantly worse adherence than patients who remained virally suppressed on monotherapy. Monotherapy failures did not show primary resistance mutations in the protease gene and were successfully reinduced with prerandomization nucleosides. Mean change in CD4 cells/microL: +70 (monotherapy) and +8 (triple) (P = 0.27). Mean serum fasting lipids remained stable in both groups. No serious adverse events were observed.

CONCLUSION

Most of the patients maintained with lopinavir/ritonavir monotherapy remain with undetectable viral load after 48 weeks. Failures of lopinavir/ritonavir monotherapy were not associated with the development of primary resistance mutations in the protease gene and could be successfully reinduced adding back prior nucleosides.

Urinary Concentrations and Bactericidal Activity Against Amoxicillin-Nonsusceptible Strains of Escherichia coli with Single-Dose, Oral, Sustained-Release Amoxicillin/Clavulanic Acid: A PhaseI, Open-Label, Noncomparative Clinical Trial in Healthy Volunteers

BACKGROUND

Urinary tract infections (UTIs) account for 5 to 6 million medical consultations in the United States each year. Worldwide, an estimated 20% to 30% of women aged 20 to 40 years have at least 1 episode of the most common type of UTI (uncomplicated cystitis) in their lifetime, with Escherichia coli being the causative pathogen in 80% of cases. Antibacterial activity in urine has been shown to be correlated with outcomes of uncomplicated cystitis.

OBJECTIVE

The objectives of this study were to determine urinary concentrations and ex vivo bactericidal activity of sustained-release (SR) amoxicillin/clavulanic acid 2000/125 mg against intermediately resistant and resistant strains of E coli over 72 hours and compare them with those of a susceptible strain. This study also investigated whether urinary concentrations obtained after dosing cover E coli strains categorized as intermediately resistant and resistant based on current Clinical and Laboratory Standards Institute (formerly NCCLS) breakpoints in uncomplicated cystitis.

METHODS

This Phase I, open-label, noncomparative study in healthy male volunteers was conducted at the Pharmacology Unit, Autónoma University, Madrid, Spain. Subjects received a single oral dose of amoxicillin/clavulanic acid 2000/125 mg SR. The amoxicillin/clavulanic acid MICs were 8/4 microg/mL (susceptible), 16/8 microg/mL (intermediately resistant), and 32/16 and 64/32 microg/mL (resistant). Urine samples were collected before (baseline; time 0) and at the following intervals: 0-2, 2-4, 4-8, 8-12, 12-16, 16-24, 24-36, 36-48, 48-60, and 60-72 hours after dosing. Killing curves with urine samples were performed with initial inocula of approximately 10(7) colony-forming units (CFU)/mL, and bactericidal activity (defined as >3 log(10) CFU/mL and >99.9% reduction in bacterial counts) was calculated as the difference between log(10) initial inoculum and log(10) CFU/mL after 4 hours of incubation of each sample.

RESULTS

Twelve volunteers were included (mean [SD] age, 24.83 [5.64] years; mean [SD] height, 175.75 [7.56] cm; and mean [SD] weight, 73.55 [9.19] kg). No statistically significant differences between the activities in the 12-16-hour interval compared with baseline were found in any of the strains tested. Bactericidal activity against the susceptible and intermediately resistant strains (MICs 8/4 and 16/8 g/mL, respectively) was obtained up to 8 hours after dosing. Bactericidal activity against the resistant strains (MICs 32/16 and 64/32 microg/mL) was obtained in the 2-4-hour interval.

CONCLUSIONS

In this Phase I study in healthy volunteers, urinary concentrations after dosing with amoxicillin/clavulanic acid 2000/125 mg SR showed bactericidal activity against the amoxicillin-susceptible and intermediately resistant strains of E coli.

Pulmonary damage and bacterial load in assessment of the efficacy of simulated human treatment-like amoxicillin (2,000 milligrams) therapy of experimental pneumococcal pneumonia caused by strains for which amoxicillin MICs differ

An experimental rat pneumonia model using two amoxicillin-susceptible (MICs, < or =0.015 and 2 microg/ml) and two non-amoxicillin-susceptible (MIC, 4 microg/ml) Streptococcus pneumoniae strains was developed for testing the efficacy of amoxicillin administered to simulate human serum kinetics after treatment with amoxicillin-clavulanate (2,000 and 125 mg, respectively, twice a day, for 2.5 days). The end points for efficacy were reductions in bacterial loads in the lungs and reductions in levels of pulmonary damage. For the amoxicillin-susceptible strains (serotypes 23F and 14), a decrease greater than 4.5 log(10) CFU/pair of lungs was obtained, and the time for which the serum antibiotic concentration (SAC) was higher than the MIC (T(S)(A)(C)(>)(MIC)) was greater than 60% of the dosing interval. For non-amoxicillin-susceptible strains, the decrease in bacterial load was 1.34 to 1.75 log(10) CFU/pair of lungs, with a T(S)(A)(C)(>)(MIC) of 46.7% of the dosing interval. An in vitro study showed that serotype 9V non-amoxicillin-susceptible strains behaved as tolerant-like to concentrations similar to those in the in vivo model. The high and maintained SACs (T(S)(A)(C)(>)(MIC), >46% for all strains) significantly diminished lung injury (affected area of the lung and lung weight), compared to that in controls, by all strains, regardless of the MIC, bactericidal behavior in in vitro killing curves, or the serotype of the infecting strain. These results show the importance of host therapeutic end points in the evaluation of antibiotic efficacy. The antibiotic was more efficacious, for one nonsusceptible strain tested, when the treatment was started early (1 h postinoculation [p.i.]) than when treatment was delayed (24 h p.i.).

Effect of opsonophagocytosis mediated by specific antibodies on the co-amoxiclav serum bactericidal activity against Streptococcus pneumoniae after administration of a single oral dose of pharmacokinetically enhanced 2000/125 mg co-amoxiclav to healthy volunteers

OBJECTIVES

To measure the effect of opsonophagocytosis mediated by complement activated by specific antibodies on the co-amoxiclav serum bactericidal activity against Streptococcus pneumoniae strains with reduced susceptibility to beta-lactams (amoxicillin MICs of 2, 4, 8 and 16 mg/L).

METHODS

An open Phase I study measuring ex vivo bactericidal activity after anti-pneumococcal vaccination and an oral dose of 2000/125 mg sustained-release co-amoxiclav was carried out. The ex vivo bactericidal activity was investigated through killing curves over 3 h [assuring polymorphonuclear neutrophil (PMN) viability] with serum samples collected 1.5 h and 5 h after dosing. Global killing was measured as the area under the killing curve (AUKC; log cfu x h/mL). The AUKC of the control growth curve of S. pneumoniae in Hanks' balanced salt solution (AUKC(K)) was used as control. The effect of the presence of complement and/or PMN was evaluated by the difference in the AUKC(K) and the different AUKCs obtained in the presence of inactivated serum (AUKC(IS)), active serum (AUKC(S)), inactivated serum plus PMN (AUKC(IS+PMN)) and active serum plus PMN (AUKC(S+PMN)).

RESULTS

Significant differences were found in all cases between the bactericidal activity of active serum+PMN (AUKC(K) - AUKC(S+PMN)) and that of inactivated serum (AUKC(K) - AUKC(IS)) with therapeutic indexes ranging from 0.56 to 3.04. At 1.5 h after dosing, a significantly higher bactericidal activity of co-amoxiclav was obtained when opsonophagocytosis occurred (samples with active serum and PMN) than when not occurring (killing curves with inactivated serum and without PMN), for all amoxicillin non-susceptible strains.

CONCLUSIONS

The results of this ex vivo study suggest that the collaboration of co-amoxiclav and complement-mediated opsonophagocytosis activated by specific antibodies may lay new approaches to overcome in vivo amoxicillin non-susceptibility.

A phase I, dose-finding study of irinotecan (CPT-11) short i.v. infusion combined with fixed dose of 5-fluorouracil (5-FU) protracted i.v. infusion in adult patients with advanced solid tumours

PURPOSE

Irinotecan (CPT-11) and 5-fluorouracil (5-FU) are effective cytotoxic agents in the treatment of solid tumours. Continuous i.v. infusion (CI) of 5-FU is significantly more active and better tolerated than bolus i.v. 5-FU. This phase I pharmacokinetic and clinical study evaluated escalating CPT-11 doses administered every 3 weeks combined with a fixed dose of 5-FU CI over 14 days to find the maximum tolerated dose (MTD) of this combined chemotherapy.

PATIENTS AND METHODS

Patients with solid tumours showing failure with previous standard treatment or for whom no established curative therapy existed received CPT-11 i.v. over 90 min (six dose levels were evaluated: 150, 175, 200, 250, 300 and 350 mg/m(2)) plus a fixed dose of 5-FU CI 250 mg/m(2) per day over 14 days. If the MTD was not reached at CPT-11 level 6, then 5-FU was increased to 300 mg/m(2). In step 2, 5-FU was administered as a true protracted infusion at the recommended dose found during step 1. In step 3, the recommended dose of CPT-11 was divided and administered in a weekly schedule for 4 weeks combined with a fixed dose of 5-FU CI 250 mg/m(2), and then followed by 2-5 weeks rest.

RESULTS

Neutropenia and diarrhoea were the main toxicities, leading to early termination of infusion in three of six patients in level 7. Therefore, CPT-11 350 mg/m(2) + 5-FU 250 mg/m(2) CI over 14 days was identified as the recommended dose. In step 2, CPT-11 dose had to be reduced to 300 mg/m(2) due to toxicity. The weekly schedule of CPT-11 75 mg/m(2) + 5-FU 250 mg/m(2) CI was feasible with only one patient experiencing severe diarrhoea. No interactions were found in the kinetics parameters of CPT-11 or 5-FU for the different dose levels studied.

CONCLUSION

CPT-11 300 mg/m(2) + 5-FU 250 mg/m(2) protracted infusion is the recommended dose for phase II trials, neutropenia and diarrhoea being the dose-limiting toxicities.

Bactericidal activity of amoxicillin against non-susceptible Streptococcus pneumoniae in an in vitro pharmacodynamic model simulating the concentrations obtained with the 2000/125 mg sustained-release co-amoxiclav formulation

OBJECTIVES

To investigate the bactericidal activity against Streptococcus pneumoniae of simulated amoxicillin serum concentrations obtained in humans after 2000/125 mg sustained-release (SR) and 875/125 mg co-amoxiclav administered twice and three times a day, respectively.

METHODS

An in vitro computerized pharmacodynamic simulation was carried out and colony counts were determined over 24 h. Ten strains non-susceptible to amoxicillin (four of them exhibiting an MIC of 4 mg/L, five strains with an MIC of 8 mg/L and one strain with an MIC of 16 mg/L) were used.

RESULTS

With amoxicillin 2000 mg, an initial inoculum reduction >99.99% was obtained for strains with an MIC of 4 mg/L, > or =99% for strains with an MIC of 8 mg/L and 70.6% for the strain with an MIC of 16 mg/L at 24 h sampling time. At this sampling time, no reduction of initial inocula was obtained with amoxicillin 875 mg/8 h for two of the four strains with an MIC of 4 mg/L, three of the five strains with an MIC of 8 mg/L or for the strain with an MIC of 16 mg/L.

CONCLUSIONS

The new co-amoxiclav 2000/125 mg SR formulation appears to offer advantages versus previous formulations with respect to bactericidal activity against current amoxicillin non-susceptible strains.

PHASE I PHARMACOKINETIC STUDY OF A SINGLE INTRAVESICAL INSTILLATION OF GEMCITABINE ADMINISTERED IMMEDIATELY AFTER TRANSURETHRAL RESECTION PLUS MULTIPLE RANDOM BIOPSIES IN PATIENTS WITH SUPERFICIAL BLADDER CANCER

PURPOSE

In this phase I study we determined the pharmacokinetic and toxicity profiles of a single intravesical instillation of gemcitabine administered immediately after complete transurethral resection (TUR) plus multiple random biopsies.

MATERIALS AND METHODS

Ten patients with superficial bladder cancer clinically staged as Ta/T1 with no carcinoma in situ were included. A single dose of gemcitabine was administered intra-vesically immediately after TUR plus 6 random biopsies. Five patients received 1,500 mg and 5 received 2,000 mg diluted in 100 ml saline. Retention time in the bladder was 60 minutes. Concentrations of gemcitabine and dFdU (2',2'-difluoro-2'-deoxyuridine) were determined by high pressure liquid chromatography assay.

RESULTS

Treatment was clinically well tolerated in all patients. Two patients in the 1,500 mg group had minimal hipogastric discomfort and 1 in the 2,000 mg group had grade 1 bladder spasms. There was no remarkable systemic toxicity on hematology or biochemistry at any dose level on day 12 or 30. One patient per dose level showed tumor recurrence on 3-month repeat cystourethroscopy. Mean maximum gemcitabine concentration was 1.8 microg/ml and the mean last AUC was 158 microg/ml*minute. There was large interpatient variability but no significant differences between the 2 dose levels.

CONCLUSIONS

Single intravesical instillation of gemcitabine immediately after TUR and multiple random biopsies for superficial bladder cancer are a safe and well tolerated treatment. The favorable toxicity and pharmacokinetic profiles of intravesical gemcitabine support future phase II studies with this agent.

Does acetaminophen interfere in the antibiotic treatment of acute otitis media caused by a penicillin-resistant pneumococcus strain? A gerbil model

The possible interference of acetaminophen, combined with antibiotics, in the treatment of acute otitis media (AOM) caused by a penicillin-resistant (minimal inhibitory concentration [MIC], 2 microg/mL), amoxicillin/clavulanic acid- and erythromycin-sensitive pneumococcus was evaluated in a gerbil model. Animals were challenged with approximately 5 x 106 bacteria in each ear through transbullar instillation. Acetaminophen was administered s.c. at 50 mg/kg 30 min before each antibiotic dose. Amoxicillin/clavulanic acid and erythromycin (2.5 and 10 mg/kg) were administered s.c. at 2, 10, and 18 h after inoculation. Samples were obtained from the middle ear (ME) on day 2 after inoculation for bacterial count. The overall results showed no difference between animals that received acetaminophen, with or without antibiotics, and those that did not receive acetaminophen. The antibiotic concentrations in the ME were practically identical in both groups of animals, so acetaminophen did not interfere with the pharmacokinetics of antibiotics in the ME. However, both antibiotics significantly reduced the number of culture-positive and the bacterial concentration in ME samples when compared with antibiotic-untreated animals. Both antibiotics, whether combined with acetaminophen or not, lowered the number of AOM to <25%, but >75% of animals presented otitis media with effusion, and no differences were shown between groups. A high rate of bacterial eradication from the ME correlated with antibiotic serum concentrations being over the MIC of the infecting organism for only >15% of the dose interval and with an ME concentration exceeding the MIC by a factor of 1.7. In this experimental model, acetaminophen had neither a synergistic nor an antagonistic effect on the antibiotics tested.

Antibacterial properties of gemifloxacin and trovafloxacin in urine ex vivo: phase I study

Urine bactericidal titers (UBTs) against Escherichia coli ATCC 25922 and Staphylococcus saprophyticus ATCC 1970 were determined after the administration of single oral doses of gemifloxacin at 320 mg and trovafloxacin at 200 mg to healthy volunteers. Gemifloxacin presented significantly lower experimental versus mathematically predicted UBTs over 72 h, due to the effect of urine on the susceptibility of the E. coli strain. Experimental UBTs were significantly higher for gemifloxacin than trovafloxacin against both strains over 72 h.

Bioequivalence of allopurinol and its metabolite oxipurinol in two tablet formulations

OBJECTIVE

To test for the bioequivalence of two allopurinol 300 mg tablet formulations (generic allopurinol (Normon) and Zyloric tablets).

METHOD

A single dose study was carried out in 24 healthy volunteers with a two-sequence, crossover block-randomized design. Blood samples were taken prior to each administration and at 19 points within 72 h after the dose. Plasma concentrations of allopurinol and oxypurinol were determined by HPLC. The pharmacokinetic parameters Cmax and Tmax were obtained directly from plasma allopurinol and oxypurinol concentrations. ke was estimated by log-linear regression and AUC was calculated by the linear trapezoidal rule for both allopurinol and oxypurinol. The pharmacokinetic parameters AUC and Cmax were tested for equivalence after log-transformation of data. Differences of Tmax were evaluated by a non-parametric test. The 90% standard confidence intervals of the mean values for the test/reference ratios were for AUC and for Cmax, within the acceptable bioequivalence limits of 0.80-1.25 for both allopurinol and oxypurinol.

CONCLUSION

The two formulations are bioequivalent and therefore interchangeable.

Absence of an interaction between ibuprofen and zaleplon

The potential interaction between zaleplon and ibuprofen was studied. Healthy adult volunteers were given a dose of zaleplon 10 mg alone, a dose of ibuprofen 600 mg alone, or a dose of zaleplon 10 mg and a dose of ibuprofen 600 mg concomitantly in an open-label, randomized, three-period crossover study. There was a seven-day washout period between treatments. Venous blood samples were collected for pharmacokinetic analysis at various intervals up to 14 hours after drug administration. A total of 17 subjects (11 men and 6 women) completed the study. There were no significant differences between zaleplon monotherapy and combination therapy in mean +/- SD, of zaleplon clearance (CL) (2.80 +/- 0.72 versus 2.72 +/- 0.89 L/hr/kg, respectively), maximum plasma concentration (Cmax) (37.1 +/- 17.9 versus 39.8 +/- 20.0 ng/mL), or area under the concentration-versus-time curve (AUC) (56.7 +/- 22.8 versus 59.2 +/- 22.0 ng.hr/mL). There were no significant differences between ibuprofen monotherapy and combination therapy in ibuprofen CL (71.6 +/- 17.0 versus 71.7 +/- 14.9 L/hr/kg), Cmax (40.8 +/- 10.2 versus 40.4 +/- 10.0 micrograms/mL), or AUC (127.6 +/- 29.6 versus 126.4 +/- 29.7 micrograms.hr/mL). Three subjects had one or more adverse effects with zaleplon alone, one subject had one or more with ibuprofen alone, and one subject had one or more with combination therapy. The adverse effects were mild and resolved without intervention. There was no evidence of a significant interaction between zaleplon and ibuprofen.

[Hospitalizations because of drugs: a prospective study]

A study was carried out during five months in La Paz Hospital with the objective to know the proportion of admissions due to an adverse reaction to pharmaceutical drugs (RAM) or due to an acute drug intoxication. For this purpose the reports of all patients seen at the Medical Emergency Room were analyzed on a daily basis. Out of 1,847 patients who needed hospital admission during this time period, 88 (4.8%) were considered to need so due to RAM or an acute intoxication. Out of 145 acute intoxications treated, 16 patients (0.9% of total admissions) had to be hospitalized. RAM constituted 3.9% of admissions, with upper GI tract hemorrhages the most frequent cause (62.5%; 72 cases). The groups of drugs responsible in most RAM were the analgesics and NSAIDs, in particular acetylsalicylic acid, followed by hypoglycemic drugs and digoxin.

[Adverse reactions to drugs as a reason for consulting the emergency service of a general hospital]

The reports from the emergency service of La Paz General Hospital were daily reviewed for 4 months to investigate the number of consultations which, on the judgement of the physician on care, were due to adverse reactions to drugs. An overall number of 11,326 patients consulted. In 438 (3.9%) it was considered that the consultation was due to one or more definite, likely or possible adverse drug reactions. In 69 patients (15.8%), the reactions were considered to be severe, and 54 (12.3%) required admission; 59 reactions (13.4%) were moderate, and 310 (70.8%) were mild. The most common localizations were the skin and its appendages (37.7%) and gastrointestinal tract (25.3%). The most commonly implicated pharmacologic groups were analgesic and non-steroidal anti-inflammatory drugs (33.6%) and antimicrobials (22.1%). The incidence of adverse reactions was significantly higher in women (4.4% vs 3.3% in males, p less than 0.01). Depending on the age groups (14-29, 30-59, greater than or equal to 60 years) the incidence of nonallergic adverse reactions was significantly higher in patients aged 60 years or more (1.5%, 2%, 2.9%; chi 2 = 15.2, gl = 2, p less than 0.001). In presumably allergic adverse reactions, the incidence was significantly higher among those under 30 years (2.9%, 2.2%, 0.5%; chi 2 = 50.2; gl = 2, p less than 0.0001). The incidence of severe adverse reactions was significantly higher in patients over age 60 years (0.2%, 0.6%, 1.2%, chi 2 = 29.2, gl = 2, p less than 0.001). In 32% of cases the adverse reactions might have been prevented.