Nivolumab Plus Ipilimumab Versus EXTREME Regimen as First-Line Treatment for Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck: The Final Results of CheckMate 651

PURPOSE

CheckMate 651 (ClinicalTrials.gov identifier: NCT02741570) evaluated first-line nivolumab plus ipilimumab versus EXTREME (cetuximab plus cisplatin/carboplatin plus fluorouracil ≤ six cycles, then cetuximab maintenance) in recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN).

METHODS

Patients without prior systemic therapy for R/M SCCHN were randomly assigned 1:1 to nivolumab plus ipilimumab or EXTREME. Primary end points were overall survival (OS) in the all randomly assigned and programmed death-ligand 1 combined positive score (CPS) ≥ 20 populations. Secondary end points included OS in the programmed death-ligand 1 CPS ≥ 1 population, and progression-free survival, objective response rate, and duration of response in the all randomly assigned and CPS ≥ 20 populations.

RESULTS

Among 947 patients randomly assigned, 38.3% had CPS ≥ 20. There were no statistically significant differences in OS with nivolumab plus ipilimumab versus EXTREME in the all randomly assigned (median: 13.9 v 13.5 months; hazard ratio [HR], 0.95; 97.9% CI, 0.80 to 1.13; P = .4951) and CPS ≥ 20 (median: 17.6 v 14.6 months; HR, 0.78; 97.51% CI, 0.59 to 1.03; P = .0469) populations. In patients with CPS ≥ 1, the median OS was 15.7 versus 13.2 months (HR, 0.82; 95% CI, 0.69 to 0.97). Among patients with CPS ≥ 20, the median progression-free survival was 5.4 months (nivolumab plus ipilimumab) versus 7.0 months (EXTREME), objective response rate was 34.1% versus 36.0%, and median duration of response was 32.6 versus 7.0 months. Grade 3/4 treatment-related adverse events occurred in 28.2% of patients treated with nivolumab plus ipilimumab versus 70.7% treated with EXTREME.

CONCLUSION

CheckMate 651 did not meet its primary end points of OS in the all randomly assigned or CPS ≥ 20 populations. Nivolumab plus ipilimumab showed a favorable safety profile compared with EXTREME. There continues to be a need for new therapies in patients with R/M SCCHN.

The relationship between white matter integrity of superior longitudinal fascicle and cognitive functions in chronic schizophrenia

Introduction

Some evidence suggests that disruption of integrity in the superior longitudinal fascicle (SLF) may influence cognitive functions in chronic schizophrenia (CS) but the results are inconclusive.

Objectives

Using diffusion tensor imaging tractography, we investigated the differences in fiber integrity between patients with CS and healthy controls (HC) together with the relationship between fiber integrity and cognitive functions.

Methods

Forty-two patients with CS and 32 HC took part in the study. Assessment of cognitive functions was performed using Measurement and Treatment Research to Improve Cognition in Schizophrenia.

Results

showed group differences, left and right in fractional anisotropy (FA) and mean diffusivity (MD) of the SLF, where patients showed less integrity than controls. Patients performed worse attention/vigilance, working memory, verbal learning, visual learning, reasoning and problem solving, and social cognition tasks than HC. However, when premorbid IQ and level of education were controlled for, the differences were no longer statistically significant in verbal learning and social cognition. In patients with CS, a positive correlation was found between FA of the left SLF and attention/vigilance and working memory. Moreover, in this group there was a negative correlation between MD of the left and right SLF and working memory and social cognition.

Conclusions

These findings provide evidence that SLF disruption appears in patients with CS and might account for impairment of cognitive functioning. This research was funded by the Polish Minister of Science and Higher Education’s program named “Regional Initiative of Excellence” number 002/RID/2018/2019 to the amount of 12 million PLN.

Disclosure

No significant relationships.

A review of the Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe (TOPHAT) flap for wound coverage during ray amputations of the toes

INTRODUCTION

Exposure of the adjacent Metatarsal-Phalangeal Joint (MTPJ) commonly occurs after application of Topical Negative Pressure Wound Therapy (TNPWT) for a ray amputation wound. This is due to mechanical soft tissue erosion or trauma to the adjacent digital artery from direct pressure effect. This results in toe gangrene requiring a ray amputation and ultimately a larger wound bed. We describe the use of the Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe (TOPHAT) flap - a filleted toe flap to protect the adjacent MTPJ capsule combined with a novel Negative Pressure Wound Therapy with instillation and dwell-time (NPWTi-d) dressing technique. The flap protects the adjacent joint capsule and reduces the wound burden whilst allowing the wound to benefit from TNPWT, thereby accelerating wound healing.

MATERIAL AND METHODS

A retrospective review was conducted of patients with toe gangrene requiring ray amputation that underwent the TOPHAT flap on in our institution from 2019 and 2020. Complications such as wound dehiscence, hematoma, flap necrosis and secondary infection were recorded. Other outcomes recorded were time taken to final skin grafting and time taken for complete wound epithelialization.

RESULTS

9 patients underwent treatment with the TOPHAT flap. 2 patients had flap necrosis. 7 patients progressed to definitive skin coverage with skin grafting. One patient subsequently had progressive arterial disease despite successful skin grafting and required above knee amputation. The mean time to final skin grafting and complete wound epithelialization was 49.5 days and 107.5 days respectively. All patients were satisfied with the outcomes and were able to return to their pre-morbid function.

CONCLUSIONS

The TOPHAT flap has a consistent vascular supply that provides durable soft tissue coverage. It is a robust and easily reproducible technique to accelerate wound healing after ray amputations even in patients with peripheral vascular disease.

Malignant bowel obstruction: effectiveness and safety of systemic chemotherapy

OBJECTIVES

Although systemic chemotherapy is often administered to patients with malignant bowel obstruction (MBO), its benefit remains unknown. This study assessed the outcomes of patients who received systemic chemotherapy as part of MBO treatment.

METHODS

For this retrospective cohort study, data were extracted from records of patients hospitalised due to MBO in a tertiary cancer centre from 2008 to 2020. Eligible patients were not candidates for surgery and received systemic chemotherapy targeting the underlying malignancy causing MBO. Primary objective was to assess patient outcomes after chemotherapy; secondary objectives were rates of intestinal function recovery, hospital discharge and grade ≥3 toxicities. The primary endpoint was overall survival (OS).

RESULTS

A total of 167 patients were included: median age was 55 (18-81) years, 91% had an Eastern Cooperative Oncology Group (ECOG) performance status ≥2, 75.5% had gastrointestinal tumours and 70% were treatment-naive. The median OS after chemotherapy was 4.4 weeks (95% CI 3.4 to 5.5) in the overall population. No OS difference was observed according to treatment line (p=0.24) or primary tumour (p=0.13). Intestinal function recovery occurred in 87 patients (52%), out of whom 21 (24.1%) had a reobstruction. Hospital discharge was possible in 74 patients (44.3%). Grade≥3 adverse events occurred in 26.9% of the patients, and a total of 12 deaths (7%) attributed to toxicities were observed after chemotherapy.

CONCLUSIONS

MBO was associated with a dismal prognosis in this mostly treatment-naive population. The administration of chemotherapy yielded a significant risk of toxicities, whereas it did not appear to provide any relevant survival benefit in this scenario.

Pre-NELA vs NELA - has anything changed, or is it just an audit exercise?

BACKGROUND Following evidence suggestive of high mortality following emergency laparotomies, the National Emergency Laparotomy Audit (NELA) was set up, highlighting key standards in emergency service provision. Our aim was to compare our NHS trust's adherence to these recommendations immediately prior to, and following, the launch of NELA, and to compare patient outcome. METHODS This was a retrospective study of patients who underwent an emergency laparotomy over the course of 6 months - 3 months either side of the initiation of NELA. RESULTS There were 44 patients before the initiation of NELA (pre-NELA, PN group) and 55 in the first 3 months of NELA (N group). We saw a significant increase in the proportion of patients whose decision to operate was made by the consultant: 75.0% in the PN group vs 100% in N group (subsequent data presented in this order) (P < 0.001). The presence of a consultant surgeon (75.0% vs 83.6%, P = 0.321) and anaesthetist (100.0% vs 90.9%, P = 0.064) in theatres were comparable in both groups. Risk stratification based on Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (P-POSSUM) score showed no difference in high-risk patients in both groups (47.7% vs 36.4%, P = 0.306). With the NELA initiative, however, significantly more patients were admitted directly from theatres to the critical care unit, when compared with the pre-NELA period (9.1% vs 27.3%, P = 0.038). This also reflected a significant reduction in unexpected escalation to a higher level of care during this period (10.0% vs 0%, P = 0.036). Significantly more patients had uneventful recovery in the NELA period (52.3 vs 76.4%, P = 0.018), although there was no difference in 30-day mortality between the groups (2.3% vs 7.3%, P = 0.378). CONCLUSIONS This study demonstrated a greater degree of consultant involvement in the decision to operate during NELA. More high-risk patients have been identified preoperatively with diligent risk assessment and, hence, have been proactively admitted to critical care units following laparotomy, which may account for the significant reduction in unexpected escalation to level 2 or level 3 care and thus in overall better patient outcomes.

Measuring outcome after cardiac arrest: construct validity of Cerebral Performance Category

INTRODUCTION

Approximately half of the survivors of cardiac arrest have cognitive impairments due to hypoxic brain injury. To describe the outcome after a cardiac arrest, the Cerebral Performance Category (CPC) is frequently used. Although widely used, its validity is still debatable.

OBJECTIVE

To investigate the construct validity of the Cerebral Performance Category in survivors of a cardiac arrest. Participants were 18 years and older that survived a cardiac arrest more than six months.

METHODS

Cross-sectional design. A method to administer the CPC in a structured and reproducible manner was developed. This 'Structured CPC' was administered by a structured interview. Construct variables were Cognitive Failure Questionnaire (CFQ), Barthel Index (BI), Frenchay Activity Index (FAI), Community Integration Questionnaire (CIQ) and Quality of Life after Brain Injury (Qolibri). Associations were tested based on Spearman correlation coefficients.

RESULTS

A total of 62 participants responded. In 58 (94%) patients the CPC was determined, resulting in CPC 1 (48%), CPC 2 (23%) and CPC 3 (23%). The CPC-scoring correlated significantly with the CFQ (r=-0.40); BI (r=-0.57); FAI (r=-0.65), CIQ (r=-0.53) and Qolibri (r=-0.67).

DISCUSSION AND CONCLUSIONS

In this study we developed the 'Structured CPC' to improve the transparency and reproducibility of the original CPC. A moderate correlation between the 'Structured CPC' and the constructs 'activities', 'participation' and 'quality of life' confirmed the validity of the 'Structured CPC'.

CLINICAL MESSAGE

The 'Structured CPC' can be used as an instrument to measure the level of functioning after cardiac arrest.

Abstract 3579: Identification of biomarkers of AXL-mediated drug resistance in head and neck squamous cell carcinoma

Background:

Head and neck squamous cell carcinoma (HNSCC) is the fifth most common cancer. In 2013, there were ∼53,000 newly diagnosed cases and ∼11,000 deaths related to HNSCC in the USA. Overexpression of EGFR is seen in 90% HNSCC; but, only ∼10% of patients treated with the anti-EGFR antibody cetuximab show increased response rates to cetuximab and these eventually gain resistance by poorly-characterized mechanisms. We showed an association between EMT and resistance to EGFR inhibitors in lung cancers (LC) and HNSCC using a 76-gene EMT signature. AXL was identified as a therapeutic candidate linking EMT and drug resistance, showing significantly higher expression in erlotinib resistant cell lines. Other groups have linked AXL to drug resistance in HNSCC, LC and breast cancers. Here we identify signaling pathways that are regulated by AXL, mediate drug resistance, and identify potential therapeutic targets to combine with AXL inhibition.

Methods:

Using 6 clinical cohorts including The Cancer Genome Atlas (TCGA N = 493) and PROSPECT (N = 142) across 3 cancer types, we identified genes whose mRNA expression was highly correlated with AXL. Protein profiling by reverse phase protein array (RPPA) to analyze total and phospho-proteins in HNSCC cell lines, pre- and post-AXL inhibitor treatment was used to identify pathways altered upon AXL inhibition. The response to AXL inhibition was assayed in HNSCC cell lines by proliferation assays and correlated to mRNA and protein expression.

Results:

Using gene-expression and RPPA analysis we saw the highest association of AXL with pathways involved in EMT (TGF-β, Rho GTPases), autophagy and immune response. Following treatment with an AXL inhibitor, we observed a decrease in phospho-proteins in the PI3K-AKT pathway, increased expression of markers associated with apoptosis, an epithelial phenotype, and p-EGFR. Using an AXL knockdown model system in HNSCC cell lines, we validated an increase in EGFR signaling (EGFR and p-Erk), epithelial (E-cadherin), apoptotic (cleaved PARP and caspase-7) and DNA repair proteins (RAD51, ku-80 and PARP) and a decrease in Slug, Twist and ZEB-1, indicating that AXL may be directly involved in mediating EMT. AXL knockdown reduced proliferation of HNSCC cell lines and AXL inhibition was able to re-sensitize resistant HNSCC cell lines to erlotinib, an EGFR tyrosine kinase inhibitor.

Conclusions:

In summary, we identified potential therapeutic targets that are upregulated with AXL expression in HNSCC and LC patient tumors and cell lines. Using AXL inhibitor and knockdown in HNSCC cell lines, we validated biomarkers involved in EMT, EGFR signaling and apoptosis that are altered upon AXL inhibition. AXL inhibition led to an epithelial phenotype in cells and re-sensitized resistant cells to erlotinib. Studies are ongoing to validate the mechanisms of AXL-mediated drug resistance and to identify potential combination treatments that can synergize with AXL-inhibition.

Citation Format: Kavitha Balaji, Robert Cardnell, Lixia Diao, Pan Tong, Milena Mak, You Hong Fan, Fatemeh Masrorpour, Steven L. Warner, David J. Bearss, Ignacio Wistuba, Gordon B. Mills, John Heymach, Khandan Keyomarsi, Jing Wang, Lauren Averett Byers. Identification of biomarkers of AXL-mediated drug resistance in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3579. doi:10.1158/1538-7445.AM2015-3579

Is there a role of taurine bromamine in inflammation? Interactive effects with nitrite and hydrogen peroxide

OBJECTIVE AND DESIGN

The myeloperoxidase system of neutrophils generates chlorinating and brominating oxidants in vivo. The major haloamines of the system are taurine chloramine (TauCl) and taurine bromamine (TauBr). It has been demonstrated in vitro that TauCl exerts both antiinflammatory and anti-bacterial properties. Much less is known about TauBr. The present study was conducted to compare bactericidal and immunoregulatory capacity of TauBr with that of the major chlorinating oxidants: HOCl and TauCl. Moreover, the effect of nitrites and H(2)O(2) on TauBr activity was investigated.

MATERIALS

TauBr was prepared by reaction of HOBr with taurine. The reaction was monitored by UV absorption spectra.

METHODS

Bactericidal activity of TauBr, TauCl and HOCl was tested by incubation of E. coli with the compounds and determined by the pour-plate method. To test the anti-inflammatory activity the compounds were incubated with LPS and IFN-gamma stimulated murine peritoneal macrophages. The production of following mediators was measured: nitrites by Griess reaction; TNF-alpha, IL-6, IL-10, IL-12p40 using capture ELISA. In some experiments the compounds were incubated with either nitrites or H(2)O(2).

RESULTS

In our experimental set-up TauBr and HOCl exerted strong bactericidal effects on E. coli (MBC = 110 microM and 8 microM, respectively), while TauCl (< 1000 microM) did not kill test bacteria. However, both, TauBr and TauCl, at noncytotoxic concentrations (< 300 microM) inhibited the cytokine and nitric oxide production by macrophages. H(2)O(2) completely abolished the biological activities of TauBr but not those of TauCl. Nitrites did not affect any activity of TauBr or TauCl while they diminished the HOCl(-) mediated bacterial killing.

CONCLUSION

TauBr, despite very low concentration of Br(-) in body fluids, may support TauCl and HOCl in the regulation of inflammatory response and in killing of bacteria by neutrophils. However, TauBr activity in vivo will depend on the presence of H(2)O(2) and possible other mediators of inflammation which can compete with target molecules for TauBr.

Utility of zanamivir for chemoprophylaxis of concomitant influenza A and B in a complex continuing care population

OBJECTIVE

To describe compliance with and the safety and prophylactic efficacy of zanamivir among patients at risk of developing influenza-related complications after exposure to both influenza A and B viruses.

DESIGN

Nonrandomized trial using both historical and contemporaneous controls from ward populations within the same facility.

SETTING

A 547-bed urban hospital providing complex continuing care and rehabiltation.

PATIENTS

Fifty patients on a single ward concomitantly exposed to both influenza A and B during an influenza outbreak.

INTERVENTIONS

All patients were screened for symptoms of influenza and nasopharyngeal swabs were sent for viral culture prior to treatment (two oral inhalations [2 x 5 mg] twice daily for 5 days) or prophylaxis (two oral inhalations [2 x 5 mg] once daily for 14 days) with zanamivir. Patient symptoms, compliance, and drug tolerance were monitored daily. Demographic data, comorbidities, vaccination status, and functional status (Katz score) were collected for all patients.

RESULTS

The mean age of the patients was 70.6 years (standard deviation, +/- 16.4 years). Ninety-four percent had two or more comorbidities, 71% were dependent in two or more activities of daily living, 63% had been vaccinated for influenza, and 82% had received amantadine. Zanamivir was well tolerated, with 93% of the patients completing their course. The efficacy for preventing symptomatic infection was 82% and 91% (95% confidence interval, 62% to 98%) based on historical and contemporaneous controls, respectively.

CONCLUSION

These data suggest that zanamivir can be used safely and effectively as a prophylactic agent in the management of influenza outbreaks in a complex continuing care population with multiple comorbidities.

Evaluation of a recombinant line blot for diagnosis of Epstein-Barr Virus compared with ELISA, using immunofluorescence as reference method

A commercial line blot using recombinant antigens was compared with a commercial ELISA and 'in-house' IFA (reference test). Two panels were evaluated: Panel A was selected to distinguish between primary infections (89), past infections (20) and seronegatives (8) in immunocompetent individuals. In panel B, patients with a high number of reactivations were included: immunosuppressed patients (37), lymphoma (19), nasopharyngeal carcinoma (10), chronic fatigue syndrome (14). Blood donors (43) and cross-reactive sera (29) were added as controls. Line blot and IFA were concordant in 94% of primary infections, 100% of seronegatives and 100% of past infections, similar to ELISA. Results differed significantly with regard to reactivations. When compared with IFA, the incidence of reactivations was overestimated by the blot, 24 and 58% in blood donors and cross-reactive sera, respectively. ELISA showed a similar problems with 21 and 34% indeterminate results, respectively. The line blot is easy to carry out, has a good concordance with the reference IFA for primary infections, and is, therefore, a sufficient choice for distinguishing primary infection from seronegative and past infection. EBV reactivation assessment will require other methods such as EBV viral load.

Novel immunoblot assay using four recombinant antigens for diagnosis of Epstein-Barr virus primary infection and reactivation

A new immunoblot assay, composed of four Epstein-Barr virus (EBV)-encoded recombinant proteins (virus capsid antigen [VCA] p23, early antigen [EA] p138, EA p54, and EBNA-1 p72), was compared with an immunofluorescence assay on a total of 291 sera. The test was accurate in 94.5% of cases of primary EBV infection, while an immunoglobulin G anti-VCA p23 band with strong intensity correlated with reactivation.

The effect of different ceramic materials on the fracture resistance of dentin-bonded crowns

This in vitro study investigated the fracture resistance of dentin-bonded crowns constructed from four ceramic materials: feldspathic porcelain, aluminous porcelain, a glass-ceramic core material (Dicor), and a leucite-enriched ceramic (Empress). Forty sound maxillary premolar teeth were chosen and divided at random into four equal groups. The teeth were prepared with a standardized crown minimal preparation. The restored teeth were subjected to compressive loading. When the mode of fracture of the specimens was examined, it was found that four mode V (severe) fractures occurred in the Empress group, compared with none in the aluminous porcelain group and one each in the feldspathic porcelain and Dicor groups. Statistical analysis indicated that the loads required to fracture Dicor specimens were significantly greater than those required to fracture the feldspathic and aluminous porcelain crowns but were not significantly different from the loads achieved by the Empress specimens.

Stabilization of nerve growth factor in controlled release polymers and in tissue

We have studied the release of nerve growth factor (NGF), a protein under consideration for treatment of Alzheimer's Disease, from polymer matrices and microspheres to characterize the stability of NGF, the dynamics of NGF release, and the distribution of NGF within the brain interstitium. Poly(ethylene-co-vinyl acetate) (EVAc) disks and poly(L-lactic acid) (PLA) microspheres were formed by codispersing NGF with one of a variety of molecules. The mass of mouse NGF (mNGF) detected following release from EVAc disks into buffered saline varied five-fold over the range of codispersants studied, with carboxymethyldextran providing optimal release, while the mass of recombinant human NGF (rhNGF) released varied four-fold from both EVAc disks and PLA microspheres, with albumin and carboxymethyldextran providing optimal release. Variation of the codispersant species significantly affected NGF release into buffered saline; it also had a noticeable, but small, effect of the amount of NGF found in the brain tissue following implantation of a polymer device. To improve NGF retention in tissue, NGF was conjugated to 70,000 molecular weight dextran and incorporated into a polymeric device. The distribution of NGF was enhanced by conjugation; comparison of NGF concentrations in the brain to a mathematical model of diffusion and elimination suggested that the elimination rate of NGF-dextran conjugate in the tissue was over seven times slower than the elimination rate of NGF. These results indicate that variation of the properties of the controlled release system may be useful in regulating the time course of NGF delivery to tissue, and that modification of the NGF itself can improve penetration and retention in the brain.

Pharmacokinetics of recombinant human granulocyte-macrophage colony-stimulating factor: the effects of zidovudine

Recombinant human granulocyte-macrophage colony-stimulating factor (rHu GM-CSF) enhances bone marrow production of and stimulates granulocytes, macrophages, and eosinophils. Granulocyte-macrophage colony-stimulating factor may be used concomitantly with zidovudine in human immunodeficiency virus (HIV)-positive patients to minimize zidovudine-associated neutropenia. This open-label, randomized, placebo-controlled study was performed to evaluate the pharmacokinetic disposition of rHu GM-CSF in HIV-positive, asymptomatic patients in the absence and presence of concomitant zidovudine administration. Eight participants received rHu GM-CSF (5 micrograms/kg subcutaneously) daily for 4 days in combination with placebo or zidovudine (200 mg orally every 8 hours) in a randomized, crossover fashion, with each study period separated by a 3-day washout phase. Pharmacokinetic blood sampling was performed over 16 hours on days 1 and 4 of both treatment periods, and subsequent analysis of serum was performed using an enzyme-linked immunosorbent assay. Pharmacokinetic results of rHu GM-CSF at steady state (days 4 of periods I and II) in the absence (placebo) and presence of zidovudine included apparent total body clearance, half-life, and apparent volume of distribution, all of which were not significantly altered with concomitant administration of zidovudine. Mean pharmacokinetic results of rHu GM-CSF after the first dose (days 1 of periods I and II) were similar to steady-state values; however, total body clearance was significantly increased at steady state compared with the results of the first dose. Concurrent administration of zidovudine does not influence the pharmacokinetic disposition of rHu GM-CSF after single or multiple doses.

Distribution of drugs following controlled delivery to the brain interstitium

Intracranial controlled release polymers have been used for drug delivery to the brain, bypassing the blood brain barrier (BBB). By understanding the rates and patterns of transport in the local tissues, it is possible to design delivery systems that provide the optimal spatial and temporal pattern of chemotherapy within the intracranial space. This paper reviews the kinetics of drug release from polymeric controlled release implants, and describes the fate of drug molecules following release into the brain interstitium. Potential improvements in drug delivery based on the understanding of the mechanisms of drug release, transport and elimination are discussed.

Clinical research in aggressive patients, pitfalls in study design and measurement of aggression

1. Experience from scale validation studies and from controlled drug trials provided clues for optimalisation of studies in aggressive patients. 2. Definitions of target behaviour, selection of patients and measurement of aggression are reviewed and recommendations are presented.

Oral and intravenous zidovudine pharmacokinetics: the effect of granulocyte-macrophage colony stimulating factor

Combination therapy with zidovudine and recombinant human granulocyte-macrophage colony stimulating factor (rHu GM-CSF) may be warranted, owing to the bone marrow suppressive effects of zidovudine. A study of 16 patients, 8 of whom had acquired immune deficiency syndrome (AIDS) and 8 of whom were infected with human immunodeficiency virus (HIV) but were asymptomatic, was conducted. The effect of 4 days of rHU GM-CSF versus placebo on intermittent zidovudine therapy (200 mg every 8 hours) was evaluated using a randomized, cross-over study design. Pharmacokinetics of oral and intravenous zidovudine were determined on days 1 (oral), 3 (oral), and 4 (intravenous) of rHu-GM-CSF (placebo) administration. After intravenous dosing, zidovudine plasma clearance for placebo and rHu GM-CSF averaged 1.4 +/- 0.2 and 1.3 +/- 0.2 L/hr/kg, respectively (P = 0.017), mean residence time averaged 1.5 +/- 0.5 and 1.9 +/- 0.6 hours, respectively (P = 0.012), and the steady-state volume of distribution was 2.0 +/- 0.7 and 2.3 +/- 0.7 L/kg, respectively (P = 0.027) for the two treatment arms. Stratified data for patients with AIDS and those with asymptomatic HIV infection revealed no significant difference in plasma clearance or mean residence time between the two patient groups. These pharmacokinetic results indicate that dosage adjustments for zidovudine are not warranted when administered with rHu GM-CSF owing to the small changes observed. However, the statistically significant increase in Vss suggests the possibility of enhanced zidovudine cellular uptake in the presence of rHu GM-CSF.

Eltoprazine in aggressive mentally handicapped patients: a double-blind, placebo- and baseline-controlled multi-centre study. The Eltoprazine Aggression Research Group

The efficacy of eltoprazine, a mixed 5-HT1 agonist, in treating aggressive behaviour in mentally handicapped patients was evaluated in a double-blind, placebo- and baseline-controlled study. In the total sample of 160 patients who entered the 8 week double-blind treatment phase, efficacy was not demonstrated. Also in a 28 week double-blind follow-up study, efficacy could not be demonstrated. Post-hoc exploratory analyses suggested eltoprazine was significantly better than placebo in reducing aggression scores of a subgroup of severely aggressive patients. There was no evident relationship between the plasma level of eltoprazine and therapeutic effect or safety and tolerance. The overall safety and tolerance of chronic eltoprazine treatment was good. In the discussion, several issues and pitfalls of aggression research are dealt with.

Effect of dobutamine on oxygen supply and uptake in healthy volunteers

We have measured the changes in VO2 and the VO2:DO2 relationship during infusion of dobutamine in healthy volunteers. Nine healthy, adult, non-obese, male physicians were infused with an incremental infusion of dobutamine starting at 2.5 micrograms kg-1 min-1 increasing to 5.0 and then 7.5 micrograms kg-1 min-1 for 15 min each. VO2 and cardiac index were measured every five minutes. VO2I (VO2m-2) increased from a baseline of 128 (SEM 6.1) ml min-1 m-2 to 159 (8.0) ml min1 m-2 (P < 0.05) at the end of infusion with 7.5 micrograms kg-1 min-1. The corresponding changes for DO2I (DO2 m-2) were from 643 (35) ml min-1 m-2 to 1240 (142) ml min-1 m-2 (P < 0.05). The coefficient of correlation for pairs of VO2 and DO2 values, at baseline and each dobutamine infusion in individual subjects, ranged from 0.89 to 0.99 (mean 0.95, SD 0.03). Dobutamine has potent calorigenic effects; demonstration of a positive correlation between VO2 and DO2 after infusion of dobutamine does not necessarily imply an underlying tissue oxygen debt.

Protein surface topology-probing by selective chemical modification and mass spectrometric peptide mapping

Aminoacetylation of lysine residues and the modification of arginine by 1,2-cyclohexanedione to N7,N8-(dihydroxy-1,2-cyclohexylidene)arginine were used for probing the surface topology of hen-eggwhite lysozyme as a model protein. The molecular identification of lysine and arginine modification sites was provided by molecular weight determinations of modified and unmodified tryptic peptide mixtures (peptide mapping) using 252Cf plasma desorption mass spectrometry. At conditions of limited chemical modification, mass-spectrometric peptide-mapping analyses of lysozyme derivatives enabled the direct assignment of relative reactivities of lysine and arginine residues at different reaction times and reagent concentrations. The relative reactivities of lysine residues showed a direct correlation with their surface accessibilities from x-ray structure data. For the reaction with 1,2-cyclohexanedione, a selective modification at Arg-5, -125, -112, and -73 was identified, and an inverse correlation of relative reactivities with the surface accessibility ratios of the N7- and the N8-guanidino functions was obtained. By examination of the x-ray structural data of lysozyme, this selective modification was attributed to intramolecular catalysis because of the presence of neighboring proton acceptor groups, such as the Asp-119 carboxylate group for Arg-125 and the Trp-123 and Arg-125 carbonyl groups for Arg-5.

Pharmacokinetics of eltoprazine in healthy male subjects after single dose oral and intravenous administration

The kinetics, safety and tolerability of eltoprazine hydrochloride were studied in an open, cross-over, partially randomised design after single oral (8 mg) and intravenous (3 and 8 mg) doses to 12 healthy male subjects. After intravenous administration, the mean t1/2 ranged from 7 to 9 h, the MRT was 11 h, CL was 487 +/- 148 (3 mg dose) and 471 +/- 56 (8 mg dose) ml kg-1 h-1, while CLR was 226 +/- 124 (3 mg dose) and 189 +/- 38 (8 mg dose) ml kg-1 h-1. The Vss was 3.3 +/- 0.7 (3 mg dose) and 3.8 +/- 0.5 (8 mg dose) 1 kg-1. Cumulative renal excretion was 40%. The AUC and the cumulative urinary excretion were directly proportional to dose within the range of 3-8 mg. Values of tmax varied from 1 to 4 h after oral administration. The mean Cmax value was 24 ng ml-1 after an oral dose of 8 mg. The plasma elimination half-life after oral administration was 9.8 +/- 3.9 h. Absolute oral bioavailability was 110 +/- 32%. Dose-dependent somnolence was observed.