Phase II trial of iboctadekin (rhIL-18) on a daily X 5 schedule in metastatic melanoma (MM)

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Background: Interleukin-18 (IL-18) is an immunostimulatory cytokine with potent antitumor activity in preclinical models. Two phase I studies of recombinant human (rh) IL-18 explored a wide dose range (0.03–1.0 mg/kg) without reaching a maximum tolerated dose (MTD) on the daily × 5 schedule. Pharmacodynamic data including inflammatory cytokine production and activation of lymphocyte subsets revealed optimal biologic activity at the lower end of the dose range (0.01–0.2 mg/kg) as did 2 unconfirmed partial responses (PRs) in a MM and a renal cancer patient (pt) at 0.1 mg/kg. Methods: An open-label, randomized, phase II trial in 60 adult pts with previously untreated MM was conducted to evaluate the efficacy and safety of rhIL-18 administered as a 2-hour IV infusion daily × 5 every 28 days for 6 cycles. Pts with PS ≤ 1, without known CNS involvement, and with adequate end organ function were randomized in stage 1 to 3 dose levels of IL-18 stratified according to AJCC M stage 1a/b vs. 1c. Two confirmed responses for a given dose level in Stage 1 were required to enroll 20 additional pts/level in Stage 2. The 1° objective was determination of overall response rate (ORR) for each dose level. Progression-free survival (PFS), tolerability, and immunogenicity were 2° endpoints. Results: 64 pts were treated at 3 dose levels. Nine pts remain on study. One pt experienced a confirmed PR. Based on preliminary data, the difference in PFS 6 months (mos) was significant (p=0.03) for 0.01 vs 0.1 mg/kg. Most common toxicities were mild to moderate fever, rigors, chills, n/v, and headache. Anti-IL18 antibody (Ab) development correlated with dose level. No clinically significant adverse events were associated with Ab development. Conclusion: Iboctadekin has an acceptable tolerability profile and has activity in MM but insufficient confirmed responses have been observed at this time to initiate Stage 2. Preliminary PFS 6 months indicates an advantage for pts treated at the lowest dose.

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Extreme hypoventilation reduces ventilator-induced lung injury during ventilation with low positive end-expiratory pressure in saline-lavaged rabbits

OBJECTIVE

To compare the degrees of ventilator-induced lung injury caused by two ventilation protocols.

DESIGN

Randomized trial.

SETTING

University animal laboratory.

SUBJECTS

Sixteen New Zealand white rabbits.

INTERVENTIONS

After five sequential saline lung lavages, eight pairs of anesthetized rabbits were allocated randomly to receive either of two ventilation protocols for 4 hrs during neuromuscular blockade. Both groups received 3 cm H2O of positive end-expiratory pressure and 100% oxygen. Control group animals received an estimated tidal volume of 12 mL/kg, an inspiratory time of 0.7 sec, and a ventilatory rate adjusted for a PaCO2 of 35 to 45 torr (4.7 to 6 kPa). Study group animals were ventilated through an intratracheal catheter, with inspiratory time of 1.5 secs, ventilatory rate of 20 breaths/min, and peak inspiratory pressure of 4 to 8 cm H2O, adjusted to maintain PaCO2 at 150 to 250 torr (20 to 33 kPa).

MEASUREMENTS AND MAIN RESULTS

Arterial blood gases were measured every 30 mins. After 4 hrs, a final lung lavage was performed. Physiologic parameters, cell counts and protein concentration in the final lavage, and lung histology were compared between groups. The alveolar-arterial oxygen tension gradient was higher in the study group over the first 1.5 hrs, but the time profile showed significantly (p = .001) greater improvement in the study group. After 4 hrs, the mean alveolar-arterial oxygen tension gradient was lower in the study group (94 torr [12.5 kPa] vs. 201 torr [26.8 kPa]). The increase in neutrophil count from the initial to the final lung lavage was lower in the study group (0.27 x 10(7) cells/L vs. 2.01 x 10(7) cells/L, p = .037), as was the absolute value of the neutrophil count in the final lavage (1.33 x 10(7) cells/L vs. 3.02 x 10(7) cells/L, p = .04). The median hyaline membrane score was lower in the study group (0.5 vs. 3.0) but the difference was not statistically significant.

CONCLUSION

These findings suggest that a very low tidal volume reduces ventilator-induced lung injury in saline-lavaged rabbits during ventilation at low lung volume.

Asthma control during long-term treatment with regular inhaled salbutamol and salmeterol

BACKGROUND

The adverse effects of long term treatment of asthma with the short acting beta agonist fenoterol have been established in both epidemiological and clinical studies. A study was undertaken to investigate the efficacy and safety of long term treatment with salbutamol and salmeterol in patients with mild to moderate bronchial asthma.

METHODS

In a two centre double dummy crossover study 165 patients were randomly assigned to receive salbutamol 400 micrograms q.i.d., salmeterol 50 micrograms b.i.d., or placebo via a Diskhaler. All patients used salbutamol as required for symptom relief. The study comprised a four week run in and three treatment periods of 24 weeks, each of which was followed by a four week washout. Asthma control was assessed by measuring mean morning and evening peak expiratory flow rate (PEFR), a composite daily asthma score, and minor and major exacerbation rates. Washout assessments included methacholine challenge and bronchodilator dose response tests. Analysis was by intention to treat.

RESULTS

Data from 157 patients were analysed. Relative to placebo, the mean morning PEFR increased by 30 l/min (95% CI 26 to 35) for salmeterol but did not change for salbutamol. Evening PEFR increased by 25 l/min (95% CI 21 to 30) and 21 l/min (95% CI 17 to 26), respectively (p < 0.001). Salmeterol improved the asthma score compared to placebo (p < 0.001), but there was no overall difference with salbutamol. Only daytime symptoms were improved with salbutamol. The minor exacerbation rates were 0.29, 0.88, and 0.97 exacerbations/patient/year for salmeterol, salbutamol and placebo, respectively (p < 0.0001 for salmeterol). The corresponding major exacerbation rates were 0.22, 0.51 and 0.40, respectively (p < 0.03 for salmeterol). For salbutamol the asthma score deteriorated over time (p < 0.01), and the time spent in major exacerbation was significantly longer compared with placebo (12.3 days (95% CI 4.2 to 20.4) versus 8.4 days (95% CI 5.2 to 11.6), p = 0.02). There was no evidence of rebound deterioration in asthma control, lung function, or bronchial hyper-responsiveness following cessation of either active treatment, and no evidence of tolerance to salbutamol or salmeterol.

CONCLUSIONS

Regular treatment with salmeterol is effective in controlling asthma symptoms and reduces minor more than major exacerbation rates. Salbutamol was associated with improved daytime symptoms but subtle deterioration in asthma control occurred over time. Salbutamol should therefore be used only as required.

Heritable genetic alterations in a xeroderma pigmentosum group G/Cockayne syndrome pedigree

A search for genetic alterations within the XPG gene has been conducted on skin and blood cells cultured from a newly characterized xeroderma pigmentosum (XP) patient (XP20BE). This patient is the ninth known case that falls into the extremely rare XP complementation group G. Four genetic markers within the XPG gene (including two polymorphisms) demonstrated the Mendelian distribution of this gene from the parents to the patient and to an unaffected sibling. The patient (XP20BE) inherited a G to T transversion from his father in exon 1 of the XPG gene that resulted in the conversion of a glutamic acid at codon 11 to a termination codon. The patient also inherited an XP-G allele from his mother that produces an unstable or poorly expressed message. The cause of the latter defect is still uncertain. In addition to these alterations, XP20BE cDNA contained an mRNA species with a large splicing defect that encompassed a deletion from exon 1 to exon 14. This splicing defect, however, appears to be a naturally occurring low-frequency event that results from abnormal splicing that occurs between certain conserved non-consensus splicing signals within the human XPG gene.

Pressure-limited ventilation with permissive hypercapnia and minimum PEEP in saline-lavaged rabbits allows progressive improvement in oxygenation, but does not avoid ventilator-induced lung injury

OBJECTIVE

To determine whether pressure-limited intermittent mandatory ventilation with permissive hypercapnia and positive end-expiratory pressure (PEEP) titrated to arterial oxygen tension (PaO2) prevents or reduces acute lung injury, compared to conventional ventilation, in saline-lavaged rabbits.

DESIGN

Prospective randomised trial.

SETTING

University animal laboratory.

SUBJECTS

18 New Zealand White rabbits.

INTERVENTIONS

Following five sequential saline lung lavages, anaesthetised rabbits were randomly allocated in pairs to receive either of two ventilation protocols using intermittent mandatory ventilation. The study group had peak inspiratory pressure limited to 15 cm H2O and arterial partial pressure of carbon dioxide (PaCO2) was allowed to rise. The control group received 12 ml/kg tidal volume with rate adjusted for normocarbia. PEEP and fractional inspired oxygen (FIO2) were adjusted to maintain, PaO2 between 8 and 13.3 kPa (60 and 100 mm Hg) using a predetermined protocol. At 10 h or following death, lung lavage was repeated and lung histology evaluated.

MEASUREMENTS AND MAIN RESULTS

The mean increase in lavage cell counts and protein concentration and hyaline membrane scores were not significantly different between the groups. Oxygenation progressively improved more in the study group (p = 0.01 vs control for PaO2/FIO2 ratio and alveolar-arterial oxygen tension gradient (AaDO2)). PEEP was similar and the mean airway pressure higher in the control group, suggesting that this probably resulted from less ventilator-induced injury in the study group. Four deaths occurred in the control group (three due to pneumothorax and one to hypoxaemia) and none in the study group (p = 0.08).

CONCLUSIONS

This ventilatory protocol may have failed to prevent lung overdistension or it may have provided insufficient PEEP to prevent injury in this model; PEEP greater than the lower inflection point of the pressure-volume curve has been shown to prevent injury almost entirely.

The clinical course of treated and untreated Gaucher disease. A study of 45 patients

One hundred nineteen patients with Gaucher disease were examined in the past 13 years. Of these 45 were examined 3 or more times over a time-span exceeding one year and all such patients are included in this study. Adult patients showed little progression of disease. There were few alterations in the blood counts, no increase in size of liver and spleen, and changes in skeletal lesions were largely confined to pre-existing lesions. Some children appeared to have more progressive disease, but since many of the children in this study were treated with alglucerase, it is difficult to draw conclusions about the natural progression of the disease at earlier ages. Treatment with alglucerase resulted in gradual normalization of blood counts, decrease in the size of liver and spleen, and parallel decreases in the serum angiotensin converting enzyme and chitotriosidase levels. Skeletal symptoms were decreased in all patients, and skeletal lesions showed modest improvement in patients treated for two years or more. The response of patients to low dose/high frequency (2.3 U/Kg 3 x weekly; 30 U/Kg/Mo) therapy was indistinguishable from the response observed and previously reported by others with much larger doses. Changing the dosage from 30 U/Kg/Mo to 120 U/Kg/Mo was not attended by any significant changes in response. Criteria for the selection of patients for treatment with alglucerase are proposed. We suggest that a starting dose of 15 to 30 U/Kg/month, fractionated 3 times weekly be used for all patients, regardless of severity or site of involvement, and that upward dosage adjustments be made only in such rare patients who may not respond adequately to this dose in 6 to 12 months.

Cell surface oligosaccharide modulation during differentiation: VI. The effect of biomodulation on the senescent and neoplastic cell phenotype

These investigations test the hypothesis developed previously, that there are biomolecules which control and integrate cellular differentiation. Our specific interest in cellular differentiation lies in the area of what we refer to as basal or primitive cellular differentiation mechanisms. These mechanisms are common to all cells, and are required for simple recognition and growth regulation. We have investigated two models, the IMR-90 human fetal lung fibroblast model as a representative of normal growth control, and the CG model, canine glioma cells, a transplantable growth transformed cell line. These two models represent normal, and aberrant cellular differentiation control. In previous studies we have shown that the arrangement of the cell surface oligosaccharide structure on these cell types are predictive of phenotypic transition. We have developed, and partially characterized a series of BIOMODULATORS (BM) which delay the onset of display of neoplastic cells. Three classes of BIOMODULATOR have been explored; (1) a large molecular weight natural product (25-35 kDa), PokeWeed Mitogen (PWM); (2) a small molecular weight natural product (500 Da) Cellular Activator and Differentiator (CAD) and a number of natural and synthetic analogs; and (3) an indolizidine alkaloid natural product, Swainsonine (Sw) which has a known cellular target (oligosaccharide biosynthesis). Preliminary data is presented which structurally links some of these BIOMODULATORS in terms of their effective stereochemistry. These BIOMODULATORS, when used before PDL 38, prevent the cell surface oligosaccharide display changes typical of morphological senescence and delay their onset to PDL 100 or more. These BIOMODULATORS also appear to have regulatory effects on the neoplastic cell models. This re-regulation results in increases in generation time and an increase in the ability of these cells to be recognized by cytotoxic lymphocytes. Proton NMR linewidth measurements of the fraction of 'bound' water associated with the cellular surface of treated and untreated cell populations showed induced physical changes in the cell surface related to the use of the BIOMODULATOR and correlated to the oligosaccharide display changes. These data were interpreted as indicating an increase in the organizational level of these cells. The data for normal and neoplastic cell populations are compared and contrasted in an effort to form the basis for an analytical approach to the control and integration of differentiation mechanisms.