Chronic Granulomatous Disease: Epidemiology, Pathophysiology, and Genetic Basis of Disease

Chronic Granulomatous Disease is one of the classic primary immunodeficiencies of childhood. While the incidence and severity of bacterial and fungal infections have been greatly reduced in this patient population, much remains to be learned about the pathophysiology of the disease, particularly for autoinflammatory manifestations. In this review, we examine the epidemiology, pathophysiology, and genetic basis for CGD.

A randomized phase II study comparing capecitabine alone with capecitabine and oral cyclophosphamide in patients with advanced breast cancer-cyclox II

BACKGROUND

Capecitabine and cyclophosphamide are active in patients with advanced breast cancer, have non-overlapping toxic effects and synergy pre-clinically. We explored the efficacy and toxic effect of an all-oral combination of capecitabine with cyclophosphamide versus capecitabine alone in a multicentre, randomized, phase II study.

PATIENTS AND METHODS

Patients with locally advanced or metastatic breast cancer were randomized to treatment with capecitabine given continuously (666 mg/m(2) b.i.d. days 1-28) alone (C) or with oral cyclophosphamide (100 mg/m(2) days 1-14 of a 28-day cycle) (CCy) for up to six cycles.

RESULTS

Eighty-two patients were randomized. There was no complete response. The proportions with partial response were 36% on C and 44% on CCy, a difference of 7.9% [95% confidence interval (CI) -13.4 to 29.1]. Significant toxic effect was uncommon: grade ≥3 diarrhoea in 4 (10%) versus 1 (3%) patients; grade ≥3 fatigue in 2 (5%) versus 5 patients (13%) and grade ≥2 hand-foot syndrome in 7 (17%) versus 11 (28%) patients receiving C versus CCy, respectively. Median progression-free survival was 3.1 months on C and 6.9 months on CCy, not significantly different statistically. There was no difference in overall survival.

CONCLUSION

The difference in tumour response suggests a reasonable chance that CCy is superior to C alone.

A phase 1 study of AS1409, a novel antibody-cytokine fusion protein, in patients with malignant melanoma or renal cell carcinoma

PURPOSE

AS1409 is a fusion protein comprising a humanized antibody BC1 linked to interleukin-12 (IL-12). It is designed to deliver IL-12 to tumor-associated vasculature using an antibody targeting the ED-B variant of fibronectin.

EXPERIMENTAL DESIGN

We conducted a phase 1 trial of weekly infusional AS1409 in renal carcinoma and malignant melanoma patients. Safety, efficacy, markers of IL-12-mediated immune response, and pharmacokinetics were evaluated.

RESULTS

A total of 11 melanoma and 2 renal cell carcinoma patients were treated. Doses of 15 and 25 μg/kg were studied. Most drug-related adverse events were grade 2 or less, and included pyrexia, fatigue, chills, headache, vomiting, and transient liver function abnormalities. Three dose limiting toxicities of grade 3 fatigue and transaminase elevation were seen at 25 μg/kg. IFN-γ and interferon-inducible protein-10 (IP-10) were elevated in all patients, indicating activation of cell-mediated immune response; this was attenuated at subsequent cycles. Antidrug antibody responses were seen in all patients, although bioassays indicate these do not neutralize AS1409 activity. Plasma half-life was 22 hours and not dose-dependent. Five patients received 6 cycles or more and a best response of at least stable disease was seen in 6 (46%) patients. Partial response was seen in a melanoma patient, and disease shrinkage associated with metabolic response was maintained beyond 12 months in another melanoma patient despite previous rapid progression.

CONCLUSIONS

The maximum tolerated dose was established at 15 μg/kg weekly. AS1409 is well tolerated at this dose. Evidence of efficacy assessed by RECIST, functional imaging, and biomarker response warrants the planned further investigation using this dose and schedule in malignant melanoma.

Systematic review of histamine type 2 receptor antagonists as an adjunct to curative surgical resection in gastrointestinal malignancies

e15085

Background: H2RAs have induced regression in a number of malignancies. The mechanisms that may contribute to this effect include inhibition of T-suppressor lymphocytes, increased tumor infiltrating lymphocytes and blockade of histamine-induced tumor proliferation and angiogenesis. Unique to cimetidine is its ability to inhibit vascular endothelial expression of the cell adhesion molecule E-selectin, to which many GI tumor cells adhere via carbohydrate antigen ligands. The optimal use of H2RAs in cancer patients could therefore be as adjuvant therapy rather than for metastatic disease. Methods: This systematic review examines the impact of H2RAs on the overall survival of patients when used as an adjunct to curative surgical resection for a GI malignancy. Using a sensitive search strategy, randomized controlled trials were identified in relevant databases. Criteria for study selection included: patients with colorectal or gastric cancer surgically resected with curative intent; H2RAs used i) at any dose, ii) for any length of time, iii) with any other treatment modality and iv) in the pre-, peri- or post-operative period. The results were stratified for both the type of malignancy and the H2RA used and analyzed by meta-analysis using Cochrane Collaboration software. Results: Of 350 trials identified, 8 were eligible for inclusion and had sufficient data for analysis, including a total of 1461 patients. Meta-analysis revealed a risk ratio for mortality of 0.86 (95% CI 0.76–0.99, p = 0.03) for patients randomised to H2RAs. Trials of colorectal cancer patients where cimetidine was the H2RA being evaluated demonstrated a significant survival advantage, risk ratio 0.53 (95% CI 0.33–0.84, p = 0.007). All other subgroups demonstrated a non-significant trend favouring H2RAs. Conclusions: H2RAs, and cimetidine in particular, appear to confer a survival benefit when given as an adjunct to curative surgical resection of GI cancers. The trial designs were heterogeneous and further large studies are warranted.

No significant financial relationships to disclose.

A phase I study of AS1409, a novel antibody-cytokine fusion protein, in patients with malignant melanoma (MM) or renal cell carcinoma (RCC)

3024

Background: AS1409 (huBC1-huIL-12) is a fusion protein combining a humanized antibody specific for the ED-B splice variant of fibronectin with human IL-12. ED-B-fibronectin is expressed in tumor vasculature. IL-12 stimulates T and NK cell activity. Responses to IL12 occur in MM and RCC, but with high systemic toxicity. AS1409 is designed to target IL-12 to tumor vasculature. Methods: Patients with MM or RCC were treated in a dose-escalating trial of weekly i.v. AS1409 for 6 weeks with a starting dose of 15mcg/kg. Patients without unacceptable toxicity or disease progression could continue therapy. IFN-gamma and IP-10 were measured as biomarkers of activation of cellular immunity. Results: 13 patients (9 males; median age 53 years; 11 MM, 2 RCC) were treated (7 at 15mcg/kg, 6 at 25mcg/kg). DLTs observed at 25 mcg/kg were transaminase elevation and fatigue. Other toxicities included flu-like syndrome, fever, myalgia, and mucositis. Three patients continued to receive AS1409 beyond 6 weeks and 1 patient remained on treatment beyond 30 weeks. All patients showed elevation of IFN-gamma and IP10 following the first dose, although subsequently attenuated; prominent anti-drug antibody (ADA) responses were seen. A partial response was seen in a patient with MM metastatic to lymph nodes treated at 15mcg/kg, and a best response of stable disease was seen in 4 patients. Mean AS1409 half-life was 19.3 ±5.3h, mean distribution volume was 0.25 ± 0.098L/kg and clearance was 9.8 ± 6.5mL/hr/kg. Conclusions: At 15mcg/kg AS1409 was well tolerated. Biomarker activation and objective radiological evidence of anticancer activity was observed at this dose. Further study of AS1409 is focussed on optimizing dosing and scheduling, characterizing the ADA response, and antibody biodistribution.

[Table: see text]

Colorectal cancer survival following adjuvant chemotherapy with weekly i.v. fluorouracil 425 mg/m2 and folinic acid 50mg

e15089

Background: Adjuvant chemotherapy for colorectal cancer (CRC) using fluorouracil (5FU) and folinic acid (FA) has been proven effective and the QUASAR trial showed that a weekly administration schedule was as effective as, and less toxic than, the same daily doses delivered over 5 days every 4 weeks (the “Mayo regimen”). However the 5FU dose used (370 mg/m2) was lower than in some trials and a higher 5FU dose was considered desirable if tolerated. We therefore implemented a weekly regimen using 5FU 425 mg/m2 and DL-folinic acid 50mg in 2001 and retrospectively evaluated its efficacy and tolerability. Methods: Patients with non-metastatic CRC at assessment by medical oncologists in this institution between 2001 and 2004 were included in the analysis. Data was gathered on patient characteristics, duration of adjuvant chemotherapy and survival. Actuarial survival was calculated using the Kaplan-Meier method. Results: 417 patients (pts) were seen: 181 females, 236 males; median age 67 yrs (24–89); 291 with colon cancer, 126 with rectal cancer; 1 stage 1; 100 stage 2, 316 stage 3. Median follow-up was 6.2 years. 210 pts with colon cancer received adjuvant weekly 5FU/FA (32 stage 2, 178 stage 3) as did 58 pts with rectal cancer (50 of whom also received concurrent chemoradiation). 75% of pts with colon cancer received all 30 planned doses and 59% of rectal cancer pts received all 20 planned doses. 3 year survival for all pts treated with this regimen was 83.0% and for the subgroups with colon and rectal cancer it was 82.4% and 84.5% respectively. For stage 2 and 3 colon cancer pts treated with this regimen 3 year survival was 87.9% and 76.0% respectively; for stage III rectal cancer pts it was 84.1%. Conclusions: These outcomes compare favorably on indirect comparison with results from the QUASAR trial (which reported 3 year survival of 70.6%) and suggest that using a higher 5FU dose in this regimen is tolerable and may be advantageous.

No significant financial relationships to disclose.

A phase I pharmacokinetic study of PR-104, a hypoxia-targeting agent, in patients with solid tumors

3516

Background: PR-104 is a novel pre-prodrug (precursor of a prodrug) designed to form a cytotoxic nitrogen mustard (alkylating agent) in hypoxic regions of tumors. Following IV administration, PR-104 is converted by systemic phosphatases to the alcohol intermediate PR-104A, which, under hypoxic conditions, is reduced to form the active DNA-crosslinking mustard species PR-104H. This phase I trial defines a Maximally Tolerated Dose (MTD) and pharmacokinetics (PK) for this schedule. Methods: Patients (pts) with relapsed/recurrent solid tumors received PR-104 as a 1-hour IV infusion every 3 weeks with PK sampling on days 1–2 of cycle 1. Cohorts of ≥3 pts were treated starting at 135 mg/m2. Results: 23 pts have been enrolled: median age 51 years (range 29–72); 13 (57%) male. Most pts had received prior radiation or chemotherapy and had metastatic disease. Six dose levels (135, 216, 354, 550, 770, and 1,100 mg/m2) have been evaluated. Dose-limiting toxicity (DLT) was observed in one patient at 1,100 mg/m2 (grade 3 fatigue) and this dose level was expanded to 6 pts. In the first 4 cohorts, 54 adverse events (AEs) were considered drug-related by the investigator including nausea (26% of all AEs), fatigue (19%), vomiting (11%) and anorexia (6%); remaining AEs each constituted < 3% of the total. Of 16 grade 3 AEs, 3 were considered drug-related by the investigator (anemia, dehydration and vomiting). Prophylactic anti-emetics largely prevented nausea and vomiting at higher doses, at which dose-related decreases in neutrophils and platelets were seen. Conclusions: PR-104 has shown manageable toxicities similar to other cytotoxic agents, with no serious mucositis, diarrhea or alopecia. DLT is likely to be myelosuppression based on preclinical and current clinical data, with the MTD close to 1,100 mg/m2. The preclinical PK target for the alcohol intermediate has been exceeded at higher doses and, while no objective responses have been documented, reductions in tumor volume have been seen at these doses.

[Table: see text]

No significant financial relationships to disclose.

Pharmacokinetics of 5,6-dimethylxanthenone-4-acetic acid (AS1404), a novel vascular disrupting agent, in phase I clinical trial

PURPOSE

5,6-Dimethylxanthenone-4-acetic acid (DMXAA) (AS1404) is a novel antitumour agent that selectively disrupts tumour vasculature and induces cytokines. The purpose of this study was to determine the pharmacokinetics (PK) of DMXAA in cancer patients enrolled in a phase I clinical trial.

METHODS

DMXAA was administered as a 20-min i.v. infusion every 3 weeks and doses were escalated in cohorts of patients according to a predefined schema. PK samples were taken over the first 24 h of at least the first cycle.

RESULTS

DMXAA was administered to 63 patients at 19 dose levels from 6 to 4,900 mg m(-2), and 3,700 mg m(-2) was established as the maximum tolerated dose. The PK observed over the dose range showed a non-linear fall in clearance from 16.1 to 1.42 l h(-1) m(-2) and resultant increase in the area under the concentration-time curve (AUC) from 1.29 to 12,400 microM h. In contrast, the increase in peak plasma concentrations from 2.17 to 1,910 microM approximated linearity. DMXAA was highly protein-bound to albumin (>99%) until saturation occurred at higher doses, leading to a rapid increase in the free fraction (up to 20%) and greater concentrations of DMXAA bound to non-albumin proteins. However, the main determinant of the non-linearity of the PK appeared to be sequential saturation of elimination mechanisms, which include hydroxylation, glucuronidation and perhaps hepatic transport proteins. This resulted in an exaggerated non-linear increase in free DMXAA plasma concentrations and AUC compared to total drug.

CONCLUSIONS

The PK of DMXAA are well-defined, with a consistent degree of non-linearity across a very large dose range.

Population pharmacokinetics (PK) of the vascular-disrupting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) in cancer patients

13076

Background: DMXAA (AS1404) is a small-molecule vascular-disrupting agent that selectively disrupts established tumor blood vessels. It is being evaluated in phase II trials in combination with cytotoxics. DMXAA is extensively metabolized, predominantly by UDP-glucuronosyltransferase (UGT) 2B7 and 1A9, and exhibits concentration-dependent protein binding. The study aim was to develop a population PK model for DMXAA and to examine covariates influencing drug disposition. Methods: 3,050 DMXAA total plasma concentrations were measured in 124 cancer patients receiving DMXAA monotherapy as a 20-min iv infusion weekly or every three weeks at doses from 6 to 4900 mg/m2 in 3 phase I trials. PK models were fitted to the data from all patients simultaneously using the program NONMEM. Potential covariates including age, body weight, height, body surface area (BSA), sex, and liver and kidney function tests were screened with general additive model analysis and tested in the PK model. Results: DMXAA concentration-time profiles after multiple-dose administration were well described by a 3-compartment model with saturable elimination (Michaelis-Menten kinetic) from the central compartment. BSA and sex were significant covariates on the volume of distribution of the central compartment (V1) and the maximum elimination capacity (Vm), respectively, accounting for 10 and 12% of interindividual variation (IIV) in these parameters. Population estimates for Vm, Km (concentration at which half-maximal elimination rate is achieved), and V1 were 122 × (1 + 0.502 × (2-SEX)) (μM/h) [females had lower Vm than males; SEX = 1 for males, 2 for females], 103 μM, and 8.15 × (BSA/1.8)0.69 (L), respectively. In the final model, IIV in Vm was 52%. Conclusions: DMXAA plasma disposition is characterized by a saturable elimination process. BSA-guided dosing for DMXAA is important. Evaluation of other covariates that reflect drug glucuronidation (e.g., UGT polymorphisms) may account for a greater fraction of the substantial unexplained PK variability. The population PK model will aid development of limited PK sampling strategies and investigation of PK-pharmacodynamic relationships in further trials.

[Table: see text]

Clinical aspects of a phase I trial of 5,6-dimethylxanthenone-4-acetic acid (DMXAA), a novel antivascular agent

The antitumour action of 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is mediated through tumour-selective antivascular effects and cytokine induction. This clinical phase I trial was conducted to examine its toxicity, maximum tolerated dose, pharmacokinetics (PK) and pharmacodynamics (PD). A secondary objective was to assess its antitumour efficacy. DMXAA was administered every 3 weeks as a 20-min i.v. infusion. Dose escalation initially followed a modified Fibonacci schema but was also guided by PK and toxicity. A total of 63 patients received 161 courses of DMXAA over 19 dose levels ranging from 6 to 4900 mg m(-2). DMXAA was well tolerated at lower doses and no drug-related myelosuppression was seen. Rapidly reversible dose-limiting toxicities were observed at 4900 mg m(-2), including confusion, tremor, slurred speech, visual disturbance, anxiety, urinary incontinence and possible left ventricular failure. Transient prolongation of the corrected cardiac QT interval was seen in 13 patients evaluated at doses of 2000 mg m(-2) and above. A patient with metastatic cervical carcinoma achieved an unconfirmed partial response at 1100 mg m(-2), progressing after eight courses. The results of PK and PD studies are reported separately. DMXAA has antitumour activity at well-tolerated doses.

Induction of endothelial cell apoptosis by the antivascular agent 5,6-Dimethylxanthenone-4-acetic acid

5,6-Dimethylxanthenone-4-acetic acid, synthesised in this laboratory, reduces tumour blood flow, both in mice and in patients on Phase I trial. We used TUNEL (TdT-mediated dUTP nick end labelling) assays to investigate whether apoptosis induction was involved in its antivascular effect. 5,6-Dimethylxanthenone-4-acetic acid induced dose-dependent apoptosis in vitro in HECPP murine endothelial cells in the absence of up-regulation of mRNA for tumour necrosis factor. Selective apoptosis of endothelial cells was detected in vivo in sections of Colon 38 tumours in mice within 30 min of administration of 5,6-Dimethylxanthenone-4-acetic acid (25 mg x kg(-1)). TUNEL staining intensified with time and after 3 h, necrosis of adjacent tumour tissue was observed. Apoptosis of central vessels in splenic white pulp was also detected in tumour-bearing mice but not in mice without tumours. Apoptosis was not observed in liver tissue. No apoptosis was observed with the inactive analogue 8-methylxanthenone-4-acetic acid. Positive TUNEL staining of tumour vascular endothelium was evident in one patient in a Phase I clinical trial, from a breast tumour biopsy taken 3 and 24 h after infusion of 5,6-Dimethylxanthenone-4-acetic acid (3.1 mg x m(-2)). Tumour necrosis and the production of tumour tumour necrosis factor were not observed. No apoptotic staining was seen in tumour biopsies taken from two other patients (doses of 3.7 and 4.9 mg x m(-2)). We conclude that 5,6-Dimethylxanthenone-4-acetic acid can induce vascular endothelial cell apoptosis in some murine and human tumours. The action is rapid and appears to be independent of tumour necrosis factor induction.

Measurement of plasma 5-hydroxyindoleacetic acid as a possible clinical surrogate marker for the action of antivascular agents

BACKGROUND

Serotonin (5HT), a naturally occurring vasoactive substance, is released from platelets into plasma under various pathological conditions. Recently, anticancer drugs that act by selectively disrupting tumour blood flow have been found to increase plasma 5HT concentrations in mice. Two such antivascular agents, flavone acetic acid (FAA) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA), have completed Phase I clinical trial and raise the important question of whether suitable surrogate markers for antivascular effects can be identified.

METHODS

5HT is unstable to storage, precluding routine clinical assay, but the 5HT metabolite, 5-hydroxyindoleacetic acid (5HIAA) accumulates in plasma following 5HT release and is a more suitable marker because of its greater stability. We have developed an automated procedure for the assay of the low concentrations of 5HIAA found in humans by combining solid-phase extraction with high-performance liquid chromatography (HPLC).

RESULTS

Efficient separation of 5HIAA from possible interfering substances in human plasma, including a variety of pharmaceutical agents, was achieved on C18 columns using cetyltrimethylammonium bromide (CETAB) as an organic modifier. Adequate precision, accuracy and sensitivity were achieved by electrochemical detection (ECD) at +400 mV. Analysis of plasma from two patients treated with DMXAA in a Phase I trial demonstrated DMXAA-induced elevation of plasma 5HIAA with a time course similar to that previously described in mice.

CONCLUSIONS

Measurement of changes in plasma 5HIAA provides a new approach to the monitoring of therapies with an antivascular effect. The assay is sensitive to dietary sources of 5HT, which should be minimised.

Identification and reactivity of the major metabolite (beta-1-glucuronide) of the anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) in humans

1. The novel anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is extensively metabolized by glucuronidation and 6-methylhydroxylation, resulting in DMXAA acyl glucuronide (DMXAA-G) and 6-hydroxymethyl-5-methylxanthenone-4-acetic acid (6-OH-MXAA). 2. The major human urinary metabolite of DMXAA was isolated and purified by a solid-phase extraction (SPE) method. The isolated metabolite was hydrolysed to free DMXAA by strong base, and by beta-glucuronidase. Liquid chromatography-mass spectrometry (LC-MS) and spectral data indicated the presence of a molecular ion [M + 1]+ at m/z 459, which was consistent with the molecular weight of protonated DMXAA-G. 3. The glucuronide was unstable in buffer at physiological pH, plasma and blood with species variability in half-life. Hydrolysis and intramolecular migration were major degradation pathways. 4. In vitro and in vivo formation of DMXAA-protein adducts was observed. The formation of DMXAA-protein adducts in cancer patients receiving DMXAA was significantly correlated with plasma DMXAA-G concentration and maximum plasma DMXAA concentration. 5. At least five metabolites of DMXAA were observed in patient urine, with up to 60% of the total dose excreted as DMXAA-G, 5.5% as 6-OH-MXAA and 4.5% as the glucuronide of 6-OH-MXAA. 6. These data suggest that the major metabolite in patients' urine is DMXAA beta-1-glucuronide, which may undergo hydrolysis, molecular rearrangement and covalent binding to plasma protein. The reactive properties of DMXAA-G may have important implications for the pharmacokinetics, pharmacodynamics and toxicity of DMXAA.

Metastatic breast cancer 42 years after bilateral subcutaneous mastectomies

Subcutaneous mastectomy has a possible role as prophylaxis in patients at high risk of developing breast cancer. A case history is presented of a woman who developed metastatic breast carcinoma 42 years after bilateral subcutaneous mastectomies for non-malignant disease. This case is presented to draw attention to the persistent risk of developing breast cancer even decades after subcutaneous mastectomy and to point out that the role of such surgery in preventing breast cancer has still not been clarified. The appropriateness of prophylactic mastectomy for an individual is better assessed on the absolute risk of breast cancer developing over a defined period rather than the relative risk.

Adjuvant chemotherapy for non-metastatic osteosarcoma of the extremities in two New Zealand cancer centres

BACKGROUND

Adjuvant chemotherapy significantly improves survival of patients with non-metastatic osteosarcoma but most of the data come from trials conducted in major international cancer centres.

AIM

To review the efficacy and toxicity of an adjuvant chemotherapy regimen used in two regional cancer centres in New Zealand.

METHODS

Retrospective review of patients treated for non-metastatic high-grade osteosarcoma of the extremities. The regimen (POMA) consists of high-dose-methotrexate 8 g/m2 and vincristine 1.5 mg/m2 (maximum 2 mg) on days 1 and 8 followed by folinic acid then doxorubicin 50 mg/m2 and cisplatin 100 mg/m2 on day 15. This cycle was repeated every 35 days. Following amputation patients received six cycles while in selected patients two cycles were planned prior to limb salvage surgery followed by a further four cycles. Actuarial survival was calculated using the Kaplan-Meier method.

RESULTS

Twenty patients were treated with POMA between 1986 and 1993. Amputation was performed in 16 patients and limb-salvage surgery in four. Sixteen patients (80%) remain alive with no evidence of disease at a median follow-up of 40 months. Thirteen patients (65%) have been continuously disease-free. Actuarial survival at five years is 70%. Seven patients relapsed, six in lungs, of whom four underwent pulmonary metastasectomy; three of these remain free of disease 31, 35 and 40 months later. There was no local relapse. The toxicity of POMA is significant but tolerable.

CONCLUSION

The results obtained at two regional cancer centres in New Zealand using POMA compare favourably to those achieved in clinical trials performed at major international cancer centres.