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.

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.

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.

Phase I study of the cytotoxic agent N-[2-(dimethylamino)ethyl]acridine-4-carboxamide.

N-[2-(Dimethylamino)ethyl]acridine-4-carboxamide (DACA) is a new DNA-intercalating drug with a dual mode of cytotoxic action that is thought to involve topoisomerases I and II. On the basis of novelty of action and promising preclinical activity against solid tumours in mice, DACA was selected for clinical trial under the auspices of the Cancer Research Campaign, United Kingdom. We report the phase I findings of a 3-h infusion regimen, repeated 3-weekly, of escalating doses through 18-1000 mg/m2 given to 31 patients with solid malignancies. A maximum tolerated dose (MTD) of 750 mg/m2 was identified, with 3 of 6 cycles being abandoned at 1000 mg/m2. Dose-limiting toxicity took the form of infusional arm pain, in some cases associated with facial discomfort, that was of rapid onset and subsided quickly on the cessation of infusion. The mechanism is unclear but is modulated to some extent by the rate of drug delivery, and it was unaffected in this study by concurrent anti-inflammatory or opiate medication. No host or tumour anti-proliferative activity was observed at these doses, and only minimal toxicity of any other kind was evident. Animal data suggest that the MTD achieved with this schedule may be sub-therapeutic in humans. It is therefore important that efforts be continued to explore methods of giving higher doses of DACA.

Late results of surveillance of clinical stage I nonseminoma germ cell testicular tumours: 17 years' experience in a national study in New Zealand.

OBJECTIVE: To re-evaluate a national prospective study in New Zealand after 17 years to define whether orchidectomy alone and surveillance for nonseminoma germ cell testicular tumour (NSGCTT) is a sound policy and matches the results achieved by other treatment protocols. PATIENTS AND METHODS: Between 1980 and 1997, 248 men with stage I NSGCTT, from six New Zealand centres, were managed by orchidectomy alone and surveillance, with treatment of relapses using combination chemotherapy. RESULTS: Seventy of the 248 patients (28%) relapsed; 42 of 92 (46%) with vascular and/or lymphatic invasion (VLI) in the primary tumour relapsed, whereas only 26 of 151 (17%) without this feature relapsed (P<0.001). VLI was the only identifiable risk factor for relapse in this series. Only one relapse occurred >28 months after orchidectomy. Despite poor compliance in some patients (12%) their survival was not prejudiced. Three patients died from disease despite chemotherapy at relapse. At 17 years and a median follow-up of 53 months, 242 of the 248 men are disease-free and the disease-specific survival rate is 98%. CONCLUSIONS: This study shows that orchidectomy alone and treatment of relapses produces excellent long-term results without the adverse effects associated with retroperitoneal node dissection or elective chemotherapy for high-risk cases.

Bilateral germ cell testicular tumors in New Zealand: experience in Auckland and Christchurch 1978-1994.

PURPOSE: The incidence of germ cell testicular tumors (GCTTs) is increasing world wide, and with effective treatment, the majority of patients are being cured. Thus, the clinical and social impact of a second testicular tumor is becoming more important. The frequency, cumulative risk, and relative risk of developing a second testicular cancer in New Zealand have been documented and compared with other reports. PATIENTS AND METHODS: The records of 741 men presenting with germ cell testicular cancer in Auckland and Christchurch between 1978 and 1994 have been reviewed, and these data have been compared with data from other published studies. Cumulative risk was assessed by the Kaplan-Meier method. RESULTS: Over 2% of the study population developed a second germ cell testicular cancer. The cumulative risk was 5.2% over 15 years. The relative risk of developing a contralateral testicular tumor is 27.5 times higher than age-matched New Zealand peers. These results match the only comparable report in the literature. Five of the 16 bilateral tumors (31%) were synchronous, which is a higher incidence than in any other reported series. There was no concordance of histology in the first and second tumors. Prior exposure to cisplatin combination chemotherapy did not prevent the development of a second tumor. CONCLUSION: Men who are cured of a germ cell testicular cancer have a greatly increased risk of developing a second testicular cancer. Such patients should be informed of this risk and ideally kept under long-term surveillance.

Respiratory depression following morphine and morphine-6-glucuronide in normal subjects.

1. Morphine 6-glucuronide (M6G) is a metabolite of morphine with analgesic activity. A double-blind, randomised comparison of the effects of morphine and M6G on respiratory function was carried out in 10 normal subjects after i.v. morphine (10 mg 70 kg-1) or M6G (1, 3.3 and 5 mg 70 kg-1). Analgesic potency was also assessed using an ischaemic pain test and other toxic effects were monitored. 2. Following morphine there was a significant increase in arterial PCO2, as measured by blood gases 45 min post dose (0.54 +/- 0.24 (s.d.) kPa, P < 0.001), and in transcutaneous PCO2 from 15 min post dose until the end of the study period (4 h), whereas blood gas and transcutaneous PCO2 were unchanged after M6G at 1.0, 3.3 and 5.0 mg 70 kg-1. This increased PCO2 following morphine was associated with an increase in expired CO2 concentration (FECO2) (0.20 +/- 0.14% expired air at 15 min post dose, P = 0.002), compared with small but significant reductions in FECO2 following morphine 6-glucuronide (-0.15 +/- 0.17% at 1 mg 70 kg-1 P = 0.030, -0.14 +/- 0.15% at 3.3 mg 70 kg-1 P = 0.017, -0.18 +/- 0.11% at 5 mg 70 kg-1 P = 0.024). Maximum transcutaneous PCO2 was significantly increased after morphine (0.63 +/- 0.28 kPa P = 0.009), but was not changed after M6G at 1 mg (0.10 +/- 0.34 kPa P = 0.11) 3.3 mg (0.06 +/- 0.37 kPa P = 0.34) or 5 mg (0.26 +/- 0.07 kPa P = 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Phase II trial of procarbazine, vincristine and lomustine (POC) chemotherapy in metastatic cutaneous malignant melanoma.

40 patients with symptomatic metastatic melanoma were treated with procarbazine, vincristine and lomustine (POC). 4 patients had received chemotherapy previously. Responses were seen in 8 patients (20%), 4 of whom had a complete remission. All responding patients had some tumour shrinkage after one cycle. The median duration of response was 27 weeks, with 2 patients remaining in complete remission at 6 and 6.5 years. The median survival for the whole group was 22 weeks, whilst that of the responding patients was 35 weeks. Using conventional anti-emetics, the principal toxicities were nausea and vomiting, severe in 15% of cycles. Other nonhaematological toxicity was uncommon. Neutropenia (WHO grade 3 or 4) occurred in 11% of cycles and thrombocytopenia in 8%. The response rate of metastatic melanoma to POC chemotherapy was similar to other cytotoxic regimens though toxicity, other than nausea and vomiting, was minimal. The rapid response allows patients with unresponsive disease to be identified early, avoiding continuing toxicity.

Palliation of biliary obstruction in patients with advanced breast cancer using endoscopic stents.

Endoscopic insertion of a biliary endoprosthesis was successful in eight patients with extrahepatic biliary obstruction caused by breast cancer metastases. The serum bilirubin level was significantly reduced in seven patients and in four this was accompanied by marked symptomatic improvement. Endoprostheses required replacement after a median of 8 (range 3-127) weeks. Two patients responding to systemic anticancer therapy survived 27 and 43 months. Endoscopically placed stents offer effective palliation of extrahepatic biliary obstruction caused by metastatic breast cancer and long-term survival may be possible.

Where injecting drug users receive HIV counseling and testing.

In 1990, nearly 1.5 million human immunodeficiency virus (HIV) antibody tests were performed at publicly funded sites. Eight percent of those tests were performed for self-identified illegal injecting drug users (IDU). The authors examined data from 28 project areas using a client record data base that permitted an analysis of self-reported risk behavior by type of service delivery site. Among self-identified IDUs, 68 percent of those tested and 82 percent of those found to be seropositive had obtained HIV counseling and testing services in settings other than drug treatment centers. The findings indicate that HIV-prevention programs for IDUs need to be available in various service delivery settings, not just in drug treatment programs. Strong links and cooperation between sites offering HIV counseling and testing and sites providing drug treatment programs are important to preventing HIV transmission to and from IDUs.

Results of the surveillance policy of stage I non-seminomatous germ cell testicular tumours.

A series of 115 patients with clinical Stage I non-seminomatous germ cell testicular tumours were managed with orchiectomy and close surveillance (median follow-up 36 months, range 3-119); 34 (29.5%) relapsed, 21 within 6 months, 29 within a year and the latest at 28 months. At relapse all patients were treated with platinum or analogue-based drug combinations, supplemented in 7 by retroperitoneal node dissection; 30 patients achieved durable remissions and 2 have had further relapses successfully treated. Two died; both had malignant teratoma intermediate with primary stage T1 and vascular and/or lymphatic invasion of primary tumour. At a median follow-up time of 36 months, the survivors (98.3%) demonstrate no evidence of disease, these results matching the outcome of other methods of management. Vascular and/or lymphatic invasion was associated with an enhanced relapse rate but specific histology, T stage of the primary and pre-orchiectomy serum alpha-fetoprotein status did not appear to favour relapse. The first sign of relapse was tumour marker alone in 10 patients, radiological features alone in 12, or both in 10 patients. However, in 2 cases the relapse was first detected clinically. Furthermore, pre-orchiectomy and relapse marker status did not correlate well. These points emphasise the importance of all aspects of follow-up, none of which can be safely omitted.

Morphine 6-glucuronide: a metabolite of morphine with greater emetic potency than morphine in the ferret.

1. The emetic potencies of morphine and its metabolite morphine 6-glucuronide have been determined in the ferret by constructing dose-response curves for mean total retches and vomits for subcutaneous doses of 0.05 mg kg-1 to 5 mg kg-1. Morphine 6-glucuronide induced retching and vomiting at lower doses than morphine and at a maximal dose induced more retching and vomiting than morphine. 2. The emesis induced by both morphine and morphine 6-glucuronide was abolished by the preadministration of naloxone (0.5 mg kg-1 s.c.). 3. The 5-HT3 receptor antagonists granisetron and ondansetron (1 mg kg-1, s.c.) failed to abolish or reduce emesis induced by either compound. 4. At a high-dose (5 mg kg-1), morphine but not morphine 6-glucuronide failed to induce emesis and abolished the emesis induced by the cytotoxic drug, cyclophosphamide (200 mg kg-1, i.p.). 5. Preliminary pharmacokinetic studies of intravenous and subcutaneous morphine and morphine 6-glucuronide revealed that morphine 6-glucuronide accounts for less than 1% of the metabolic product of morphine in the ferret. Peak plasma levels of the two compounds after their subcutaneous administration were obtained within 10 min. The metabolic profile of morphine was not dose-dependent. There was no relationship between plasma level and emetic response for either compound.

Explanation at the opioid receptor level for differing toxicity of morphine and morphine 6-glucuronide.

The radiolabelled opioid receptor binding affinities of morphine and its active metabolite morphine 6-glucuronide at the total mu, mu 1, mu 2 and delta receptors were determined. Morphine 6-glucuronide was found to have a 4-fold lower affinity for the mu 2 receptor (IC50 17 nM and 82 nM for morphine and morphine 6-glucuronide respectively, P = 0.01), the receptor postulated to be responsible for mediating the respiratory depression and gastrointestinal effects after morphine. This provides a possible explanation for the reduced respiratory depression and vomiting seen following morphine 6-glucuronide in man. A similar reduction in affinity of morphine 6-glucuronide was seen at the total mu receptor whilst there was no significant difference seen at the mu 1 or delta receptor. Hence the increased analgesic potency of morphine 6-glucuronide over morphine remains unexplained.

A less toxic regimen of 5-fluorouracil and high-dose folinic acid for advanced gastrointestinal adenocarcinomas.

The combination of high-dose folinic acid with 5-fluorouracil has shown improved response rates in several trials in advanced colorectal carcinoma. This however is at the expense of increased toxicity: regimens using weekly bolus injections produce diarrhoea in most patients and occasional toxic deaths from this, whilst those using daily injections for one week in four report both diarrhoea and severe oral mucositis. Both types of regimen have significant rates of myelosuppression. A recent report described a different schedule of 5-fluorouracil and folinic acid, which appeared better tolerated but equally active (De Gramont et al., 1988). Here we report results using the same programme, in 64 patients with advanced adenocarcinomas. (Forty three colorectal, ten gastric, six pancreatic and five of unknown primary.) Patients received 200 mg m-2 folinic acid by infusion over 2 h followed by an IV bolus of 5-fluorouracil 400 mg m-2 then an infusion of 5-fluorouracil 400 mg m-2 over 22 h. This was repeated over the next 24 h. The schedule was given every 2 weeks for a total of six to 12 courses depending upon the response. The overall response rate was 26% in 62 evaluable patients. No toxicity greater than WHO Grade II occurred. Diarrhoea and mucositis did occur in around 10% of treatments but were not troublesome. No febrile neutropenic episodes were seen. Despite previous reports which described only modest activity for this combination against stomach cancers, this regimen demonstrates low toxicity but retains good activity in the palliative treatment of both gastric and colonic adenocarcinomas.

Monitoring and documenting community-based organization outreach activities for populations at risk for HIV.

Street outreach has been demonstrated to be an effective strategy for reaching persons who are not served by traditional health-care programmes and are at high risk for contracting the human immunodeficiency virus (HIV) and subsequent acquired immune deficiency syndrome (AIDS). The U.S. Centers for Disease Control (CDC) supports street outreach programmes through a number of mechanisms that offer funding and technical assistance to State and local health departments, community-based organizations, and national organizations. A recent systematic review of four outreach programmes and reviews of other CDC-supported outreach revealed the need for guidance concerning systems of monitoring and documenting services.

Periventricular enhancement: a non-pathognomonic sign of intracerebral tumours.

Four cases of periventricular contrast enhancement on computed tomography due to different tumours are reported, emphasizing that periventricular contrast enhancement is a non-specific radiological sign.

Disease relapse in patients with stage I nonseminomatous germ cell tumor of the testis on active surveillance.

Thirty-six patients with apparent stage I nonseminomatous germ cell tumor (NSGCT) of the testis were treated by inguinal orchidectomy and intensive follow-up only. Assessment included measurement of serum alpha fetoprotein (alpha FP) and beta human chorionic gonadotropin (beta HCG) (tumor markers) and chest x-ray monthly for 1 year, then twice monthly for 1 year, with computed tomographic (CT) scans of abdomen and chest repeated three times monthly for the first year and six times monthly for the second year. Median follow-up was 36 months (range, 14 to 92 months). Relapse occurred in 12 patients (33.3%) at a median of 7 months (range, 2 to 28 months). Elevated markers were of limited importance in relapse detection, confirming the need for close clinical and radiological follow-up. Of nine histological factors examined in the primary tumor only the presence of lymphatic invasion was associated with a significantly higher relapse rate. All patients were treated at relapse with cisplatin-based chemotherapy. Four underwent surgery in addition, two before and two after chemotherapy. Eleven were rendered disease-free, but four had a second relapse. One patient has died, one is alive with disease, and ten are disease-free. Chemotherapy failed to cure six patients who had relapsed but bulk of disease was not a factor. Despite the good overall result reported here, optimal postorchidectomy management of apparent stage I disease remains to be defined.