Phase I and pharmacokinetic study of KRN8602 alone and with filgrastim in patients with advanced cancer.

PURPOSE: To determine the recommended dose, toxicity profile, and pharmacokinetics of KRN8602 (MX2-hydrochloride), a novel morpholino anthracycline with potent cytotoxicity against anthracycline-sensitive and resistant experimental tumors in vitro and in vivo. PATIENTS AND METHODS: KRN8602 was administered alone in increasing doses to patients with advanced cancer or high-grade gliomas until dose-limiting toxicity (DLT) was observed in three or more of five patients treated in a dose level. Because neutropenia was dose limiting, further escalation was investigated with filgrastim support. RESULTS: Fifty-six assessable patients completed at least one cycle of chemotherapy. The recommended dose of KRN8602 alone was 40 mg/m2. Dose escalation was limited by neutropenia. The recommended dose of KRN8602 with filgrastim was 70 mg/m2, and limiting toxicities were neutropenia, diarrhea, and vomiting. The most commonly experienced nonhematologic toxicity was nausea and vomiting. Alopecia and mucositis were infrequent and mild. Pharmacokinetic parameters showed substantial variation, although the area under the plasma concentration-time curve (AUC) and maximum concentration both increased with dose. There was no relationship between pharmacokinetic parameters and toxicity. CONCLUSION: KRN8602 at doses of 40 mg/m2 when administered alone and 70 mg/m2 when administered with filgrastim appeared to be manageable. The major DLTs were neutropenia and, at higher doses, diarrhea and vomiting. The efficacy of this drug is currently being tested in phase II studies.

Effect of filgrastim on the pharmacokinetics of MX2 hydrochloride in patients with advanced malignant disease.

PURPOSE: To investigate the effect of granulocyte colony-stimulating factor (G-CSF) on the pharmacokinetics and pharmacodynamics of the new morpholino anthracycline drug MX2. METHODS: A total of 25 patients with advanced malignant disease participated in a dose-escalation study in the first cycle of treatment given i.v. at doses of 50-80 mg/m2 (74-152 mg) with concomitant filgrastim (G-CSF, 5 microg/kg) given daily beginning at 24 h after the dose of MX2. RESULTS: The mean fast distribution half-life (1.5 +/- 1.0 min) and the mean plasma clearance (2.18 +/- 0.95 l/min) were significantly lower than the respective mean values found in a previous study in which 27 patients had received MX2 (16.8-107.5 mg) alone (3.3 +/- 2.2 min and 2.98 +/- 1.68 l/min, respectively; P < 0.05). There was no correlation between plasma clearance and the delivered dose for the combined MX2-alone and MX2-filgrastim groups, indicating that the lower clearance observed in the G-CSF group was probably not due to the higher dose. Elimination half-lives of the metabolites M1 and M4 were significantly greater in the filgrastim group (19.8 +/- 14.7 and 11.8 +/- 5.0 h for M1 and 14.8 +/- 4.1 and 12.3 +/- 6.3 h for M2, respectively). Unlike the MX2-alone group, there was no relationship in the MX2-filgrastim group between the relative nadir neutrophil count and the dose or between the duration of grade IV neutropenia and the dose of MX2. CONCLUSIONS: This study shows that filgrastim decreased the plasma clearance of MX2 by approximately 25%, possibly by inhibition of metabolism.

Pharmacokinetics and pharmacodynamics of MX2 hydrochloride in patients with advanced malignant disease.

The purpose of the present study was to investigate the pharmacokinetics and pharmacodynamics of the new morpholino anthracycline drug MX2. A total of 27 patients with advanced cancer participated in a dose-escalation study in the first cycle of treatment with drug given i.v. at doses of 10-50 mg/m2 (total dose 16.8-107.5 mg). The mean total systemic plasma clearance (CL) of MX2 was 2.98 +/- 1.68 l/min, the mean volume of distribution at steady state was 1460 +/- 749 l and mean elimination half-life was 10.8 +/- 5.1 h. The area under the plasma concentration-time curve (AUC) of MX2 was linearly related to the dose per kilogram and the dose per body surface area (r2 = 0.43, P < 0.01 and r2 = 0.44, P < 0.01, respectively). CL did not correlate with total body weight, lean body mass or body surface area. The mean elimination half-lives of the metabolites M1, M2, M3 and M4 were 11.8 +/- 5.0, 21.9 +/- 11.8, 19.0 +/- 11.3 and 12.3 +/- 6.3 h, respectively. The fractional Emax model produced a much better fit to the relative nadir neutrophil count versus dose data (r2 = 0.42) than to the relative nadir neutrophil count versus AUC or peak concentration (Cmax) data (r2 = 0.15 and 0.09, respectively). There seemed to be a threshold dose of about 65 mg of MX2 at or above which a large proportion of patients had a nadir neutrophil count of less than 0.5 x 10(9)/l. This study shows that the pharmacokinetics of MX2 are similar to those of other anthracyclines. With other anthracyclines the degree of myelosuppression seems to depend more on the AUC and Cmax than on the delivered dose; however, with MX2 the degree of myelosuppression depends more on the dose given than on drug exposure expressed as the AUC or Cmax.

Comparative pharmacokinetics of KRN8602, a new morpholino anthracycline, and adriamycin in tumor-bearing mice.

It has been reported that KRN8602 shows antitumor effects similar or superior to those of Adriamycin (ADM) against several murine and human cell lines and has been found to be effective against multidrug resistant tumor cells. We investigated the pharmacokinetics of KRN8602, a new morpholino anthracycline, in comparison with ADM in mice bearing colon26 adenocarcinoma. After intravenous administration, both drugs disappeared triexponentially from the plasma and KRN8602 was eliminated faster than ADM. The rate of elimination of KRN8602 from tissues was also faster than than of ADM. The relative order of the area under the curve (AUC) of KRN8602 was spleen > tumor > small intestine > lung > kidney > heart > liver > brain > plasma, while that of ADM was spleen > kidney > lung > liver > heart > small intestine > tumor > plasma. ADM was not detectable in the brain. The AUC of KRN8602 was higher than that of ADM in the tumor and brain, but it was lower in other tissues. The tissue-to-plasma concentration ratio (KPapp) of KRN8602 was higher than that of ADM in the tumor, spleen, small intestine and brain. KRN8602 was metabolized to several metabolites. The concentrations of M1 and M2 (glycoside-type metabolites) was relatively high in the spleen. M3 (aglycone-type metabolite) showed a very high AUC ratio in the liver (34%). In tumor, M1 and M2 concentrations were low and M3 was not detected. KRN8602 had a greater activity than ADM and M2 had a cytotoxic activity similar to KRN8602 against colon26 cells in an MTT assay. These results suggest that the strong antitumor effect of KRN8602 against colon26 is due not only to its strong cytotoxic activity but also to its marked transferability into tumors. KRN8602 shows better selective toxicity than ADM, because KRN8602 is more selective for tumors than ADM and less is transferred to normal tissues.

The antitumor effect of MX2, a new morpholino anthracycline, against malignant glioma cell lines and its subcellular distribution.

The chemotherapeutic effect of MX2 (3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin), a new lipophilic morpholino anthracycline, against rat C6 and human T98G glioma cells, was examined in vitro and in vivo. The subcellular distribution of MX2 was also studied. The drug concentrations of MX2 required for the 50% inhibition of cell growth (IC50) for C6 and T98G cells were 25.5 +/- 1.3 ng/ml and 70.6 +/- 6.8 ng/ml, respectively, which were much lower than the IC50 values for nimustine (ACNU). A C6 subline resistant to ACNU, C6/ACNU, was established by continuous exposure to graded concentrations of ACNU. The IC50 of MX2 for C6/ACNU was 28.3 +/- 2.2 ng/ml, indicating no cross-resistance to MX2. In the rats bearing the intracerebral C6 tumors, the life span was increased by about 40 to 100% after intravenous administration of MX2 at doses ranging from 1 to 3 mg/kg of body weight. Confocal laser scanning microscopy demonstrated visually the good accumulation of MX2 in the implanted intracerebral C6 tumors, as well as its predominant distribution in the cytoplasm over the nucleus in both cell lines in vitro. Ultrastructural studies also demonstrated the cytotoxic effects of MX2 against glioma cells. Our results suggest that MX2 may be a useful chemotherapeutic agent in the treatment of malignant gliomas and that confocal laser scanning microscopy is useful for the study of the cellular pharmacokinetics of anthracycline derivatives, such as MX2.

Subcellular localization and cellular pharmacokinetics of MX2, a new morpholino anthracycline in glioma cells using confocal laser scanning microscopy.

The cellular uptake, subcellular distribution and retention of MX2, a new morpholino anthracycline, were compared with those of adriamycin (ADM) using confocal laser scanning microscopy (CLSM) in rat C6 and human T98G glioma cell lines. The tumor cells were exposed to 1-30 micrograms ml-1 of MX2 and ADM for 120 min and further incubated without drugs for 120 min after washing twice with medium. During incubation, real-time subcellular distribution of MX2 and ADM in living tumour cells were observed at various intervals using CLSM. For analysis of the in vivo uptake. Wistar rats bearing the C6 glioma were intravenously administered MX2 at a dose of 5 mg per kg body weight 60 min before sacrifice. The fluorescence of MX2 was predominantly seen in the cytoplasm in both C6 cells and T98G cells, although it was also present in the nucleus. In contrast, that of ADM was mainly confined to the nucleus in both cell lines. The fluorescent intensity of ADM in the nucleus after 120 min of exposure was approximately 1.5-fold higher than that of MX2 at the same dose exposure, probably indicating a greater amount of ADM accumulated in the nucleus than MX2. The influx and efflux of MX2 were much more rapid and greater than those of ADM in both cell lines. There was almost no difference in subcellular distribution among the doses tested in this study. The subcellular distribution of MX2 in vivo was almost similar to that of MX2 in vitro. These results suggest other mechanisms by which MX2 exerts its cytotoxic effects on tumour cells together with the inhibition of DNA topoisomerase II, which has been reported previously. It is considered that the CLSM technique is useful for the study of the cellular pharmacokinetics of antitumour agents such as anthracycline derivatives.

[Pharmacokinetics of MX2, a new morpholino anthracycline, in CSF following intravenous injection].

MX2 x HCl is a new morpholino anthracycline derivative with molecular weight 622.07, and highly lipophilic. In the animal experiments, MX2 was found to cross the blood brain barrier after i.v. injection. Its distribution into the brain was increased by intracarotid injection. In the present study, we examined the distribution of MX2 into the cerebrospinal fluid (CSF) after i.v. administration (5 mg/kg) in normal rabbits. Five min after injection, plasma concentration of MX2 reached to the maximum level (4344.5 ng/ml). CSF concentration of MX2 was at the highest level (75.8 ng/ml) 10 min after injection, and thereafter decreased gradually in parallel with plasma concentration. At 5 hrs after injection, CSF concentration became 26.7 ng/ml, AUC half time of elimination, and mean residence time were 3093.8 ng.hr/ml, 4.57 hrs and 5.10 hrs in plasma and 212.3 ng.h/ml, 5.23 hrs and 7.14 hrs in CSF, respectively. These results indicate that MX2 is able to distribute into CSF after i.v. injection, and expected to be a new anticancer drug for brain and leptomeningeal tumors.

[Pharmacokinetics and antitumor activity of MX2, a new morpholino anthracycline in brain tumor intracerebral transplanted in rats].

Pharmacokinetics and antitumor activity of MX2.HCl (MX2), a new morpholino anthracycline, were investigated in rats transplanted 9L gliosarcoma cells in the brain. (1) Pharmacokinetics: AUC of MX2 in the brain tumors which received intracarotid and intravenous injection of 2mg/kg of MX2 were 117.50 and 55.94 micrograms.hr/g, respectively. AUC of the brain tissue was 1.38-3.90 micrograms.hr/g. (2) Antitumor activity: The inhibition of cell growth at the concentration of 0.1 micrograms/ml was 73.1% with MTT assay. The mean survival time in tumor-bearing rats after intracarotid and intravenous injection of 2mg/kg of MX2 prolonged significantly. Therefore, it seems that MX2 will become an efficacious drug for the treatment of malignant glioma.

[Pharmacokinetics of KRN 8602 in cancer patients].

The pharmacokinetic properties of KRN 8602, an anthracycline compound, was studied by HPLC following intravenous administration of KRN 8602 to cancer patients. The results were as follows. (1) The plasma concentration-time curve declined as a triphasic function (alpha, beta, gamma) (t1/2 (alpha) = 0.02910, +/- 0.0054 hr, t1/2 (beta) = 0.704 +/- 0.319 hr, t1/2 (gamma) 8.37 +/- 1.37 hr). The blood cell concentration was higher than that in plasma. (2) The distribution volumes of the tissue compartment were larger than those of the central compartment. This result suggested that KRN 8602 would be easily transferred into the tissues. (3) The area under the curve (AUC) of KRN 8602 increased in proportion to the increase of dosage. (4) The metabolites of KRN 8602 were detected in plasma, blood cell and urine. (5) Urinary excretion of KRN 8602 and its metabolites were extremely low.

[Distribution and acute toxicity of a new morpholinoanthracycline, MX2, in normal rat brain after intra-arterial injection].

Intra-arterial infusion chemotherapy has been applied for the treatment of malignant brain tumors to increase the distribution of the drug into the tumor. MX2, a new morpholinoanthracycline, is a lipophilic compound, and has a strong antineoplastic effect against human and rat glioma cells. In this report, the acute toxicity and distribution of MX2 after intracarotid injection were studied using female Wistar rats weighing 150 g. To test the acute toxicity, various doses ranging 1.5 to 6 mg/kg was administered. All rats died within 4 days when received more than 3 mg/kg of intra-arterial or intravenous MX2. No rats died if the dose was reduced to less than 2 mg/kg. For the purpose to examine distribution in the brain, rats which received 2 mg/kg of intra-carotid MX2 were killed 5 to 120 min. after injection. The level of MX2 in the ipsilateral brain tissue reached to the maximum 5 min. after injection, and then rapidly decreased. The maximum concentration of MX2 in the ipsilateral brain was 25-fold higher than that in the contralateral brain, and 20-fold higher than that after intravenous injection of the same dose. The AUC (area under the curve) in the ipsilateral brain after intra-carotid injection was 8.0-fold higher than that in the contralateral brain, and 7.3-fold higher than that after intravenous injection of the same dose. These results indicate that intra-carotid administration can increase the distribution of MX2 in the normal brain.

Antitumor activity and pharmacokinetics of a morpholino-anthracycline derivative (KRN8602) against human breast carcinoma xenografts serially transplanted into nude mice.

The antitumor activity and pharmacokinetics of (7R, 8S, 10S)-10-((3-deamino- 3-(4-morpholino)-2,3,6-trideoxy-alpha-L-lyxo-hexopyranosyl)oxy)-8- ethyl- 7,8,9,10-tetrahydro-1,6,7,8,11-pentahydroxy-5,12-naphthacenedione hydrochloride (KRN8602) were evaluated using five human breast carcinoma xenografts in nude mice. The maximum non-toxic dose of KRN8602 was 2 mg/kg by q4d x 3 intraperitoneal and peroral administration. KRN8602 showed significant antitumor activity against MX-1, which is less sensitive to adriamycin, with the chemotherapeutic indices of 13.0 for po administration and 9.5 for ip injection. Although KRN8602 also inhibited the growth of T-61 significantly, the antitumor activity of this agent against the other three breast carcinoma xenografts was limited. To elucidate this discrepancy, pharmacokinetic analysis and MTT assay were conducted using the KRN8602-sensitive MX-1 and KRN8602-insensitive R-27. While no differences were observed in the area under the curve and the peak concentration of KRN8602 for each tumor, a difference in the sensitivity of the tumor strains was obvious in MTT assay. The efficacy of this agent seemed to depend on the sensitivity of each type of tumor cell rather than the concentration of agent in tumor tissues. If it were possible to select patients with sensitive tumor cells to this agent by the MTT assay, the phase II trial might be completed within a short period by reducing the number of studied patients.

[Thiol-dependent protective systems in alimentary prevention of the toxic effect of carminomycin]. / Tiolzavisimye zashchitnye sistemy pri alimentarnoi profilaktike toksicheskogo deistviia karminomitsina.

The state of the thiol-dependent systems i.e. concentration of the SH-groups, activity of glutathione reductase and glutathione-S-transferase, carminomycin antitumor and toxic effects was studied under conditions of tumor growth and carminomycin therapy with the use of prophylactic rations (PR) aimed at stimulating the cell thiol-dependent and antioxidant systems for decreasing the drug toxic action. It was shown that addition of sulfur-containing amino acids, selenium and vitamin E to the ration of healthy and tumor-bearing rats (Walker carcinosarcoma 256) induced a decrease in the level of the SH-groups in the liver just likely promoting efficient extrahepatic usage of glutathione. After administration of carminomycin a long with the PR use, the liver showed the thiol-preserving capacity evidenced by a decrease or complete elimination of the above effect of the ration. The use of PR resulted in a marked increase in the glutathione-S-transferase activity in cytosol and to a lesser extent in the liver microsomes. A regulating effect of the PR on the activity of glutathione reductase was observed: its inhibition in the healthy animals and stimulation after carminomycin administration in the heart of the healthy animals and the liver of the tumor-bearing animals.

Anthracycline incorporation in human lymphocytes. Kinetics of uptake and nuclear concentration.

Fluorescence emission spectra from anthracycline-treated cells suspended in buffer have been studied. The kinetics of uptake and the nuclear concentration of anthracyclines in human lymphocytes have thus been determined using the fluorescence properties of these drugs. Four anthracyclines have been used: adriamycin (ADR), 4'-O-tetrahydropyranyl-adriamycin (THP-ADR), carminomycin (CAR) and aclacinomycin A (ACM). We have shown that no quenching of the drug fluorescence is obtained through interaction of the drugs with the various components of the cell except the nucleus. No quenching is observed with cells lacking nucleus such as platelets and erythrocytes. Quenching of drug fluorescence occurs when drugs intercalate between base pairs of DNA only. This allows rapid determination of the amount of drug intercalated between nuclear base pairs in the steady state. We have thus estimated that one molecule of drug can bind for every 10, 8.3, 10 and 6.7 DNA base pairs in the case of ADR, THP-ADR, ACM and CAR, respectively. The kinetics of drug incorporation into the nucleus, once the cells have been solubilized with triton X-100, is very fast for the four drugs. However, the kinetics of drug uptake by the intacts cells strongly depends on the nature of the drug. When 10(9) cells/l are incubated with 1 microM drug, 50% of the final nuclear concentration is reached within 97 min, 3.2 min, 3.0 min and 1.2 min in the case of ADR, THP-ADR, CAR and ACM, respectively. The kinetics directly correlates with the polarity of the molecule.

[Pharmacokinetics of anthracycline antibiotics deposited by polymers]. / Izuchenie farmakokinetiki antratsiklinovykh antibiotikov deponirovannykh polimerami.

An increase of doxorubicin concentration in different organs and tissues and its decrease in the peripheral blood were observed when studying pharmacokinetics of this drug administered in the 10% solution of polyvinylpyrrolidone. A prolonged and stable release of carminomycin from glue composition MK-10-0 "carminacryl" confirms an expediency of alpha-cyanoacrylate use for deposition of anthracycline antibiotics with the aim of loco-regional chemotherapy.