Simultaneous determination of the peptide-mitomycin KW-2149 and its metabolites in plasma by high-performance liquid chromatography

A gradient high-performance liquid chromatographic (HPLC) method is described for the quantification of KW-2149 and its two major metabolites in plasma. The method involves a sample clean-up by solid-phase extraction on C18 columns, separation of the respective compounds by HPLC on a YMC ODS-AQ column (5-microm particle size, 150x6 mm I.D.), using a methanol-water gradient system as an eluent, and measurement by UV absorbance detection at 375 nm. The limits of quantitation were 10 ng/ml for KW-2149 and M-16, and 15 ng/ml for M-18. Recoveries from plasma were higher than 92% on C18 extraction columns. Intra-day precision, expressed as %C.V., was between 1.4 and 6.5%. Intra-day accuracy ranged from 94 to 107%. Precision and accuracy of variability of inter-assays increased somewhat; however, were still within acceptable ranges. The ability of the method to quantify KW-2149 and two major metabolites simultaneously, with precision, accuracy and sensitivity, make it useful in monitoring the fate of this new mitomycin in cancer patients.

Determination of the new anticancer agent KW 2149, 7-N-[2-[2-(gamma-L-glutamylamino)ethyl)dithio)ethyl]mitomycin C, an analogue of mitomycin C

The new mitomycin 7-N-[2-[2-(gamma-L-glutamylamino)ethyl)dithio)ethyl] mitomycin C (KW 2149) (I) proved to be active against a wide variety of experimental tumours. In order to perform pharmacokinetic studies with the new drug in Phase I sessions, a fast and reliable method has been developed based on the data of previous assays for mitomycin C. XAD-2 was preferred for isolation of I from blood plasma. The recovery of I was 50% whereas that of mitomycin C was 85%. Optimal separation was obtained on octadecyl silica columns with methanol-water (45:55, v/v) as mobile phase, while ultraviolet absorbance detection was performed at 375 nm. The assay enabled determination of I in a plasma concentration range of 20-1000 ng/ml using porfiromycin as internal standard.

High mitomycin C concentration in tumour tissue can be achieved by isolated liver perfusion in rats

To enable the treatment of hepatic metastasis with higher, theoretically more effective, doses of systemically toxic anticancer drugs, an isolated liver perfusion (ILP) technique was developed in WAG/Ola rats. First, in a toxicity study the maximally tolerated dose (MTD) of mitomycin C (MMC) was determined for a 25-min ILP and for hepatic artery infusion (HAI) after the administration of a bolus dose. The MTD in the ILP setting (4.8 mg/kg) was 4 times that using HAI (1.2 mg/kg). Subsequently, in a rat colorectal hepatic-metastasis model, concentrations of MMC in tumour, liver, plasma and perfusate were measured during a 25-min ILP to investigate the expected pharmacokinetic advantage of ILP. The mean plasma level determined after ILP (1.2 as well as 4.8 mg/kg MMC) was significantly lower (P less than 0.001) than that obtained following HAI. This may explain both the absence of severe systemic toxicity and the higher MTD in ILP-treated groups. No significant difference in mean tumour and liver tissue concentrations of MMC were found when the groups treated with 1.2 mg/kg drug via HAI vs ILP were compared. The mean MMC concentration in tumour tissue was significantly higher (almost 5 times; P less than 0.05) in rats treated by ILP with the MTD (4.8 mg/kg) than in those treated via HAI with the MTD (1.2 mg/kg). ILP of MMC can be safely performed using a dose 4 times higher than the MTD in the HAI setting, leading to an almost 5-fold concentration of MMC in hepatic metastasis. ILP of MMC may therefore represent a promising therapy for metastasis confined to the liver.

[Pharmacokinetics and local availability of mitomycin. The influence of vasoconstriction and chemoembolization]

The influence of the vasopressin-pro-drug glycylpressine (GP) and of a chemoembolisation with Spherex starch-particles (SP) on the availability of mitomycin (CAS 50-07-7, mitomycin C, MMC) was investigated in 30 patients with liver metastases, MMC administration was performed after blocking of the common hepatic artery by different concentrations of SP and after different time-intervals of GP. The comparison of plasma-levels after bolus injection without GP and after administration of MMC after 2, 5 and 15 min of vasoconstriction and after chemoembolisation with 450 mg or 900 mg SP, respectively, showed a remarkable reduction in the systemic circulation of MMC in the blood vessel system at about 40% (GP) and 45% (SP). A statistically significant influence on the pharmacokinetics of MMC with regard to CO, Vd, T 1/2zp, AUC and Cl(tot) was found, but not in t1/2el, t1/2biol and Vl. Both methods cause a distinctly accelerated diffusion of MMC into the tissue of the tumor region by change of the hemodynamics, leading to lowered side-effects. Thus the clinical picture was improved by MMC.

[A case of hepatocellular carcinoma treated by intrahepatic arterial administration of anticancer agents: serial determination of the concentration of the chemotherapeutic agents in serum and dialysate during hemodialysis]

The concentration of adriamycin (ADR) and mitomycin C (MMC) were measured in serum and dialysate in a patient with hepatocellular carcinoma complicating chronic renal failure. ADR at a dose of 20 mg and MMC at 10 mg were administered through the hepatic artery or peripheral vein during hemodialysis. ADR and MMC became undetectable after 24 hours and 2 hours, respectively. On the other hand, while MMC was detected in dialysate, but ADR was not. Consequently, it was speculated smaller molecular weight of MMC (334.34) than that of ADR (579.99) might be responsible for the appearance of MMC in dialysate. These results suggest that hemodialysis may be effective in reducing side effects of certain anticancer agents. Serum concentration of the anticancer agents injected through hepatic artery was similar to that injected intravenously.

Extracorporeal removal of anticancer drugs in hepatic artery infusion: the effect of direct hemoperfusion combined with venovenous bypass

The effect of a new extracorporeal system combining direct hemoperfusion (DHP) with venovenous bypass was evaluated in the elimination of anticancer drugs in hepatic artery infusion. Adriamycin (3 mg/kg) and mitomycin C (1 mg/kg) were given to mongrel dogs through the hepatic artery with three different durations of 1, 10, and 20 minutes. Plasma drug levels were determined at the inlet and outlet of DHP and right external jugular vein (systemic level). Blood flow through DHP averaged 200 ml/min. In dogs without DHP (group I; n = 4), systemic levels of adriamycin and mitomycin C increased rapidly with 1-minute infusion, reaching the peak values of 6.61 +/- 2.44 (mean +/- SD) and 2.20 +/- 1.05 micrograms/ml, respectively. With DHP under single venous bypass (group II; n = 5), the peak values were reduced to 1.25 +/- 1.02 and 0.79 +/- 0.52 microgram/ml. Moreover, the peak levels were markedly reduced by DHP under hepatic venous isolation (group III; n = 6), the values being 0.41 +/- 0.15 and 0.13 +/- 0.07 microgram/ml with 1-minute infusion. The drug-removal rates were improved substantially in group III compared with group II. The longer the duration of infusion, the higher the removal rates tended to be in group III. These results indicate that effective elimination of anticancer drugs can be accomplished by this system during intraarterial chemotherapy of the liver.

[Effect of degradable starch microspheres (DSM) on hepatic hemodynamics]

The effect of intra-arterial infusion of degradable starch microspheres (DSM) on hepatic arterial blood flow was measured using a transit-time ultrasonic blood flow meter. Before the infusion of DSM, the mean hepatic arterial flows were 316 +/- 79 ml/min. After infusion, the mean flows decreased to 43 +/- 86 ml/min (86%). RI-angiography using 99mTc-macroaggregated albumin (MAA) was performed to measure hemodynamic changes in the liver. T/N ratio of 99mTc-MAA accumulation was increased from 0.37 to 0.62. Based on the peripheral MMC blood levels after combined infusion with DSM and MMC, the mean AUC with MMC plus DSM was decreased to 55% of that of AUC with MMC alone. These results show that combined use of DSM is effective for intra-arterial chemotherapy against the hepatic cancer.

Pharmacokinetic analysis in intraperitoneal hyperthermic chemotherapy of far-advanced gastric cancer patients

The pharmacokinetics of mitomycin C (MMC) has been evaluated in 10 far-advanced gastric cancer patients by means of an intraperitoneal hyperthermic perfusion (IPHP) using MMC to prevent and/or treat peritoneal dissemination. Further, misonidazole (MIS), which was used as a thermosensitizer, also was evaluated. The IPHP was performed for 120 min right after surgical procedure, using a closed-circuit with an inflow perfusate temperature from 46.3 approximately 47.5 degrees C and an outflow temperature of 44.0 approximately 46.0 degrees C. The MMC level in the perfusate was 10 micrograms/ml at the onset of IPHP and thereafter decreased to 1.7 +/- 0.4 micrograms/ml minutes later. The average AUC (area under the curve) in the perfusate was 3.3 micrograms/ml during the IPHP. The MMC level in the peripheral blood was 0.15 +/- 0.04 micrograms/ml 30 min after start of the IPHP and increased to 0.18 +/- 0.05 micrograms/ml at the end of IPHP. Additionally, the MIS level in the peripheral blood was 64.7 +/- 10.3 micrograms/ml 60 min after the IPHP, 60.6 +/- 9.2 micrograms/ml at 120 min, and then decreased to 32.8 +/- 10.3 micrograms/ml at 12 hours after IPHP. The AUC was calculated as being 975 micrograms.hr/ml. Again, the level in the portal vein blood was calculated from the peritoneal permeability and the peripheral blood level of the drug. From data, it was concluded that the perfusate and portal vein blood level of MMC, the peripheral blood level of MIS, as well as the perfusate temperature, are important in providing a favorable, safe, antitumoral treatment.

[Blood levels of mitomycin C in patients given by various routes of administration]

Twenty mg of mitomycin C was administered to patients with colo-rectal cancer through various routes of administration. The values of pharmacokinetic parameters were as follows Intra-arterial administration (3 patients with rectal cancer): T1/2 alpha 8.4 min, T1/2 beta 63.8 min, maximum concentration (5 min after ia injection) 0.83 microgram/ml, AUC0-120 25.0 micrograms/ml/min. Intra-portal administration (7 patients with colon cancer): T1/2 alpha 6.1 min, T1/2 beta 61.0 min, maximum concentration (5 min after iv.) 0.75 microgram/ml, AUC0-120 25.3 micrograms/ml/min. Intra-peritoneal administration (14 patients with colon cancer): maximum concentration (20-30 min after i.p.) 0.23 microgram/ml, AUC0-120 21.1 micrograms/ml/min. Intra-pelvic administration (7 patients with rectal cancer): maximum concentration (20-30 min after i.p.) 0.06 micrograms/ml, AUC0-120 7.3 micrograms/ml/min. The reduction curve of intra-arterial administration closely resembles to that of intra-portal administration. Maximum blood level and AUC of intracavitary administration were relatively low compared with those of administration into blood vessels. Bone marrow suppression was seen in patients given mitomycin C into blood vessels and wound healing disturbance such as anastomotic leakage were noted in patients by intra-cavitary administration.

[Preventive effects of intra-arterial infusion chemotherapy of liver metastasis in non-resectable pancreatic cancer]

This is a study which evaluates intra-arterial chemotherapy for non-resectable carcinoma of the pancreas without liver metastasis (locally advanced). Twenty-one patients received ia-chemotherapy (MA-CP: Methotrexate + Angiotensin II----Citrovorum factor + Prostaglandin E1). They showed a 39% 1-year survival rate and 92% of 1-year cumulative rate of survival without liver metastasis. These incidences were significantly higher than those of (13%, 50%) 52 patients who underwent systemic chemotherapy (control). As the reason for such significant differences, we suspected that a high dose of chemotherapeutic view after MTX had been infused into the pancreatic-supplying arteries. This speculation was confirmed by the serial determination of the MTX concentration in the portal blood.

Chemotherapy in a pregnant rat model. 1. Mitomycin-C: pregnancy-specific kinetics and placental transfer

Although cancer complicates pregnancy infrequently, its occurrence jeopardizes maternal and fetal well-being. Treatment with chemotherapeutic agents may adversely affect rapidly dividing fetal tissue, while physiologic changes in pregnancy may alter maternal drug disposition. Previous work on placental transfer and pregnancy-specific kinetics of antineoplastic agents is limited, making the establishment of treatment guidelines for the pregnant cancer patient difficult. Using a pregnant rat model and sensitive HPLC methodology we quantitated the placental transfer and resulting fetal exposure of mitomycin-C (MMC), an alkylating agent. Following maternal dosing, the relative fetal exposure was 6.4%, indicating that MMC does cross the placenta, although to a limited degree. Significant pregnancy-specific alterations in drug disposition, including higher plasma concentrations and decreased clearances in pregnant animals, highlight the need for drug-level monitoring and possible dosage modification when these agents are used in pregnancy.

Clinical trial with surgery and intraperitoneal hyperthermic perfusion for peritoneal recurrence of gastrointestinal cancer

To treat six patients with peritoneal recurrence after radical operation for gastrointestinal cancer, an intraperitoneal hyperthermic perfusion (IPHP), combined with surgical resection of recurrent tumors, intestinal by-pass anastomosis, or both, was carried out. Immediately after complete resection of the intraperitoneal recurrent tumors, a 2- to 3-hour IPHP was performed under hypothermic general anesthesia at about 32 degrees C, using a perfusate containing 10 micrograms/ml or 20 micrograms/ml of mitomycin C (MMC) warmed at the inflow temperature of 46.6 degrees C to 46.9 degrees C. The apparatus used for IPHP was designed for intraperitoneal perfusion as a closed circuit. Although five of the six patients had a malignant peritoneal effusion at the time of admission, the effusion disappeared soon after IPHP, and no cancer cell was present in the lavage from Douglas' pouch. The other patient had a recurrent tumor at the anastomotic region after low anterior resection for rectal cancer and complete resection of the recurrent tumor, combined with IPHP, was carried out. One patient with a recurrent gastric cancer died of hepatic metastasis and cancerous pleuritis 5 months after this treatment, and the other five are in good health 12.8 +/- 5.1 months after IPHP. On the other hand, five patients with intra-abdominal recurrent gastric cancer, who received only surgical treatment within the same period of time, died 3.0 +/- 2.1 months after the surgery. Postoperatively, in the six patients with IPHP, transitory hepatic dysfunction, hypoproteinemia, and thrombocytopenia occurred. These results show that IPHP using MMC combined with surgery is a safe, reliable treatment for patients with peritoneal recurrence of gastrointestinal cancer.

Phase-system switching as an on-line sample pretreatment in the bioanalysis of mitomycin C using supercritical fluid chromatography

One of the problems of the application of supercritical fluid chromatography (SFC) in bioanalysis is the fact that many sample pretreatment procedures deliver the solutes of interest in a polar solvent, which upon injection will dramatically disturb the phase system characteristics of the SFC system. The phase-system switching approach, recently introduced for liquid chromatography-mass spectrometry, can be used to avoid this problem. Plasma samples containing the thermolabile and pH-sensitive cytostatic drug Mitomycin C (MMC) were injected onto a short precolumn. After washing and drying of the precolumn the compound of interest was desorbed using a supercritical fluid and analyzed by SFC. Up to 1 ml of plasma containing 20 ng of MMC has been analyzed in this way.

Behavior and resorption of mitomycin C following multiple intravesical administrations

Although several pharmacological data of intravesical mitomycin C (MMC) are available now, data about resorption following subsequent intravesical instillations with different instillation times are lacking. We have analyzed MMC concentrations in blood plasma and urine following eight subsequent instillations, with 0.5- and 1.0-h instillation times. The relationships between urinary pH, urinary MMC concentrations, and MMC blood plasma concentrations were determined, as well as the stability of MMC in urine at pH 5-8 at 37 degrees C. An average of 40.3 and 46.4% of the total parent drug was recovered for the 0.5- and 1.0-h instillations, respectively. Blood plasma concentrations of MMC could be measured in nearly all patients and were independent of instillation times, urine concentration, or urinary pH. Resorption of MMC and recovery was stable during eight subsequent instillations. It was demonstrated that MMC can be degradated in urine at physiological conditions (pH less than 6; 37 degrees C). However, neither an influence of prolongation of the instillation time on MMC recovery from urine, nor a significant correlation between urinary pH and urinary MMC concentrations could be demonstrated. Since MMC can be degradated at pH less than 6 within 0.5 h, buffering of instillation fluids containing MMC is recommended. Reuse of instilled MMC, therefore, cannot be advised.

In vitro antitumor activity of mitomycin C derivative (RM-49) and new anticancer antibiotics (FK973) against lung cancer cell lines determined by tetrazolium dye (MTT) assay

Seven small- (SCLC) and four non-small-cell (NSCLC) lung cancer cell lines were used to examine the in vitro cytotoxicity of cytotoxic drugs such as (1aS-(1a alpha,8 beta,8a alpha,8b alpha]-8-[aminocarbonyl)oxy)methyl)-4,8a- dimethoxy-1,1a,2,8,8a,8b-hexahydro-7-hydroxy-5-methyl-6- nitrosoazirino(2',3':3,4)-pyrrolo-(1,2-a)indole (RM-49) and 11-acetyl-8-carboxymethyl-4-formyl-14oxa-1,11-diaze- tetracyclo(7.4.1.0(2,7),0(10,12]tetradeca-2-4-6-trien-6,9-++ +diyl-diacetate (FK973). In vitro cytotoxicities of RM-49 and FK973 were compared with those of mitomycin C (MMC), cisplatin (CDDP), carboplatin (CBDCA), etoposide (VP16), adriamycin (ADM) and vindesin (VDS). Drug sensitivity was determined using a tetrazolium (MTT)-based assay. Average IC50 values of these two drugs were not statistically different compared with that of MMC, although FK973 showed strong antitumor activity against SCLC cell lines such as LT3, N857, and H69 at the same concentration. The predicted peak plasma concentration (predicted PPC) calculated by the formula proposed by Scheithauer, log (predicted PPC) = -0.788 + (0.755 x log(LD50], and relative antitumor activity, RAA (PPC/IC50), of RM-49 were higher than those of other drugs such as MMC, CDDP, CBDCA, and ADM against SCLC cell lines (P less than or equal to 0.05), and those of FK973 were also higher than those of other drugs such as MMC, CDDP, CBDCA, and ADM against SCLC cell lines (P less than or equal to 0.05). Based on these promising in vitro studies, the clinical trials of RM-49 and FK973 were warranted.

[Assessment of therapeutic effects by transcatheter arterial embolization (TAE) in hepatic malignant tumors with degradable starch microspheres (DSM)]

Transcatheter arterial embolization (TAE) with degradable starch microspheres (DSM) was carried out for fourteen cases with hepatic malignancies including twelve cases with hepatocellular carcinoma (HCC), one case with cholangiocarcinoma and one with metastatic liver cancer. DSM combined with anticancer agents were administered through a catheter introduced by Seldinger's method, in ten cases and through subcutaneously implanted drug delivery system (Port-A-Cath) in four cases. The dose of DSM was 900 mg/body and adriamycin 30-40 mg/m2 through the catheter or 12-14 mg/m2 through Port-A-Cath was used for HCC and cholangiocarcinoma. A same dose of DSM and mitomycin C 15 mg/m2 was administered for metastatic liver cancer through the catheter immediately after angiography. Results were as follows: 1) Partial response (PR) was obtained in six cases (50%) with HCC, and there were two other cases with minor response (MR). PR in cholangiocarcinoma and CR in metastatic liver cancer were obtained. 2) There were no adverse effects in four cases with Port-A-Cath. 3) The concentration of adriamycin in the peripheral venous blood was lower than that of one shot therapy, and decreased rapidly within an hour. These results suggested that good therapeutic effects can be obtained by TAE with DSM combined with anticancer agents for hepatic malignancies.

[Repeated intra-arterial chemotherapy combined with mitomycin C and degradable starch microspheres in inoperable metastatic hepatic cancer]

Intra-arterial chemotherapy combined with mitomycin C (MMC) and degradable starch microspheres (DSM) was prescribed repeatedly for 14 patients with inoperable hepatic metastasis. This intra-arterial treatment was repeated 2.7 times on the average. The average dose of DSM and MMC in a single infusion was 685 +/- 201 mg and 13.8 +/- 3.8 mg, respectively. To analyse the degradation time of DSM, MMC concentrations in the peripheral blood were measured by HPLC method. RI-angiography using 99mTc macroaggregated albumin(MAA) was performed to estimate the hemodynamic changes in the liver. Antitumor efficacy was evaluated in terms of tumor regression measured by CT scan. An objective tumor response was observed in 9/14 patients(64.2%): CR 1/14; PR 6/14; MR 2/14. Elevated CEA levels were decreased in 11/12 patients (91.7%). Based on the peripheral MMC blood levels after combined infusion with DSM and MMC, an occlusion of intrahepatic vessels with DSM continued at least for 30 minutes. Again, RI-angiography with 99mTc-MAA plus DSM revealed the increased accumulation in the tumor, compared to 99mTc-MAA only. Side effects possibly attributable to DSM were observed in 14/38 treatments, though they were slight and temporary. Thus, these results indicate that this combined intra-arterial infusion of DSM and MMC achieve, higher regional selectivity.

Intraperitoneal hyperthermic perfusion combined with surgery effective for gastric cancer patients with peritoneal seeding

Fifteen patients with far-advanced gastric cancer were given surgical treatment followed by intraperitoneal hyperthermic perfusion (IPHP) with mitomycin C (MMC) and misonidazole (MIS), a thermosensitizing drug. Immediately after extensive resection of the abdominal tumors, a 2-hour IPHP was performed at the inflow temperature of 44.7 to 48.7 C, using equipment designed for treatment of cancerous peritoneal seeding as a closed circuit, and under hypothermic general anesthesia at 30 to 31 C. In nine of the 15 patients with peritoneal seeding and/or ascites, cancerous ascites was absent after this treatment. In all cases, repeated cytologic examinations of the lavage from Douglas's pouch were negative. The postoperative courses were uneventful except for Patients 1 and 10, in whom slight leakage occurred. All patients were discharged and are in good health at the time of this writing, 7.2 +/- 4.6 months after the treatment. The Case 4 Patient recently died in a traffic accident. In all patients, transient hepatic dysfunction and hypoproteinemia occurred after the operation. This extensive surgery combined with IPHP using MMC and MIS was well tolerated and is a safe antitumor treatment for gastric cancer with peritoneal dissemination. Neurotoxicity due to MIS was nil.

The pharmacokinetic plasma profile of mitomycin C, measured after sequential intermittent intravenous administration

The pharmacokinetic plasma profile of mitomycin C (MMC) was studied during sequential courses in man. MMC was given repeatedly as i.v. bolus injections at fixed dose levels to the same patient either as a single agent or as part of different combination chemotherapy regimens. Large interindividual variations between the various pharmacokinetic parameters were observed. Statistical analysis showed no significant differences between average pharmacokinetic parameters when comparing the first and the second MMC injection, except for the total body clearance (Cltot). The Cltot was higher for the second injection when compared to the first injection in a group of patients who received MMC as a single agent (10 patients). For a group of patients receiving MMC as part of a combination therapy the average values of Cltot of the first when compared to the second injection were not statistically different (nine patients). This observation could not be correlated with clinical observations on toxicities.

[Clinical study of intraperitoneal chemotherapeutic perfusion (IPCP) of mitomycin C (MMC) and intraperitoneal administration of cisplatin]

IPCP was performed in an attempt to control ascites production by malignant tumors, and its inhibitory effect on ascites production was studied. The subjects were 24 patients who underwent surgery at this department between April 1981 and April 1986, consisting of 19 cases of ovarian cancer, 3 cases of cancer of the uterine body, 1 case of retroperitoneal tumor, and 1 case of metastatic ovarian cancer. As the treatment at the time of laparotomy, 30 mg of MMC was dissolved in 300 ml of normal saline and intraperitoneally administered. After holding for 30 minutes, it was discharged by cleaning out the abdominal cavity with 3,000 ml of normal saline. Immediately before closure of the wound, (A): MMC 10 mg, OK-432 100 KE, neocarzinostatin 4,000 units, or (B): (A) + cisplatin 100mg, was intraperitoneally injected, and the wound was closed without washing out this anticancer cocktail after drainage of the abdominal cavity and abdominal wall. Among the present 24 cases, (A) was applied in 17 cases, and (B) in 7 cases. The inhibitory effect on ascites production was 87.5% or 21/24 cases, specifically 88.2% (15/17) in the (A) group and 85.7% (6/7) in the (B) group. There were no particular side effects.

Pharmacokinetics of mitomycin-C in plasma and tumor tissue of cervical cancer patients and in selected tissues of female rats

Mitomycin-C (MMC) is an alkylating agent which has shown significant activity in gynecologic cancers, both in vivo and in vitro. We determined the delivery of MMC to target tissue by comparing plasma and tumor tissue concentrations of MMC as measured by high-performance liquid chromatography (HPLC) in five patients with cervical cancer. In a companion study, we measured MMC concentrations in plasma and selected tumors of female rats given an equivalent dose. In patients, the mean terminal half-life and total body clearance rates of MMC were 40 min and 275 ml/min/m2, respectively. The mean cervical tumor to plasma concentration of MMC was 1.26 +/- 0.34 (mean +/- SE, n = 4). In female rats, the terminal half-life and total body clearance rates of MMC were 28.4 min and 270 ml/min/m2, respectively. Tissue concentrations of MMC in rats were lower than plasma concentrations measured at corresponding times. The highest concentrations were found in lung and uterus (including cervix) with lower concentrations in ovary and liver. The mean half-life for elimination of MMC from tissues of rats was 20.3 +/- 2.8 min (mean +/- SE, n = 6). Based on similar pharmacokinetic parameters in rats and patients, the rat appears to be a suitable model for the disposition of MMC in human patients. The near equivalent drug concentrations found in tumor and plasma of patients suggests that the in vitro tests conducted at concentrations based on plasma level may be relevant to cervical tumor tissue, as well.

Mitomycin C skin toxicity studies in mice: reduced ulceration and altered pharmacokinetics with topical dimethyl sulfoxide

A series of toxicologic and pharmacokinetic studies were performed in BALB/c mice administered intradermal (ID) mitomycin C (MMC) at doses of .015 to 0.25 mg. Dose-dependent skin ulcers were produced at clinically relevant MMC dose levels of .05 and .075 mg (3.6 to 10.7 mg/m2). These doses produced peak ulcers of 0.15 to 0.22 cm2, respectively, one to five days after injection. The integrated ulcer area X time values (area under the curve [AUC] ulceration) were 0.89 and 3.11 cm2 X d. A large number of local pharmacologic adjuvants were found to be ineffective at reducing MMC ulceration after proximal ID injection. These included diphenhydramine, catalase, heparin, hyaluronidase, hydrocortisone, cysteine, N-acetylcysteine, lidocaine, vitamin E, and superoxide dismutase. Also, neither topical heating nor cooling of skin reduced MMC ulcerations. In contrast, a single topical application of a 100% dimethyl sulfoxide (DMSO) solution completely prevented 0.025 mg MMC-induced skin ulceration and significantly reduced .075 mg MMC ulceration (P less than .05 by multiple range tests). Topical DMSO also altered the disposition of ID MMC in mouse skin but not in plasma. Unexpectedly, the DMSO applications slowed MMC elimination from the skin. DMSO significantly increased the AUC for MMC in skin from 0.89 to 2.25 ng/h/mL of tissue (P less than .05). DMSO did not alter the degree of protein binding in skin tissue nor the in vitro chemical stability of MMC in skin tissue homogenates. These results show that experimental MMC-induced skin ulcers in mice can be ameliorated with an immediate application of topical DMSO. This effect is not due to enhanced systemic drug uptake, but may be due to reduced reactivity of MMC with target cellular nucleophiles.

[Intraarterial bolus infusion followed by rapid removal of anticancer agents with hemocarboperfusion under local hyperthermia in advanced hepatic cancer]

Reported herein is a new multidisciplinary treatment modality for unresectable hepatic cancer in which local hyperthermia and intraarterial infusion of bolus anticancer agent are simultaneously undertaken while anticancer agent leaking from the hepatic bed into the general circulation is rapidly removed by charcoal hemoperfusion. Local hyperthermia induced by exposure to 13.56-MHz radiofrequency waves was conducted between one and one and a half hours once or twice a week. During the hyperthermia treatment, a bolus of either 1 mg/kg Mitomycin C or 2 mg/kg Adriamycin was injected into the hepatic artery via a Vascular Access Port, the catheter portion of which had been surgically inserted into the hepatic artery and the reservoir of which had been implanted subcutaneously. In general, a regular dose of 6 mg of Mitomycin C was injected into the Vascular Access Port during the following hyperthermia procedures. In seven of nine patients (78%) treated with this method, a marked reduction in tumor size of more than 50% was observed on computed tomograms. A light to moderate degree of side effects such as leukocytopenia, thrombocytopenia, liver dysfunction or hair loss were noticed after the bolus infusion, but were not so serious as to threaten the patients' lives.

Mitomycin C plasma levels after intravesical instillation with and without hyaluronidase

In 20 patients undergoing transurethral resection for bladder tumor or multiple transurethral biopsies for monitoring after transurethral resection, mitomycin C, 20 mg., was instilled into the bladder immediately after the procedure. Mitomycin C was associated with hyaluronidase, 200.000 U, in 10 patients. Serum levels of mitomycin were determined by column chromatography 30 and 60 minutes after instillation. Hyaluronidase was not found to make any difference in mitomycin absorption. Potential expansions of the therapeutic modalities for preventing recurrent bladder tumor by hyaluronidase are discussed.

A bioassay to measure cytotoxicity of plasma from patients treated with mitomycin C

The unpredictable clinical toxicity observed in patients treated with mitomycin C and the observation that this agent must be reduced to an active form before alkylating target molecules have led to the development of a bioassay which is capable of detecting biologically active forms of mitomycin C in the plasma of drug-treated patients. The bioassay makes use of a repair-deficient mutant of Chinese hamster ovary cells, UV-20, which is 40 to 60 times more sensitive to mitomycin C than its wild-type parent. A standard curve relating in vitro cell colony-forming ability of UV-20 versus drug concentration in the plating medium has been determined. Mitomycin C levels in patient plasma as low as 1 ng/ml can be detected, compared to the 5-ng/ml limit of detection obtained with a high-pressure liquid chromatography assay for the parent compound. This assay has been utilized to detect active drug in plasma obtained from patients with colorectal cancer treated with mitomycin C as a single agent. At the completion of drug injection, serial blood samples were collected in heparinized tubes, and aliquots of plasma were extracted and assayed for mitomycin C levels by high-pressure liquid chromatography, diluted and assayed directly for their toxicity for UV-20 cells, or frozen at -20 degrees C to be assayed at a later time. The activity detected by immediate bioassay was stable up to 2 mo in frozen samples. Plasma pharmacokinetics determined by the bioassay in seven patients were no different than those determined by high-pressure liquid chromatography. No stable, cytotoxic species other than the parent compound were detected by the bioassay in the plasma of patients treated with mitomycin C.

Pharmacology of intraperitoneal infusion 5-fluorouracil and mitomycin-C

The pharmacokinetics of intraperitoneal infusion 5-fluorouracil and bolus administration mitomycin-C have been evaluated and permit one to determine the exposure advantage for this route of administration. as with other forms of regional chemotherapy, the limiting toxicity is locoregional. The therapeutic efficacy of this approach awaits the design and conduct of clinical trials.

[A clinical trial of a new mitomycin C derivative, KW-2083 (7-N-(p-hydroxyphenyl)-mitomycin C)]

KW-2083 [7-n-(p-hydroxyphenyl)-mitomycin C] is a new mitomycin C (MMC) derivative. Its myelotoxicity was compared with that of MMC by using colony-forming unit-spleen (CFU-S) from the femurs of C57BL/6 mice. As a result, it was estimated that the intensity of myelotoxicity of MMC was four times greater than that of KW-2083. Based on this data, a clinical trial of KW-2083 was conducted in 24 cases with various types of advanced solid tumors. KW-2083 was administered by i.v. injection at a dose of 40 mg/body every week. Out of 15 evaluable cases, a case of ovarian cancer showed a partial response. One case of each of ovarian cancer and gastric cancer showed minor response. However, as with mitomycin C, the dose-limiting toxicity of KW-2083 was leukopenia and thrombocytopenia. Other toxicities encountered were nausea, vomiting, anorexia, phlebitis and hepatic dysfunction. There were no cases with renal toxicity. Plasma concentration of KW-2083 was bioassayed in 3 cases who received 40 mg/body as an i.v. bolus injection. Plasma concentration-time curves fitted to a one-compartment model and half-life values averaged 27.6 min. The effective and low toxic dose schedules of KW-2083 should be investigated further.

Systemic blood levels after intra-arterial administration of microencapsulated mitomycin C in cancer patients

Systemic delivery of mitomycin C (MMC) was studied in 6 patients administered microencapsulated MMC (MMC-mc) by an intra-arterial route (IA): 3 IA liver infusions, 3 IA pelvic infusions. Pharmacokinetic data revealed a lower blood MMC availability (peak plasma levels, AUC 0-4 hours) for the pelvis than for the liver; this was attributed to differences in the blood flow infusion rates at these two sites of administration. Direct comparison of systemic MMC exposure was possible for one patient, who received both IA liver MMC (10 mg in standard form, which served as the control) and IA liver MMC-mc (20 mg the day after). The 65% reduction in MMC-mc bioavailability observed for this patient indicates a quantitative local improvement in exposure to the drug and correlates well with the low incidence of systemic side effects noted in preliminary clinical studies.

Detecting mitomycin C in human plasma during intravesical therapy

Mitomycin C (MMC) concentrations in plasma and urine were measured in five patients with intact bladder during intravesical instillation therapy. No MMC was detected in plasma by a selective high performance liquid chromatographic (HPLC) method. The detection limit of the method is 1 ng/ml. Our results are in accordance with clinical experiences of the lack of systemic toxicity during MMC instillation therapy. There was a remarkable loss of MMC in the voided urine. The probable explanation could be that a considerable amount of MMC is absorbed into the bladder wall.

Effects of intra-arterially infused biodegradable microspheres containing mitomycin C

We prepared biodegradable microspheres containing about 5% mitomycin C (MMC) and of 45 +/- 8 microns in diameter. These preparations were infused into the rat hepatic artery as a preclinical model of intra-arterial infusion treatment for patients with inoperable hepatic tumor. The leaked MMC levels in the hepatic vein decreased below the assay limitation 2 hours after conventional MMC injection, whereas in the case of MMC microsphere the leaked drug levels were maintained at almost the same concentration for over 2 hours after infusion. The entrapped period of MMC microspheres within the hepatic artery was at least 2 weeks, and the necrobiotic foci due to antitumor effects of the condensed MMC released from the microspheres were observed in the area fed by these entrapped arterioles. This phenomenon was never observed in the case of conventional MMC and placebo microspheres. Intra-arterial infusion of MMC microspheres may be a promising clinical treatment for patients with malignant hepatic tumor.

Development and application of a sensitive enzyme immunoassay for 7-N-(p-hydroxyphenyl)mitomycin C

An antibody specific for 7-N-(p-hydroxyphenyl)mitomycin C (M-83) was developed and used in a simple and sensitive enzyme immunoassay for detection of this anticancer drug in serum. The imino group of M-83 was covalently coupled to mercaptosuccinyl groups introduced into bovine serum albumin with a cross-linker, N-maleoylaminobutyric acid. The resulting conjugate was then used for the production of a specific antibody to M-83 in rabbits. Enzyme labeling of M-83 was performed using beta-D-galactosidase (EC 3.2.1.23) via m-maleoylbenzoic acid. Antibody production was of sufficiently high titer in rabbits to allow the development of a highly sensitive enzyme immunoassay for the free drug which accurately measures 15 pg of M-83 per assay tube. This assay was monospecific to M-83 and showed almost no cross-reactivity with a variety of other mitomycin analogues (mitomycin A, B, and C; porfiromycin; and acetylmitomycin C). Using this assay, preliminary pharmacokinetic study was undertaken using serial serum samples obtained from a patient who received the drug i.v., revealing a biphasic fashion of the kinetics, with an alpha-serum half-life of 9.7 min and a beta-serum half life of 80 min. An i.v. injection of M-83 into rats and assay of serum concentration revealed a similar biphasic response with an alpha-serum half-life of 8.3 min and a beta-serum half-life of 62 min.

Pharmacokinetics of mitomycin C in dogs: application of a high-performance liquid chromatographic assay

A normal-phase high-performance liquid chromatographic (HPLC) assay was developed for the determination of mitomycin C in plasma and urine. The method involves extraction of mitomycin C from plasma or urine into ethyl acetate-2-propanol-chloroform (70:15:15) with UV detection at 365 nm. Quantitation was performed with an internal standard (porfiromycin) by the peak height ratio method. Excellent correlation was obtained between the HPLC assay and the established microbiological cup-plate bioassay. The pharmacokinetics of mitomycin C were investigated in beagle dogs following a 1-mg/kg iv (22-mg/m2) bolus dose. The plasma mitomycin C concentration versus time data were analyzed by using an open three-compartment model. The average volume of distribution was 1.90 L or 17% of body weight for the central compartment and 7.7 L or 68% of body weight for the terminal elimination phase. The volumes of distribution at steady state, calculated by model-dependent and -independent methods, compared very well with each other and were 6.5 L or 58% of body weight. Total body clearance averaged 112 mL/min, and the mean terminal plasma half-life was 53 min. The 0-24-h urinary excretion of intact mitomycin C accounted for 19% of the dose. The terminal half-life and percent urinary recovery of mitomycin C in dogs is similar to that in humans. Based on these observations, the dog appears to be a good model for studying the disposition of mitomycin C.

Disposition and pharmacokinetics of a polymeric prodrug of mitomycin C, mitomycin C-dextran conjugate, in the rat

The disposition and pharmacokinetics of a polymeric prodrug of mitomycin C (MMC), mitomycin C-dextran conjugate (MMCD), following iv bolus administration was studied in rats. Three types of MMCD, conjugates with dextran of molecular weights of 10,000, 70,000, and 500,000, were tested and disposition of carrier dextran and MMC was determined by 14C radioactivity counting and bioassay, respectively. Radioactivity was accumulated in the reticuloendothelial system such as the liver, spleen, and lymph nodes after injection of all three types of 14C-MMCD, but not in the lung, heart, and muscle. Renal distribution of 14C-MMCD varied with the molecular size of the carrier. After injection of cold MMCD, plasma concentrations of MMC in the free and conjugated forms were determined separately on the bases of bioassay. Similar sustained plasma levels of MMC were detected regardless of the carrier size although the concentration-time profiles of MMCD varied with the size of dextran. These plasma concentration data were fitted to a compartment model including a first order conversion process from MMCD to MMC in the central and peripheral compartments of MMCD. Kinetical analysis revealed that MMCD acts as a reservoir of MMC which behaves characteristically as a macromolecule while supplying active MMC in the body.

Pharmacokinetics of mitomycin C in non-oat cell carcinoma of the lung

The disposition kinetics of the cancer chemotherapeutic agent mitomycin C have been studied in six male patients receiving mitomycin C in combination with cisplatin and vinblastine for non-oat cell carcinoma of the lung. Following rapid IV administration of mitomycin C (10 mg/m2), serum concentration-time course data were biexponential, with biologic half-lives of 46.2 +/- 12.1 min (mean +/- SD). Pharmacokinetic analysis of data by the CSTRIP and NONLIN digital computer programs generated parameters which suggested extensive distribution (V area = 656.8 +/- 169.8 ml X kg-1, mean +/- SD) and, as reported for other alkylating agents, rapid elimination (total body clearance = 10.3 +/- 3.2 ml X kg-1 X min-1, mean +/- SD). Interpatient variations in pharmacokinetic parameters were relatively small, suggesting that close monitoring of mitomycin C therapy might be unnecessary in patients with normal renal and hepatic function.

Effects of total body irradiation followed by bone marrow transplantation on the disposition kinetics of mitomycin-C in the rat

The effects of total body irradiation followed by bone marrow transplantation on the disposition kinetics of intravenously-administered mitomycin-C have been studied in the Wistar-Furth rat. Five test animals received total body irradiation (1000 rads) followed by intravenous administration of 3 X 10(8) bone marrow cells per kg body weight. Five control animals were sham-irradiated and received an equal volume of blank suspension medium. One day after these treatments, each rat received mitomycin-C (10 mg/kg) by rapid intravenous injection and serial blood samples were obtained. Serum mitomycin-C concentrations were measured by high performance liquid chromatography and pharmcokinetic parameters were calculated after NONLIN analysis of data. Smaller total body clearances in test animals were probably due to radiation-induced inhibition of microsomal enzyme activity. Reduced volumes of distribution were observed in test animals although the reason for this is unclear. Future studies should assess the clinical significance of these results.

The stability and antitumor activity of recycled (intravesical) mitomycin C

Although intravesical mitomycin C (MMC) is effective in the treatment of superficial bladder cancer, its expense is a major factor limiting its use. These authors have analyzed the antitumor activity and stability of MMC following 2-hour intravesical instillation in consideration of recycling the drug or using a smaller dose over a longer retention time. The first voided urine samples from 11 patients who received 40 mg MMC intravesically were measured for MMC content by high performance liquid chromatography (HPLC). An average of 50% of the parent drug was recovered. MMC from the urine samples inhibited the growth of a transplantable murine transitional cell carcinoma as effectively as stock drug. Moreover, MMC is relatively stable in human urine at body temperature. These findings suggest that recovery and reuse of the intravesically administered drug is possible and if sterility and appropriate concentrations can be established for the initial and subsequent doses, the drug may be able to be recycled.

[Pharmacokinetics of mitomycin C in cancer patients during prolonged administration of the preparation]

The mitomycin C levels in the blood of patients subjected to prolonged intravenous injection of the drug in 200-300 ml of isotonic sodium chloride solution for 15-50 minutes were determined in the microbiological test system consisting of E. coli and 1.5 per cent of agar in the meat-peptone broth with restricted contents of the nutrients. Such administration of the drug usually provided lower blood levels than intravenous injections of the drug in analogous doses. However, the drug renal excretion was also less intensive. It suggested that the drug administered for a prolonged period was more completely absorbed by the host tissues. This was confirmed by much lower blood levels of the drug, when the tumors were large, as compared to those in patients with insignificant residues of the tumor tissue after surgical resections. The curves of mitomycin C distribution in the blood indicate that the pharmacokinetics of the drug in patients with tumors is a multi-factorial function.

Absorption of doxorubicin-hydrochloride and mitomycin-C after instillation into noninfected and infected bladders of dogs

The described investigations were carried out in order to determine the degree of absorption of doxorubicin, and mitomycin-C after intravesical instillation into noninfected or Staphylococcus aureus-infected bladders in beagle dogs. The drug concentrations in the bladder wall were determined using diffusion chambers with permeable membranes. Two hours after end of instillation of 10 mg. doxorubicin, a concentration of 1.4 ng. per ml. was measured in the bladder wall of noninfected animals, and 3.75 ng. per ml. in that of infected animals (p less than 0.05). The simultaneously measured serum concentration reached mean peak levels after 30 minutes. The concentrations in infected animals were 3 times higher (1.9 ng. per ml.) than in noninfected animals (0.6 ng. per ml.) (p less than 0.05). After instillation of 1 mg. per kg. bw. mitomycin-C the concentration in both groups of animals was below 0.06 micrograms per ml. Doxorubicin concentrations were determined with a radioimmunoassay and mitomycin-C with a micro-agar diffusion method.

Reversed-phase high-performance liquid chromatographic determination of mitomycin C in human serum

A reversed-phase high-performance liquid chromatographic method is presented by which the cancer chemotherapeutic agent, mitomycin C, may be measured in human serum. A mobile phase of methanol:water (35:65) passed through a mu-Bondapak C-18 column at a rate of 1.0 ml/min produced a sharp, symmetrical band for mitomycin C. An improved serum extraction procedure, using a reversed-phase sample preparation cartridge, proved to be efficient and reproducible. Recovery over a concentration range of 10-100 ng/ml was 81.6% with a between-day coefficient of variation of 4.6% (n = 5). The within-day coefficient of variation at 50 ng/ml was 5.6% (n = 10). Ultraviolet detection at a wavelength of 365 nm was sensitive to serum concentrations of 10 ng/ml. Serum concentration-time course data from lung cancer patients receiving mitomycin C by rapid intravenous injection are presented.

[Serum levels of mitomycin C following a high-dose continuous hyperthermic peritoneal perfusion]

Valid therapeutic means have not been established for treatment of disseminated peritoneal metastasis of carcinoma. Continuous hyperthermic peritoneal perfusion (CHPP) with high-dose of mitomycin-C (MMC) was applied to 26 patients with peritoneal metastasis from gastric, rectal or ovarian cancers. Levels of MMC in the sera and in the perfusate were measured. The results obtained were: 1. Approximately a half of the dose of MMC added into the perfusion fluid was recovered. 2. When perfused with 100 mg of MMC, the maximum serum concentration of MMC was equivalent to 1/3 of the maximum serum level when injected with 10 mg of MMC intravenously. Therefore, MMC which could not be detected in CHPP seemed to be retained in the abdominal cavity. 3. Bone marrow inhibition caused by CHPP was observed in only 2 of 26 patients. 4. The total dose of 300 mg of MMC, consisting of the maximum dose of 100 mg each, is acceptable in CHPP without any severe side effect. 5. CHPP exerts antitumor effects when utilizing hyperthermia and a high-dose of MMC on the disseminated peritoneal foci of carcinoma.