Intrathecal chemotherapy with MX2 for treating glioma dissemination in vivo.

We examined whether the intrathecal MX2 chemotherapy for treating dissemination of malignant glioma would be a feasible therapy. In the toxicity study, physiological and histological neurotoxicity was not observed in the rats treated with less than 100 microg/kg of MX2 administered intracisternally. But physiological side effects were observed in the treatment group of more than 200 microg/kg and histological brain toxicity was in the treatment group of more than 1000 microg/kg. Dissemination models were induced in rats by intracisternal inoculation of C6 glioma cells. The median survival times of the rats treated with 100 microg/kg of intrathecal MX2 on day 1, 3, or 7 after tumor inoculation were prolonged by 52.4% (p = 0.0006), 31.5% (p = 0.0007), and 7.1% (p = 0.0180), respectively, compared to that of untreated control animals. Intrathecal MX2 treatment also cured 33.6% of rats in the treatment group. These findings suggested that there was a possibility that intrathecal MX2 would be a safe and effective method for treating dissemination of malignant glioma.

Phase II trial of pre-irradiation KRN8602 (MX2) in malignant glioma patients.

KRN8602 (MX2) is a newly developed morpholino anthracycline that crosses the blood-brain barrier where it becomes distributed in brain tissue after intravenous administration. This morpholino anthracycline has been found to be effective against human glioma cells and the intracerebrally transplanted tumors in vivo, We performed a phase II trial using KRN8602 as a single agent in malignant glioma patients who had not received prior adjuvant therapy. The 13 patients (5 glioblastomas, 7 anaplastic astrocytomas and 1 malignant oligodendroglioma) enrolled received at least 1 cycle of KRN8602 at 35 mg/m2/day in 3-4 week intervals by intravenous bolus. Ten of these patients could be evaluated for response, and 13 for toxicity. Three patients (1 glioblastoma and 2 anaplastic astrocytomas) demonstrated a complete response (3/10, 30%). Concerning side effects, myelosuppression was moderately severe, with 30.7% of patients developing grade 3 leukopenia. Severe nausea/vomiting was observed in 69% of the patients, however, cardiotoxicity was not observed. The results indicate that KRN8602 demonstrated modest activity against malignant glioma with relatively severe, but manageable toxicity. Further assessment of the efficacy and toxicity of KRN8602 against malignant glioma may be worthwhile.

New drugs in recurrent high grade gliomas.

BACKGROUND: The incidence of Central Nervous System (CNS) neoplasias ranges from 3.8 to 5.1 cases per 100,000 inhabitants. In the presence of recurrence, the treatment is problematic; chemotherapy is experimental, primarily because the response is palliative and of limited duration. MATERIALS AND METHODS: This article analyzes the new drugs that have been introduced for the treatment of these patients in recent years, the objective response, the TTP and the MST. RESULTS: The most encouraging results to date come from studies of temozolomide, which is one of the most active and best tolerated drugs in recent years. CONCLUSION: New approaches to chemotherapy treatment are necessary. Enrollment of patients into rigorous, well-conducted, clinical trials, both at tumor diagnosis and after tumor recurrence, will generate new information regarding investigational therapies and may offer improved therapies for patients with malignant gliomas.

An investigation of the cytotoxicity of the morpholino anthracycline MX2 against glioma cells in vitro.

MX2 is a novel morpholino anthracycline reported to have lower systemic toxicity than other anthracyclines. It has similar antitumour activity to adriamycin and is cytotoxic towards multi-drug resistant cells and anthracycline sensitive sublines of human and murine tumour cells. In this study MX2 showed a marked cytocidal effect compared to M2, the most cytotoxically active metabolite, and the nitrosourea, BCNU, when 30 ng/ml of each drug was added to separate flasks of C6 glioma cells grown in monolayer. The colony formation of C6 glioma cells was markedly inhibited by MX2 in a dose dependent manner. The LD50 values for MX2, M2 and BCNU were 10.5 ng/ml, 15.8 ng/ml and 465 ng/ml respectively. MX2 is likely to be bound to the main plasma protein, albumin, and can also interact with the plasma lipoproteins, particularly high density lipoprotein. The results in this study strongly support the further investigation of MX2 as a potential chemotherapeutic agent against brain tumours.

KRN8602 (MX2-hydrochloride): an active new agent for the treatment of recurrent high-grade glioma.

PURPOSE: To assess the efficacy and toxicity of KRN8602 when administered as an intravenous bolus to patients with recurrent high-grade malignant glioma. PATIENTS AND METHODS: Patients with recurrent or persistent anaplastic astrocytoma or glioblastoma multiforme who had not received recent chemotherapy or radiotherapy and were of good performance status (Eastern Cooperative Oncology Group score < or = 2) were treated with an intravenous bolus of 40 mg/m(2) KRN8602 every 28 days. Tumor responses were assessed radiologically and clinically after every second cycle of therapy. Treatment was continued until documented progression or a total of six cycles. RESULTS: A median of three cycles (range, one to six cycles) of KRN8602 was administered to 55 patients, 49 of whom received at least two cycles and were, therefore, assessable for response. The overall response rate (disease stabilization or better) was 43% (95% confidence interval, 29% to 58%). There were three complete responses, one partial response, seven minor responses, and 10 patients with stable disease. The median time to progression was 2 months (range, 1.5 to 37 months) and overall survival was 11 months (range, 1.5 to 40 months). Neutropenia was the most common toxicity, although it was generally of brief duration, and there were only seven episodes of febrile neutropenia in 176 cycles delivered. Nonhematologic toxicity was mostly gastrointestinal (nausea and vomiting, diarrhea) and events were grade 2 or lower except for a single episode of grade 3 vomiting. CONCLUSION: KRN8602 is an active new agent with minimal toxicity in the treatment of relapsed or refractory high-grade glioma. Further studies with KRN8602 in combination with other cytotoxics and in adjuvant treatment of gliomas are warranted.

A prospective randomized trial of KRN8602 and cytosine arabinoside vs. daunorubicin and cytosine arabinoside in adult patients with newly diagnosed acute myelogenous leukemia. The KRN8602 Leukemia Study Group.

A prospective randomized study was conducted to compare the efficacy and toxicity of two anthracyclines for the treatment of patients with acute myelogenous leukemia (AML). Fifty-eight patients were randomized and received induction therapy consisting of cytosine arabinoside (AraC) 100 mg/m2/day for 7 days combined with either KRN8602 (3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride [KRN]) 15 mg/m2/day for 5 days (KRN/AraC group) or daunorubicin (DNR) 40 mg/m2/day for 3 days (DNR/AraC group). Complete remission rate was 78.6% (22/28) in the KRN/AraC group and 73.1% (19/26) in the DNR/AraC group. There was a higher incidence of nausea/vomiting and anorexia observed in the KRN/AraC group compared to the DNR/AraC group, while the incidence of other adverse effects (stomatitis, diarrhea, and infectious complications) were similar between both groups. No electrocardiogram (ECG) abnormalities were observed after treatment in the KRN/AraC group, while in the DNR/AraC group, one patient showed ECG abnormality and three patients exhibited either arrhythmia, heart failure, or tachycardia. Mental disorder was reported in two cases in the KRN/AraC group. These findings suggest that KRN/AraC is similar in effectiveness to DNA/AraC but more toxic in central nervous system and gastrointestinal symptoms and less toxic regarding cardiac function in patients with previously untreated AML.

A phase II study of KRN8602(MX2), a novel morpholino anthracycline derivative, in patients with recurrent malignant glioma.

KRN8602(MX2) is a newly developed morpholino-anthracycline that has been found to cross the blood-brain barrier and be distributed in brain tissue after intravenous administration and to be effective against human glioma cells and the intracerebrally transplanted tumors in vivo. In order to confirm these promising preclinical observations clinically, we performed a phase II trial of KRN8602 in patients with recurrent malignant glioma. The 44 patients enrolled received at least 2 cycles of KRN8602 35 mg/m2/day at 3-4 week intervals by intravenous bolus. Of the 44 patients, 37 could be evaluated for response, and 39 for toxicity. One patient with anaplastic astrocytoma had a complete response (1/37, 3%), and 2 patients with anaplastic astrocytoma and 1 with brain stem glioma had a partial response (3/37, 8%). The overall response rate was 11% (4/37). All patients who responded had received prior chemotherapy that included nitrosoureas. No response was observed in the patients with glioblastoma. Myelosuppression was moderately severe, with 72% of patients developing grade 3 or 4 leukopenia. Severe nausea/vomiting was observed in 31% of the patients. No severe cardiotoxicity was observed. The results indicate that KRN8602 has modest activity against recurrent malignant glioma with relatively severe, but manageable toxicity. It seems to be worthwhile to further assess the efficacy and toxicity of KRN8602 against malignant glioma, which is generally less sensitive to chemotherapy.

Phase II study of KRN8602, 3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride, MX2 x HCl in patients with metastatic breast cancer.

PURPOSE: KRN8602 (3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride, MX2 x HCl) is a newly developed anthracycline that has been found to be effective against multidrug-resistant tumor cells in vitro and in vivo. In order to clinically confirm these promising preclinical observations, we performed a phase II trial of KRN8602 in patients with anthracycline-resistant metastatic breast cancer. METHODS: Of 41 patients registered with metastatic breast cancer, 37 were eligible and were given at least two cycles of KRN8602 15 mg/m2 per day at 3-4 week intervals by intravenous bolus injection on days 1, 2, and 3. RESULTS: Of the 37 patients, 6 (16.2%, with a 95% confidence interval of 4.3-28.1%) had a partial response (PR). No complete responses (CRs) were observed. The difference between response rates according to prior history of anthracycline administration was not significant. Myelosuppression was moderately severe, with grade 3 or 4 leukopenia occurring in 65%. Severe nausea/vomiting was observed in 44% of the patients. CONCLUSIONS: The results indicate that KRN8602 has modest activity in refractory metastatic breast cancer and is associated with relatively severe toxicity. Furthermore, the preclinical finding that KRN8602 overcomes anthracycline resistance was not reliably reproduced in this clinical phase II trial.

[Phase II study of KRN8602 (MX2) for malignant lymphoma].

We performed a clinical phase II study of KRN8602, a new anthracycline derivative, for relapsed or recurrent malignant lymphoma. KRN8602 was given at doses of 12-15 mg/m2 for 3 consecutive days, repeating every 3-4 weeks. Among 44 patients entered into the study, 36 were evaluable for safety, and 35 were evaluable for efficacy. The response rate was 18.2% (6PR/33) for non-Hodgkin's lymphoma and 0% (0/2) for Hodgkin's disease. Major toxicities were bone marrow suppression and gastrointestinal toxicity. Leukopenia was observed in 77.8%, thrombocytopenia in 44.4%, hemoglobin decrease in 44.4%, nausea and vomiting in 94.4% and anorexia in 80.6%. However, all toxicities were clinically manageable.

[Early phase II study of KRN8602 (MX2), a novel anthracycline derivative for acute leukemia].

We performed an early phase II study of KRN8602, a new anthracycline derivative for refractory or relapsed acute leukemias. KRN8602 was given at a dose of 15 mg/m2 for 3 to 5 consecutive days, repeating every 3-4 weeks. Among 53 patients entered in the study, 51 were evaluable for safety, and 46 were evaluable for efficacy. The response rate at schedules of 3 and 4 consecutive days was 9.1% (1 PR/11), while that at a schedule of 5 consecutive days was 22.9% (3 CR + 5 PR/35). With the 5 consecutive day schedule, the response rates were 21.4% (1 CR + 2 PR/14) for acute myelogenous leukemia and 29.4% (2 CR + 3 PR/17) for acute lymphocytic leukemia, but no response was observed in 4 patients with blastic crisis of chronic myelogenous leukemia. Major toxicities were nausea/vomiting and anorexia, however, all these toxicities were clinically manageable. From these results it is concluded that KRN8602 is effective against acute leukemias, and the optimal dose is 15 mg/m2 for 5 consecutive days.

[Phase III clinical trial of KRN8601 (rhG-CSF) for neutropenia in patients with human immunodeficiency virus infection].

The efficacy of KRN8601 for neutropenia associated with HIV infection was evaluated in 24 patients. KRN8601 was infused intravenously at a dosage of 200 micrograms/m2 for 14 consecutive days. Neutrophil counts recovered in 19 (90.5%) out of 21 evaluable patients by KRN8601 treatment. The concomitant myelosuppressive agents for the treatment of HIV infection and complications could be continued without dose reduction in 15 (88.2%) out of 17 patients. The clinical improvement was observed in 66.7% (12/18) of patients who were treated with anti-microbial agents for opportunistic infections which indicates that KRN8601 shows an additive effect on infections when it was given with anti-microbial agents. Adverse events and abnormal laboratory findings were observed in 3 and 7 patients, respectively, and they were reversible and tolerable. This study demonstrated that KRN8601 improved neutropenia with HIV infection, made possible to continue the full dose of myelosuppressive treatments and have additive effect on the treatment of secondary infections.

[New antitumor drugs for malignant lymphoma: a review].

We summarize here the antitumor activity of newly developed drugs against malignant lymphoma. Irinotecan hydrochloride (CPT-11) showed a CR rate of 15% and an excellent response (CR + PR) rate of 42% in patients with non-Hodgkin's lymphoma who had prior treatment. In patients with ATL, 13% achieved CR and a response rate was 39%. MST-16, a new orally administered bis(2, 6-dioxopiperazine) analogue, showed a CR of 3% and PR of 28% (response rate 31%), among patients with ATL, 9% of 23 patients achieved CR and the response rate was 44%. Phase I studies of fludarabine demonstrated a high response rate of 64%, especially in follicular lymphoma, with a number of patients achieving CR. Subsequent phase II studies demonstrated a response rate of 89% in patients with indolent lymphoma. KRN 8602 was developed in an attempt to improve the clinical efficacy of currently used anthracyclines. KRN 8602 has been shown to produce less cardiotoxicity and alopecia, yet has comparable antitumor effects to ADM, and also has demonstrated an antitumor effect on ADM-resistant tumors. CPT-11 and MST-16 were found effective not only in refractory non-Hodgkin's lymphoma, but also in patients with ATL, which had no standard therapy. Fludarabine has been demonstrated to be a very active drug in indolent lymphoid neoplasms, particularly CLL and low grade lymphoma. These new drugs are expected to overcome malignant lymphoma refractory to treatment thus far.

MX2; 3'-deamino-3'-morpholino-13-deoxy-10-hydroxycarminomycin (KRN8602) in refractory metastatic breast cancer: results of a preliminary phase II trial.

We performed a preliminary phase II clinical trial of MX2; 3'-deamino-3'-morpholino-13-deoxy-10-hydroxycarminomycin (KRN8602) in patients with metastatic breast cancer who had failed to respond to previous chemotherapeutic regimens after clinical evidence of systemic disease. Twelve patients at a single institute received KRN8602 at a dose of 35 mg/m2 intravenously once every three weeks. All the patients were followed-up until their disease progressed. There was one complete response lasting 17 weeks and one partial response lasting eight weeks. Among the 12 patients, World Health Organization (WHO) grades 3 and 4 neutropenia were observed in five and two patients, respectively. Grade 3 anemia was observed in three patients but severe thrombocytopenia was not observed. Grade 3 nausea/vomiting was observed in eight patients. Alopecia was not observed. The results of this preliminary phase II trial suggest a need for further testing of the anti-tumor activity of KRN8602 in patients with metastatic breast cancer.

[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.

[New anthracyclines].

Idarubicin showed the superior activity against Acute Non-Lymphocytic Leukemia (ANLL) in the prospective randomized trials comparing to daunorubicin and it is judged that the analog will become the first choice in the treatment on ANLL. Anthracyclines including SM-5887, KRN-8602, ME-2303 under studies in Japan have shown comparable or superior antitumor activities and lower cardiac toxicities compared to doxorubicin in preclinical studies and therefore the results obtained in clinical trials are expected. Phase II trials of anthrapyrazoles which is an analog of mitoxantrone are in progress. Among three compounds entered it is of note that CI-941 has demonstrated an excellent activity against advanced breast cancer.

[The morphological aspects of the protective action of enterosorbent K(2)9 during the use of the antitumor anthracycline antibiotic carminomycin]. / Morfologicheskie aspekty protektornogo deistviia énterosorbenta K(2)9 pri primenenii protivoopukholevogo antratsiklinovogo antibiotika karminomitsina.

The authors substantiate morphologically the protector effect of K(2)9 enterosorbent during its parallel use with the antitumour anthracyclin antibiotic carminomycin. The agent was administered intraperitoneally in animals at the maximum tolerable dose. Use of the K(2)9 enterosorbent reduces the cardiotoxic effect of carminomycin.

[Experience with using carminomycin in oncological clinical practice]. / Opyt klinicheskogo primeneniia karminomitsina v onkologicheskoi praktike.

Carminomycin is an original antitumor antibiotic from the anthracycline group isolated at the Institute of New Antibiotics (USSR) in 1973. Pharmacological investigation of carminomycin revealed its satisfactory absorption from the gastrointestinal tract which proved to be a distinguishing property of the antibiotic as compared to other anthracyclines such as adriamycin and rubomycin. The clinical trials of carminomycin showed that it was mainly active against soft tissue sarcoma and breast cancer, lymphosarcoma, neuroblastoma, Wilms' tumor and Ewing's sarcoma in children, as well as acute leukemia. Various regimens for the antibiotic administration were applied: short-term, single and long-term. Suppression of hemopoiesis was considered as a limiting toxic effect. By the data available carminomycin had lower cardiotoxicity as compared with rubomycin and adriamycin. Development of oral carminomycin is believed promising.

[Alimentary methods of maintaining the superoxide dismutase activity in the tissues of rats during growth of a transplanted tumor and administration of carminomycin]. / Alimentarnye sposoby podderzhaniia superoksiddismutaznoi aktivnosti v tkaniakh krys v usloviiakh rosta transplantirovannoi opukholi i vvedeniia karminomitsina.

The aim of the experiment was to study the effect of three specialized food rations on activity of superoxide dismutase (SOD) in tissues of rats with transplanted Walker's carcinosarcoma 256 exposed to carminomycin. It was shown that the three specialized rations were able to significantly modify the SOD activity in the tissues of the rats with Walker's carcinosarcoma 256 at the background of treatment with carminomycin. Thus, the ration enriched with copper and zinc salts and folic acid activated SOD in the animals of all the groups. Still, the effect was higher in the tumor-bearing animals and the rats treated with carminomycin i.e. under conditions of oxidative stress. The use of the ration enriched with sulfur-containing amino acids, sodium selenide and vitamin E led to decreasing of the efficiency of the fermentative dismutation of O2 in the healthy rats and marked activating of SOD in the tumor-bearing animals. The ration containing lyophilized vegetables and vitamin E provided a significant increase in the SOD activity in the healthy rats. However, its potential was not sufficient for overcoming the SOD inhibiting effect of the tumor growth.

New anthracycline antitumor antibiotics.

Doxorubicin is an essential component of the treatment of aggressive lymphoma, childhood solid tumors, bone and soft tissue sarcomas, and breast cancer and additional indications are emerging. On the other hand, daunorubicin has occupied the central position of interest in the treatment of acute leukemia. Epirubicin has a spectrum very similar to doxorubicin but lesser toxicity. The ability to protect against cardiotoxicity with ICRF-187 further enhances clinical interest in exploiting modifications in doze intensity to therapeutic advantage. Idarubicin has at least equivalent activity to daunorubicin and doxorubicin in leukemia. New areas of research in relation to anthracycline antibiotics include introduction of new the analogs, insight into mechanisms of resistance, the reversal of multidrug resistance in vitro, the protection of cardiac toxicity, and the study of other important biochemical reactions relevant to cytotoxicity. Orally active anthracyclines such as idarubicin and compounds which lack cross-resistance with the parent drugs or have other mechanisms for cytotoxicity are being developed. It is likely that these modifications will lead to an expanding therapeutic spectrum for these already widely useful drugs.

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.