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.

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.

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.

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.

Effect of MX2, a new morpholino anthracycline, against experimental brain tumors.

A new lipophilic morpholino anthracycline derivative, MX2, has an antitumor activity against a wide spectrum of experimental tumors. We examined the effect of MX2 against experimental brain tumors. At a low dose, MX2 exhibited strong growth inhibitory activity against human and rat glioma cells. The survival time of rats with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells was significantly prolonged by intravenous MX2. The growth of subcutaneously implanted glioma in rats was significantly retarded by intravenous MX2. These results suggest that MX2 warrants further experimental evaluation of its efficacy against malignant brain tumors including gliomas.

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.

Role of DNA-binding in the cytotoxicity of an anthracycline, R20X2 and its morpholino analog, MX2.

3'-Deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin (MX2), a morpholino anthracycline derived from 13-deoxo-10-hydroxycarminomycin (R20X2) was 16 times less cytotoxic than R20X2 against cultured P388 leukemia cells. The reduced cytotoxicity of MX2 was not explainable by intracellular or intranuclear concentration of the drug or by its DNA-intercalating activity. Binding of MX2 and R20X2 to DNA was measured, after isolating the DNA fraction from an incubation mixture of the drugs with P388 cells or with calf thymus DNA. The amount of R20X2 bound to the DNA was obviously larger than that of MX2, and was dependent on incubation time. These data suggest that the poor binding activity of MX2 to DNA contributes to its reduced cytotoxicity.

Cytotoxic and mutagenic in vitro effect of 7-O-epoxyalkyl derivatives of daunomycinone. Part IX.

The cytotoxic effect of (7S)- and (7R)-O-epoxyalkyl derivatives of daunomycinone on leukemia P388 cells was followed in in vitro tests and their mutagenicity was determined by means of the bacterial SOS chromotest. The biological effects of the substances were compared with those of daunomycin, carminomycin and nogalamycin. The most efficient derivative proved to be the (7S)-9-acetyl-4-methoxy 7-O-(2,3-epoxypropyl)-7,8,9,10-tetrahydro-6,9,11-trihydroxy-5, 12-naphthacenequinone 10 which inhibited the DNA and RNA synthesis and proliferation of P388 cells on the level of daunomycin or carminomycin. The cytotoxic and mutagenic action of 7-O-epoxyalkyl derivatives of daunomycinone was affected by the length of alkyl and its configuration.

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.

[Colony-forming ability of bone marrow hematopoietic cells in mice with transplanted leukemia during administration of carminomycin]. / Kolonieobrazuiushchaia sposobnost' gemopoéticheskikh kletok kostnogo mozga myshei s perevivnym leikozom pri vvedenii karminomitsina.

Effects of carminomycin on the colony-forming ability of bone marrow haemopoietic stem cells (CFUs) were compared in normal mice with steady state and actively regenerating bone marrow, and in P-388 and La leukemia-bearing mice. CFUs assays were performed 24 h after treatment of donor mice with the increasing doses of the drug. Leukemia-bearing mice received carminomycin on the 5th day after transplantation. The dose-effect curves were exponential for CFUS normal mice with both the steady state and active proliferation state of bone marrow. The maximal effect was found 24 h after injection of 0.7 mg/kg of carminomycin (ED50 for CFUS) being more pronounced in regenerating bone marrow. The dose-effect curves for leukemias were also exponential. In the case of La leukemia the killing of CFUs by carminomycin was the highest as compared with P-388 leukemia.

[Effect of carminomycin on the enzyme systems of the metabolism of active forms of oxygen and on free-radical lipid oxidation in August rats with Walker carcinosarcoma 256]. / Vliianie karminomitsina na fermentnye sistemy metabolizma aktivnykh form kisloroda i svobodnoradikal'noe okislenie lipidov u krys linii August s kartsinosarkomoi Uoker 256.

The influence of carminomycin (CM) on enzymic systems of metabolism of oxygen active forms, free radical lipid peroxidation and microviscosity of membrane lipids as well as toxic and antitumour action of CM were studied in normal and tumour-bearing rats. Detected responses of the system of superoxide anion- and H2O2 metabolism reflected the role of active oxygen forms in CM toxicity. The investigation results of the lipid peroxidation fluorescent products level and microsomal lipid phase microviscosity did not suppose stimulation of lipid peroxidation as key mechanism for CM toxic effects. Problems on the prevention and treatment of anthracyclines side effects are discussed.

[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.

[Phase I clinical study of MX2 (KRN 8602)].

KRN 8602 is a new antineoplastic drug with the chemical structure, 3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride. This drug was developed in an attempt to improve the clinical efficacy of currently used anthracyclines. In preclinical studies, KRN 8602 has been shown to produce less cardiotoxicity and alopecia, yet has comparable antitumor effects to adriamycin. In addition, KRN 8602 has shown antitumor effects on adriamycin-resistant tumors. A phase I clinical study was undertaken to determine the toxicity of KRN 8602 given as a single i.v. dose. Toxicity evaluation included CBC with differentials, platelet counts, SMA chemistry profile, EKG, urinalysis, plain chest X-ray and physical examination. Myelosuppression was the major side effect noted with leukopenia, and especially neutropenia, being dose-limiting. The degree of WBC suppression was dose-related and MTD appears to be 30 mg/m2. Nausea and vomiting were observed in cases who had received more than 10 mg/m2. No patient had alopecia. No obvious cardiotoxicity in this study. Maximum total cumulative dose of KRN 8602 was 450 mg/m2. Further observation is necessary to confirm this point. In this study of 10 cases, one breast carcinoma with bilateral lung metastasis revealed definite regression of metastasis for more than 18 months with this agent alone. This patient had previous chemo- and hormone therapy, containing adriamycin. The above preliminary phase I clinical study suggests strongly the usefulness of KRN 8602, and further investigations are indicated.

[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.

[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.

[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.

[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.

[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.

[Current status of clinical results of new antitumor drugs].

This review describes the current clinical results of phase I and II trials of new antitumor drugs such as the new anthracyclines: epirubicin, idarubicin, esorubicin, carminomycin and marcellomycin; the second generation cisplatin: carboplantin, CHIP, TNO-6, DACCP and JM-40; mitoxantrone, AMSA, AZQ, Tiazofurin, DFMO and others.

[Study of toxicity and antineoplastic activity of 14-substituted derivatives of rubomycin and carminomycin]. / Izuchenie toksichnosti i protivoopukholevoi aktivnosti 14-zameshchennykh proizvodnykh rubomitsina i karminomitsina.

Toxicity and antitumor activity of five derivatives of rubomycin and carminomycin were studied in animals. The derivatives were prepared by modification of the methyl C-14 group. These were the following: 14-chlorrubomycin, 14-chlorcarminomycin, 14-salicyloyloxyrubomycin, 14-salicyloyloxycarminomycin and 14-quinaldinoyloxyrubomycin. The chemotherapeutic study revealed that, in their activity, all the compounds were inferior to the starting antibiotics. Unlike the other derivatives, 14-chlorcarminomycin induced a significant inhibition of leukemia P-388 development (the average lifespan of the mice amounted to 165 per cent as compared to the control). However, in the magnitude of its effect, the derivative was inferior to carminomycin.