Toxicology and pharmacokinetics of (1,1-bis(aminomethyl)cyclohexane)oxalatoplatinum(II) (TNO-38)

Preclinical studies on toxicology and pharmacokinetics were performed for (1,1-bis(aminomethyl)cyclohexane)oxalatoplatinum(II) (TNO-38) in rats and a dog after ld₁₀ and ld₅₀ assessment in mice. In drug-treated rats, ura and creatinine concentrations were 1,4-1.9 times those in control rats. Histopathology showed necrosis of tubular epithelium of the kidneys, which was comparable to damage observed after treatment with cisplatin (CDDP), and extensive necrosis of crypt epithelium, especially in the ileum.Similar to CDDP, TNO-38 was emetic in the dog. Non-specific subacute inflammatory changes were observed in the ileum. Renal damage was much less pronounced.Half-lives of distribution and elimination were 6.2 min and 5.2 days, respectively. The cumulative excretion of Pt in urine over 1 and 7 days after drug treatment was 38.3 and 49.3% of the dose, respectively. Twelve weeks after drug administration, Pt concentrations were highest in kidneys and liver.TNO-38 is adequately water soluble. Its reported antitumour activity is consistently lower than that of CDDP. The drug's toxicity was, in general, comparable to that of CDDP. Its pharmacokinetic profile was very similar to that of CDDP. It is concluded that TNO-38 should probably not be further evaluated in clinical studies.     

Antitumor effects of three platinum complexes, (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutanedicarboxylato)-platinum (II) monohydrate (DWA2114R), cis-diammine-(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA) and cis-diamminedichloroplatinum(II) (CDDP), in mice.

(-)-(R)-2-Aminomethylpyrrolidine(1,1-cyclobutanedicarboxylato++ +)platinum(II) monohydrate (DWA2114R), cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA) and cis-diamminedichloroplatinum(II) (CDDP) were compared for their antitumor effects and nephrotoxicity-inducing activities at the same dosage (1/8, 1/4, 1/3, 1/2, 2/3 or 3/4 of the LD10 or LD10) on the basis of their intravenous lethal doses in mice. DWA2114R was effective against murine tumor lines, Colon 26 and Colon 38 carcinomas, M5076 ovarian sarcoma and P388 L1210 leukemias, implanted subcutaneously (s.c.). Triple injection every other day of DWA2114R was more effective than a single injection at each sublethal dose. The antitumor effects of DWA2114R against these tumors were more effective than or were similar to those of CBDCA and CDDP. The antitumor effect against CDDP-resistant L1210 leukemia implanted s.c. was only observed in the treatment of DWA2114R, but not in CBDCA and CDDP. No excellent antitumor effects of three platinum complexes were observed against Lewis lung carcinoma and B16 melanoma implanted s.c. even at triple injection every other day, and no effect was obtained against Meth-A fibrosarcoma under similar conditions. While the treatment of CDDP showed marked increases in levels of blood urea nitrogen and of urinary protein and sugar at effective doses in the antitumor evaluations, the treatment of DWA2114R as well as CBDCA showed no increase in these parameters. These results indicate that DWA2114R represents a desirable second generation antitumor platinum complex.     

Clinical trials of Herceptin(R) (trastuzumab)

This report summarises the clinical efficacy and safety findings from clinical trials of the new anti-HER2 monoclonal antibody Herceptin(R) (trastuzumab). Data from pivotal trials indicate that trastuzumab is active when added to chemotherapy in patients with advanced metastatic breast cancer. In particular, the combination significantly prolonged the median time to disease progression, increased the overall response rate, increased the duration of response, and improved median survival time by approximately 25% compared with chemotherapy alone. Furthermore, trastuzumab is active as a single agent in women with HER2-positive metastatic breast cancer, inducing durable objective tumour responses. In total, 15% of patients who had received extensive prior treatment for metastatic disease had an objective response. The median duration of response was 9.1 months following administration of single-agent trastuzumab. Notably, 2% of patients were free of disease progression at 6 months. The safety profile of trastuzumab either given alone or in combination was favourable.     

Synergism of cytotoxicity between cis-diaminedichloro-platinum-(ii) and cis-diamine(1,1-cyclobutanedicarboxylate)-platinum-(ii)

In an attempts to increase the antitumor effect and to reduce normal tissue toxicity, the combined cytotoxic effect of cis-Diamminedichloroplatinum (II) (CDDP) and cis-diammine(1,1-cyclobutane dicarboxylate) platinum (II) (CBDCA) was investigated using HeLa and colon 26 cell lines and the combination index (CI). Cytotoxicity of the combination of CDDP and CBDCA on 27 surgically resected specimens of human gastric and colorectal adenocarcinomas was also evaluated using the in vitro succinate dehydrogenase inhibition (SDI) test. The CI values varied with the dose ratio examined (1:1-1:6) of CDDP and CBDCA, with findings that CI<1, synergy, was obtained at fraction affected (Fa)>0.75 for HeLa cells and at Fa<0.9 for colon 26 cells in cases of a dose ratio of 1:1 to 1:2. Of all 27 clinical human adenocarcinomas, the succinate dehydrogenase (SD) activity was significantly lower in cancer cells concomitantly exposed to both CDDP and CBDCA than in those exposed to either drug alone. These positive effects of a combination of two platinum analogues on human malignant tissues have heretofore not been reported, which would warrant the clinical application of this combination for human malignant tumors.     

In vitro evaluation of dichloro-bis(pyrazole)palladium(II) and dichloro-bis(pyrazole)platinum(II) complexes as anticancer agents

Introduction  Cisplatin (cis-diamminedichloroplatinum) was first identified for its anti-bacterial activity, and was later also shown to be an efficient anticancer agent. However, the therapeutic use of this anticancer drug is somewhat limited by its toxic side effects, which include nephrotoxicity, nausea, and vomiting. Furthermore the development of drug-resistant tumours is commonly observed following therapy with cisplatin. Hence there is a need for improved platinum derived drugs to overcome these limitations. Aims  Apoptosis contributes significantly to the cytotoxic effects of anticancer agents such as cisplatin; therefore in this study the potential anticancer properties of a series of pyrazole palladium(II) and platinum(II) complexes, [(3,5-R₂pz)₂PdCl₂] {R = H (1), R = Me (2)} and [(3,5-R₂pz)₂PtCl₂] {R = H (3), R = Me (4)}, were evaluated by assessment of their pro-apoptotic activity. Methods  The induction of apoptosis was measured in CHO cells by the detection of phosphatidylserine (PS) exposure using the annexin V and APOPercentage™ assays; DNA fragmentation using the Terminal deoxynucleotide transferase dUTP Nick End Labelling (TUNEL) assay; and the detection of activated caspase-3. Results  The platinum complexes were shown to be considerably more active than the palladium complexes, with complex 3 demonstrating the highest level of cytotoxic and pro-apoptotic activity. The LD₅₀ values for complex 3 and cisplatin were 20 and 70 μM, respectively, demonstrating that the cytotoxic activity for complex 3 was three times higher than for cisplatin. Various human cancer cell lines, including CaSki, HeLa, as well as the p53 mutant Jurkat T cell line were also shown to be susceptible to complex 3. Conclusions  Collectively, this in vitro study provides insights into action of palladium and platinum complexes and demonstrates the potential use of these compounds, and in particular complex 3, in the development of new anticancer agents.     

Non-surgical (medical) treatment of hepatocellular carcinoma (HCC)

Choice of treatment for HCC depends mainly on the size of tumor and patient's liver function because more than 80% of HCC patients are associated with liver cirrhosis. Percutaneous ethanol injection therapy (PEIT), transcatheter arterial embolization (TAE) and intraarterial infusion chemotherapy are, at present, commonly used treatments for HCC in Japan. PEIT is a safe and reliable treatment, in which absolute ethanol is injected to the tumor through a fine needle under US guide. PEIT is indicated for tumors of small size, which can not be removed surgically. The survival rate of PEIT for small liver cancer, less than 2 cm in diameter, is similar with the one of surgically removed cases. TAE is indicated for advanced HCC. Chemoembolization with Lipiodol is commonly used with good result. After TAE has been often performed, the survival rate of HCC patients was dramatically increased. In future, TAE combined with percutaneous transhepatic portal embolization or PEIT would be applied more often to obtain complete destruction of the lesion for advanced HCC. Intraarterial infusion chemotherapy is indicated for advanced HCC, in which TAE can not be performed. MMC, ADM and CDDP are commonly used anti-cancer drugs. Recently frequent infusion of these drugs has become possible by using implantable reservoir with good result. We have performed chemosensitivity test by SRCA for HCC specimens obtained by biopsy using a fine needle.     

Initial (prefibrotic) stages of idiopathic (primary) myelofibrosis (IMF) - a clinicopathological study.

A clinicopathological follow-up study including sequential bone marrow biopsies was performed on 79 patients with idiopathic (primary) myelofibrosis (IMF) to characterize initial (prefibrotic) stages and to elucidate whether development of fibrosis was accompanied by corresponding clinical findings. For this purpose our cohort of patients was divided into two groups of which the first presented with the generally accepted signs and symptoms of IMF (group I; n = 60). Most patients of the second group (group II; n = 19) showed mild to moderate therapy-refractory anemia, minimal to slight splenomegaly and frequently thrombocytosis, but no bone marrow fibrosis at onset. Hematopoiesis was consistent with a striking hypercellularity in comparison to the age-related involution by adipose tissue, a conspicuous clustering and histotopographic dislocation of megakaryocytes, a neutrophil granulocytic proliferation and a reduction of erythropoietic islets with arrest of maturation. Most remarkable was the dysplastic cytology of megakaryocytes with a definitive deviation of differentiation resulting in bizarre forms. Follow-up examinations revealed that at later stages group II patients were not distinguishable from the first group with more advanced IMF. For this reason, these patients were regarded as presenting initial, prefibrotic IMF characterized by distinctive bone marrow features at the beginning. The prominent abnormalities of megakaryopoiesis together with the granulocytic proliferation were extremely helpful to differentiate prefibrotic IMF with accompanying thrombocythemia from essential thrombocythemia (ET). Dynamics of fiber progression were calculated by regarding increase in density per time. Speed of progression during the first year of observation proved to be significantly higher in group II patients with prefibrotic IMF in comparison to full-blown cases (group I). In conclusion, with respect to prospective clinical trials, diagnostic criteria for IMF should be re-evaluated by also taking initial, prefibrotic stages into account.     

A phase I study of bevacizumab (B) in combination with everolimus (E) and erlotinib (E) in advanced cancer (BEE)

Purpose

VEGF, mTOR, and EGFR inhibitors have demonstrated anti-tumor and anti-angiogenic effects alone and in combination with each other. This study evaluated the safety, tolerability, and pharmacokinetics of bevacizumab, everolimus, and erlotinib combination.

Methods

Doublet therapy consisted of bevacizumab at 10 mg/kg every 14 days and everolimus 5 mg daily which escalated to 10 mg daily. Erlotinib 75 mg daily was added to the phase II dose recommended phase II dose (RPTD) of bevacizumab and everolimus. Dose-limiting toxicity (DLT) was assessed in cycle 1.

Results

Forty-eight patients with advanced solid malignancies were evaluable for DLT and efficacy. No DLTs were observed in the doublet dose escalation. Two DLTs (grade 3 mucositis and grade 3 rash) were observed with the addition of erlotinib 75 mg daily. Consequently, triplet doses were adjusted and were better tolerated. Four patients had a partial response. Median progression-free survival (PFS) for the doublet therapy was 6.0 months (0.5 to 32+ months) and 5.5 months (0.8 to 27+ months) for the triplet therapy. Systemic exposure of everolimus was significantly higher in combination with erlotinib (476 ± 161 ng h/mL) compared to when given alone (393 ± 156 ng h/mL; P = 0.020).

Conclusions

The RPTD for the doublet therapy is bevacizumab 10 mg/kg every 14 days and everolimus 10 mg daily, and the RPTD for the triplet therapy is bevacizumab 5 mg/kg every 14 days, everolimus 5 mg and erlotinib 75 mg daily. Prolonged disease stability was demonstrated in tumors known to respond to mTOR inhibition and potentially resistant to VEGF blockade.     

Antitumor activity of a new platinum complex (R)-(-)-2-aminomethylpyrrolidine (1,1-cyclobutane dicarboxylato) platinum (II) (DWA2114R) by its serial administration

Antitumor activity of a newly synthesized platinum complex, DWA2114R, by the serial administration was examined and compared with that of cis-diammine-1,1-cyclobutane dicarboxylato platinum (II) (CBDCA). In mice transplanted s.c. with tumor, the serial i.p. administration resulted in the increases of both maximal tolerated dose (MTD) and growth inhibitory ratio (GIR) of DWA2114R than single administration. Such increases in MTD and GIR were also shown by CBDCA, but the degree of these increases, such as the ratio of MTD or GIR by the serial administration compared to that at the single administration, was higher in DWA2114R than CBDCA. GIR of DWA2114R by the serial administration was higher than that of CBDCA at the doses to induce the same toxicity which was estimated by body weight loss. In addition, in the experiment using ascites tumor-bearing mice, better antitumor activity of DWA2114R was shown by the elongation of survival time. These results indicate that the cumulative toxicity of DWA2114R is lower than that of CBDCA, which causes the therapeutic advantages of DWA2114R in the serial administration.     

A new orally active antitumor 1R,2R-cyclohexanediamine-platinum(IV) complex: trans-(n-valerato)chloro(1R,2R-cyclohexanediamine) (oxalato)platinum(IV)

Purpose: The authors have previously reported that trans-bis(n-valerato)(1R,2R-cyclohexanediamine) (oxalato)platinum(IV) (C5-OHP), an oxaliplatin derivative, is an orally active antitumor agent in an intraperitoneal (i.p.) L1210 murine leukemia model. In this study, several oxaliplatin derivatives of the general formula trans-(carboxylato)chloro(1R,2R-cyclohexanediamine)(oxalato)platinum(IV) were synthesized in order to find new derivatives with greater oral activity than C5-OHP in a clinically predictive tumor model. In the formula, the carboxylate and chloride ligands are situated in axial positions. Methods: Four complexes with the axial carboxylate ligands n-butyrate, n-valerate, n-caproate or n-heptanoate were synthesized and designated C4-OHP-Cl, C5-OHP-Cl, C6-OHP-Cl and C7- OHP-Cl, respectively. The oral antitumor activity of the complexes was evaluated against the murine reticulosarcoma M5076 implanted subcutaneoulsy (s.c.) in to male BDF₁ mice. The complexes were administered orally daily for 5 days in two cycles initiated on days 5 and 12 postimplantation. The physicochemical properties were examined by measuring the concentrations of the complexes in test solutions at intervals by HPLC. The pharmacokinetic behaviors of C5-OHP-Cl, C6-OHP-Cl and C5-OHP following a single oral administration were studied in non-tumor-bearing male BDF₁ mice. Results: Of the complexes synthesized in this study, C5-OHP-Cl, which exhibited high activity in the i.p. L1210 model, was found to be orally active in the s.c. M5076 model while C5-OHP was not. The in vitro reduction of the complexes by ascorbate was much more rapid than that of C5-OHP, while the complexes were more stable than C5-OHP in HCl-acidic and alkaline solutions. Pharmacokinetic study showed that C_max and AUC_0–24h values of plasma total and filterable platinum of C5-OHP-Cl were four to six times greater than those of C5-OHP, indicating that C5-OHP-Cl was absorbed more than C5-OHP. Conclusion: C5-OHP-Cl was found to be a superior l-OHP derivative C5-OHP, exhibiting significant oral antitumor activity in the s.c. M5076 model. The enhanced activity of C5-OHP-Cl was considered to be due in part to increased susceptibility to reduction and increased gastrointestinal absorption. C5-OHP-Cl is a suitable candidate for further study as an oral cancer chemotherapy agent. Received: 22 January 1998 / Accepted: 20 May 1998     

Natural killer (NK) and lymphokine activated killer (LAK) cell activity in patients (PTS) treated with flavone acetic acid (FAA)

Natural killer (NK) cell activity was measured in nine patients with different solid tumors treated with flavone acetic acid (FAA). In three of them, NK cell activity was significantly increased, in two instances even after repeated courses of treatment. A significant increase in lymphokine activated killer (LAK) cell activity was also observed in three of four patients after in vivo treatment with FAA and in vitro incubation of lymphocytes with recombinant Interleukin-2. We observed some inter-individual variability in drug clearance, but no apparent correlation between drug plasma levels (neither peak nor AUC values) and the effects on NK and LAK activity.