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.     

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.     

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.     

Concurrent chemoradiotherapy (CRT) with S-1 and cisplatin (CDDP) in patients (pts) with locally advanced head and neck cancer (HNC)

The standard care for unresectable locally advanced head and neck cancer (HNC) is concurrent chemoradiotherapy (CRT). Although there is no standard regimen of CRT, a platinum-based regimen has shown a better survival benefit than other regimens. The control arm in a randomized trial for unresectable locally advanced HNC is radiotherapy concurrent with CDDP (100 mg/m2, every 3 weeks), which has been considered to be too toxic for clinical practice in Western countries and has required frequent dose modifications. Because the Japanese also have been considered unable to tolerate this regimen, no prospective study of it has been conducted in Japan. Most Japanese patients with locally advanced head and neck cancer have received concurrent chemoradiotherapy with 5-FU and CDDP (70-80 mg/m2). S-1 has shown high activity in HNC with a response rate of 34%. Furthermore, a combination of cisplatin and S-1 therapy for HNC has been reported to have good efficacy. With this rationale in mind, we conducted a phase I study of CRT with S-1 and CDDP for unresectable locally advanced squamous cell carcinoma of the head and neck. The CR rate was very promising, though preliminary, and warrants further investigation. The Japan Clinical Oncology Group (JCOG) is planning a multicenter phase II study of concurrent chemoradiotherapy with S-1 and CDDP for locally advanced unresectable HNC.     

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.     

The interaction between protein-kinase-C (pkc) and estrogens (review)

The interactions between protein kinase C (PKC) and the steroid hormone estradiol or its receptor (ER) are reviewed. Estradiol upregulates PKC both in vitro and in vivo in the ovary, the anterior pituitary and in mammary tissue of several mammalian species. The antiestrogen tamoxifen inhibits PKC. Activation of PKC leads to a marked decrease of ER protein and ERmRNA in human breast cancer cells and some other cell lines. Inhibition or down-regulation of PKC enhances ER binding. These results indicate that there are links between the PKC signal transduction pathway and the steroid receptor family. Further studies are needed to clarify the role of PKC isoforms in normal and cancerous tissues which are known to be influenced by estradiol.     

Methylglyoxal-bis(guanylhydrazone) (Methyl-GAG): current status and future prospects

Initial clinical trials of methyl-GAG (MGBG) showed that repetitive daily administration produced severe, occasionally fatal, toxic reactions. After two decades of neglect, recent studies have shown that doses of 500-600 mg/sq m administered every 7-14 days are very well tolerated. Moreover, current results indicate that MGBG has useful antitumor activity in patients with advanced malignant lymphoma and carcinomas of the head and neck, esophagus, and lung (non-small cell). The drug's mechanism of cytotoxic action and its toxic effects are not shared by most other cancer chemotherapeutic drugs. Furthermore, Phase II and Phase III evaluation are required to determine the therapeutic potential of this unique agent.     

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.     

Arachidonate lipoxygenase (ALOX) and cyclooxygenase (COX) polymorphisms and colon cancer risk

In the human colon, arachidonic acid is metabolized primarily by cyclooxygenase (COX) and arachidonate lipoxygenase (ALOX) to bioactive lipids, which are implicated in colon cancer risk. Several polymorphisms in ALOX and COX genes have been identified, including G-1752A, G-1699A and Glu254Lys in ALOX5; Gln261Arg in ALOX12; Leu237Met and Val481Ile in COX1; and C-645T and Val511Ala in COX2. Because of the significant role of arachidonic acid metabolism in colon cancer, we hypothesized that these polymorphisms could influence susceptibility to colon cancer. We addressed this hypothesis in African-Americans and Caucasians using colon cancer cases (n = 293) and hospital- (n = 229) and population-based (n = 304) control groups. Polymorphisms did not differ between the control groups (P > 0.05); thus, they are combined for all analyses presented. ALOX5 Glu254Lys and COX2 C-645T and Val511Ala allele frequencies differed between Caucasians and African-American controls (P < 0.001). The ALOX5 -1752 and -1699 polymorphisms were in linkage disequilibrium (P < 0.001) and associated with a decreased risk in Caucasians in ALOX5 haplotype analyses (P = 0.03). Furthermore, an inverse association was observed between A alleles at positions -1752 and -1699 of ALOX5 and colon cancer risk in Caucasians, but not in African-Americans. Caucasians with A alleles at ALOX5 -1752 had a reduced odds of colon cancer versus those with G alleles [odds ratio (OR) (GA versus GG), 0.63; 95% confidence interval (CI), 0.39-1.01; OR (AA versus GG), 0.33; 95% CI, 0.07-1.65, P(trend) = 0.02]. Similar results were observed for ALOX5 G-1699A [OR (GA versus GG), 0.59, 95% CI, 0.37-0.94; OR (AA versus GG), 0.27, 95% CI, 0.06-1.32, P(trend) = 0.01]. Statistically significant associations with colon cancer were not observed for the other polymorphisms investigated. We have shown for the first time that a haplotype containing ALOX5 G-1752A and G-1699A in a negative regulatory region of the promoter may influence colon cancer risk in Caucasians.     

Immunoglobulins (Ig) in circulating immune complexes (CIC) in cancer and inflammatory bowel disease (IBD)

Chronically inflamed tissues and most malignancies have antigenic properties. Patients with long-standing inflammatory bowel disease (IBD) are prone to development of colorectal cancer, which is known to shed antigens in the bloodstream. In an effort to study immunological aspects of these diseases, sera from patients with IBD and colorectal cancer were evaluated for presence of circulating antigen-antibody immune complexes (CIC), and compared to normal controls. CIC were precipitated by polyethylene glycol (PEG) and found to be elevated in all diseased groups. Dissociation of CIC and quantification of their antibody component revealed significant elevation of each immunoglobulin in IBD and in patients with colorectal cancer versus control: IgG = 1.776 +/- 1.573 vs 0.734 +/- 0.618 (P less than 0.001); IgA = 0.368 +/- 0.452 vs 0.090 +/- 0.198 (P less than 0.001); IgM = 0.434 +/- 0.235 vs 0.080 +/- 0.285 (P less than 0.001) serum total Ig levels were consistently much higher than CIC Ig. No correlation was found between the individual serum Ig components and the precipitable complexes-bound Ig, suggesting a selective recognition of antigenic components in the CIC, rather than non-specific association and subsequent precipitation of serum Ig. CIC may represent an easily accessible source of immunological determinants for the study of malignant and chronic inflammatory diseases.     

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.     

Preliminary results of alternating combination chemotherapy (CT) and hyperfractionated radiotherapy (HART) in advanced rhabdomyosarcoma (RMS)

In an attempt to reduce treatment (Rx) related acute toxicity and improve protocol compliance without compromising local control nor overall survival, a Phase II single arm pilot employing alternating intensive multiagent CT and radiotherapy (RT) in children with gross residual or metastatic RMS was begun at Memorial Sloan-Kettering Cancer Center (MSKCC) in 1984. Hyperfractionated radiotherapy (HART) was adopted to allow for timely delivery of both the RT and CT. From July, 1984 through July, 1986 12 patients (pts), aged 2 to 23 yr (median 10 yr) were enrolled on study. CT treatment was delivered over approximately 14 months and included 2 induction and 5 maintenance cycles. The induction CT consisted of two repetitive cycles of Vincristine, Dactinomycin, Cyclophosphamide, Adriamycin, Bleomycin, and Methotrexate; the maintenance CT included the same agents as reduced drug doses. The HART was delivered to the primary site during cycle I of induction at fractions of 150 cGy BID to a total dose of 5400 cGy in 2 courses of 3000 cGy and 2400 cGy, respectively. One hundred percent of patients completed the recommended dose of HART; 0% required unplanned interruptions of HART due to treatment toxicity. With a median follow-up (f/u) from diagnosis of surviving patients of 25 months (range 20-30), the local control rate is 83% (10/12 pts) and the overall survival, 58% (7/12 pts). The median time (MT) to any failure, local or metastatic, is 9 months (mo); and to death, 14 mo. Comparison of results with 12 historical controls with concomitant split-course standard fractionation RT (180-200 cGy/per fraction) and T6 CT during a MSKCC trial from 1975-1984, matched by site and stage of primary, revealed that 9 pts (75%) completed the recommended dose of RT, and 7 pts (58%) required interruptions of RT. With a median f/u of 78 mo (range 34-109), the local control rate was 75% (9/12 pts) and the overall survival, 42% (5/12 pts). The MT to any failure was 14 mo; and to death, 18 mo. These results indicate that the mode of alternating CT and HART (HART T6) as employed in this pilot study is well tolerated. It appears to offer a significant improvement in protocol compliance over previous protocols using concomitant CT and RT without any apparent compromise in local primary control or survival rates with a median f/u suggestive of adequate elapsed time for the appearance of most relapses and deaths in advanced RMS.