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A series of binuclear DNA-binding ligands was prepared by linking two (2,2':6',2"-terpyridine)platinum(II) moieties via alpha omega-dithiols of the type HS-[CH2]n-SH where n = 4-10. A monomeric analogue was also synthesized. Compounds were characterized by elemental analysis and electronic and n.m.r. spectroscopy. Viscometric measurements with sonicated rod-like DNA fragments and covalently closed circular DNA were performed to investigate the mode of binding of these agents. The ligands with n = 5 and 6 function as bis intercalators and form a single 'base-pair sandwich' in violation of neighbour-exclusion binding. Bifunctional reaction occurs for the ligand with n = 7, whereas the ligands with n = 8 and 10 show a preference for mixed monofunctional/bifunctional binding. The data do not permit definitive assignment of the binding mode of the ligands with n = 4 and 9. All compounds are growth-inhibitory against mouse leukaemia L1210 cells in culture with IC50 values in the range 2-14 microM.

The binding of platinum (II)-terpyridine complexes to DNA was studied by using equilibrium dialysis.Optical absorption methods were used to measure the ability of the ligands to aggregate in aqueous buffer. requirement for a single G C base-pair at the highest-affinity site. However, in the binuclear ligands chromophore specificity is severely compromised. Similar experiments indicate that 9-aminoacridine and selected methylene-linked diacridines show no significant sequence selectivity.

One hundred eight patients with recurrent or metastatic transitional cell carcinoma of the urothelial tract were randomized to receive cisplatin (C) 80 mg/m2 on day 1 every 4 weeks, or methotrexate (M) 50 mg/m2 on days 1 and 15 plus C 80 mg/m2 on day 2 every 4 weeks (C + M). Fifty-three eligible patients were randomized to C + M and 55 to C. In the C + M arm, 45% of patients responded (complete response [CR], 9%) and 31% (CR, 9%) in the C arm (P = .18). In the C arm, 20 patients failing or relapsing after C received M. Two patients responded, and four with progressive disease (PD) and one with a previous partial response (PR) showed no change. The median survival was 8.7 months (C + M arm) and 7.2 months (C arm), P = .7. Relapse-free survival was not significantly different, but C + M was associated with a significantly increased time to disease progression (median, 5.0 months, v 2.8 months for C arm). The response of untreated patients (37%) was not different from those with prior treatment (39%). On the C + M arm, 92% of patients and 96% of patients on the C arm received 85% or more of the scheduled C dose. Significantly more grade 3 or 4 hematological toxicity (27% v 2%; P = .01) and mucositis (20% v 0%; P = .0005) occurred in patients on the C + M arm. Although the initial response rates seen on the combination arm look superior, and the time to disease progression is increased, these effects have not translated into a clinically important increase in the duration of survival and were associated with increased toxicity.

The platinum(II) organoamides [Pt(NRCH2)2L2] (L = pyridine (py), R = p-HC6F4, C6F5,p-IC6F4,p-CIC6F4,p-C6F5C6F4; L = 4-methylpyridine, R = p-HC6F4) and [Pt(NRCH2CH2NR')(py)2] (R = p-HC6F4, R' = C6F5, p-BrC6F4, or p-MeC6F4) inhibit the growth of murine L1210 leukemia cells in culture with ID50 values for continuous exposure in the range 0.6-2.7 microM. Representative complexes are also active against L1210 cells in 2-h pulse exposures, as well as against the cisplatin-resistant variant L1210/DDP and human colonic carcinoma cell lines HT 29 and BE. Three complexes [Pt(NRCH2)2L2] (R = p-HC6F4, C6F5, or p-IC6F4) have good activity (T/C greater than or equal to 180%) against P388 leukemia in mice, and all other compounds tested are active except when R = p-C6F5C6F4, L = py. Although the molecular basis of the biological activity of these complexes is not known, the observation of good activity for amineplatinum(II) compounds with no hydrogen substituents on the nitrogen donor atoms introduces a new factor in the anticancer behavior of platinum(II) complexes.

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The disposition of the cisplatin analogue carboplatin was studied in seven patients with small cell lung cancer. Carboplatin 100 mg/m2 was administered without hydration by a 1-h infusion with VP16-213 120 mg/m2 on days 1, 2 and 3 of each course. Plasma and urine collections were made on days 1 and 3 of the first course of treatment. Carboplatin levels in plasma ultrafiltrate and urine were quantitated using a specific and sensitive, high-performance liquid chromatographic assay which involved sample clean-up on a Dowex-2 column prior to injection. Estimates of pharmacokinetic parameters determined using either compartmental or non-compartmental methods were comparable. There was no difference between carboplatin pharmacokinetic parameters determined on days 1 and 3 of treatment. The mean (+/- SD) carboplatin half-life determined from plasma data on day 1 was 105 +/- 30.4 min and was not significantly different from that determined using urinary excretion rate data (107 +/- 51.7 min). Urinary excretion rate plots showed that carboplatin elimination was mono-exponential for up to 14 h after infusion. Total-body clearance was 105 +/- 40.0 ml min-1 m-2, renal clearance 64.3 +/- 44.1 ml min-1 m-2, and volume of distribution 17.3 +/- 4.2 l/m2 on the 1st day of treatment. Of the administered dose, 58.4% +/- 21.2% was recovered in urine over a 24-h period after the start of the infusion. The mean renal clearance of carboplatin was comparable to creatinine clearance. Carboplatin disposition was clearly defined in the patients studied using analytical methodology specific for the unchanged drug.