Quantification of the bombesin/gastrin releasing peptide antagonist RC-3095 by liquid chromatography-tandem mass spectrometry.

Bombesin (BN) and its mammalian equivalent, gastrin-releasing peptide (GRP), stimulate cell proliferation and are involved in the pathogenesis of several types of human cancer. BN/GRP and their receptors were shown to be critical for the growth of various human malignancies, such as small-cell lung, prostate, ovary, stomach and breast cancers in the human tumor xenograft model. In the present study, a fast, sensitive, robust method was developed for the determination and quantification of a BN/GRP receptor antagonist RC-3095 (D-Tpi-Gln-Trp-Ala-Val-Gly-His-Leupsi(CH2NH)Leu-NH2), in human plasma by liquid chromatography coupled with tandem mass spectrometry. RC-3095 was extracted from 0.2 ml human plasma by protein precipitation using cold acetonitrile (0.4 ml). The method has a chromatographic run of 10 min using a C(8) analytical column (150 mm x 4.6 mm i.d.) and the linear calibration curve over the range was linear from 20 to 10000 ng ml(-1) (r(2)>0.994). The between-run precision, based on the relative standard deviation replicate quality controls, was 5.7% (60 ng ml(-1)), 7.1% (600 ng ml(-1)) and 6.8% (8000 ng ml(-1)). The between-run accuracy was +/-0.0, 2.1 and 3.1% for the above-mentioned concentrations, respectively. The developed procedure allows the quantitative determination of peptide RC-3095 for pharmacokinetics studies in human plasma.

Phase II trial of cisplatin plus decitabine, a new DNA hypomethylating agent, in patients with advanced squamous cell carcinoma of the cervix.

On the basis of the demonstrated single-agent activity of cisplatin in patients with advanced cervical cancer and the observation of in vitro synergism between this agent and decitabine, a new DNA hypomethylating agent, we designed a phase II trial in which the combined use of the two agents are used as first-line therapy in patients with recurrent and/or metastatic disease. Eligible patients were those with histopathologically proven diagnosis of squamous cell carcinoma of the cervix, which was not considered suitable for curative surgery and/or irradiation, having measurable disease, leukocyte counts more than or equal to 4,000/microl, thrombocyte counts more than or equal to 100,000/microl, serum creatinine more than or equal to 1.5 mg/dl, and normal liver function tests. Initial dose of cisplatin was 40 mg/m(2), whereas decitabine was 50 mg/m(2) for 3 consecutive days every 21 days. Because of toxicity, the dose of cisplatin was reduced to 30 mg/m(2). Twenty-five patients were included in the study; 24 of them were eligible for the evaluation of toxicity, whereas 21 of them were eligible for the evaluation of tumor responses. Nineteen (79.2%) patients had received prior radiotherapy. A total of 75 cycles of chemotherapy were administered to the patients, with a median of 3 cycles (range: 1-8) per patient. The most frequently observed side effect was neutropenia, which was National Cancer Institute- Common Toxicity Criteria grades III and IV in 68.0% of cases. One patient died of complications caused by drug-related neutropenic sepsis. The most common nonhematologic grades III and IV toxicities were nausea and vomiting, which occurred in 17.3% and 9.3% of the cycles, respectively. Of a total of 21 patients evaluable for tumor response, 8 (38.1%) achieved a partial response, whereas stable disease was documented in 5 cases (23.8%). Median progression-free interval (PFI) was 16 weeks, and median survival was 19 weeks (95% CI 7.9-31.2). Objective responses were more frequent in patients with metastatic lesions in nonirradiated sites. Cisplatin- decitabine combination was moderately active in patients with advanced squamous cell carcinoma of the cervix, mainly in patients presenting with metastatic disease at previously nonirradiated sites. However, this regimen produced significant hematologic toxicity. Further studies with this combination including a larger patient population, preferably with the concomitant administration of hematopoietic growth factors, are warranted.