plitidepsin and Thyroid-Neoplasms

To assess clinical benefit of plitidepsin (Aplidine) in patients with advanced medullary thyroid carcinoma (MTC).. We retrospectively reported the outcome of 10 patients with advanced MTC among 215 patients who have entered the phase I program with plitidepsin.. Median number of cycles was 5. Using World Health Organization criteria, 1 among 5 patients with measurable disease displayed a confirmed partial response, whereas 8 patients experienced a stable disease, and 1 patient had a progressive disease, corresponding to a disease control rate of 90%. Two patients treated at the maximum tolerated dose experienced muscular dose-limiting toxicity possibly related to palmitoyl transferase inhibition. One of these 2 patients was able to continue therapy with no dose reduction with the prophylactic addition of l-carnitine, which is used in the treatment of the carnitine palmitoyl transferase deficiency type 2.. Plitidepsin seems to be able to induce clinical benefit in patients with pretreated MTC, and its toxicity has been manageable at the recommended dose.

Topics: Adult; Aged; Antineoplastic Agents; Bone Neoplasms; Carcinoma, Medullary; Depsipeptides; Female; Follow-Up Studies; Humans; Liver Neoplasms; Lung Neoplasms; Male; Marine Toxins; Maximum Tolerated Dose; Middle Aged; Peptides, Cyclic; Survival Rate; Thyroid Neoplasms; Treatment Outcome

To evaluate the antitumor response, time-to-event efficacy endpoints and toxicity of plitidepsin (Aplidin) 5 mg/m as a 3-hour intravenous (i.v.) infusion every 2 weeks in patients with unresectable advanced medullary thyroid carcinoma (MTC).. Sixteen patients with MTC and disease progression or large tumor burden received plitidepsin. Tumor response and time-related parameters were evaluated according to Response Evaluation Criteria in Solid Tumors. Secondary efficacy endpoints were marker response (calcitonin and carcinoembryonic antigen), clinical benefit and quality of life. Safety was assessed using the National Cancer Institute Common Toxicity Criteria.. A total of 141 cycles (median, 9 per patient; range, 1-24) were administered. No complete responses or partial responses (PR) were found, and 12 patients had stable disease for >8 weeks. Median follow-up was 15.0 months. Median time to progression was 5.3 months. Median overall survival could not be calculated, but 86.7% and 66.0% of patients were alive at 6 and 12 months. Marker response included 1 unconfirmed PR and 2 stabilizations for calcitonin, and 1 unconfirmed PR and 4 stabilizations for calcitonin and carcinoembryonic antigen. One patient showed clinical benefit. Quality of life scores generally decreased during the study. Most treatment-related adverse events were mild or moderate. Grade 3 lymphopenia was the only severe hematological toxicity found (2 patients). Severe nonhematological toxicities were grade 3 creatine phosphokinase increase (2 patients, with no myalgia or muscular weakness) and transient grade 3 alanine aminotransferase increase (5 patients).. Single-agent plitidepsin given as 3-hour i.v. infusions every 2 weeks was generally well tolerated but showed limited clinical activity in patients with unresectable advanced MTC.

Topics: Adult; Aged; Brain Stem Neoplasms; Depsipeptides; Female; Humans; Infusions, Intravenous; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Peptides, Cyclic; Prognosis; Survival Rate; Thyroid Neoplasms; Treatment Outcome

Anaplastic thyroid cancer (ATC) is one of the most aggressive and highly lethal human cancers. Median survival after diagnosis is 4-6 months despite available radiotherapy and chemotherapy. Additional treatments are needed for ATC. Vascular endothelial growth factor (VEGF) is a potent angiogenic stimulus, which is expressed by ATC. Previously, anti-VEGF antibody was used to block VEGF-dependent angiogenesis in ATC xenografts. This treatment induced partial (56%) but not complete tumor regression. Aplidin (APLD) is a marine derived antitumor agent currently in phase II clinical studies. Multiple activities of this compound have been described which likely contribute to its antiproliferative effect. Notably, APLD has been shown to have antiangiogenic properties which include: inhibition of VEGF secretion, reduction in the synthesis of the VEGF receptor (FLT-1), and blockade of matrix metalloproteinase production by endothelial cells. We hypothesized that Aplidin, with its broad spectrum of action and antiangiogenic properties, would be a potentially effective drug against ATC.. Thirty BALB/c nu/nu mice were injected with ATC cells (ARO-81, 1 x 10(6)) and allowed to implant for 3 weeks. Animals were randomized to receive daily intraperitoneal injections of vehicle, low dose (0.5 mg/kg/day), or high dose (1.0 mg/kg/day) APLD. After 3 days, the animals were killed and the tumors were removed, weighed, and divided for RNA and protein analyses.. APLD significantly reduced ATC xenograft growth (low dose, 20% reduction, P = 0.01; high dose, 40% reduction, P < 0.001). This was associated with increased levels of apoptosis related proteins polyadenosylribose polymerase 85 (PARP-85, 75% increase, P = 0.024) and caspase 8 (greater than fivefold increase, P = 0.03). APLD treatment was further associated with lost or reduced expression of several genes that support angiogenesis to include: VEGF, hypoxia inducible factor 1(HIF-1), transforming growth factor-beta (TGFbeta), TGFbeta receptor 2 (TGFbetaR2), melanoma growth stimulating factor 1 (GRO1), cadherin, and vasostatin.. This data supports the hypothesis that APLD may be an effective adjunctive therapy against ATC. The demonstrated molecular impact against angiogenic related genes specifically supports future strategies combining APLD with VEGF interacting agents.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Blotting, Western; Carcinoma; Depsipeptides; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Mice; Mice, Inbred BALB C; Neovascularization, Pathologic; Peptides, Cyclic; Thyroid Neoplasms; Xenograft Model Antitumor Assays

Undifferentiated (anaplastic) thyroid carcinoma is a highly aggressive human cancer with very poor prognosis. Although there have been a few studies of candidate treatments, the fact that it is an infrequent tumor makes it very difficult to design clinical trials. A strong association has been observed between undifferentiated thyroid carcinoma and TP53 mutations in numerous molecular genetic and expression studies. Plitidepsin (Aplidin, PharmaMar, Madrid, Spain) is a novel anticancer compound obtained from a sea tunicate. This compound has been reported to induce apoptosis independently of TP53 status. We investigated the actions of plitidepsin in human thyroid cancer cells. In initial experiments using primary cultured cells from a differentiated (papillary) carcinoma, we found that 100 nmol/L plitidepsin induced apoptosis, whereas lower doses were cytostatic. Because our aim was to study the effects of plitidepsin at clinically relevant concentrations, subsequent experiments were done with a dosage regimen reflecting plasma concentrations observed in previously reported clinical trials: 100 nmol/L for 4 hours, followed by 10 nmol/L for 20 hours (4(100)/20(10) plitidepsin). This plitidepsin dosage regimen blocked the proliferation of a primary undifferentiated/anaplastic thyroid carcinoma culture obtained in our laboratory and of a commercial cell line (8305C) obtained from an undifferentiated thyroid carcinoma; however, it did not induce apoptosis. The proportion of cells in the G(1) phase of the cell cycle was greatly increased and the proportion in the S/G(2)-M phases greatly reduced, suggesting that plitidepsin blocks G(1)-to-S transition. Levels of the cyclin D1/cyclin-dependent kinase 4/p21 complex proteins were decreased and, in line with this, the levels of unphosphorylated Rb1 increased. The decrease in cell cycle proteins correlated with hypoacetylation of histone H3. Finally, we did experiments to assess how rapidly tumor cells return to their initial pretreatment proliferative behavior after 4(100)/20(10) plitidepsin treatment. Cells from undifferentiated tumors needed more than 3 days to recover logarithmic growth, and after 7 days, cell number was still significantly lower than in control cultures. 4(100)/20(10) plitidepsin inhibited the growth in soft agar. Together, our data show that plitidepsin is able to block in vitro cell cycle progression at concentrations similar to serum concentrations observed in vivo, and that this effect is pe

Topics: Adult; Agar; Aged; Antineoplastic Agents; Apoptosis; Carcinoma; Cell Cycle; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Clinical Trials as Topic; Depsipeptides; Dose-Response Relationship, Drug; Female; Flow Cytometry; Gene Expression Regulation, Neoplastic; Genes, p53; HeLa Cells; Histones; Humans; Immunoblotting; Male; Middle Aged; Models, Statistical; Peptides, Cyclic; Thyroid Gland; Thyroid Neoplasms; Time Factors; Tumor Cells, Cultured; Tumor Suppressor Protein p53