Tags

Type your tag names separated by a space and hit enter

Potent antitumor activity and improved pharmacological profile of ST1481, a novel 7-substituted camptothecin.
Cancer Res. 2001 Oct 01; 61(19):7189-95.CR

Abstract

Relevant drawbacks of the molecular structure and mechanism of the action of camptothecins are the instability of the E ring lactone and the reversibility of drug-target interaction. Such features are expected to limit the clinical efficacy of conventional camptothecins. In an attempt to overcome these limitations and to improve the pharmacological profile of camptothecins, a novel series of seven modified lipophilic analogues was synthesized based on the hypothesis that lipophilicity could promote a rapid cellular accumulation and stabilization of drug-target interaction. A novel analogue (ST1481) of the series, characterized by a potent antitopoisomerase and cytotoxic activity, was selected for preclinical development. A detailed preclinical study of ST1481 was performed in the H460 non-small cell lung tumor model using oral administration and various treatment schedules. Under all of the conditions, ST1481 exhibited an impressive efficacy in terms of tumor growth inhibition (tumor volume inhibition percentage > 99%), log(10) cell kill, rate of complete responses (including "cures"), and an improvement of the therapeutic index compared with topotecan (used as the reference drug). The cytotoxic potency was also reflected by the in vivo potency, because the drug activity was observed at doses as low as 0.25 mg/kg with the daily schedule. In contrast to topotecan, no cross-resistance to ST1481 was found in ovarian carcinoma cells overexpressing P-glycoprotein (A2780/DX). A similar trend in the improvement of activity was also observed in the same tumor model growing in vivo with a 100% rate of complete tumor regressions. A rapid intestinal absorption and good oral bioavailability were supported by in vivo distribution studies, because the peak values of drug accumulation were found from 1 to 2 h after administration. The relevant liver accumulation may account for a marked effect of ST1481 against liver metastases induced by the ovarian carcinoma IGROV-1. In conclusion, the results support the hypothesis that a potent lipophilic camptothecin with a proper substituent at the position 7 may have therapeutic advantages likely related to a rapid intracellular uptake and tissue distribution, stabilization of the drug-target complex, and good oral bioavailability. Overall, the results support the preclinical interest of ST1481 in terms of efficacy, potency, toxicity profile, and ability to overcome multidrug resistance.

Authors+Show Affiliations

Istituto Nazionale per lo Studio e la Cura dei Tumori, 20133 Milano, Italy.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11585754

Citation

De Cesare, M, et al. "Potent Antitumor Activity and Improved Pharmacological Profile of ST1481, a Novel 7-substituted Camptothecin." Cancer Research, vol. 61, no. 19, 2001, pp. 7189-95.
De Cesare M, Pratesi G, Perego P, et al. Potent antitumor activity and improved pharmacological profile of ST1481, a novel 7-substituted camptothecin. Cancer Res. 2001;61(19):7189-95.
De Cesare, M., Pratesi, G., Perego, P., Carenini, N., Tinelli, S., Merlini, L., Penco, S., Pisano, C., Bucci, F., Vesci, L., Pace, S., Capocasa, F., Carminati, P., & Zunino, F. (2001). Potent antitumor activity and improved pharmacological profile of ST1481, a novel 7-substituted camptothecin. Cancer Research, 61(19), 7189-95.
De Cesare M, et al. Potent Antitumor Activity and Improved Pharmacological Profile of ST1481, a Novel 7-substituted Camptothecin. Cancer Res. 2001 Oct 1;61(19):7189-95. PubMed PMID: 11585754.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Potent antitumor activity and improved pharmacological profile of ST1481, a novel 7-substituted camptothecin. AU - De Cesare,M, AU - Pratesi,G, AU - Perego,P, AU - Carenini,N, AU - Tinelli,S, AU - Merlini,L, AU - Penco,S, AU - Pisano,C, AU - Bucci,F, AU - Vesci,L, AU - Pace,S, AU - Capocasa,F, AU - Carminati,P, AU - Zunino,F, PY - 2001/10/5/pubmed PY - 2001/10/19/medline PY - 2001/10/5/entrez SP - 7189 EP - 95 JF - Cancer research JO - Cancer Res. VL - 61 IS - 19 N2 - Relevant drawbacks of the molecular structure and mechanism of the action of camptothecins are the instability of the E ring lactone and the reversibility of drug-target interaction. Such features are expected to limit the clinical efficacy of conventional camptothecins. In an attempt to overcome these limitations and to improve the pharmacological profile of camptothecins, a novel series of seven modified lipophilic analogues was synthesized based on the hypothesis that lipophilicity could promote a rapid cellular accumulation and stabilization of drug-target interaction. A novel analogue (ST1481) of the series, characterized by a potent antitopoisomerase and cytotoxic activity, was selected for preclinical development. A detailed preclinical study of ST1481 was performed in the H460 non-small cell lung tumor model using oral administration and various treatment schedules. Under all of the conditions, ST1481 exhibited an impressive efficacy in terms of tumor growth inhibition (tumor volume inhibition percentage > 99%), log(10) cell kill, rate of complete responses (including "cures"), and an improvement of the therapeutic index compared with topotecan (used as the reference drug). The cytotoxic potency was also reflected by the in vivo potency, because the drug activity was observed at doses as low as 0.25 mg/kg with the daily schedule. In contrast to topotecan, no cross-resistance to ST1481 was found in ovarian carcinoma cells overexpressing P-glycoprotein (A2780/DX). A similar trend in the improvement of activity was also observed in the same tumor model growing in vivo with a 100% rate of complete tumor regressions. A rapid intestinal absorption and good oral bioavailability were supported by in vivo distribution studies, because the peak values of drug accumulation were found from 1 to 2 h after administration. The relevant liver accumulation may account for a marked effect of ST1481 against liver metastases induced by the ovarian carcinoma IGROV-1. In conclusion, the results support the hypothesis that a potent lipophilic camptothecin with a proper substituent at the position 7 may have therapeutic advantages likely related to a rapid intracellular uptake and tissue distribution, stabilization of the drug-target complex, and good oral bioavailability. Overall, the results support the preclinical interest of ST1481 in terms of efficacy, potency, toxicity profile, and ability to overcome multidrug resistance. SN - 0008-5472 UR - https://www.unboundmedicine.com/medline/citation/11585754/Potent_antitumor_activity_and_improved_pharmacological_profile_of_ST1481_a_novel_7_substituted_camptothecin_ L2 - http://cancerres.aacrjournals.org/cgi/pmidlookup?view=long&pmid=11585754 DB - PRIME DP - Unbound Medicine ER -