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Targeting the Somatostatin Receptor 2 with the Miniaturized Drug Conjugate, PEN-221: A Potent and Novel Therapeutic for the Treatment of Small Cell Lung Cancer.
- Source :
-
Molecular cancer therapeutics [Mol Cancer Ther] 2019 Nov; Vol. 18 (11), pp. 1926-1936. - Publication Year :
- 2019
-
Abstract
- Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma with a 95% mortality rate with no improvement to treatment in decades, and new therapies are desperately needed. PEN-221 is a miniaturized peptide-drug conjugate (∼2 kDa) designed to target SCLC via a Somatostatin Receptor 2 (SSTR2)-targeting ligand and to overcome the high proliferation rate characteristic of this disease by using the potent cytotoxic payload, DM1. SSTR2 is an ideal target for a drug conjugate, as it is overexpressed in SCLC with limited normal tissue expression. In vitro , PEN-221 treatment of SSTR2-positive cells resulted in PEN-221 internalization and receptor-dependent inhibition of cellular proliferation. In vivo , PEN-221 exhibited rapid accumulation in SSTR2-positive SCLC xenograft tumors with quick clearance from plasma. Tumor accumulation was sustained, resulting in durable pharmacodynamic changes throughout the tumor, as evidenced by increases in the mitotic marker of G <subscript>2</subscript> -M arrest, phosphohistone H3, and increases in the apoptotic marker, cleaved caspase-3. PEN-221 treatment resulted in significant antitumor activity, including complete regressions in SSTR2-positive SCLC xenograft mouse models. Treatment was effective using a variety of dosing schedules and at doses below the MTD, suggesting flexibility of dosing schedule and potential for a large therapeutic window in the clinic. The unique attributes of the miniaturized drug conjugate allowed for deep tumor penetration and limited plasma exposure that may enable long-term dosing, resulting in durable tumor control. Collectively, these data suggest potential for antitumor activity of PEN-221 in patients with SSTR2-positive SCLC.<br /> (©2019 American Association for Cancer Research.)
- Subjects :
- Animals
Cell Line, Tumor
Cell Proliferation drug effects
Cell Survival drug effects
Female
Gene Expression Regulation, Neoplastic drug effects
Humans
Immunoconjugates chemistry
Immunoconjugates pharmacology
Lung Neoplasms metabolism
Mice
Miniaturization
Small Cell Lung Carcinoma metabolism
Up-Regulation
Xenograft Model Antitumor Assays
Immunoconjugates administration & dosage
Lung Neoplasms drug therapy
Maytansine chemistry
Receptors, Somatostatin antagonists & inhibitors
Small Cell Lung Carcinoma drug therapy
Subjects
Details
- Language :
- English
- ISSN :
- 1538-8514
- Volume :
- 18
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Molecular cancer therapeutics
- Publication Type :
- Academic Journal
- Accession number :
- 31649014
- Full Text :
- https://doi.org/10.1158/1535-7163.MCT-19-0022