1
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: not found
      • Article: not found

      Antibody Conjugation of a Chimeric BET Degrader Enables in vivo Activity

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The ability to selectively degrade proteins with bifunctional small molecules has the potential to fundamentally alter therapy in a variety of diseases. However, the relatively large size of these chimeric molecules often results in challenging physico-chemical properties (e. g., low aqueous solubility) and poor pharmacokinetics which may complicate their in vivo applications. We recently discovered an exquisitely potent chimeric BET degrader (GNE-987) which exhibited picomolar cell potencies but also demonstrated low in vivo exposures. In an effort to improve the pharmacokinetic properties of this molecule, we discovered the first degrader-antibody conjugate by attaching GNE-987 to an anti-CLL1 antibody via a novel linker. A single IV dose of the conjugate afforded sustained in vivo exposures that resulted in antigen-specific tumor regressions. Enhancement of a chimeric protein degrader with poor in vivo properties through antibody conjugation thereby expands the utility of directed protein degradation as both a biological tool and a therapeutic possibility.

          Related collections

          Most cited references29

          • Record: found
          • Abstract: found
          • Article: not found

          Catalytic in vivo protein knockdown by small-molecule PROTACs.

          The current predominant therapeutic paradigm is based on maximizing drug-receptor occupancy to achieve clinical benefit. This strategy, however, generally requires excessive drug concentrations to ensure sufficient occupancy, often leading to adverse side effects. Here, we describe major improvements to the proteolysis targeting chimeras (PROTACs) method, a chemical knockdown strategy in which a heterobifunctional molecule recruits a specific protein target to an E3 ubiquitin ligase, resulting in the target's ubiquitination and degradation. These compounds behave catalytically in their ability to induce the ubiquitination of super-stoichiometric quantities of proteins, providing efficacy that is not limited by equilibrium occupancy. We present two PROTACs that are capable of specifically reducing protein levels by >90% at nanomolar concentrations. In addition, mouse studies indicate that they provide broad tissue distribution and knockdown of the targeted protein in tumor xenografts. Together, these data demonstrate a protein knockdown system combining many of the favorable properties of small-molecule agents with the potent protein knockdown of RNAi and CRISPR.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Selective Small Molecule Induced Degradation of the BET Bromodomain Protein BRD4

            The Bromo- and Extra-Terminal (BET) proteins BRD2, BRD3, and BRD4 play important roles in transcriptional regulation, epigenetics, and cancer and are the targets of pan-BET selective bromodomain inhibitor JQ1. However, the lack of intra-BET selectivity limits the scope of current inhibitors as probes for target validation and could lead to unwanted side effects or toxicity in a therapeutic setting. We designed Proteolysis Targeted Chimeras (PROTACs) that tether JQ1 to a ligand for the E3 ubiquitin ligase VHL, aimed at triggering the intracellular destruction of BET proteins. Compound MZ1 potently and rapidly induces reversible, long-lasting, and unexpectedly selective removal of BRD4 over BRD2 and BRD3. The activity of MZ1 is dependent on binding to VHL but is achieved at a sufficiently low concentration not to induce stabilization of HIF-1α. Gene expression profiles of selected cancer-related genes responsive to JQ1 reveal distinct and more limited transcriptional responses induced by MZ1, consistent with selective suppression of BRD4. Our discovery opens up new opportunities to elucidate the cellular phenotypes and therapeutic implications associated with selective targeting of BRD4.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              PROTAC-induced BET protein degradation as a therapy for castration-resistant prostate cancer

              Prostate cancer has the second highest incidence among cancers in men worldwide and is the second leading cause of cancer deaths of men in the United States. Although androgen deprivation can initially lead to remission, the disease often progresses to castration-resistant prostate cancer (CRPC), which is still reliant on androgen receptor (AR) signaling and is associated with a poor prognosis. Some success against CRPC has been achieved by drugs that target AR signaling, but secondary resistance invariably emerges, and new therapies are urgently needed. Recently, inhibitors of bromodomain and extra-terminal (BET) family proteins have shown growth-inhibitory activity in preclinical models of CRPC. Here, we demonstrate that ARV-771, a small-molecule pan-BET degrader based on proteolysis-targeting chimera (PROTAC) technology, demonstrates dramatically improved efficacy in cellular models of CRPC as compared with BET inhibition. Unlike BET inhibitors, ARV-771 results in suppression of both AR signaling and AR levels and leads to tumor regression in a CRPC mouse xenograft model. This study is, to our knowledge, the first to demonstrate efficacy with a small-molecule BET degrader in a solid-tumor malignancy and potentially represents an important therapeutic advance in the treatment of CRPC.
                Bookmark

                Author and article information

                Journal
                ChemMedChem
                ChemMedChem
                Wiley
                1860-7179
                1860-7187
                November 19 2019
                January 07 2020
                November 14 2019
                January 07 2020
                : 15
                : 1
                : 17-25
                Affiliations
                [1 ]Genentech Inc. 1 DNA Way South San Francisco CA 94080 USA
                [2 ]Wuxi Apptec 288 Fute Zhong Road Waigaoqiao Free Trade Zone Shanghai 200131 China
                Article
                10.1002/cmdc.201900497
                31674143
                1801f4f6-a755-4721-aeeb-5291dd9d77c0
                © 2020

                http://onlinelibrary.wiley.com/termsAndConditions#vor

                http://doi.wiley.com/10.1002/tdm_license_1.1

                History

                Comments

                Comment on this article