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Chembiochem : a European Journal of... Dec 2023Small molecules inducing protein degradation are important pharmacological tools to interrogate complex biology and are rapidly translating into clinical agents....
Small molecules inducing protein degradation are important pharmacological tools to interrogate complex biology and are rapidly translating into clinical agents. However, to fully realise the potential of these molecules, selectivity remains a limiting challenge. Herein, we addressed the issue of selectivity in the design of CRL4 recruiting PROteolysis TArgeting Chimeras (PROTACs). Thalidomide derivatives used to generate CRL4 recruiting PROTACs have well described intrinsic monovalent degradation profiles by inducing the recruitment of neo-substrates, such as GSPT1, Ikaros and Aiolos. We leveraged structural insights from known CRL4 neo-substrates to attenuate and indeed remove this monovalent degradation function in well-known CRL4 molecular glues degraders, namely CC-885 and Pomalidomide. We then applied these design principles on a previously published BRD9 PROTAC (dBRD9-A) and generated an analogue with improved selectivity profile. Finally, we implemented a computational modelling pipeline to show that our degron blocking design does not impact PROTAC-induced ternary complex formation. We believe that the tools and principles presented in this work will be valuable to support the development of targeted protein degradation.
Topics: Ubiquitin-Protein Ligases; Proteolysis
PubMed: 37418539
DOI: 10.1002/cbic.202300351 -
Blood Advances Dec 2023
Topics: Humans; Multiple Myeloma; Bortezomib; Thalidomide; Renal Insufficiency; Dexamethasone
PubMed: 37922425
DOI: 10.1182/bloodadvances.2023011428 -
Journal of Medicinal Chemistry Nov 2023Immunomodulatory imide drugs (IMiDs) such as thalidomide, pomalidomide, and lenalidomide are the most common cereblon (CRBN) recruiters in proteolysis-targeting chimera...
Immunomodulatory imide drugs (IMiDs) such as thalidomide, pomalidomide, and lenalidomide are the most common cereblon (CRBN) recruiters in proteolysis-targeting chimera (PROTAC) design. However, these CRBN ligands induce the degradation of IMiD neosubstrates and are inherently unstable, degrading hydrolytically under moderate conditions. In this work, we simultaneously optimized physiochemical properties, stability, on-target affinity, and off-target neosubstrate modulation features to develop novel nonphthalimide CRBN binders. These efforts led to the discovery of conformationally locked benzamide-type derivatives that replicate the interactions of the natural CRBN degron, exhibit enhanced chemical stability, and display a favorable selectivity profile in terms of neosubstrate recruitment. The utility of the most potent ligands was demonstrated by their transformation into potent degraders of BRD4 and HDAC6 that outperform previously described reference PROTACs. Together with their significantly decreased neomorphic ligase activity on IKZF1/3 and SALL4, these ligands provide opportunities for the design of highly selective and potent chemically inert proximity-inducing compounds.
Topics: Proteolysis; Proteolysis Targeting Chimera; Ubiquitin-Protein Ligases; Ligands; Nuclear Proteins; Transcription Factors; Adaptor Proteins, Signal Transducing
PubMed: 37902300
DOI: 10.1021/acs.jmedchem.3c00851 -
European Journal of Medicinal Chemistry Sep 2023Multiple myeloma (MM) is a hematologic neoplasm of plasma cells that is currently deemed incurable. Despite the introduction of novel immunomodulators and proteasome... (Review)
Review
Multiple myeloma (MM) is a hematologic neoplasm of plasma cells that is currently deemed incurable. Despite the introduction of novel immunomodulators and proteasome inhibitors, MM remains a challenging disease with high rates of relapse and refractoriness. The management of refractory and relapsed MM patients remains a formidable task, primarily due to the emergence of multiple drug resistance. Consequently, there is an urgent need for novel therapeutic agents to address this clinical challenge. In recent years, a significant amount of research has been dedicated to the discovery of novel therapeutic agents for the treatment of MM. The clinical utilization of proteasome inhibitor carfilzomib and immunomodulator pomalidomide has been successively introduced. As basic research continues to advance, novel therapeutic agents, including panobinostat, a histone deacetylase inhibitor, and selinexor, a nuclear export inhibitor, have progressed to the clinical trial and application phase. This review aims to furnish a comprehensive survey of the clinical applications and synthetic pathways of select drugs, with the intention of imparting valuable insights for future drug research and development geared towards MM.
Topics: Humans; Multiple Myeloma; Neoplasm Recurrence, Local; Panobinostat; Histone Deacetylase Inhibitors; Proteasome Inhibitors; Immunologic Factors; Antineoplastic Combined Chemotherapy Protocols
PubMed: 37210838
DOI: 10.1016/j.ejmech.2023.115492 -
Clinical Lymphoma, Myeloma & Leukemia Sep 2023The increasing use of anti-CD38 monoclonal antibodies (αCD38 mAbs) for newly diagnosed or early relapsed multiple myeloma (MM), especially in non-transplant eligible...
BACKGROUND
The increasing use of anti-CD38 monoclonal antibodies (αCD38 mAbs) for newly diagnosed or early relapsed multiple myeloma (MM), especially in non-transplant eligible patients, may lead to more patients developing αCD38 mAb-refractory disease earlier in the treatment course with fewer treatment options.
PATIENTS AND METHODS
We analyzed the efficacy and safety of selinexor-based triplets (selinexor+dexamethasone [Sd] plus pomalidomide [SPd, n = 23], bortezomib [SVd, n = 16] or carfilzomib (SKd, n = 23]) in a subset of STOMP (NCT02343042) and BOSTON (NCT03110562) study patients treated previously with αCD38 mAbs.
RESULTS
Sixty-two patients (median 4 prior therapies, range 1 to 11, 90.3% refractory to αCD38 mAb) were included. Overall response rates (ORR) in the SPd, SVd and SKd cohorts were 52.2%, 56.3%, and 65.2%, respectively. Overall response rate was 47.4% among patients who had MM refractory to the third drug reintroduced in the Sd-based triplet. Median progression-free survival in the SPd, SVd, and SKd cohorts was 8.7, 6.7, and 15.0 months, respectively, and median overall survival was 9.6, 16.9, and 33.0 months, respectively. Median time to discontinuation in the SPd, SVd, and SKd cohorts was 4.4, 5.9, and 10.6 months, respectively. The most common hematological adverse events were thrombocytopenia, anemia, and neutropenia. Nausea, fatigue, and diarrhea were primarily grade 1/2. Adverse events were generally manageable with standard supportive care and dose modifications.
CONCLUSION
Selinexor-based regimens may offer effective and well-tolerated therapy to patients with relapsed and/or refractory MM who had disease previously exposed or refractory to αCD38 mAb therapy and could help address the unmet clinical need in these high-risk patients.
Topics: Humans; Antibodies, Monoclonal; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Multiple Myeloma
PubMed: 37393120
DOI: 10.1016/j.clml.2023.06.001 -
Biomedicine & Pharmacotherapy =... Jul 2023CD4 + regulatory T cells (Tregs) play a central role in regulating and suppressing anti-tumor immune responses. FoxP3 is a transcription factor and master regulator of...
CD4 + regulatory T cells (Tregs) play a central role in regulating and suppressing anti-tumor immune responses. FoxP3 is a transcription factor and master regulator of the Treg lineage. We developed and characterized a proteolysis targeting chimeric (PROTAC) drug that targets FoxP3 (PF). PF was created by linking the FoxP3 binding peptide P60 to pomalidomide, a ligand for E3 ligase. Ternary complex formation between PF, FoxP3, and cereblon (component of an E3 ligase) was confirmed using surface plasmon resonance assay (cooperativity factor of 2.27). PF decreased mouse and human FoxP3 expression in vitro in a proteasome-dependent manner. In mice, PF decreased FoxP3 in both the spleen and peripheral lymphocytes. PF-treated lymphocytes (human or mice) were better at stimulating CD8 + lymphocyte proliferation and activation. PF treatment decreased RENCA tumor growth in mice. PF enhanced antitumor immunity associated with αPD1 or mTOR inhibitor (mTORi). Lymphocytes from mice treated with PF and mTORi showed reduced metastatic tumor growth in untreated mice, providing further evidence for an adaptive immune response as the mechanism of action. We showed that PF binds FoxP3 and decreases FoxP3 expression in Tregs, reducing Treg function and generating antitumor immunity.
Topics: Animals; Humans; Mice; Forkhead Transcription Factors; Lymphocyte Activation; Neoplasms; Proteolysis; T-Lymphocytes, Regulatory; Transcription Factors; Proteolysis Targeting Chimera
PubMed: 37182514
DOI: 10.1016/j.biopha.2023.114871 -
Advances in Hematology 2023Graft-versus-host disease (GVHD) is a potentially fatal complication of allogeneic hematopoietic stem cell transplant. The mainstay of treatment is corticosteroids,... (Review)
Review
BACKGROUND
Graft-versus-host disease (GVHD) is a potentially fatal complication of allogeneic hematopoietic stem cell transplant. The mainstay of treatment is corticosteroids, which are ineffective in 30-50% of cases. Steroid-refractory GVHD (SR-GVHD) confers a poor prognosis, with high mortality rates despite appropriate therapy. While there is no reliable treatment for SR-GVHD, a variety of novel therapeutic options are slowly emerging and have yet to be examined simultaneously.
OBJECTIVES
This review evaluates the potential of novel therapeutic options, as well as their efficacy and safety, for the treatment of SR-GVHD. . The literature search was conducted in PubMed, Cochrane, and Embase, employing MeSH terms and keywords. The studies had to be prospective phases 1, 2, or 3. We excluded retrospective and nonoriginal studies.
RESULTS
While the only approved drug for acute GVHD is ruxolitinib with an impressive overall response rate of 73.2% and a complete response of 56.3%, several monoclonal antibodies and other agents are currently under investigation, offering promising results. These include anti-CD2, anti-CD147, IL-2 antagonist, a mixture of anti-CD3 and anti-CD7 antibodies, anti-CD25, monoclonal antibody to a4b7 on T-cells, anti-CD26, pentostatin, sirolimus, denileukin diftitox, infliximab, itacitinib, and alpha-1 antitripsin. However, the toxicities associated with these novel drugs need further investigation. For chronic GVHD, approved options include ruxolitinib with an ORR of up to 62%, ibrutinib with an ORR of up to 77%, and belumosudil with an ORR of up to 77%. Meanwhile, emerging treatments include tyrosine kinase inhibitors such as nilotinib, rituximab, and low-dose IL-2, as well as axatilimab and pomalidomide.
CONCLUSION
While their efficacy needs to be better evaluated through large-scale, multicenter, randomized clinical trials, these novel agents show potential and could provide a better alternative for SR-GVHD treatment in the future.
PubMed: 38094101
DOI: 10.1155/2023/9949961 -
Communications Chemistry Feb 2024Pomalidomide is an E3 ligase recruiter exploited by PROTACs to degrade target proteins, but its application is hampered by the off-target degradation of other vital...
Pomalidomide is an E3 ligase recruiter exploited by PROTACs to degrade target proteins, but its application is hampered by the off-target degradation of other vital endogenous zinc finger (ZF) proteins. Now, the off-target ZF binding of pomalidomide-based PROTACs is evaluated by a high-throughput imaging screening platform, and minimization of off-target degradation as well as enhanced potency are achieved through selective functionalization at the C5 position of the phthalimide ring.
PubMed: 38409444
DOI: 10.1038/s42004-024-01125-2 -
Blood Advances Oct 2023We conducted a phase 1/2 study of carfilzomib, pomalidomide, and dexamethasone (KPd) and KPd with daratumumab (Dara-KPd) in relapsed/refractory multiple myeloma. The...
We conducted a phase 1/2 study of carfilzomib, pomalidomide, and dexamethasone (KPd) and KPd with daratumumab (Dara-KPd) in relapsed/refractory multiple myeloma. The primary end points were identification of a maximum tolerated dose (MTD) of KPd for phase 1, and rates of overall response (ORR) and near complete response (nCR) after 4 cycles of KPd and Dara-KPd, respectively, for phase 2. The MTD for KPd was carfilzomib 20/27 mg/m2 on days 1, 2, 8, 9, 15, and 16 (cycles 1-8) and days 1, 2, 15, and 16 for cycles 9 and beyond; oral pomalidomide 4 mg on days 1 to 21; and oral dexamethasone 40 mg weekly in 28-day cycles. Sixty-six patients received KPd, including 34 at the MTD. The ORR after 4 cycles of KPd at the MTD was 27/34 (79%; 95% confidence interval [CI], 62%-91%), meeting the statistical threshold for efficacy. At a median follow-up of 44 months, the median progression-free survival (PFS) was 13 months and overall survival (OS) 44 months. Twenty-eight patients received Dara-KPd. The rate of nCR or better after 4 cycles was 11/28 (39%; 95% CI, 22%-59%), meeting the statistical threshold for efficacy. As the best response to Dara-KPd, the ORR was 25/28 (89%) and the rate of measurable residual disease negativity by flow cytometry (10-5) was 17/26 (65%). At a median follow-up of 26 months, the median PFS and OS for Dara-KPd were not reached. Dara-KPd induced deeper and more durable responses than KPd without compromising safety in a predominantly high-risk, lenalidomide-refractory population, warranting further evaluation of this quadruplet. This trial is registered at www.clinicaltrials.gov as #NCT01665794.
Topics: Humans; Multiple Myeloma; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone
PubMed: 36763537
DOI: 10.1182/bloodadvances.2022008866 -
Nature Communications Nov 2023Temporal control of protein levels in cells and living animals can be used to improve our understanding of protein function. In addition, control of engineered proteins...
Temporal control of protein levels in cells and living animals can be used to improve our understanding of protein function. In addition, control of engineered proteins could be used in therapeutic applications. PRoteolysis-TArgeting Chimeras (PROTACs) have emerged as a small-molecule-driven strategy to achieve rapid, post-translational regulation of protein abundance via recruitment of an E3 ligase to the target protein of interest. Here, we develop several PROTAC molecules by covalently linking the antibiotic trimethoprim (TMP) to pomalidomide, a ligand for the E3 ligase, Cereblon. These molecules induce degradation of proteins of interest (POIs) genetically fused to a small protein domain, E. coli dihydrofolate reductase (eDHFR), the molecular target of TMP. We show that various eDHFR-tagged proteins can be robustly degraded to 95% of maximum expression with PROTAC molecule 7c. Moreover, TMP-based PROTACs minimally affect the expression of immunomodulatory imide drug (IMiD)-sensitive neosubstrates using proteomic and biochemical assays. Finally, we show multiplexed regulation with another known degron-PROTAC pair, as well as reversible protein regulation in a rodent model of metastatic cancer, demonstrating the formidable strength of this system. Altogether, TMP PROTACs are a robust approach for selective and reversible degradation of eDHFR-tagged proteins in vitro and in vivo.
Topics: Animals; Tetrahydrofolate Dehydrogenase; Proteolysis Targeting Chimera; Escherichia coli Proteins; Escherichia coli; Trimethoprim; Proteomics; Ubiquitin-Protein Ligases; Proteolysis
PubMed: 37923771
DOI: 10.1038/s41467-023-42820-3