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Nature Chemistry Feb 2024Proteolysis-targeting chimeras (PROTACs) are molecules that induce proximity between target proteins and E3 ligases triggering target protein degradation. Pomalidomide,...
Proteolysis-targeting chimeras (PROTACs) are molecules that induce proximity between target proteins and E3 ligases triggering target protein degradation. Pomalidomide, a widely used E3 ligase recruiter in PROTACs, can independently degrade other proteins, including zinc-finger (ZF) proteins, with vital roles in health and disease. This off-target degradation hampers the therapeutic applicability of pomalidomide-based PROTACs, requiring development of PROTAC design rules that minimize off-target degradation. Here we developed a high-throughput platform that interrogates off-target degradation and found that reported pomalidomide-based PROTACs induce degradation of several ZF proteins. We generated a library of pomalidomide analogues to understand how functionalizing different positions of the phthalimide ring, hydrogen bonding, and steric and hydrophobic effects impact ZF protein degradation. Modifications of appropriate size on the C5 position reduced off-target ZF degradation, which we validated through target engagement and proteomics studies. By applying these design principles, we developed anaplastic lymphoma kinase oncoprotein-targeting PROTACs with enhanced potency and minimal off-target degradation.
Topics: Proteolysis; Ubiquitin-Protein Ligases; Proteins; Thalidomide
PubMed: 38110475
DOI: 10.1038/s41557-023-01379-8 -
Biomedicines Jul 2023Multiple myeloma (MM) is a cancerous condition characterized by the proliferation of plasma cells within the hematopoietic marrow, resulting in multiple osteolytic... (Review)
Review
Multiple myeloma (MM) is a cancerous condition characterized by the proliferation of plasma cells within the hematopoietic marrow, resulting in multiple osteolytic lesions. MM patients typically experience bone pain, kidney damage, fatigue due to anemia, and infections. Historically, MM was an incurable disease with a life expectancy of around three years after diagnosis. However, over the past two decades, the development of novel therapeutics has significantly improved patient outcomes, including response to treatment, remission duration, quality of life, and overall survival. These advancements include thalidomide and its derivatives, lenalidomide and pomalidomide, which exhibit diverse mechanisms of action against the plasma cell clone. Additionally, proteasome inhibitors such as bortezomib, ixazomib, and carfilzomib disrupt protein degradation, proving specifically toxic to cancerous plasma cells. Recent advancements also involve monoclonal antibodies targeting surface antigens, such as elotuzumab (anti-CS1) and daratumumab (anti-CD38), bispecific t-cell engagers such as teclistamab (anti-BCMA/CD3) and Chimeric antigen receptor T (CAR-T)-based strategies, with a growing focus on drugs that exhibit increasingly targeted action against neoplastic plasma cells and relevant effects on the tumor microenvironment.
PubMed: 37509726
DOI: 10.3390/biomedicines11072087 -
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 -
Nature Communications Dec 2023Thalidomide and its analogs are molecular glues (MGs) that lead to targeted ubiquitination and degradation of key cancer proteins via the cereblon (CRBN) E3 ligase....
Thalidomide and its analogs are molecular glues (MGs) that lead to targeted ubiquitination and degradation of key cancer proteins via the cereblon (CRBN) E3 ligase. Here, we develop a direct-to-biology (D2B) approach for accelerated discovery of MGs. In this platform, automated, high throughput, and nano scale synthesis of hundreds of pomalidomide-based MGs was combined with rapid phenotypic screening, enabling an unprecedented fast identification of potent CRBN-acting MGs. The small molecules were further validated by degradation profiling and anti-cancer activity. This revealed E14 as a potent MG degrader targeting IKZF1/3, GSPT1 and 2 with profound effects on a panel of cancer cells. In a more generalized view, integration of automated, nanoscale synthesis with phenotypic assays has the potential to accelerate MGs discovery.
Topics: Ubiquitin-Protein Ligases; Peptide Hydrolases; Ubiquitination; Proteolysis; Biology
PubMed: 38114468
DOI: 10.1038/s41467-023-43614-3 -
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 -
Nature Medicine Feb 2024Due to evolving treatment standards for newly diagnosed multiple myeloma, many patients will be triple-class exposed after initial relapses and have poor survival. Novel...
Due to evolving treatment standards for newly diagnosed multiple myeloma, many patients will be triple-class exposed after initial relapses and have poor survival. Novel therapies and combinations are therefore required to improve outcomes. B cell maturation antigen (BCMA)-targeted biologics have emerged as an important new area of therapeutics for relapsed multiple myeloma. The two-part ALGONQUIN trial evaluated various doses and schedules of the anti-BCMA antibody-drug conjugate belantamab mafodotin plus pomalidomide and dexamethasone for patients who are lenalidomide refractory and proteosome inhibitor exposed. The primary endpoints, including evaluating dose-limiting toxicities, establishing the recommended Part 2 dose (RP2D) and overall response rate for patients treated at the RP2D, were met. Secondary efficacy endpoints included progression-free survival and overall survival. Patients treated on study (N = 87) had a median of three previous regimens and 55.2% were triple-class refractory. At the RP2D the most common adverse events were decrease in best-corrected visual acuity (71.1%), keratopathy (65.8%), fatigue (57.9%), infection (47.4%; 7.9% grade ≥3), neutropenia (39.5%) and thrombocytopenia (39.5%). For RP2D patients (n = 38), the overall response rate was 85.3%, ≥very good partial response 75.7% and estimated two-year progression-free survival 52.8% (95% confidence interval, 33.9% to 82.4%), at a median follow-up of 13.9 months. The RP2D schedule was associated with manageable antibody-drug conjugate-associated corneal adverse events and improved tolerability without compromising efficacy. Belantamab mafodotin plus pomalidomide and dexamethasone induced durable responses with promising overall survival in relapsed multiple myeloma, the results of which are yet to be confirmed in the phase 3 DREAMM-8 study. ClinicalTrials.gov Identifier: NCT03715478 .
Topics: Humans; Multiple Myeloma; Treatment Outcome; Dexamethasone; Antineoplastic Combined Chemotherapy Protocols; Immunoconjugates; Thalidomide; Antibodies, Monoclonal, Humanized
PubMed: 38177852
DOI: 10.1038/s41591-023-02703-y