STAT3 is a promising therapeutic target for human cancers and other diseases. Herein, we report our development of novel STAT3 proteolysis-targeting chimera degraders using high-affinity STAT3 and Von Hippel-Lindau 1 ligands, which led to the discovery of SD-2301 as a highly potent, selective, and efficacious STAT3 degrader. SD-2301 achieved DC50 = 4 nM and Dmax of >95% and is >100 times more potent than SD-36 and SD-91. SD-2301 is highly selective for inducing STAT3 degradation over other Signal Transducer and Activator of Transcription members. SD-2301 inhibited cell growth with IC50 = 5-11 nM in the SU-DHL-1 and SUP-M2 lymphoma cell lines. SD-2301 displayed an excellent pharmacokinetic profile in mice and achieved rapid and persistent depletion of STAT3 protein in native and xenograft tumor tissues in mice. SD-2301 was capable of achieving complete and long-lasting tumor regression in vivo and is a promising STAT3 degrader for the treatment of human cancers and other human diseases.

Signal transducer and activator of transcription 3 (STAT3) is a promising therapeutic target for human cancers and other human diseases. Herein, we report on the design, synthesis, and evaluation of novel STAT3 PROTAC degraders using high-affinity STAT3 ligands and cereblon ligands. Our study led to the discovery of SD-965 as a potent, selective, and efficacious STAT3 degrader. A single intravenous administration of SD-965 effectively induces rapid, complete, and durable depletion of STAT3 protein in mouse native and human xenograft tumor tissues with no depletion of other STAT proteins. SD-965 is capable of achieving tumor regression even with weekly administration in human leukemia and lymphoma xenograft models in mice without any signs of toxicity. SD-965 represents a promising STAT3 degrader for extensive evaluation for the treatment of human cancers and other human diseases.

KRAS G12D and G12V mutants account for >50% of human cancers carrying a mutated KRAS protein, and targeting KRAS proteins by induced protein degradation represents an attractive cancer therapeutic strategy. Herein, we present the design, synthesis, and evaluation of PROTAC KRAS degraders using a novel cereblon ligand, which led to the discovery of CW-10201 as a promising KRAS degrader. CW-10201 effectively induced degradation of KRASG12D and KRASG12V mutants at low nanomolar concentrations in cells and attained IC50 values of 2–4 nM in inhibition of cell growth in cancer cell lines carrying KRASG12D or KRASG12V mutation. It demonstrated excellent pharmacokinetic and pharmacodynamic properties in mice. CW-10201 was capable of attaining tumor regression in the SW1990 KRASG12D mutated xenograft tumor model and effectively inhibited tumor growth in the SW620 KRASG12V xenograft tumor model in mice at well-tolerated doses. CW-10201 represents a promising KRASG12D and KRASG12V degrader for extensive evaluation and optimization for the treatment of human cancers.

STAT3 is a promising therapeutic target for human cancers and other diseases. Herein, we report our development of novel STAT3 proteolysis-targeting chimera degraders using high-affinity STAT3 and Von Hippel-Lindau 1 ligands, which led to the discovery of SD-2301 as a highly potent, selective, and efficacious STAT3 degrader. SD-2301 achieved DC50 = 4 nM and D-max of >95% and is >100 times more potent than SD-36 and SD-91. SD-2301 is highly selective for inducing STAT3 degradation over other Signal Transducer and Activator of Transcription members. SD-2301 inhibited cell growth with IC50 = 5-11 nM in the SU-DHL-1 and SUP-M2 lymphoma cell lines. SD-2301 displayed an excellent pharmacokinetic profile in mice and achieved rapid and persistent depletion of STAT3 protein in native and xenograft tumor tissues in mice. SD-2301 was capable of achieving complete and long-lasting tumor regression in vivo and is a promising STAT3 degrader for the treatment of human cancers and other human diseases.

Abstract Oncogenic mutation of KRAS is one of the most promising targets for cancer. Treatment with inhibitors inevitably lead to rapid onset of resistance, and loss of therapeutic effect after months. KRAS PROTACs may offer superior efficacy by eliminating mutated protein, disrupting scaffolding function and activating immune response, thus overcoming the rapid development of resistance. Using new E3 ligands developed in house, our compounds achieved less than 1 nM DC50 and IC50 in in vitro assays with G12D, G12V and G12C mutated cell lines. They exhibited excellent pharmacokinetic and pharmacodynamic properties in mice, and outstanding pharmacokinetic in rats, dogs, and monkeys. At 10 mg/kg, qW, the compounds achieved a remarkable TGI of over 92% in SW620 xenograft, a robust and challenging model of KRASG12V mutation. Additionally in an efficacy study with mice bearing SW1990 xenograft, at 10 mg/kg, qW, the compounds regressed the tumors by over 90%. Citation Format: Changwei Wang, Prithwish Ghosh, Shicheng Jin, Longchuan Bai, Donna McEachern, Angelo Aguilar, Qiuxia Li, Bo Wen, DUXIN SUN, Shaomeng Wang. Design and synthesis of highly efficacious CRBN-based pan-KRAS degraders targeting cancers with KRAS G12D, G12V and G12C mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5151.

Immune checkpoint blockade (ICB) has transformed cancer therapy1,2. The efficacy of immunotherapy depends on dendritic cell-mediated tumour antigen presentation, T cell priming and activation3,4. However, the relationship between the key transcription factors in dendritic cells and ICB efficacy remains unknown. Here we found that ICB reprograms the interplay between the STAT3 and STAT5 transcriptional pathways in dendritic cells, thereby activating T cell immunity and enabling ICB efficacy. Mechanistically, STAT3 restrained the JAK2 and STAT5 transcriptional pathway, determining the fate of dendritic cell function. As STAT3 is often activated in the tumour microenvironment5, we developed two distinct PROTAC (proteolysis-targeting chimera) degraders of STAT3, SD-36 and SD-2301. STAT3 degraders effectively degraded STAT3 in dendritic cells and reprogrammed the dendritic cell-transcriptional network towards immunogenicity. Furthermore, STAT3 degrader monotherapy was efficacious in treatment of advanced tumours and ICB-resistant tumours without toxicity in mice. Thus, the crosstalk between STAT3 and STAT5 transcriptional pathways determines the dendritic cell phenotype in the tumour microenvironment and STAT3 degraders hold promise for cancer immunotherapy.

MDM2 is a key negative regulator of the tumor suppressor p53 and an attractive target for cancer therapy. We report the discovery of MD-4251, the first orally efficacious MDM2 degrader developed using PROTAC technology. MD-4251 induces potent and rapid MDM2 degradation in RS4;11 cells (DC50 = 0.2 nM; Dmax = 96% at 2 h), leading to robust p53 activation. It selectively inhibits the growth of acute leukemia cell lines with wild-type p53, with minimal activity in p53 mutant lines. MD-4251 shows excellent oral bioavailability in mice, favorable metabolic stability, and no CYP or hERG liabilities. A single oral dose induces sustained MDM2 depletion and attains complete tumor regression in vivo. These results support MD-4251 as a promising therapeutic candidate for cancers through depletion of MDM2.

Dysregulated STAT3 signaling is a hallmark of tumorigenesis and therapeutic resistance across a wide spectrum of cancers, yet strategies for directly targeting STAT3 have, to date, met with limited clinical success. We have developed SD-1240, a rationally designed heterobifunctional PROTAC degrader that recruits the VHL E3 ligase to facilitate the selective and potent degradation of STAT3. In cellular models of anaplastic large cell lymphoma (ALCL), SD-1240 elicited rapid, robust and selective STAT3 protein depletion with low nanomolar potency (DC50 5–10 nM; Dmax >95%), leading to marked cytotoxicity (IC50: 5–50 nM in a panel of ALCL cell lines). Notably, SD-1240 achieved selective STAT3 depletion in both ALCL cell lines and human peripheral blood mononuclear cells (PBMCs), while sparing other STAT family members (STAT1/2/4/5/6), as demonstrated by both quantitative proteomics and immunoblotting. In vivo, systemic administration of SD-1240 induced rapid and durable STAT3 degradation in both tumor and normal tissues, with STAT3 depletion sustained up to 168 hours post-dose. This pharmacodynamic effect translated into profound, dose-dependent tumor growth inhibition in ALCL xenograft models at doses ranging from 1–10 mg/kg (IV, weekly), without observable toxicity or weight loss in treated mice. Mechanistic studies revealed that transcriptional profiling of SD-1240–treated tumors showed broad suppression of canonical STAT3 gene targets and inhibition of multiple oncogenic and pro-survival signaling pathways. Collectively, these data establish SD-1240 as a highly selective, potent, and well-tolerated degrader of STAT3, capable of inducing durable pharmacodynamic and antitumor responses in preclinical mouse tumor models. These findings support the advancement of SD-1240 as a promising clinical candidate for the treatment of STAT3-driven malignancies. This work is funded by NIH/NCI R01CA244509), Proteovant Therapeutics and Oncopia Therapeutics Longchuan Bai, Haibin Zhou, Dimin Wu, Ranjan Acharyya, Hoda Metwally, Donna McEachern, Bo Wen, Duxin Sun, Jeanne A. Stuckey, Shaomeng Wang. SD-1240, a VHL-based STAT3 degrader, induces optent and selective STAT3 depletion and suppresses tumor growth in ALCL preclinical models [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2025 Oct 22-26; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2025;24(10 Suppl):Abstract nr B132.

Immune checkpoint blockade (ICB) has transformed cancer therapy. Immunotherapy efficacy depends on dendritic cell (DC)-mediated tumor antigen presentation, T-cell priming and activation. However, the relationship between the key transcription factors in DCs and ICB efficacy remains unknown. Here, we discover ICB reprogrammed the interplay between the STAT3- and STAT5-transcriptional pathways in DCs, thereby activating T-cell immunity and enabling ICB efficacy. Mechanistically, STAT3 restrained the JAK2- and STAT5-transcriptional pathway, determining the fate of DC function. As STAT3 is often activated in the tumor microenvironment (TME), we designed two types of specific PROTAC degraders of STAT3, SD-36 and SD-2301. STAT3-degraders effectively degraded STAT3 in DCs and reprogramed the DC-transcriptional network toward immunogenicity. Furthermore, STAT3-degrader monotherapy was efficacious in treating advanced tumors and ICB-resistant tumors without toxicity in mice. Thus, the crosstalk between the STAT3- and STAT5-transcriptional pathways determines the DC phenotype in the TME and STAT3 degradation holds promise for cancer immunotherapy. Supported in part by research grants from the Breast Cancer Research Foundation, the U.S., NIH/NCI R01 grants (CA217648, CA123088, CA099985, CA193136, CA152470, and CA244509), and the NIH/NCI through the University of Michigan Rogel Cancer Center Grant (CA46592). J.-X.L. and W.J.L. are supported by the Division of Intramural Research, the National Heart, Lung, and Blood Institute, the NIH. Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)

IKZF2 (Helios) is a transcription factor that is selectively expressed by Tregs and is essential for preserving the function and stability of Tregs in the tumor microenvironment (TME), where it suppresses the anti-tumor immune response. Targeted IKZF2 degradation by small molecules represents a promising strategy for the development of a new class of cancer immunotherapy. Herein, we describe the discovery of PVTX-405, a potent, effective, highly selective, and orally efficacious IKZF2 molecular glue degrader. PVTX-405 degrades IKZF2 (DC50 = 0.7 nM and Dmax = 91%) while sparing other CRBN neo-substrates. Degradation of IKZF2 by PVTX-405 increases production of inflammatory cytokine IL-2 and reduces the suppressive activity of Tregs, leading to an increase in Teff cell proliferation. Once-daily oral administration of PVTX-405 as single agent significantly delays the growth of MC38 tumors in a syngeneic tumor model using humanized CRBN mice. PVTX-405 in combination with anti-PD1 or anti-LAG3 significantly increases animal survival compared to anti-PD1 or anti-LAG3 alone. Together, these results demonstrate that PVTX-405 is a promising IKZF2 degrader for clinical development for the treatment of human cancers.

Immunosuppressive Tregs, regulated by IKZF2 (Helios), promote tumor immune evasion and resistance to immune checkpoint therapies (ICTs). Targeting IKZF2 degradation offers a promising cancer immunotherapy approach. We developed a novel series of iso-indolinone-based glutarimides, identifying compound 55 as a potent, selective IKZF2 degrader with >90% Dmax in Jurkat cells, outperforming benchmarks DKY709 and PVTX-405. It exhibits strong selectivity over IMiD neo-substrates, favorable solubility, metabolic stability, and oral bioavailability in rodents. PK/PD studies confirmed profound, persistent IKZF2 degradation in mouse spleen and thymus after a single oral dose. As a promising early-stage tool, 55 provides a foundation for further preclinical evaluation in cancer immunotherapy.

The bromodomain-containing protein BRD9 has emerged as an attractive therapeutic target. In the present study, we successfully identified a number of highly potent BRD9 degraders by using two different cereblon ligands developed in our laboratory. Further optimization led to the discovery of CW-3308 as a potent, selective, and orally bioavailable BRD9 degrader. It displayed degradation potency (DC50) < 10 nM and efficiency (D max) > 90% against BRD9 in the G401 rhabdoid tumor and HS-SY-II synovial sarcoma cell lines and had a high degradation selectivity over BRD7 and BRD4 proteins. CW-3308 achieved 91% of oral bioavailability in mice. A single oral dose efficiently reduced the BRD9 protein by >90% in the synovial sarcoma HS-SY-II xenograft tumor tissue. Oral administration effectively inhibited HS-SY-II xenograft tumor growth in mice. CW-3308 is a promising lead compound for further optimization and extensive evaluation for the treatment of synovial sarcoma, rhabdoid tumor, and other BRD9-dependent human diseases.

Abstract Prostate cancer remains the leading cause of cancer-related death globally in men. While current AR-targeted therapies are effective for the treatment of prostate cancer and improve patient survival, resistance in patients typically develops within 18 months. CBP/p300 are AR transcriptional co-activators and are promising therapeutic targets for the treatment of castration-resistant prostate cancer (CRPC). We developed a series of highly potent, selective, and orally efficacious CBP/p300 PROTAC degraders, with CBPD-409 being the best compound. CBPD-409 induces robust CBP/p300 degradation with DC50 0.2-0.4 nM and displays strong anti-proliferative effects with IC50 1.2-2.0 nM in VCaP, LNCaP and 22Rv1 AR+ cell lines. It has a favorable oral pharmacokinetic profile and achieves 50% of oral bioavailability in mice. A single oral administration of CBPD-409 at 1 mg/kg achieves >95% depletion of CBP/p300 proteins in the VCaP tumor tissue at 3 h and 24 h time points. CBPD-409 exhibits strong and dose/schedule-dependent tumor growth inhibition and is more potent and efficacious than two CBP/p300 inhibitors CCS1477 and GNE-049 and the AR antagonist Enzalutamide. To further improve the degradation potency and the oral bioavailability in rats, we developed a new class of CBP/p300 degraders based on our optimized CRBN ligand TX-16. Our efforts led to the discovery of CBPD-268 as an exceptionally potent, effective, and orally efficacious degrader of CBP/p300 proteins. In the VCaP, LNCaP and 22Rv1 cell lines, CBPD-268 induces consistent and robust CBP/p300 degradation with DC50 of ≤0.03 nM and Dmax >95%, leading to potent cell growth inhibition. CBPD-268 has excellent oral bioavailability in both mice and rats and has a good ADME profile. Oral administration of CBPD-268 at 0.3-3 mg/kg resulted in profound and persistent depletion of CBP and p300 proteins in tumor tissues and achieved strong antitumor activity in the VCaP and 22Rv1 xenograft tumor models in mice, including tumor regression in the VCaP tumor model. CBPD-268 was well tolerated in mice and rats and displayed a therapeutic index of >10. Taken together, CBPD-409 and CBPD-268 are highly promising CBP/p300 degraders for further extensive evaluations for the treatment of CRPC and other types of human cancers. Citation Format: Zhixiang Chen, Mi Wang, Dimin Wu, Lijie Zhao, Tianfeng Xu, Hoda Metwally, Yu Wang, Donna McEachern, Wei Jiang, Longchuan Bai, Jie Luo, Meilin Wang, Ruiting Li, John Takyi-Williams, Lu Wang, Qiuxia Li, Bo Wen, Duxin Sun, Arul M. Chinnaiyan, Shaomeng Wang. Discovery of CBPD-409 and CBPD-268 as highly potent and orally efficacious CBP/p300 PROTAC degraders for the treatment of castration-resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4504.

CBP/p300 proteins are key epigenetic regulators and promising targets for the treatment of castration-resistant prostate cancer and other types of human cancers. Herein, we report the discovery and characterization of CBPD-268 as an exceptionally potent, effective, and orally efficacious PROTAC degrader of CBP/p300 proteins. CBPD-268 induces CBP/p300 degradation in three androgen receptor-positive prostate cancer cell lines, with DC50 ≤ 0.03 nM and Dmax > 95%, leading to potent cell growth inhibition. It has an excellent oral bioavailability in mice and rats. Oral administration of CBPD-268 at 0.3-3 mg/kg resulted in profound and persistent CBP/p300 depletion in tumor tissues and achieved strong antitumor activity in the VCaP and 22Rv1 xenograft tumor models in mice, including tumor regression in the VCaP tumor model. CBPD-268 was well tolerated in mice and rats and displayed a therapeutic index of >10. Taking these results together, CBPD-268 is a highly promising CBP/p300 degrader as a potential new cancer therapy.

CBP/p300 are critical transcriptional coactivators of the androgen receptor (AR) and are promising cancer therapeutic targets. Herein, we report the discovery of highly potent, selective, and orally bioavailable CBP/p300 degraders using the PROTAC technology with CBPD-409 being the most promising compound. CBPD-409 induces robust CBP/p300 degradation with DC50 0.2-0.4 nM and displays strong antiproliferative effects with IC50 1.2-2.0 nM in the VCaP, LNCaP, and 22Rv1 AR+ prostate cancer cell lines. It has a favorable pharmacokinetic profile and achieves 50% of oral bioavailability in mice. A single oral administration of CBPD-409 at 1 mg/kg achieves >95% depletion of CBP/p300 proteins in the VCaP tumor tissue. CBPD-409 exhibits strong tumor growth inhibition and is much more potent and efficacious than two CBP/p300 inhibitors CCS1477 and GNE-049 and the AR antagonist Enzalutamide. CBPD-409 is a promising CBP/p300 degrader for further extensive evaluations for the treatment of advanced prostate cancer and other types of human cancers.

STAT6 is an attractive therapeutic target for human cancers and other human diseases. Starting from a STAT6 ligand with Ki = 3.5 μM binding affinity, we obtained AK-068 with Ki = 6 nM to STAT6 and at least >85-fold binding selectivity over STAT5. Using AK-068 and cereblon ligands, we discovered AK-1690 as the first, potent and selective PROTAC STAT6 degrader. AK-1690 effectively induces degradation of STAT6 protein in cells with DC50 values of as low as 1 nM while showing minimal effect on other STAT members up to 10 μM. A single dose of AK-1690 effectively depletes STAT6 in mouse tissues. Determination of the first cocrystal structure of STAT6 in complex with AK-1690 provides a structural basis for their interactions. AK-1690 is a powerful tool with which to investigate the roles of STAT6 in human diseases and biological processes and a promising lead compound for further optimization.

Abstract Activation of the tumor suppressor p53, through inhibition of the MDM2 protein, has been pursued as a cancer therapeutic strategy and has produced many distinct inhibitors that are in clinical trials. A limitation arising from inhibiting the MDM2-p53 interaction is the upregulation of MDM2, itself a target gene of p53, and this attenuates the activation of p53 and efficacy of the inhibitors. To circumvent this limitation, we previously reported the first PROTAC based MDM2 degraders. These induced and sustained robust degradation of MDM2, achieved stronger p53 activation, and more potent anticancer activity than MDM2 inhibitors thus representing a new therapeutic strategy for targeting MDM2. Currently, all the PROTAC based MDM2 degraders are all dosed intravenously. Here we describe our design, synthesis, and optimizations that led to the discovery of the first orally bioavailable PROTAC based MDM2 degrader and our investigation of its therapeutic potential and mechanism of action. Consistent with its design to effectively degrade MDM2, our PROTAC effectively induces rapid degradation of MDM2 resulting in accumulation of wild-type p53 protein and activates p53 transcriptional activity in leukemia cells without accumulation of MDM2 protein. Consequently, it potently inhibits cell growth and induces apoptosis at low nano-molar concentrations in ALL and AML cell lines >10-100 times more potent than MDM2 inhibitors; and, after 50 mg/kg oral dose, 5 days/week for 3 weeks, it increased the median survival by 26 days of mice with disseminated RS4;11 cancer. Citation Format: Angelo Aguilar, Jiuling Yang, Yangbing Li, Donna McEachern, Shaomeng Wang. Orally bioavailable PROTAC based MDM2 degrader [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4515.

MDM2 has been pursued as an attractive therapeutic target for human cancers. Herein, we describe our discovery of MD-265 as a promising PROTAC MDM2 degrader and extensive in vitro and in vivo evaluations of its therapeutic potential and mechanism of action. MD-265 effectively depleted MDM2 protein in cancer cells at concentrations as low as 1 nM, leading to strong activation of p53 in cancer cells carrying wild-type p53. It selectively inhibited the growth of wild-type p53 leukemia cell lines and showed no activity in mutated p53 lines. MD-265 achieved persistent tumor regression in a leukemia xenograft model without causing any signs of toxicity and dramatically improved survival of mice in a disseminated leukemia model even with a weekly administration. MD-265 displayed an excellent intravenous PK profile in mice, rats, and dogs. MD-265 is a promising MDM2 degrader for advanced preclinical development for the treatment of human cancers.