tegavivint (BC2059)

CDH4 induces PTC angiogenesis and metastasis via the inhibition of β-TrCP1-dependent ubiquitination of β-Catenin.

P1, N=9, Active, not recruiting, M.D. Anderson Cancer Center | Recruiting --> Active, not recruiting | N=54 --> 9 | Trial completion date: Dec 2023 --> Dec 2024 | Trial primary completion date: Dec 2023 --> Dec 2024

P1, N=18, Recruiting, Ohio State University Comprehensive Cancer Center | Trial primary completion date: Dec 2023 --> Dec 2024

Tegavivint (TV, BC-2059), known to disrupt the binding of nuclear β-catenin and TCF7L2/LEF1 with TBL1, also inhibited co-localization of EVI1 with TBL1 and dose-dependently induced apoptosis in AML cell lines and patient-derived (PD) AML cells with 3q26.2 lesions. TV treatment repressed EVI1, attenuated enhancer activity at ERG, TCF7L2, GATA2 and MECOM loci, abolished interactions between MYC enhancers, repressing AML stemness while upregulating mRNA gene-sets of interferon/inflammatory response, TGF-β signaling and apoptosis-regulation. Co-treatment with TV and BETi or venetoclax induced synergistic in vitro lethality and reduced AML burden, improving survival of NSG mice harboring xenografts of AML with 3q26.2 lesions.

This was consistent with previous reports that BET inhibitors (e.g., OTX015, mivebresib or ABBV-075 and JQ1) are effective against 3q26.2-r AML cell lines, patient-derived (PD) AML cells and PDX models...In follow-up experiments, XIAP/cIAPs inhibitors birinapant (10-1000 nM) or SM-164 (30-1000 nM), chosen based on the MIPE screen outcomes, induced significantly more dose-dependent apoptosis in 3q26.2-r versus the other AML cell lines...Treatment with the dual mTOR/PIK3CA inhibitor NVP-BGT226 (1-30 nM) or navitoclax or Bcl-xL-specific BH3 mimetic A-1155463 also exerted lethality and synergistically induced apoptosis with mivebresib in AML cells with inv3/t(3; 3)...Co-treatment with birinapant and tegavivint also synergistically induced apoptosis in 3q26.2-r AML cells...Additionally, compared to each drug or vehicle control, co-treatment with birinapant and the BETi OTX015 (30 mg/kg/day, by oral gavage) was more effective in reducing AML burden in the xenograft model. These findings demonstrate promising preclinical activity of IAP protein inhibition against the cellular models of AML with inv3/t(3; 3) with EVI1 overexpression, supporting the rationale to further evaluate in vivo efficacy of birinapant and/or BETi-based combinations against this AML sub-type.

P1/2, N=108, Recruiting, Iterion Therapeutics | Not yet recruiting --> Recruiting | Initiation date: May 2023 --> Sep 2023

To investigate the preclinical potential of Wnt/β-catenin inhibition in the adrenal microenvironment, we developed a minimally invasive orthotopic xenograft model of ACC and demonstrated that treatment with the newly developed Wnt/β-catenin:TBL1 inhibitor Tegavivint significantly reduced tumor growth...Furthermore, this β-catenin-dependent oncogenic program can be therapeutically targeted with a newly developed Wnt/β-catenin inhibitor. These results show promise for the further clinical development of Wnt/β-catenin inhibitors in ACC and unveil a novel Wnt/β-catenin-regulated transcriptome.

P1/2, N=108, Not yet recruiting, Iterion Therapeutics

P1, N=20, Recruiting, Lapo Alinari | Trial completion date: Dec 2025 --> Mar 2027 | Trial primary completion date: Dec 2024 --> Mar 2027

Tegavivint monotherapy demonstrated antitumor activity in a range of HCC preclinical models. In vitro studies show correlation between tegavivint potency and beta-catenin mutation. In a syngeneic HCC mouse model with elevated beta-catenin, tegavivint reduces tumor growth and induces an activated T-cell subpopulation.

We recently reported that tegavivint (TV) (BC-2059), a disruptor of the nuclear TBL1/R1-β-catenin-TCF7L2 complex represses c-Myc, cyclin D1 and Survivin and inhibits growth and survival of AML LSCs. Notably, in the flank-implanted PDX of AML191 or tail-vein infused PDX of AML242 models in NSG mice, treatment with OTX015 and TV, compared to vehicle control or each drug alone, significantly reduced AML growth and improved survival, without any host toxicity. These findings highlight the promising pre-clinical efficacy of novel BETi-based combinations against AML models harboring 3q26 lesions and EVI1 overexpression.

A panel of beta-catenin regulated proteins and transcripts were identified as candidate pharmacodynamic biomarkers in patients whose desmoid tumor responded to tegavivint. Alterations in these serum proteins continued throughout the dosing interval and, for several proteins, a potential dose response correlation was observed. Further characterization of the relationship between tegavivint plasma levels, serum biomarkers, transcriptional changes and clinical responses in additional patients and time points will be presented.

P1, N=20, Recruiting, Lapo Alinari | Not yet recruiting --> Recruiting

P1, N=20, Not yet recruiting, Lapo Alinari

We have recently reported that the nuclear TBL1/R1-β-catenin-TCF7L2 complex transcriptionally regulates c-Myc, cyclin D and Survivin and sustains AML stem cells, such that the undermining of this transcriptional axis by the TBL1/R1-β-catenin-binding disruptor tegavivint (BC-2059, Iterion) represses MYC, cyclin D1 and Survivin and inhibits growth and survival of AML stem-progenitor cells. Furthermore, in the tail-vein infused and engrafted PD AML191 PDX model, treatment with TV and OTX015 or venetoclax for 6 weeks, as compared to vehicle control or each drug alone, significantly improved overall survival of the NSG mice (p < 0.01), without inducing any toxicity. These findings highlight the promising pre-clinical efficacy of novel combinations of TV and BET protein or venetoclax against AML models harboring 3q26 lesions and EVI1 overexpression.

However, given that TBL1X controls multiple oncogenic signaling pathways in cancer, treatment with tegavivint may ultimately results in drug resistance providing rationale for combination strategies. While many questions related to TBL1X function remain to be answered in lymphoma and other diseases, these data provide a growing body of evidence that TBL1X is a promising therapeutic target in oncology.

P1/2, N=147, Recruiting, Children's Oncology Group | N=38 --> 147

Tyrosine kinase inhibitors are well studied, and sorafenib is now one of the most utilized therapies, though limited by its side effect profile. In addition to nirogacestat, the gamma-secretase inhibitor AL102 is being investigated for the treatment of patients with progressing desmoid tumors in the phase II/III RINGSIDE trial. Finally, the beta-catenin inhibitor Tegavivint (BC2059) is being investigated in a phase 1 open-label trial in patients with a proven primary or recurrent desmoid tumor that is unresectable and symptomatic or progressive.

P1/2, N=38, Recruiting, Children's Oncology Group | Active, not recruiting --> Recruiting

These results indicate that TBL1 inhibition, via Tegavivint, inhibits nuclear β-catenin activity and alters the tumor immune microenvironment and enhances immune checkpoint blockade in OS. Future directions include more comprehensive profiling and molecular analysis of the tumor and immune microenvironment, and evaluation of additional immune modulatory approaches for the treatment of OS.

Tegavivint (BC-2059, Iterion) targets TBL1/R1 and disrupts its binding to β-catenin and TCF7L2, repressing MYC, cyclin D1 and Survivin, leading to apoptosis of AML cells. In the tail-vein infused and engrafted PD AML191 cell model in NSG mice, treatment with TV and/or venetoclax or OTX015 for 6 weeks significantly reduced AML burden and improved overall survival of the NSG mice more than treatment with each drug alone or vehicle control, without any toxicity. These findings highlight that targeted inhibition of TBL1/R1-nuclear β-catenin-TCF7L2 axis combined with BET protein or BCL2 inhibition is effective therapy against AML models harboring 3q26 lesions and EVI1 overexpression.

In this study we show that the combination of low concentrations of panobinostat and Tegavivint have significant in vitro and in vivo anti-MM effects including in the context of proteasome inhibitor resistance, by targeting both aerobic glycolysis and mitochondrial respiration and the down-regulation of down-stream β-catenin targets including myc, cyclinD1, and cyclinD2. The significant anti-MM effect of this novel combination warrants further evaluation for the treatment of MM patients with relapsed and/or refractory MM.

P1/2, N=38, Active, not recruiting, Children's Oncology Group | Recruiting --> Active, not recruiting

P1/2, N=38, Recruiting, Children's Oncology Group | Not yet recruiting --> Recruiting

We had previously reported the pre-clinical efficacy of targeting TBL1/R1-nuclear β-catenin-TCF7L2 by tegavivint (BC-2059, Iterion Therapeutics) against AML stem/progenitor cells...Co-treatment with TV and venetoclax or TV and OTX015 significantly reduced AML growth (determined by reduction in bioluminescence by Xenogen camera) (p < 0.05), as well as improved overall survival of the NSG mice more than treatment with each drug alone or vehicle control, without any toxicity. Collectively, these findings highlight that targeted inhibition of TBL1/R1-nuclear β-catenin-TCF7L2 by treatment with TV also inhibits EVI1 and its targets. They also demonstrate superior pre-clinical efficacy of novel TV-based combinations with BCL2 or BET protein inhibitor against AML models harboring 3q26 lesion and EVI1 overexpression.

P1/2, N=38, Not yet recruiting, Children's Oncology Group

Disruption of colocalization of nuclear β-catenin with TBL1 and TCF7L2 by the small-molecule inhibitor BC2059 combined with depletion of BRD4 by BET proteolysis-targeting chimera reduced c-Myc levels and exerted synergistic lethality in BETi-P/R sAML cells. This combination also reduced leukemia burden and improved survival of mice engrafted with BETi-P/R sAML cells or with patient-derived AML blasts innately resistant to BETi. Therefore, multi-targeted disruption of β-catenin-TCF7L2-JMJD6-MYC axis overcomes adaptive and innate BETi-resistance, exhibiting pre-clinical efficacy against human post-MPN sAML cells.

Genetic deletion of TBL1 and pharmacological approach using tegavivint, a first-in-class small molecule targeting TBL1 (Iterion Therapeutics), promotes DLBCL cell death in vitro and in vivo. Through an integrated genomic, biochemical, and pharmacologic analyses, we characterized a novel, β-CATENIN independent, post-transcriptional oncogenic function of TBL1 in DLBCL where TBL1 modulates the stability of key oncogenic proteins such as PLK1, MYC, and the autophagy regulatory protein BECLIN-1 through its interaction with a SKP1-CUL1-F-box (SCF) protein supercomplex. Collectively, our data provide the rationale for targeting TBL1 as a novel therapeutic strategy in DLBCL.

Thus, Tegavivint is a promising therapeutic agent for advanced stages of OS via its targeting of the β-catenin/ALDH1 axis.