Anti-Tumor Activity of Novel Small Molecule Wnt Signaling Inhibitor, CWP232291, In Multiple Myeloma

Abstract

3038 Multiple myeloma (MM), one of the most incurable hematological malignancies in adults, is a disorder of plasma cells characterized by accumulation of clonal proliferation of malignant plasma cells in the bone marrow (BM). Overexpression of beta-catenin, the downstream effector of the canonical Wnt signaling pathway, has been reported in both MM cell lines and patient samples. Activated Wnt signaling pathway has also been reported to play a critical role in progression of MM cell proliferation, thus highlighting the need for new therapeutic approaches, particularly those targeting Wnt molecular pathway. Here we report the discovery of a novel inhibitor of Wnt signaling CWP232291, which promotes degradation of beta-catenin. CWP232291 exhibits potent growth inhibitory activity in several MM cell lines (RPMI-8226, OPM-2, NCI-H929, JJN3, and EJM) with IC50 values of 13 – 73 nM. The inhibitory activity of CWP232291 on Wnt signaling is demonstrated by reporter gene assay and by its effect in down-regulation of Wnt target genes. Using HEK293 cells, CWP232291 treatment dose dependently reduces promoter activity of TOPflash induced by Wnt-3a-Conditioned Media, at a calculated IC50 value of 273 nM. Furthermore, MM cells treated with CWP232291 show downregulated expression of Wnt target genes such as survivin by triggering degradation of beta-catenin. Treatment of these cells with CWP232291 results in activation of caspase-3 and PARP cleavage, indicating induction of apoptosis. To investigate the potential in vivo anti-tumor efficacy of CWP232291, we utilized two MM tumor bearing mice models. Daily or intermittent intravenous (i.v.) administration of CWP232291 led to significant tumor growth inhibition (TGI) in OPM-2 (50 mg/kg, qdx5: regression and 100 mg/kg, biw: 95% TGI) and RPMI-8226 (100 mg/kg, qdx5: regression and 100 mg/kg tiw: 80% TGI) xenograft model with no obvious change in body weight. The anti-tumor efficacies of CWP232291 were dose-dependent and had strong correlations with degradation of beta-catenin in the tumor samples. Potent induction of apoptosis through cleavage of Caspase-3 and PARP and significant decrease of plasma M protein levels in OPM-2 tumor bearing mice were detected as early as 2 and up to 24 hours after single i.v. administration of CWP232291. Taken together, these data clearly demonstrate the impressive anti-tumor profile of CWP232291 with a good therapeutic window and suggest a potential therapeutic application of CWP232291 for the treatment of MM. Disclosures: Cha: Choongwae Pharma Corp.: Employment. Jung:Choongwae Pharma Corp.: Employment. Lee:Choongwae Pharma Corp.: Employment. Briaud:Theriac Pharmaceutical Corp.: Employment. Tenzin:Theriac Pharmaceutical Corp.: Employment. Jung:Choongwae Pharma Corp.: Employment. Pyon:Choongwae Pharma Corp.: Employment. Lee:Choongwae Pharma Corp.: Employment. Chung:Choongwae Pharma Corp.: Employment. Lee:Choongwae Pharma Corp.: Employment. Oh:Choongwae Pharma Corp.: Employment. Jung:Choongwae Pharma Corp.: Employment. Pai:Choongwae Pharma Corp.: Employment. Emami:Theriac Pharmaceutical Corp.: Employment.

Targeting the WNT Signaling Pathway in Cancer Therapeutics

“…CWP232291 (JW Pharmaceutical, Seoul, Republic of Korea, http://www.jw-pharma.co.kr/pharma/en/intro/pharma.jsp) is a small molecule that binds Src associated with mitosis 68K protein (Sam68) and promotes apoptosis through inhibition of the antiapoptotic WNT driven gene survivin. CWP232291 has shown both in vitro and in vivo antitumor activity in multiple myeloma [37]. Phase I enrollment is under way for patients with acute myeloid leukemia, chronic myelomonocytic leukemia, and myelodysplastic syndrome (ClinicalTrials.gov identifier NCT0139846).…”

“…shown both in vitro and in vivo antitumor activity in multiple myeloma [37]. Phase I enrollment is under way for patients with acute myeloid leukemia, chronic myelomonocytic leukemia, and myelodysplastic syndrome (ClinicalTrials.gov identifier NCT0139846).…”

Carboxylesterase Notum Is a Druggable Target to Modulate Wnt Signaling

“…C-82 ( 7 ), the active form of PRI-724, entered phase 1/2 clinical trials in 2015 as a topical agent for the treatment of the skin conditions psoriasis and systemic sclerosis . CWP-291 ( 8 , formerly CWP232291) is a peptidomimetic small molecule drug precursor to the active metabolite CWP232204 (structures undisclosed) developed by JW Pharmaceuticals that reduces β-catenin levels in a TOP-flash reporter assay in HEK293 cells (IC 50 273 nM) and is currently in phase 2 clinical trials for acute myeloid leukemia . The active form CWP-291 binds to Sam68 (an RNA-binding protein that regulates alternative splicing of the TCF-1 transcription factor in a complex with CBP) and induces β-catenin degradation …”

Therapeutic Targeting of the Leukaemia Microenvironment

“…BC2059, an anthraquinone oximeanalogue, has been shown to synergistically induce apoptosis in primary AML blasts and prolong survival of AML xenograft mice following administration with panobinostat [73]. CWP232291, a novel peptidomimetic that possess broad preclinical anti-cancer activities, has recently been tested in a phase 1 trial in patients with AML, with minimal/modest efficacy [74,126,127]. Future studies have been planned to explore the potential synergistic effects of CWP232291 with other chemotherapeutic agents [74].…”