Search

Background: Cyclin dependent kinase 7 (CDK7) is an attractive target for anticancer drugs due to its dual roles, cell cycle regulation and gene transcription/RNA processing. We synthesized UD-017, a small-molecule, highly selective, orally active CDK7 inhibitor with a novel chemotype. In this study, we characterized anticancer effects on blood cancer cells and in vivo anticancer activity in combination with chemo- or immuno-oncology agents. Methods: We first evaluated antiproliferative activities of UD-017 on blood cancer cell lines and investigated the mechanism of activity of UD-017 using NCI-H929 cells (multiple myeloma). Apoptosis was assayed by FACS analysis of Annexin V-positive and PI negative. In vivo anticancer effect was evaluated in the mouse xenograft model with NCI-H929. We further evaluated the anticancer efficacy of UD-017 in combination with chemotherapeutics in an HCT-116 xenograft mouse model and with anti PD-1 antibody in B16F10 mouse allograft model. Results: UD-017 strongly inhibited the proliferation of blood cancer cell lines (myeloma) with IC50s of 10-100 nM range, more broadly than other representative CDK inhibitors. In the similar assay, UD-017 showed no cytotoxicity to human peripheral blood mononuclear cells up to 10 μM. In the mechanism study, phosphorylation of RNA polymerase II c-terminal domain and expression of c-Myc were both inhibited concomitant with the antiproliferative activity in NCI-H929 cells. Significant apoptosis was induced at around 100 nM. In vivo, UD-017 almost completely inhibited the cancer growth at 50 mg/kg, q.d. for 14-day treatment in a NCI-H929 xenograft model in mice. In the combination assay in vivo, UD-017 showed a clear synergistic effect at 50 mg/kg with 5-fluorouracil (5-FU, 15 mg/kg, i.p.) without further affecting the side effects of 5-FU in HCT-116 (colorectal carcinoma) xenografted mice. Also, UD-017 (100 mg/kg) in combination with anti PD-1 antibody (250 μg/body, i.p.) showed add-on anticancer effect in B16F10-allografted mice. All of the mice in the combination group survived during the dosing period without decreasing the number of blood cells. Conclusions: We propose UD-017 as a novel type of anticancer drug that shows complete anticancer responses in xenograft models of myeloma cancer cells, and also shows in vivo synergy in combination with chemotherapy and anti PD-1 antibody. These data support the rationale for further advancing towards clinical development. Citation Format: Yasuhiro Aga, Sayaka Ogi, Kazuhiro Onuma, Hidetoshi Sunamoto, Takashi Matsushita, Ayumi Ogawa, toru Hasegawa, Shigeyuki Kono, Noriaki Iwase, Shigeru Ushiyama. Evaluation of anticancer activities of UD-017, a novel selective and orally available CDK7 inhibitor, in blood cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4837.

Background: Cyclin dependent kinase 7 (CDK7) is an attractive target for anticancer drugs due to its dual roles, cell cycle regulation and gene transcription/RNA processing. We synthesized UD-017, a small-molecule, highly selective, orally active CDK7 inhibitor with a novel chemotype. In this study, we characterized anticancer activities of UD-017 in vitro and in vivo using patient-derived (PD) cancer cells. Methods: We first evaluated an antiproliferative activity of UD-017 broadly in a panel of cancer cell assay including patient-derived 3-dimensional tumor clonogenic assay. To verify the potential of c-Myc expression as a biomarker, we investigated the correlation between c-Myc expression levels and anticancer activity in vitro and in vivo using a colorectal cancer cell. In the main part, anticancer efficacy of UD-017 was investigated in vivo in PD-xenograft (PDX) models using representative PD cancer cells. Results: In antiproliferative panel assays using over 100 cancer cell lines, UD-017 broadly inhibited a wide range of cancer cells from colon, breast, lung, kidney, blood, pancreas, osteosarcoma, sarcoma and urinary bladder cancers. Especially, UD-017 showed high sensitivity in solid tumor such as non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), gastric, osteosarcoma and sarcoma cells with IC50s of 10-200 nM. UD-017 showed a good correlation of c-Myc expression levels with antiproliferative activity using colorectal cancer cells in vitro, and UD-017 reduced the intratumoral MYC mRNA levels by an administration at 100 mg/kg in a HCT-116 xenograft model in mice. In PDX models, UD-017 showed strong inhibition and even regression of tumor growth, and the tumors were almost disappeared on day 14 without body weight loss in non-small cell lung cancer (LXFL1121). In a pleuramesothelioma (PXF541) PDX model, UD-017 also showed regressive effect, and in gastric cancer (GXA3067) and sarcoma (SXFS117) PDX models, UD-017 completely inhibited the tumor growth. Conclusions: We propose UD-017 as a novel type of anticancer drug that shows complete antitumor responses in patient-derived xenograft models of diverse cancer types. c-Myc expression in cancer cells may be a biomarker for the antitumor effect of UD-017. These data support the rationale for further advancing towards clinical development. Citation Format: Takashi Matsushita, Sayaka Ogi, Kazuhiro Onuma, Hidetoshi Sunamoto, Ayumi Ogawa, Toru Hasegawa, Yasunori Tokunaga, Yasuhiro Aga, Shigeru Ushiyama. UD-017, a novel highly selective and orally active CDK7 inhibitor, shows a significant anticancer activity in patient-derived cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4835.

Background: Cyclin dependent kinase 7 (CDK7) is an attractive target for cancer drugs due to its dual roles, cell cycle regulation & gene transcription/RNA procession. Recent studies show that transcription of some oncogene is highly sensitive to inhibition of transcription such as inhibition by CDK7. The dependence of cancer cells on transcription can be therefore advantageous to CDK7 inhibitors as effective anti-cancer drugs. We synthesized a novel small molecule highly selective reversible CDK7 inhibitor, UD-017. In this study, we evaluated anti-cancer activity of UD-017 in the colorectal cancer cells, HCT-116, xenograft models in mice & investigated the rationale for CDK7 inhibition as anti-cancer drugs. Experimental procedures: We first examined the pharmacokinetics profile of UD-017 after an oral administration in mice. We then evaluated the anti-tumor efficacy of UD-017 in HCT-116 xenograft models in mice. We further investigated the pharmacodynamics of UD-017 by detecting the phosphorylation levels of the retinoblastoma (cell cycle) & RNA polymerase II (transcription) & expression levels of c-myc in the tumor tissues in the same model after oral administration of UD-017. Results: UD-017 was identified as an orally available inhibitor of CDK7. The bioavailability was approximately 50% in BALB/c mice. In the HCT-116 xenograft model in mice, UD-017 inhibited the cancer growth by 33%, 64% & 88% at 25, 50 & 100 mg/kg, respectively, with clear dose-dependence by once daily administration for 14 days. Throughout the experiment, UD-017 was well tolerated with no reduction in body weights & no myelosuppression. In order to evaluate the effect of UD-017 in combination with chemotherapeutics, UD-017 was administrated with 5-fluorouracil (5-FU) to HCT-116 xenografted mice with either 50 mg/kg of UD-017 alone, or 15 mg/kg ip of 5-FU alone, or in combination of UD-017 plus 5-FU. UD-017 showed clear combination effect with 5-FU without further affecting the side effects of 5-FU. Phosphorylation of the retinoblastoma was inhibited after oral administration of UD-017 time-dependently in the tumor tissues. Phosphorylation of RNA polymerase II COOH-terminal domain (CTD) was also inhibited & expression of c-myc was decreased. PPAP cleavage was subsequently induced, causing apoptotic death of the cancer cells. Conclusion: We propose UD-017 as a novel type of anti-cancer drug that shows favorable oral pharmacokinetics profile & complete anti-tumor responses in xenograft models of colorectal cancer cells, & also shows in vivo synergy in combination with chemotherapy. These data support the rationale for further advancing towards clinical development. IND-enabling studies are in progress. Citation Format: Yasuhiro Aga, Sayaka Ogi, Yasunori Tokunaga, Ayumi Ogawa, Kazuhiro Onuma, Takashi Matsushita, Hidetoshi Sunamoto, Toru Hasegawa, Shigeru Ushiyama. In vivo anti-tumor efficacy of UD-017, a novel highly selective & orally available CDK7 inhibitor, in colorectal cancer cells xenograft models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-297. doi:10.1158/1538-7445.AM2017-LB-297

Background: Cyclin dependent kinase 7 (CDK7) is a member of the CDK family, & has a dual function relating to the cell cycle progression & gene transcription/ RNA processing. Recently CDK7 has been emerged as an attractive target for anticancer drugs due to its dual role. We synthesized UD-017, a small molecule, highly selective CDK7 inhibitor with a novel chemotype. In this study, we characterized in vitro antiproliferative profile of UD-017 & elucidated underlying mechanism how CDK7 inhibition contributes to the antiproliferation of cancer cells. Experimental procedures: We conducted a large panel of 9 CDKs & 313 other kinases assay of UD-017 to determine its selectivity & analyzed kinetics for CDK7 enzyme inhibition. We evaluated the antiproliferative activity of UD-017 in over 100 multiple types of cancer cell lines. We then investigated the mechanism of antiproliferative activity of UD-017 using human colorectal cancer cell line, HCT-116, & human multiple myeloma cell line, NCI-H929. We also explored biomarker candidates mainly using colorectal cancer cell lines. Results: UD-017 inhibited CDK7 enzyme with an IC50 value of 16 nM, which is at least 300-fold more selective against other CDKs, CDK1 through CDK9. Inhibition of UD-017 was reversible & ATP-competitive. In a panel of 313 kinases assay, the compound inhibited CDK7 almost mono-specifically. In antiproliferative panel assays using over 100 cancer cell lines, UD-017 broadly inhibited a wide range of cancer cells from colon, breast, lung, kidney, blood, pancreas & urinary bladder cancers. Specifically, it inhibited the growth of HCT-116 & NCI-H929 with GI50 values of 29 nM and 6.8 nM, respectively. In the mechanism study of the antiproliferative activity, UD-017 inhibited phosphorylation of CDK1, CDK2 & the retinoblastoma (RB) & arrested the cell-cycle. Phosphorylation of RNA polymerase II c-terminal domain was also inhibited & expression levels of c-Myc and XIAP decreased & the cleavage of PARP increased, which were followed by significant induction of apoptosis. UD-017 showed both cell cycle arrest & induction of apoptosis. In the biomarker study, c-Myc & cyclin H showed good correlation with antiproliferative activities in 6 colorectal cancer cell lines and will be candidate biomarkers of UD-017. Conclusion: UD-017 is a potent & highly selective CDK7 inhibitor, & significantly inhibits the proliferation of human cancer cells with concomitant cell cycle arrest & induction of apoptosis. In vivo anti-tumor efficacy for UD-017 is warranted. Citation Format: Takashi Matsushita, Kazuhiro Onuma, Hidetoshi Sunamoto, Ayumi Ogawa, Sayaka Ogi, Toru Hasegawa, Shigeyuki Kono, Noriaki Iwase, Yasuhiro Aga, Shigeru Ushiyama. In vitro anti-cancer activity of UD-017, a novel potent & highly selective CDK7 reversible inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-111. doi:10.1158/1538-7445.AM2017-LB-111