Takashi Owa

Anticancer and antiviral sulfonamides

The sulfonamides constitute an important class of drugs, with several types of pharmacological agents possessing antibacterial, anti- carbonic anhydrase, diuretic, hypoglycemic and antithyroid activity among others. A large number of structurally novel sulfonamide derivatives have ultimately been reported to show substantial antitumor activity in vitro and in vivo. Although they have a common chemical motif of aromatic/heterocyclic or amino acid sulfonamide, there are a variety of mechanisms of their antitumor action, such as carbonic anhydrase inhibition, cell cycle perturbation in the G1 phase, disruption of microtubule assembly, functional suppression of the transcriptional activator NF-Y, and angiogenesis (matrix metalloproteinase, MMP) inhibition among others. Some of these compounds selected via elaborate preclinical screenings or obtained through computer-based drug design, are currently being evaluated in clinical trials. The review summarizes recent classes of sulfonamides and related sulfonyl derivatives disclosed as effective tumor cell growth inhibitors, or for the treatment of different types of cancer. Another research line that progressed much in the last time regards different sulfonamides with remarkable antiviral activity. Thus, at least two clinically used HIV protease inhibitors possess sulfonamide moieties in their molecules, whereas a very large number of other derivatives are constantly being synthesized and evaluated in order to obtain compounds with less toxicity or activity against drug-resistant viruses. Several non nucleoside HIV reverse transcriptase or HIV integrase inhibitors containing sulfonamido groups were also reported. Another approach to inhibit the growth of retroviruses, including HIV, targets the ejection of zinc ions from critical zinc finger viral proteins, which has as a consequence the inhibition of viral replication in the absence of mutations leading to drug resistance phenotypes. Most compounds with antiviral activity possessing this mechanism of action incorporate in their molecules primary sulfonamide groups. Some small molecule chemokine antagonists acting as HIV entry inhibitors also possess sulfonamide functionalities in their scaffold.

Novel sulphonamide derivatives for the treatment of cancer

The sulphonamides constitute an important class of therapeutic agents in current medicinal science. After the discovery by Gerhard Domagk, of sulphamidochrysoidine (prontosil) as the first antibiotic sulpha-drug an active metabolite of the drug, sulphanilamide, was further derivatised in order to find compounds exhibiting superior antibacterial activity or different pharmacological effects. Diversification of the sulphanilamide structure led to the serial development of improved antibiotics, insulin-releasing hypoglycaemic drugs, carbonic anhydrase- (CA) inhibitory diuretics, anti-hypertensive drugs etc. It is of particular interest that various structurally novel sulphonamide derivatives have recently been reported to show substantial anti-tumour activity in vitro and/or in vivo. Although they have a common chemical motif of an aromatic/heterocyclic sulphonamide, there are a variety of mechanisms for their anti-tumour action, such as disruption of microtubule assembly, cell cycle arrest in the G1 phase, functional suppression of the transcriptional activator NF-Y, angiogenesis inhibition and carbonic anhydrase inhibition. Furthermore, some of these compounds selected via elaborate preclinical screenings are currently being evaluated in clinical trials. This review summarises recent patents and related papers which have disclosed novel classes of sulphonamide derivatives for the treatment of cancer.

E7070, a novel sulphonamide agent with potent antitumour activity in vitro and in vivo

E7070 (N-(3-Chloro-7-indolyl)-1,4-benzenedisulphonamide) was selected from our sulphonamide compound collections via antitumour screening and flow cytometric analysis. Following treatment with E7070, the cell cycle progression of P388 murine leukaemia cells was disturbed in the G1 phase. The cell-killing effect on human colon cancer HCT116 cells was found to be time-dependent. In the panel of 42 human tumour cell lines, E7070 showed an antitumour spectrum that was distinct from those of other anticancer drugs used in clinic. Animal tests using human tumour xenograft models demonstrated that E7070 could cause not only tumour growth suppression, but also tumour regression in three of five colorectal and two of two lung cancers. In the HCT116 xenograft model, E7070 was shown to be superior to 5-FU, MMC and CPT-11 (irinotecan). Furthermore, complete regression of advanced LX-1 tumours was observed in 80% of E7070-treated mice. All of these observations have promoted this drug to clinical evaluation.

A focused compound library of novel N-(7-indolyl)benzenesulfonamides for the discovery of potent cell cycle inhibitors

A series of compounds containing an N-(7-indolyl)benzenesulfonamide pharmacophore was synthesized and evaluated as a potential antitumor agent. Cell cycle analysis with P388 murine leukemia cells revealed that there were two different classes of potent cell cycle inhibitors; one disrupted mitosis and the other caused G1 accumulation. Herein described is the SAR summary of the substituent patterns on this pharmacophore template.

Selective degradation of splicing factor CAPER[alpha] by anticancer sulfonamides

Target-protein degradation is an emerging field in drug discovery and development. In particular, the substrate-receptor proteins of the cullin-ubiquitin ligase system play a key role in selective protein degradation, which is an essential component of the anti-myeloma activity of immunomodulatory drugs (IMiDs), such as lenalidomide. Here, we demonstrate that a series of anticancer sulfonamides NSC 719239 (E7820), indisulam, and NSC 339004 (chloroquinoxaline sulfonamide, CQS) induce proteasomal degradation of the U2AF-related splicing factor coactivator of activating protein-1 and estrogen receptors (CAPERα) via CRL4DCAF15 mediated ubiquitination in human cancer cell lines. Both CRISPR-Cas9-based knockout of DCAF15 and a single amino acid substitution of CAPERα conferred resistance against sulfonamide-induced CAPERα degradation and cell-growth inhibition. Thus, these sulfonamides represent selective chemical probes for disrupting CAPERα function and designate DCAFs as promising drug targets for promoting selective protein degradation in cancer therapy.

Synthesis and biological evaluation of N-(7-indolyl)-3-pyridinesulfonamide derivatives as potent antitumor agents.

We herein report the synthesis and antitumor activity of E7070 analogues containing a 3-pyridinesulfonamide moiety. E7070 was selected from our sulfonamide-based compound collections, currently undergoing Phase II clinical trials because of its tolerable toxicity profile and some antitumor responses in the Phase I setting. Of the analogues examined, ER-35745, a 6-amino-3-pyridinesulfonamide derivative, demonstrated significant oral efficacy against the HCT116 human colon carcinoma xenograft in nude mice.

Tazemetostat, an EZH2 inhibitor, in relapsed or refractory B-cell non-Hodgkin lymphoma and advanced solid tumours: a first-in-human, open-label, phase 1 study

BACKGROUND Activating enhancer of zeste homolog 2 (EZH2) mutations or aberrations of the switch/sucrose non-fermentable (SWI/SNF) complex (eg, mutations or deletions of the subunits INI1 or SMARCA4) can lead to aberrant histone methylation, oncogenic transformation, and a proliferative dependency on EZH2 activity. In this first-in-human study, we aimed to investigate the safety, clinical activity, pharmacokinetics, and pharmacodynamics of tazemetostat, a first-in-class selective inhibitor of EZH2. METHODS We did an open-label, multicentre, dose-escalation, phase 1 study using a 3 + 3 design with planned cohort expansion at the two highest doses below the maximally tolerated dose. The study was done at two centres in France: Institut Gustave Roussy (Villejuif, Val de Marne) and Institut Bergonié (Bordeaux, Gironde). Eligible patients had relapsed or refractory B-cell non-Hodgkin lymphoma or an advanced solid tumour and were older than 18 years, with Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate end-organ function. Tazemetostat was administered orally from 100 mg twice daily to 1600 mg twice daily in 28-day cycles. The primary endpoint was to establish the maximum tolerated dose or recommended phase 2 dose of tazemetostat, as determined by dose-limiting toxicities, laboratory values, and other safety or pharmacokinetic measures in cycle one according to local investigator assessment. Safety was assessed in patients who received at least one dose of tazemetostat; antitumour activity was assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01897571. The phase 1 part of the study is complete, and phase 2 is ongoing. FINDINGS Between June 13, 2013, and Sept 21, 2016, 64 patients (21 with B-cell non-Hodgkin lymphoma, and 43 with advanced solid tumours) received doses of tazemetostat. The most common treatment-related adverse events, regardless of attribution, were asthenia (21 [33%] of 64 treatment-related events), anaemia (nine [14%]), anorexia (four [6%]), muscle spasms (nine [14%]), nausea (13 [20%]), and vomiting (six [9%]), usually grade 1 or 2 in severity. A single dose-limiting toxicity of grade 4 thrombocytopenia was identified at the highest dose of 1600 mg twice daily. No treatment-related deaths occurred; seven (11%) patients had non-treatment-related deaths (one at 200 mg twice daily, four at 400 mg twice daily, and two at 1600 mg twice daily). The recommended phase 2 dose was determined to be 800 mg twice daily. Durable objective responses, including complete responses, were observed in eight (38%) of 21 patients with B-cell non-Hodgkin lymphoma and two (5%) of 43 patients with solid tumours. INTERPRETATION Tazemetostat showed a favourable safety profile and antitumour activity in patients with refractory B-cell non-Hodgkin lymphoma and advanced solid tumours, including epithelioid sarcoma. Further clinical investigation of tazemetostat monotherapy is ongoing in phase 2 studies in adults and a phase 1 study for children, which are currently enrolling patients who have B-cell non-Hodgkin lymphoma and INI1-negative or SMARCA4-negative tumours. FUNDING Epizyme and Eisai.

Microarray-Based Transcriptional Profiling of Renieramycin M and Jorunnamycin C, Isolated from Thai Marine Organisms

Renieramycin M and jorunnamycin C, two isoquinolinequinone compounds differing only at the C-22 ester side chain, were evaluated for their cytotoxic effects on human colon (HCT116) and breast (MDA-MB-435) cancer cell lines. These two compounds displayed potent cancer cell growth inhibition, their IC50 values reaching nanomolar order. To examine their effects on transcription, we carried out oligonucleotide microarray analysis with focus on the similarities and differences between the two compounds in terms of transcriptional profiles. We found that the down-regulation of PTPRK (protein tyrosine phosphatase receptor type K) can be considered as a biomarker responsive to the cytotoxic effects of this class of antitumor marine natural products.

Final results of a phase 2, open-label study of indisulam, idarubicin, and cytarabine in patients with relapsed or refractory acute myeloid leukemia and high-risk myelodysplastic syndrome

Indisulam possesses anticancer properties through down‐regulation of various cell‐cycle checkpoint molecules, thereby blocking the phosphorylation of retinoblastoma protein and inducing p53 and p21. Indisulam exhibits synergy with nucleoside analogs and topoisomerase inhibitors.

Abstract 5172: E7386, an orally active CBP/beta-catenin modulator, induces T cells infiltration into tumor and enhances antitumor activity of anti-PD-1 mAb in Wnt1 tumor syngeneic mice model

Recently, immunotherapeutic approaches have come to forefront in melanoma, non-small cell lung cancer, bladder cancer, and so on. However, sufficient benefits from these treatments have been limited. T cell infiltrating into tumor tissues is reported as one of the response biomarker candidates for the immune checkpoint inhibitors. Recent studies have shown that the activation of the Wnt/beta-catenin signaling pathway results in T cell exclusion and resistance to immune checkpoint inhibitor in melanoma patients. We established the Wnt1 tumor syngeneic mice model (Wnt1 model) by implantation of mammary adenocarcinomas isolated from MMTV-Wnt1 transgenic mice. Here we demonstrate whether E7386, a first-in-class orally active CBP/beta-catenin modulator, affects the recruitment of T cells into tumor tissues, leading to the enhancement of anti-PD-1 mAb in Wnt/beta-catenin signaling pathway activating tumor model. The mice were treated with E7386 (50 mg/kg, orally, BID) and/or anti-mouse PD-1 mAb (10 mg/kg, intraperitoneal, twice a week) for three weeks. Tumor diameters are measured with digital calipers, and the tumor volume in mm3 is calculated. Immunohistochemical (IHC) analysis was evaluated for tumor-infiltrating T cells. E7386 showed significant antitumor activity in Wnt1 model, but anti-PD-1 mAb did not. In contrast, E7386 with anti-PD-1 mAb indicated prominent antitumor activity compared to each single treatment. Enhancement of body weight loss in combination group was not observed. In IHC analysis, infiltration of T cells was limited in vehicle control group, in contrast T cell infiltration into tumors was clearly observed in both E7386 treatment group and combination group. As a result, antitumor activity of immune checkpoint inhibitor was limited in Wnt-driven tumor model and E7386 as a novel CBP/beta-catenin modulator enhanced the antitumor activity of anti-PD-1 mAb via induction of tumor-infiltrating T cells. Citation Format: Yusaku Hori, Kazuhiko Yamada, Yu Kato, Yoichi Ozawa, Takenao Odagami, Junji Matsui, Tomohiro Matsushima, Kenichi Nomoto, Hiroyuki Kouji, Takashi Owa. E7386, an orally active CBP/beta-catenin modulator, induces T cells infiltration into tumor and enhances antitumor activity of anti-PD-1 mAb in Wnt1 tumor syngeneic mice model [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 5172. doi:10.1158/1538-7445.AM2017-5172