birabresib (OTX015)

We discovered bromodomain-containing protein 4 (BRD4) degraders as novel antitumor therapeutics leveraging our internal knowledge on Y-803 (birabresib, OTX015/MK-8628), which was discovered by our company as the first-in-class BRD4 inhibitor. Since we had obtained rich structure-activity relationship (SAR) information on its core skeleton, thienodiazepine, we designed and optimized Von Hippel-Lindau (VHL)-based BRD4 degraders based on the thienodiazepine scaffold. Here, we report that we obtained a novel, best-in-class BRD4 degrader, which showed a potent antitumor effect in a xenograft model of acute myeloid leukemia (AML).

Compared to each drug alone, co-treatment with SNDX-5613 (revumenib) and FHD-286 or OTX015 and FHD-286 significantly reduced the in vivo AML burden and improved survival of the immune depleted mice, without inducing significant toxicity, in the xenograft models of MITR and MI-resistant PD MLL1-r AML cells. These findings highlight novel, targeted, drug combinations that overcome MI resistance in AML cells with MLL1-r or mtNPM1.

To overcome these limitations, we systematically evaluated the synergistic Combination effects of three drug candidates, OTX-015 (BET inhibitor), Metformin (metabolic regulator), and Anlotinib (multitargeted tyrosine kinase inhibitor), with Chidamide. Chidamide and Anlotinib synergistically inhibit Hippo signaling pathway, which reveals a novel "dual epigenetic kinase targeting" strategy for the treatment of T-ALL. Future studies should validate these findings in vivo and investigate the impact of the metabolic microenvironment on therapeutic efficacy.

5. SHR6390 and OTX015 Synergistically Inhibit the Growth of AML Xenografts In Vivo.

In AML with 3q26.2 rearrangements (r) the distal GATA2 hematopoietic enhancer becomes aberrantly relocated leading to activation of EVI1 expression. In patient-derived xenograft (PDX) models of AML with MECOM-r, compared to each drug alone, co-treatment with FHD-286 and BETi OTX015 significantly reduced AML burden and improved survival, without inducing significant toxicity. These findings highlight the FHD-286-based combinations as promising therapy of AML with chromosome 3q26.2 rearrangement and EVI1 overexpression.

MDA-NUT87 and MDA-NUT88 are the first stable human sinonasal NUT carcinoma cell lines established from the primary tumor site. They preserve the hallmark genetic and phenotypic characteristics of NUT carcinoma and show sensitivity to BET inhibition. These models represent valuable tools for mechanistic studies and high-throughput drug screening in sinonasal NUT carcinoma.

Finally, a deep-learning model for predicting the drug efficacy over patients' transcriptomic data revealed OTX015, a BET inhibitor, as a promising treatment that targets mutated FBXW7 PNI tumors. This study provides a rich resource for elucidating the molecular mechanisms of PNI tumors, laying a critical foundation for developing effective diagnostic and therapeutic strategies for PNI tumors in cervical cancer.

The alarmins, S100A8 (A8) and S100A9 (A9), are low molecular weight proteins belonging to the S100 protein family. Notably, cotreatment with TQ and ruxolitinib or OTX015 induced significantly greater survival than treatment with single agents in the NSG mice engrafted with the PDX cells. These findings clearly demonstrate the preclinical efficacy of TQ in advanced MPN-BP cells and create the rationale to further interrogate the efficacy of TQ-based combinations with the current, front-line therapies or novel agents in advanced MPNs with excess blasts.

This integrative approach comprehensively elucidated the role of pan-apoptosis-related genes in LSCC. The constructed risk model has significant clinical application value in prognostic prediction, immune landscape assessment, and drug sensitivity analysis, and has the potential to guide precision treatment strategies for LSCC patients. These findings may help advance personalized treatment plans and improve the prognosis of patients with LSCC.

In vitro transcribed and circularized BISC, when combined with the BETi OTX-015, demonstrated impressive tumor regression in BETi-resistant TNBC models without detectable toxicity. These findings establish BISC as a potent IGF2BP2 repressor and highlight the feasibility of circRNA-based therapeutic strategies to overcome BETi resistance in TNBC.

Pharmacological sensitivity analysis indicated that TMEM132A may serve as a potential target for the therapeutic agents birabresib and abemaciclib. TMEM132A demonstrates diagnostic utility as a predictive biomarker for VTE occurrence in LUAD, suggesting its potential role as a susceptibility gene in this patient cohort.

Our study demonstrates that BRD4 epigenetically regulates the H19-mediated transcriptional control of adhesion molecules involved in collective migration and metastatic dissemination. Importantly, these effects are independent of AR status, suggesting that targeting the H19/BRD4 axis may represent a promising therapeutic avenue for advanced PCa.