BRDT (Bromodomain Testis Associated)

The study exemplifies how constraining conformational flexibility can impart target selectivity. The results indicate that the macrocyclization strategy achieved an increase in pan-BD1-affinity and comparable pan-BD2-affinity compared to lead compound 1.

However, BRD4 depletion/BRDT complementation revealed that BRDT can also release paused RNA polymerase II independently of its bromodomains as we previously demonstrated not to be required for Pol II pause/release function of BRD4, underscoring the functional importance of the C-terminal domains in both BRD4 and BRDT and their potential as therapeutic targets in solid tumors. Based on this study, future investigations should explore BRD4-distinct BRDT functions and BRDT misexpression driving cancer pathogenesis.

Molibresib in combination with fulvestrant did not demonstrate clinically meaningful activity in this study.

The GI50 of K-256 in SU-DHL4 and SU-DHL6 was 12.8 nM and 7.50 nM, respectively, and K-256 induced cell death at lower concentrations than existing drugs (vs. JQ1, OTX-015, and ABBV-075, p < 0.0001; vs. dBET6 and ARV-771, p < 0.01)...As expected, the combination of K-256 with venetoclax also demonstrated synergistic effects in PDX cells, similar to those observed in cell lines (CI of 0.515 to 0.762 for inhibiting cell proliferation; 0.085 to 0.995 for inducing apoptosis)... The novel BET degrader, K-256, bound to BET proteins at lower concentrations than existing BET inhibitors and degraders, strongly suppressing MYC expression, primarily via BRD4 degradation. Additionally, K-256 demonstrated superior therapeutic effects in MYC/BCL2-related PDX models both in vitro and in vivo, suggesting that this novel drug could be a promising therapeutic agent for MYC/BCL2-related lymphoma. Its translation to future clinical applications warrants further consideration.

Molibresib in combination with fulvestrant did not demonstrate clinically meaningful activity in this study. Copy number adjusted ctDNA MR is a promising early marker for clinical benefit. Clinical trial information: NCT02964507.

This study in a larger cohort of gynecologic cancer patients confirmed the safety profile of the agent and demonstrated the feasibility of combination with carboplatin. While these results did not meet the pre-specified response criteria, evidence of clinical activity nevertheless highlights the rationale for further exploration of BRD4 inhibitors in patients with ARID1A-mutated gynecologic malignancies, possibly in combination with agents targeting potential feedback mechanisms such as the PI3K pathway, frequently activated in these cancers.

Conclusion s : Our data indicates that a) PLX51107 has an antitumor effect in CLL cells; b) the combinational treatment of Venetoclax with PLX51107 highly improved the apoptotic effect of single agent treatments. A better understanding of the key signaling pathways for CLL cells' proliferation and survival impacted by BRD4i in combination with Venetoclax would provide a proof-of-concept rationale for studies validating BRD4i as epigenetic approach to target BCR signaling in CLL.

Validation experiments using JQ1 will be conducted to assess the accuracy of available protocols and experimental technique. These drugs will then be synthesized and tested on colorectal cancer cells in different concentrations to measure their effects through procedures including MTT and qPCR assays to measure cell viability and gene expression levels.