BRD4 bromodomain containing 4
ENSG00000141867 · protein coding · Open Targets profile
Chromatin reader protein that recognizes and binds acetylated histones and plays a key role in transmission of epigenetic memory across cell divisions and transcription regulation (PubMed:20871596, PubMed:23086925, PubMed:23317504, PubMed:29176719, PubMed:29379197). Remains associated with acetylated chromatin throughout the entire cell cycle and provides epigenetic memory for postmitotic G1 gene transcription by preserving acetylated chromatin status and maintaining high-order chromatin structure (PubMed:22334664, PubMed:23317504, PubMed:23589332). During interphase, plays a key role in regulating the transcription of signal-inducible genes by associating with the P-TEFb complex and recruiting it to promoters (PubMed:16109376, PubMed:16109377, PubMed:19596240, PubMed:23589332, PubMed:24360279). Also recruits P-TEFb complex to distal enhancers, so called anti-pause enhancers in collaboration with JMJD6 (PubMed:16109376, PubMed:16109377, PubMed:19596240, PubMed:23589332, PubMed:24360279). BRD4 and JMJD6 are required to form the transcriptionally active P-TEFb complex by displacing negative regulators such as HEXIM1 and 7SKsnRNA complex from P-TEFb, thereby transforming it into an active form that can then phosphorylate the C-terminal domain (CTD) of RNA polymerase II (PubMed:16109376, PubMed:16109377, PubMed:19596240, PubMed:23589332, PubMed:24360279). Regulates differentiation of naive CD4(+) T-cells into T-helper Th17 by promoting recruitment of P-TEFb to promoters (By similarity). Promotes phosphorylation of 'Ser-2' of the C-terminal domain (CTD) of RNA polymerase II (PubMed:23086925). According to a report, directly acts as an atypical protein kinase and mediates phosphorylation of 'Ser-2' of the C-terminal domain (CTD) of RNA polymerase II; these data however need additional evidence in vivo (PubMed:22509028). In addition to acetylated histones, also recognizes and binds acetylated RELA, leading to further recruitment of the P-TEFb complex and subsequent activation of NF-kappa-B (PubMed:19103749). Also acts as a regulator of p53/TP53-mediated transcription: following phosphorylation by CK2, recruited to p53/TP53 specific target promoters (PubMed:23317504). {ECO:0000250|UniProtKB:Q9ESU6, ECO:0000269|PubMed:16109376, ECO:0000269|PubMed:16109377, ECO:0000269|PubMed:19103749, ECO:0000269|PubMed:19596240, ECO:0000269|PubMed:22334664, ECO:0000269|PubMed:22509028, ECO:0000269|PubMed:23086925, ECO:0000269|PubMed:23317504, ECO:0000269|PubMed:23589332, ECO:0000269|PubMed:24360279, ECO:0000269|PubMed:29176719}.
Each band is a group of drugs. It runs from the kind of drug on the left to the furthest stage that drug has reached in any disease on the right. Thicker bands mean more drugs.
Approved bands are highlighted. Withdrawn means the drug was pulled from the market or from development. A combined phase counts as the later one (Phase 1/2 is shown as Phase 2). Hover a band for the drug names. Source: Open Targets Platform, fetched live.
Each row is a cancer, strongest overall evidence first. The two dots show how strong the inherited (germline) and tumour-mutation (somatic) evidence is; the line between them is the gap.
Scores run from 0 (no evidence) to 1 (strongest). A missing dot at 0 means Open Targets holds no evidence of that kind. Source: Open Targets Platform, fetched live.
Tractability
- Small molecule
- Advanced Clinical, Structure with Ligand, High-Quality Ligand, Med-Quality Pocket, Druggable Family
- PROTAC
- Literature, UniProt Ubiquitination, Database Ubiquitination, Half-life Data, Small Molecule Binder
gnomAD loss of function constraint: o/e 0.11259999871253967 (upper bound 0.1710200011730194). Low values mean loss of function is poorly tolerated, a safety flag for inhibition.
Who runs trials of these drugs
Principal investigators and study chairs on 15 registry trials, updated in the last three years, of the most advanced drugs against BRD4 (pelabresib, apabetalone, birabresib, molibresib), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Michael SweeneyResverlogix Corp · 1 of 1 trials Phase 2+
- Michael WestQueen Elizabeth II Health Sciences Centre, Victoria General Site · 1 of 1 trials Phase 2+
Registry trials of pelabresib, apabetalone, birabresib, molibresib updated in the last three years, counted by the country group of their listed sites. A trial with sites in several groups counts in each; 4 of 14 have all sites in one country.
Site counts are not patients per country, and trials registered only outside ClinicalTrials.gov are not covered. Where sites are is a fact about the record, not a judgement of its quality. Europe is the EU and EEA, the UK and Switzerland. 1 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
11 trials of drugs against BRD4 were stopped early; 1 give no reason
Terminated, withdrawn and suspended interventional trials of pelabresib, apabetalone, birabresib, molibresib, ezobresib, RO-6870810, newest update first, live from ClinicalTrials.gov. Each reason is quoted exactly as the registry gives it; we do not sort reasons into safety, efficacy or business. Dates are the last registry update. Showing the 11 most recent of 11.
- terminated · 2024-08-29 · GlaxoSmithKline · matched by the registry's drug synonyms“This study has been terminated due to meeting protocol defined futility.”
- terminated · 2023-11-18 · Resverlogix Corp · Apabetalone“Unable to recruit subjects”
- withdrawn · 2023-11-18 · Resverlogix Corp · matched by the registry's drug synonyms“Changed development priorities”
- terminated · 2022-09-13 · Merck Sharp & Dohme LLC · Birabresib Dose 20 mg“This study was terminated due to limited efficacy and not due to safety reasons”
- terminated · 2022-08-10 · GlaxoSmithKline · matched by the registry's drug synonyms“This study has been terminated due to meeting protocol defined futility.”
- terminated · 2021-01-27 · Merck Sharp & Dohme LLC · Birabresib“This study was terminated due to limited efficacy and not due to safety reasons.”
- terminated · 2021-01-26 · Oncoethix GmbH, a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) · Birabresib“This study was terminated due to lack of clinical activity and not due to safety reasons.”
- terminated · 2020-11-06 · Hoffmann-La Roche · matched by the registry's drug synonyms“Portfolio prioritization”
- withdrawn · 2020-09-28 · National Cancer Institute (NCI) · Molibresib“Other - Protocol moved to Disapproved”
- withdrawn · 2020-09-28 · National Cancer Institute (NCI) · Molibresib, Molibresib Besylate“Other - Protocol moved to Disapproved”
- terminated · 2015-05-12 · Resverlogix Corp · matched by the registry's drug synonymsNo reason given
Paediatric incentives and obligations for BRD4's drugs
For pelabresib, apabetalone, birabresib, molibresib, ezobresib, RO-6870810: what EMA and FDA publish about paediatric plans, orphan status and pediatric approvals, and how many registered studies take children. Each line is a yes, no or not published fact from the record linked under it; none of it is a forecast.
- FDA pediatric target list: yes · BRD4 is on the list. Membership alone neither requires nor waives a pediatric study.Rule: Target is on FDA's Pediatric Molecular Target List (relevant targets). Source: FDA Pediatric Molecular Target List (Listed as February 2026 on the FDA Pediatric Oncology page; the file served is 9.7.22_the_relevant_molecular_target_list.xlsx, whose Summary of Changes sheet is headed 'SEPTEMBER 2022 UPDATE' (footnote date 2022-09-01)), 2026-11-11
- EU paediatric investigation plan: yes · EMEA-002406-PIP01-18 (molibresib, Treatment of breast cancer): W: decision granting a waiver in all age groups for all conditions or indications, 7 Dec 2018Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA EMEA-002406-PIP01-18, 2026-11-11
- EU orphan designation: no · No EU orphan designation names pelabresib, apabetalone, birabresib, molibresib, ezobresib, ro-6870810Rule: An EU orphan designation lists the drug as its active substance (exact name) or belongs to a medicine that does; withdrawn and expired designations are listed with their status. Source: EMA data download (dated snapshot), 2026-11-11
- Authorised in the EU: no · EMA lists no centrally authorised medicine of pelabresib, apabetalone, birabresib, molibresib, ezobresib, ro-6870810Rule: An EMA medicine record lists the drug as its active substance or INN, exact name; national-only authorisations are not in this file. Source: EMA data download (dated snapshot), 2026-11-11
- FDA orphan designation: not published · FDA's orphan designation database turns away automated requests, so this app does not read it; search it by hand at the linkRule: Would be: an FDA orphan designation names the drug. Source: FDA orphan designations search
- FDA pediatric oncology approval: no · FDA's table lists no pediatric approval of pelabresib, apabetalone, birabresib, molibresib, ezobresib, ro-6870810Rule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-11
- Registered studies open to children: yes · 3 interventional studies of pelabresib, apabetalone, birabresib, molibresib, ezobresib, ro-6870810 include patients under 18; 0 are recruiting, not yet recruiting or activeRule: The registry's age group includes Child (birth to 17 years), which also counts studies that set no minimum age. Source: ClinicalTrials.gov search, 2026-11-11
Rare pediatric disease voucher. FDA, content current as of 29 Apr 2026: “As of February 3, 2026, enactment of the Consolidated Appropriations Act, 2026, the rare pediatric disease PRV program will sunset after September 30, 2029. FDA may not award any PRVs under this program after September 30, 2029.” Voucher sale prices are not shown here; they appear only as company-reported news. FDA: Rare Pediatric Disease Designation and Priority Review Voucher Programs
All 6 drugs and clinical candidates as a table
Each drug, stage and indication links to its Open Targets record, where the trials and approvals behind it are listed. Salt forms (for example a mesylate) are listed as Open Targets records them, as separate entries.