Live from Open Targets Platform, fetched 2026-11-12 01:57 UTC. Every row links to its source record.

CSNK2A1 casein kinase 2 alpha 1

ENSG00000101266 · protein coding · Open Targets profile

Catalytic subunit of a constitutively active serine/threonine-protein kinase complex that phosphorylates a large number of substrates containing acidic residues C-terminal to the phosphorylated serine or threonine (PubMed:11239457, PubMed:11704824, PubMed:16193064, PubMed:18411307, PubMed:18583988, PubMed:18678890, PubMed:19188443, PubMed:20545769, PubMed:20625391, PubMed:22017874, PubMed:22406621, PubMed:24962073, PubMed:30898438, PubMed:31439799). Regulates numerous cellular processes, such as cell cycle progression, apoptosis and transcription, as well as viral infection (PubMed:12631575, PubMed:19387551, PubMed:19387552). May act as a regulatory node which integrates and coordinates numerous signals leading to an appropriate cellular response (PubMed:12631575, PubMed:19387551, PubMed:19387552). During mitosis, functions as a component of the p53/TP53-dependent spindle assembly checkpoint (SAC) that maintains cyclin-B-CDK1 activity and G2 arrest in response to spindle damage (PubMed:11704824, PubMed:19188443). Also required for p53/TP53-mediated apoptosis, phosphorylating 'Ser-392' of p53/TP53 following UV irradiation (PubMed:11239457). Phosphorylates a number of DNA repair proteins in response to DNA damage, such as MDC1, MRE11, RAD9A, RAD51 and HTATSF1, promoting their recruitment to DNA damage sites (PubMed:18411307, PubMed:18583988, PubMed:18678890, PubMed:20545769, PubMed:21482717, PubMed:22325354, PubMed:26811421, PubMed:28512243, PubMed:30898438, PubMed:35597237). Can also negatively regulate apoptosis (PubMed:16193064, PubMed:22184066). Phosphorylates the caspases CASP9 and CASP2 and the apoptotic regulator NOL3 (PubMed:16193064). Phosphorylation protects CASP9 from cleavage and activation by CASP8, and inhibits the dimerization of CASP2 and activation of CASP8 (PubMed:16193064). Phosphorylates YY1, protecting YY1 from cleavage by CASP7 during apoptosis (PubMed:22184066). Regulates transcription by direct phosphorylation of RNA polymerases I, II, III and IV (PubMed:12631575, PubMed:19387550, PubMed:19387551, PubMed:19387552, PubMed:23123191). Also phosphorylates and regulates numerous transcription factors including NF-kappa-B, STAT1, CREB1, IRF1, IRF2, ATF1, ATF4, SRF, MAX, JUN, FOS, MYC and MYB (PubMed:12631575, PubMed:19387550, PubMed:19387551, PubMed:19387552, PubMed:23123191). Phosphorylates Hsp90 and its co-chaperones FKBP4 and CDC37, which is essential for chaperone function (PubMed:19387550). Mediates sequential phosphorylation of FNIP1, promoting its gradual interaction with Hsp90, leading to activate both kinase and non-kinase client proteins of Hsp90 (PubMed:30699359). Regulates Wnt signaling by phosphorylating CTNNB1 and the transcription factor LEF1 (PubMed:19387549). Acts as an ectokinase that phosphorylates several extracellular proteins (PubMed:12631575, PubMed:19387550, PubMed:19387551, PubMed:19387552). During viral infection, phosphorylates various proteins involved in the viral life cycles of EBV, HSV, HBV, HCV, HIV, CMV and HPV (PubMed:12631575, PubMed:19387550, PubMed:19387551, PubMed:19387552). Phosphorylates PML at 'Ser-565' and primes it for ubiquitin-mediated degradation (PubMed:20625391, PubMed:22406621). Plays an important role in the circadian clock function by phosphorylating BMAL1 at 'Ser-90' which is pivotal for its interaction with CLOCK and which controls CLOCK nuclear entry (By similarity). Phosphorylates CCAR2 at 'Thr-454' in gastric carcinoma tissue (PubMed:24962073). Phosphorylates FMR1, promoting FMR1-dependent formation of a membraneless compartment (PubMed:30765518, PubMed:31439799). May phosphorylate histone H2A on 'Ser-1' (PubMed:38334665). {ECO:0000250|UniProtKB:P19139, ECO:0000269|PubMed:11239457, ECO:0000269|PubMed:11704824, ECO:0000269|PubMed:16193064, ECO:0000269|PubMed:18411307, ECO:0000269|PubMed:18583988, ECO:0000269|PubMed:18678890, ECO:0000269|PubMed:19188443, ECO:0000269|PubMed:20545769, ECO:0000269|PubMed:20625391, ECO:0000269|PubMed:21482717, ECO:0000269|PubMed:22017874, ECO:0000269|PubMed:22184066, ECO:0000269|PubMed:22325354, ECO:0000269|PubMed:22406621, ECO:0000269|PubMed:23123191, ECO:0000269|PubMed:24962073, ECO:0000269|PubMed:26811421, ECO:0000269|PubMed:28512243, ECO:0000269|PubMed:30699359, ECO:0000269|PubMed:30765518, ECO:0000269|PubMed:30898438, ECO:0000269|PubMed:31439799, ECO:0000269|PubMed:35597237, ECO:0000269|PubMed:38334665, ECO:0000303|PubMed:12631575, ECO:0000303|PubMed:19387549, ECO:0000303|PubMed:19387550, ECO:0000303|PubMed:19387551, ECO:0000303|PubMed:19387552}.

CSNK2A1: inherited and tumour-mutation evidence across 15 cancers

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.

Inherited (germline) variantsMutations in tumours (somatic)

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, High-Quality Pocket, Druggable Family
Antibody: GO CC high conf
PROTAC: Literature, Database Ubiquitination, Half-life Data, Small Molecule Binder

gnomAD loss of function constraint: o/e 0.15896999835968018 (upper bound 0.26965001225471497). 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 6 registry trials, updated in the last three years, of the most advanced drugs against CSNK2A1 (silmitasertib), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.

Jason Huang
Senhwa Biosciences · 1 of 2 trials Phase 2+
Ph2NCT06202521 · CX-4945 in Viral Community Acquired Pneumonia brief
Ph1NCT03897036 · Treatment Duration Increment and Pharmacodynamic Study of CX-4945 in Patients With Basal Cell Carcinoma (BCC)brief
Chandrika Behura
Penn State Health Children's Hospital · 1 of 1 trials Phase 2+
Ph1/Ph2NCT06541262 · Silmitasertib (CX-4945) in Combination With Chemotherapy for Relapsed Refractory Solid Tumors brief
Chris P. Recknor
Center for Advanced Research and Education · 1 of 1 trials Phase 2+
Ph2NCT04663737 · Evaluating Safety, Pharmacokinetics and Clinical Benefit of Silmitasertib (CX-4945) in Subjects With Moderate COVID-19 brief
Ralph Salloum
Dana-Farber Cancer Institute · 1 of 1 trials Phase 2+
Ph1/Ph2NCT03904862 · Testing the Safety and Tolerability of CX-4945 in Patients With Recurrent Medulloblastoma Who May or May Not Have Surgery brief
Jin-Ding Huang
Senhwa Biosciences · 0 of 1 trials Phase 2+
Ph1NCT05817708 · A Study of Silmitasertib (CX-4945) in Healthy Subject brief

3 of 6 trials of drugs against CSNK2A1 have sites only in United States

Registry trials of silmitasertib 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; 5 of 6 have all sites in one country.

Sites only in this groupSites here and elsewhere

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. Source: ClinicalTrials.gov, fetched live.

3 trials of drugs against CSNK2A1 were stopped early

Terminated, withdrawn and suspended interventional trials of silmitasertib, 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 3 most recent of 3.

Ph1/Ph2NCT03904862 brief why it stopped
terminated · 2026-10-19 · Pediatric Brain Tumor Consortium · matched by the registry's drug synonyms
“The decision to permanently close PBTC-053 was made following communication from the NCI that the PBTC grant will not be extended beyond March 31, 2026.”
Ph2NCT06202521 brief why it stopped
terminated · 2026-01-08 · Senhwa Biosciences, Inc. · matched by the registry's drug synonyms
“The trial ended early in March 2025 due to changes in disease epidemiology, affecting patient availability and recruitment feasibility.”
Ph2NCT04668209 brief why it stopped
terminated · 2023-11-07 · University of Arizona · Silmitasertib
“After 15 months of active enrollment and a lack of qualifying hospitalized COVID-19 patients, the Sponsor-Investigator, Marilyn Csete Glassberg, MD, decided to terminate recruitment before meeting the stated enrollment objectives.”

Paediatric incentives and obligations for CSNK2A1's drugs

For silmitasertib: 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: no · CSNK2A1 is not on the list
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: no · No EMA paediatric investigation plan decision names silmitasertib
Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA data download (dated snapshot), 2026-11-11
EU orphan designation: no · No EU orphan designation names silmitasertib
Rule: 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 silmitasertib
Rule: 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 link
Rule: 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 silmitasertib
Rule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-12
Registered studies open to children: yes · 2 interventional studies of silmitasertib include patients under 18; 1 is recruiting, not yet recruiting or active
Rule: The registry's age group includes Child (birth to 17 years), which also counts studies that set no minimum age. Source: ClinicalTrials.gov search, 2026-11-12

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 1 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.

Drug	Type	Highest stage	Indications	Source records
SILMITASERTIB	Small molecule	phase 2	Orthocoronavirinae infectious disease, COVID-19, cholangiocarcinoma, Giant Lymph Node Hyperplasia, plasma cell myeloma, basal cell carcinoma	Open Targets · ChEMBL