OncoSignal
Live from Open Targets Platform, fetched 2026-11-11 16:04 UTC. Every row links to its source record.

POLA2 DNA polymerase alpha 2, accessory subunit

ENSG00000014138 · protein coding · Open Targets profile

Accessory subunit of the DNA polymerase alpha complex (also known as the alpha DNA polymerase-primase complex) which plays an essential role in the initiation of DNA synthesis (PubMed:9705292). During the S phase of the cell cycle, the DNA polymerase alpha complex (composed of a catalytic subunit POLA1, an accessory subunit POLA2 and two primase subunits, the catalytic subunit PRIM1 and the regulatory subunit PRIM2) is recruited to DNA at the replicative forks via direct interactions with MCM10 and WDHD1 (By similarity). The primase subunit of the polymerase alpha complex initiates DNA synthesis by oligomerizing short RNA primers on both leading and lagging strands (By similarity). These primers are initially extended by the polymerase alpha catalytic subunit and subsequently transferred to polymerase delta and polymerase epsilon for processive synthesis on the lagging and leading strand, respectively (By similarity). {ECO:0000250|UniProtKB:P09884, ECO:0000250|UniProtKB:P20664, ECO:0000269|PubMed:9705292}.

3 of the 7 drugs recorded against POLA2 are approved

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.

3 small molecule drugs at Approved: GEMCITABINE HYDROCHLORIDE, FLUDARABINE PHOSPHATE, GEMCITABINE2 small molecule drugs at Phase 2: TROXACITABINE, ASPACYTARABINE2 small molecule drugs at Withdrawn: CYTARABINE, CLOFARABINESmall molecule 7Approved 3Phase 2 2Withdrawn 2

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 Withdrawn means the drug was pulled from the market or from development.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.

POLA2: 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)
00.250.50.751non-small cell lung carcinomanon-small cell lung carcinomaacute lymphoblastic leukemiaacute lymphoblastic leukemiaacute myeloid leukemiaacute myeloid leukemiaB-cell chronic lymphocytic leukemiaB-cell chronic lymphocytic leukemiaexocrine pancreatic carcinomaexocrine pancreatic carcinomaovarian carcinomaovarian carcinomabreast cancerbreast cancerbreast carcinomabreast carcinomamyelodysplastic syndromemyelodysplastic syndromeovarian cancerovarian cancerlymphoid leukemialymphoid leukemialeptomeningeal metastasisleptomeningeal metastasisnasopharyngeal carcinomanasopharyngeal carcinomamalignant pancreatic neoplasmmalignant pancreatic neoplasmpancreatic neoplasmpancreatic neoplasm

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
Approved Drug, Structure with Ligand
PROTAC
Database Ubiquitination, Half-life Data

gnomAD loss of function constraint: o/e 0.5679299831390381 (upper bound 0.7242400050163269). 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 400 registry trials, updated in the last three years, of the most advanced drugs against POLA2 (gemcitabine, fludarabine, troxacitabine, aspacytarabine), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.

195 of 386 trials of drugs against POLA2 have sites only in United States

Registry trials of gemcitabine, fludarabine, troxacitabine, aspacytarabine 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; 282 of 386 have all sites in one country.

Sites only in this groupSites here and elsewhere
United StatesUnited States: 195 trials with sites only hereUnited States: 97 trials with sites here and elsewhere292ChinaChina: 51 trials with sites only hereChina: 28 trials with sites here and elsewhere79EuropeEurope: 16 trials with sites only hereEurope: 75 trials with sites here and elsewhere91JapanJapan: 3 trials with sites only hereJapan: 41 trials with sites here and elsewhere44OtherOther: 18 trials with sites only hereOther: 89 trials with sites here and elsewhere107

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. 14 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.

1086 trials of drugs against POLA2 were stopped early; 6 of the 200 most recent give no reason

Terminated, withdrawn and suspended interventional trials of gemcitabine, fludarabine, troxacitabine, aspacytarabine, 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 25 most recent of 1086.

  • suspended · 2026-11-10 · National Cancer Institute (NCI) · gemcitabine
    “Placed on voluntary hold to new recruitment pending modification to combination monoclonal antibody treatment.”
  • suspended · 2026-11-04 · Masonic Cancer Center, University of Minnesota · Fludarabine
    “Accrual met”
  • suspended · 2026-11-04 · Institute of Hematology & Blood Diseases Hospital, China · matched by the registry's drug synonyms
    “Suboptimal treatment response”
  • terminated · 2026-11-04 · InnoPharmax Inc. · matched by the registry's drug synonyms
    “Dose-finding stage has been completed, and dose-expanding stage was not conducted due to design amendment.”
  • terminated · 2026-11-03 · Columbia University · Gemcitabine
    “Change in standard of care treatment for muscle-invasive bladder cancer”
  • suspended · 2026-11-03 · National Cancer Institute (NCI) · Gemcitabine Hydrochloride
    “Drug Supply Issues”
  • terminated · 2026-10-30 · Shenzhen Geno-Immune Medical Institute · matched by the registry's drug synonyms
    No reason given
  • terminated · 2026-10-29 · Arsenal Biosciences, Inc. · matched by the registry's drug synonyms
    “Active patients have been rolled over to a separate LTFU study.”
  • terminated · 2026-10-29 · Hebei Yanda Ludaopei Hospital · matched by the registry's drug synonyms
    “Sponsor decision to discontinue the study; the study is no longer being pursued due to sponsor strategic reprioritization and resource allocation. The decision was not based on safety concerns. Enrolled participants will complete safety follow-up per”
  • terminated · 2026-10-27 · Adicet Therapeutics · Fludarabine
    “Sponsor decision”
  • terminated · 2026-10-27 · Brandon Huffman, MD · matched by the registry's drug synonyms
    “Study stopped early due to reaching the minimum number of DLTs required for halting the study due to toxicity.”
  • terminated · 2026-10-19 · Boston Children's Hospital · Fludarabine
    “Funding terminated”
  • suspended · 2026-10-16 · National Cancer Institute (NCI) · Fludarabine
    “Placed on hold to conduct a review of events on study.”
  • suspended · 2026-10-15 · City of Hope Medical Center · Fludarabine
    “Timeline Adjustment”
  • withdrawn · 2026-10-15 · Beijing Boren Hospital · matched by the registry's drug synonyms
    “No participants.”
  • suspended · 2026-09-28 · City of Hope Medical Center · Fludarabine
    “Accrual goal”
  • terminated · 2026-09-25 · Takeda · matched by the registry's drug synonyms
    “Sponsor decision (No safety concern)”
  • withdrawn · 2026-09-24 · Case Comprehensive Cancer Center · matched by the registry's drug synonyms
    “PI left institution”
  • terminated · 2026-09-17 · Centre Oscar Lambret · Gemcitabine
    “Problems of recruitment”
  • suspended · 2026-09-15 · Roswell Park Cancer Institute · Fludarabine
    “awaiting agreement with Sponsor”
  • terminated · 2026-09-14 · Merck Sharp & Dohme LLC · Gemcitabine
    “Business Reasons”
  • withdrawn · 2026-09-11 · Fred Hutchinson Cancer Center · Fludarabine Phosphate
    “Study withdrawn before opening to accrual.”
  • suspended · 2026-09-11 · Chongqing Precision Biotech Co., Ltd · matched by the registry's drug synonyms
    “Sponsor stopped the study.”
  • suspended · 2026-09-10 · Leland Metheny · Fludarabine
    “insufficient funding”
  • terminated · 2026-09-08 · ETOP IBCSG Partners Foundation · matched by the registry's drug synonyms
    “Completion of recruitment was not feasible as accrual was slower than anticipated. Even if a benefit for denosumab could be shown, these results would be of very limited clinical impact by the time they would be available”
Paediatric incentives and obligations for POLA2's drugs

For gemcitabine, fludarabine, troxacitabine, aspacytarabine: 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.

  • EU paediatric investigation plan: yes · EMA/PE/0000230592 (gemcitabine hydrochloride, condition not given): W: decision granting a waiver in all age groups for all conditions or indications, 14 Apr 2025; EMEA-003007-PIP01-21 (gemcitabine hydrochloride, Treatment of urothelial carcinoma): W: decision granting a waiver in all age groups for all conditions or indications, 13 Aug 2021
    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: yes · EU/3/23/2782 positive 22 May 2023: Treatment of myelodysplastic syndromes; EU/3/20/2371 positive 9 Dec 2020: Treatment of acute myeloid leukaemia; EU/3/05/311 withdrawn 26 Aug 2005: Treatment of acute myeloid leukaemia
    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 gemcitabine, fludarabine, troxacitabine, aspacytarabine
    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 gemcitabine, fludarabine, troxacitabine, aspacytarabine
    Rule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-11
  • Registered studies open to children: yes · 1073 interventional studies of gemcitabine, fludarabine, troxacitabine, aspacytarabine include patients under 18; 294 are 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, 2026-11-11

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 7 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.

DrugTypeHighest stageIndicationsSource records
GEMCITABINE HYDROCHLORIDESmall moleculeapprovalovarian carcinoma, non-small cell lung carcinoma, exocrine pancreatic carcinoma, breast carcinoma, breast cancer, ovarian cancer, bladder transitional cell carcinoma, pancreatic adenocarcinoma, +60 moreOpen Targets · ChEMBL
FLUDARABINE PHOSPHATESmall moleculephase 4B-cell chronic lymphocytic leukemia, neoplasm, acute myeloid leukemia, follicular lymphoma, hematopoietic and lymphoid cell neoplasm, myelodysplastic syndrome, lymphoplasmacytic lymphoma, Waldenstrom macroglobulinemia, +75 moreOpen Targets · ChEMBL
GEMCITABINESmall moleculephase 4non-small cell lung carcinoma, neoplasm, bronchitis, pancreatic adenocarcinoma, exocrine pancreatic carcinoma, malignant pancreatic neoplasm, pancreatic neoplasm, ovarian carcinoma, +191 moreOpen Targets · ChEMBL
TROXACITABINESmall moleculephase 2chronic myeloid leukemia, acute myeloid leukemiaOpen Targets · ChEMBL
ASPACYTARABINESmall moleculephase 2acute myeloid leukemia by FAB classification, acute myeloid leukemia, myelodysplastic syndrome, acute lymphoblastic leukemiaOpen Targets · ChEMBL
CYTARABINESmall moleculewithdrawaltumor of meninges, acute myeloid leukemia, acute lymphoblastic leukemia, leptomeningeal metastasis, lymphoid leukemia, neoplasm, acute myeloid leukemia by FAB classification, non-Hodgkin lymphoma, +84 moreOpen Targets · ChEMBL
CLOFARABINESmall moleculewithdrawalacute lymphoblastic leukemia, myelodysplastic syndrome, neoplasm, acute myeloid leukemia, precursor B-cell acute lymphoblastic leukemia, T-cell acute lymphoblastic leukemia, B-cell adult acute lymphocytic leukemia, T-lymphoblastic lymphoma, +37 moreOpen Targets · ChEMBL