PIK3R1 phosphoinositide-3-kinase regulatory subunit 1
ENSG00000145675 · protein coding · Open Targets profile
Binds to activated (phosphorylated) protein-Tyr kinases, through its SH2 domain, and acts as an adapter, mediating the association of the p110 catalytic unit to the plasma membrane. Necessary for the insulin-stimulated increase in glucose uptake and glycogen synthesis in insulin-sensitive tissues. Plays an important role in signaling in response to FGFR1, FGFR2, FGFR3, FGFR4, KITLG/SCF, KIT, PDGFRA and PDGFRB. Likewise, plays a role in ITGB2 signaling (PubMed:17626883, PubMed:19805105, PubMed:7518429). Modulates the cellular response to ER stress by promoting nuclear translocation of XBP1 isoform 2 in a ER stress- and/or insulin-dependent manner during metabolic overloading in the liver and hence plays a role in glucose tolerance improvement (PubMed:20348923). {ECO:0000269|PubMed:17626883, ECO:0000269|PubMed:19805105, ECO:0000269|PubMed:20348923, ECO:0000269|PubMed:7518429}.
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 Withdrawn means the drug was pulled from the market or from development.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
- Antibody
- GO CC high conf
- PROTAC
- UniProt Ubiquitination, Database Ubiquitination, Half-life Data, Small Molecule Binder
gnomAD loss of function constraint: o/e 0.2957800030708313 (upper bound 0.4032900035381317). 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 32 registry trials, updated in the last three years, of the most advanced drugs against PIK3R1 (taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, PF-04691502, SF-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisib), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Nadene ZackCelcuity Inc · 2 of 2 trials Phase 2+
- Anthony GONCALVESInstitut Paoli-Calmettes · 1 of 1 trials Phase 2+
- Ashley MargolChildren's Hospital Los Angeles · 1 of 1 trials Phase 2+
- Daniel MorgensternThe Hospital for Sick Children - Canadian Study Chair · 1 of 1 trials Phase 2+
- David ZieglerSydney Children's Hospital - Australian Study Chair · 1 of 1 trials Phase 2+
- Donald W ParsonsChildren's Oncology Group · 1 of 1 trials Phase 2+
- Howard FineWeill Medical College of Cornell University · 1 of 1 trials Phase 2+
- Ian E KropECOG-ACRIN Cancer Research Group · 1 of 1 trials Phase 2+
- Jacques VargaftigInstitut Curie - Hôpital René Huguenin · 1 of 1 trials Phase 2+
- James GarnerKazia Therapeutics Limited · 1 of 1 trials Phase 2+
- Juanita LopezNational Health Service, United Kingdom · 1 of 1 trials Phase 2+
- Keith T FlahertyECOG-ACRIN Cancer Research Group · 1 of 1 trials Phase 2+
- Luis N Gonzalez CastroDana-Farber Cancer Institute · 1 of 1 trials Phase 2+
- Panagiotis KonstantininopoulosDana-Farber Cancer Institute · 1 of 1 trials Phase 2+
- Priscilla BrastianosMassachusetts General Hospital · 1 of 1 trials Phase 2+
Registry trials of taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, PF-04691502, SF-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisib 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; 21 of 32 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. Source: ClinicalTrials.gov, fetched live.
51 trials of drugs against PIK3R1 were stopped early; 10 give no reason
Terminated, withdrawn and suspended interventional trials of taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, PF-04691502, SF-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisib, 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 51.
- terminated · 2026-04-21 · Institut Paoli-Calmettes · matched by the registry's drug synonyms“Drug development withdrawn”
- suspended · 2026-02-13 · Dana-Farber Cancer Institute · Gedatolisib“Funding and drug supply to continue the study are pending.”
- terminated · 2026-02-04 · Centre Hospitalier Universitaire Dijon · Taselisib (GDC0032)“In accordance with the protocol, following the occurrence of two SUSARs, the TOTEM trial was stopped early for safety reasons.”
- terminated · 2025-09-08 · Institut Curie · matched by the registry's drug synonyms“No objective response was observed at the first step. The treatment was considered ineffective, with a complete clinical trial suspension.”
- withdrawn · 2023-04-27 · Roswell Park Cancer Institute · BuparlisibNo reason given
- terminated · 2022-08-22 · Vanderbilt-Ingram Cancer Center · Taselisib“Interim analysis - toxicity”
- withdrawn · 2022-07-28 · Rutgers, The State University of New Jersey · matched by the registry's drug synonyms“Research cancelled”
- terminated · 2022-07-12 · Hoffmann-La Roche · Taselisib“The Sponsor discontinued the manufacturing and development of taselisib due to modest clinical benefit and limited tolerability.”
- terminated · 2022-05-18 · SignalRX Pharmaceuticals, Inc. · matched by the registry's drug synonyms“Lack of recruitment and sponsor's priority changes”
- terminated · 2021-10-11 · Prince of Songkla University · matched by the registry's drug synonyms“Sponsor terminated to continue any clinical trials with study drug”
- terminated · 2021-02-10 · Restorbio Inc. · matched by the registry's drug synonyms“Insufficient accrual rate”
- terminated · 2021-01-13 · Won Kim · matched by the registry's drug synonyms“Lack of Accrual”
- terminated · 2020-12-19 · Novartis Pharmaceuticals · matched by the registry's drug synonyms“Decision by Sponsor to to terminate the study early.”
- terminated · 2020-12-08 · Novartis Pharmaceuticals · matched by the registry's drug synonyms“Study did not meet Phase Ib primary objective to establish the maximum tolerated dose/recommended dose for Phase II”
- withdrawn · 2020-04-28 · Abramson Cancer Center at Penn Medicine · Gedatolisib“due to business decision regarding the study drug.”
- withdrawn · 2019-11-22 · Restorbio Inc. · Dactolisib“Phase 3 trial RTB-101-204 study did not meet its primary endpoint”
- terminated · 2019-10-04 · University of Florida · Gedatolisib“Slow accrual”
- terminated · 2019-09-03 · Emory University · BuparlisibNo reason given
- terminated · 2019-04-10 · Cliniques universitaires Saint-Luc- Université Catholique de Louvain · matched by the registry's drug synonyms“Novartis decided to stop the marketing of BEZ235”
- terminated · 2019-02-05 · Dana-Farber Cancer Institute · matched by the registry's drug synonyms“Due to slow accrual the supllier of BKM120 asked we cease further enrollment.”
- terminated · 2019-01-30 · Novartis Pharmaceuticals · matched by the registry's drug synonyms“Novartis decided not to pursue further development of buparlisib program (assessment of moderate PFS benefit with know, but manageable, buparlisib profile).”
- terminated · 2019-01-29 · Anne Chang · Buparlisib“Business Decision”
- terminated · 2019-01-08 · Pfizer · matched by the registry's drug synonyms“See termination reason in detailed description.”
- terminated · 2019-01-08 · Pfizer · matched by the registry's drug synonyms“Enrollment to the study was terminated on 11Nvo2014 due to slow recruitment. There were no safety or efficacy issues that contributed to this decision.”
- terminated · 2018-10-29 · Pfizer · matched by the registry's drug synonyms“Refer to Detailed Description for documentaion of Termination Statement.”
Paediatric incentives and obligations for PIK3R1's drugs
For taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, PF-04691502, SF-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisib: 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 · PIK3R1 is not on the listRule: 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-003607-PIP01-24 (buparlisib, Treatment of head and neck epithelial malignant neoplasms): W: decision granting a waiver in all age groups for all conditions or indications, 14 Aug 2024Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA EMEA-003607-PIP01-24, 2026-11-11
- EU orphan designation: no · No EU orphan designation names taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, pf-04691502, sf-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisibRule: 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 taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, pf-04691502, sf-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisibRule: 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 taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, pf-04691502, sf-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisibRule: 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 · 10 interventional studies of taselisib, gedatolisib, dactolisib, buparlisib, paxalisib, pf-04691502, sf-1126, voxtalisib, pilaralisib, apitolisib, samotolisib, sonolisib include patients under 18; 5 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, 2026-11-12
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 24 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.