CYP17A1 cytochrome P450 family 17 subfamily A member 1
ENSG00000148795 · protein coding · Open Targets profile
A cytochrome P450 monooxygenase involved in corticoid and androgen biosynthesis (PubMed:22266943, PubMed:25301938, PubMed:27339894, PubMed:9452426). Catalyzes 17-alpha hydroxylation of C21 steroids, which is common for both pathways. A second oxidative step, required only for androgen synthesis, involves an acyl-carbon cleavage. The 17-alpha hydroxy intermediates, as part of adrenal glucocorticoids biosynthesis pathway, are precursors of cortisol (Probable) (PubMed:25301938, PubMed:9452426). Hydroxylates steroid hormones, pregnenolone and progesterone to form 17-alpha hydroxy metabolites, followed by the cleavage of the C17-C20 bond to form C19 steroids, dehydroepiandrosterone (DHEA) and androstenedione (PubMed:22266943, PubMed:25301938, PubMed:27339894, PubMed:36640554, PubMed:9452426). Has 16-alpha hydroxylase activity. Catalyzes 16-alpha hydroxylation of 17-alpha hydroxy pregnenolone, followed by the cleavage of the C17-C20 bond to form 16-alpha-hydroxy DHEA (PubMed:36640554). Also 16-alpha hydroxylates androgens, relevant for estriol synthesis (PubMed:25301938, PubMed:27339894). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH-ferrihemoprotein reductase) (PubMed:22266943, PubMed:25301938, PubMed:27339894, PubMed:9452426). {ECO:0000269|PubMed:22266943, ECO:0000269|PubMed:25301938, ECO:0000269|PubMed:27339894, ECO:0000269|PubMed:36640554, ECO:0000269|PubMed:9452426, ECO:0000305|PubMed:8027220}.
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 Withdrawn means the drug was pulled from the market or from development.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
- Approved Drug, Structure with Ligand, High-Quality Ligand, Druggable Family
- PROTAC
- Small Molecule Binder
gnomAD loss of function constraint: o/e 0.7004600167274475 (upper bound 0.965969979763031). 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 264 registry trials, updated in the last three years, of the most advanced drugs against CYP17A1 (levoketoconazole, abiraterone, orteronel, galeterone, seviteronel), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Fred SaadUniversity of Montreal Hospital Center · 3 of 3 trials Phase 2+
- Jingsong ZhangH. Lee Moffitt Cancer Center and Research Institute · 2 of 4 trials Phase 2+
- Johann de BonoRoyal Marsden NHS Foundation Trust · 2 of 2 trials Phase 2+
- Julie GraffOHSU Knight Cancer Institute · 2 of 2 trials Phase 2+
- Karim FIZAZIGustave Roussy, Villejuif · 2 of 2 trials Phase 2+
- Mary-Ellen TaplinDana-Farber Cancer Institute · 2 of 2 trials Phase 2+
- Noel ClarkeChristie Hospital Foundation Trust · 2 of 2 trials Phase 2+
- Paul CornM.D. Anderson Cancer Center · 2 of 2 trials Phase 2+
- Zachery ReichertUniversity of Michigan Rogel Cancer Center · 2 of 2 trials Phase 2+
- A/Prof. Craig GedyeAustralian and New Zealand Urogenital and Prostate Cancer Trials Group · 1 of 1 trials Phase 2+
- Aaron CinerUniversity of Maryland, Baltimore · 1 of 1 trials Phase 2+
- Abhishek SolankiEdward Hines Jr. VA Hospital, Hines, IL · 1 of 1 trials Phase 2+
- Abi Vainstein-HarasCMO · 1 of 1 trials Phase 2+
- Alberto BOSSIGustave Roussy, Cancer Campus Grand Paris - Paris · 1 of 1 trials Phase 2+
- Alexandra SokolovaOregon Health and Science University, Portland, OR, USA · 1 of 1 trials Phase 2+
Registry trials of levoketoconazole, abiraterone, orteronel, galeterone, seviteronel 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; 162 of 254 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. 10 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
78 trials of drugs against CYP17A1 were stopped early; 2 give no reason
Terminated, withdrawn and suspended interventional trials of levoketoconazole, abiraterone, orteronel, galeterone, seviteronel, 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 78.
- terminated · 2026-08-26 · Amgen · Abiraterone“Amgen made a business decision to discontinue all AMG 160 clinical trials. This decision is not related to safety.”
- terminated · 2026-07-22 · Mayo Clinic · Abiraterone Acetate/Niraparib“Sponsor decided to close due to slow accrual and lack of efficacy”
- terminated · 2026-05-15 · Corcept Therapeutics · matched by the registry's drug synonyms“The level of benefit observed did not justify enrolling patients in the Dose Expansion phase of the study.”
- terminated · 2026-04-27 · Partner Therapeutics, Inc. · Abiraterone acetate tablets“Merus terminated the study early due to changes in organizational priorities.”
- withdrawn · 2026-04-08 · Qian Qin · Niraparib/Abiraterone Acetate DAT, Abiraterone Acetate“Funder withdrew funding.”
- terminated · 2026-03-16 · M.D. Anderson Cancer Center · Abiraterone Acetate“<75% participation”
- terminated · 2026-03-10 · Epizyme, Inc. · Abiraterone/prednisone“The study was terminated early as Sponsor decided to discontinue the development of tazemetostat in metastatic castration resistant prostate cancer and the primary endpoint was not met for this study. There were no safety concerns.”
- terminated · 2026-02-20 · Telix Pharmaceuticals (Innovations) Pty Ltd · matched by the registry's drug synonyms“Telix is conducting a separate Phase 3 clinical trial - ProstACT Global NCT06520345- to expedite the development and approval process under an IND. Consequently, this necessitates the closure of the current 177Lu-TLX591-002 Phase 3 trial.”
- terminated · 2026-02-09 · MacroGenics · Abiraterone“Business reasons”
- terminated · 2026-01-08 · Exelixis · abiraterone“Sponsor decided to close the study prior to completion of enrollment. This was a business decision and not based on the safety results of the study.”
- terminated · 2025-11-04 · University of Texas Southwestern Medical Center · Abiraterone acetate“The study has been affected significantly by the COVID pandemic, drug supply/drug amendment, low recruitment interest, and FDA approval of another drug with the same indication, so this study has not met its primary endpoint data requirements.”
- withdrawn · 2025-10-22 · Northwestern University · Abiraterone“PI left institution”
- terminated · 2025-10-21 · Incyte Corporation · Abiraterone“Study terminated due to safety issues.”
- terminated · 2025-10-03 · University of Chicago · Abiraterone Oral Tablet“Closed by PI due to not meeting primary endpoint”
- withdrawn · 2025-09-29 · Latin American Cooperative Oncology Group · matched by the registry's drug synonyms“The study aimed to include multiple countries in Latin America, but only Brazil was feasible, making the intended ethnic and racial design unviable. Activities were closed and no sites were opened for recruitment.”
- terminated · 2025-09-15 · Emory University · Abiraterone“To review the safety data.”
- terminated · 2025-06-24 · Jiangsu HengRui Medicine Co., Ltd. · matched by the registry's drug synonyms“The sponsor's R\&D strategy is adjusted.”
- terminated · 2025-04-13 · Centre hospitalier de l'Université de Montréal (CHUM) · matched by the registry's drug synonyms“The cabazitaxel was recently approved by the regulatory authorities for mCRPCa”
- terminated · 2025-04-08 · Opna Bio LLC · Abiraterone acetate“study terminated due to business realignment”
- terminated · 2025-02-28 · ESSA Pharmaceuticals · Abiraterone acetate“Study was terminated early due to a lack of improved efficacy.”
- terminated · 2025-02-03 · Janssen Research & Development, LLC · Abiraterone Acetate“Administrative Decision”
- terminated · 2024-10-17 · DisperSol Technologies, LLC · Abiraterone Acetate, DST-2970 (Abiraterone)“Dose escalation portion of the study completed, one expansion cohort was eliminated due to change in standard of care, and the second cohort was not enrolled based on future development considerations.”
- withdrawn · 2024-09-19 · Baptist Health South Florida · Niraparib abiraterone acetate“Funding for the study was withdrawn.”
- terminated · 2024-09-19 · Dana-Farber Cancer Institute · Abiraterone Acetate“PI is terminating the study due to slow/low accrual”
- terminated · 2024-08-09 · Biosplice Therapeutics, Inc. · Abiraterone“Study was terminated due business reasons by Sponsor.”
Paediatric incentives and obligations for CYP17A1's drugs
For levoketoconazole, abiraterone, orteronel, galeterone, seviteronel: 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 · CYP17A1 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-002789-PIP01-20 (niraparib (tosilate monohydrate);abiraterone acetate, Treatment of prostate malignant neoplasms): W: decision granting a waiver in all age groups for all conditions or indications, 15 Jul 2021Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA EMEA-002789-PIP01-20, 2026-11-11
- EU orphan designation: no · No EU orphan designation names levoketoconazole, abiraterone, orteronel, galeterone, seviteronelRule: 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: yes · Akeega: authorised since 19 Apr 2023; Abiraterone Mylan: authorised since 20 Aug 2021; Abiraterone Krka: authorised since 24 Jun 2021; Abiraterone Accord: authorised since 26 Apr 2021; +1 moreRule: 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 levoketoconazole, abiraterone, orteronel, galeterone, seviteronelRule: 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 levoketoconazole, abiraterone, orteronel, galeterone, seviteronel include patients under 18; 4 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 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.