# PARP inhibitors

Source: https://onco.cc/technologies/parp-inhibitor/  
OnCo record `parp-inhibitor` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Pills that block a DNA repair backup, killing cancer cells that already lost their main repair system (BRCA).

## Summary

The approved PARP inhibitors are olaparib, niraparib, rucaparib and talazoparib. They are standard as maintenance in BRCA/HRD ovarian cancer (SOLO-1, PRIMA), adjuvant in germline-BRCA HER2-negative breast cancer (OlympiA, with overall survival benefit), metastatic breast (OlympiAD, EMBRACA), HRR-mutant prostate (PROfound, PROpel, TALAPRO-2), and pancreatic maintenance (POLO). Resistance via BRCA reversion; PARP1-selective saruparib aims to widen the window.

## Fields

- Kind: Technology
- Status: approved
- Last checked: 2026-09-04
- Principle: Synthetic lethality: PARP trapping converts single-strand breaks into double-strand breaks that HR-deficient cells cannot repair.
- Since: 2014
- Strengths: Oral, targeted to a germline-definable population; Overall survival benefit in adjuvant setting
- Limitations: Myelosuppression, MDS risk; Reversion resistance

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/PARP_inhibitor
- Wikipedia: https://en.wikipedia.org/wiki/PARP_inhibitor

## Connected records

- cancers: [BRCA or PALB2-mutant pancreatic ductal adenocarcinoma](https://onco.cc/cancers/brca-palb2-pdac/), [BRCA-associated triple-negative breast cancer](https://onco.cc/cancers/brca-associated-tnbc/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Male breast cancer](https://onco.cc/cancers/male-breast-cancer/), [Metastatic pancreatic ductal adenocarcinoma](https://onco.cc/cancers/metastatic-pdac/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Pancreatic acinar cell carcinoma](https://onco.cc/cancers/pancreatic-acinar-cell-carcinoma/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/), [Platinum-sensitive ovarian cancer](https://onco.cc/cancers/platinum-sensitive-ovarian-cancer/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- fronts: [Targeted Therapy](https://onco.cc/fronts/targeted-therapy/)
- targets: [BRCA1 / BRCA2 (HRD)](https://onco.cc/targets/brca/), [PARP](https://onco.cc/targets/parp/)
- drugs: [Iniparib](https://onco.cc/drugs/iniparib/), [Niraparib](https://onco.cc/drugs/niraparib/), [Olaparib](https://onco.cc/drugs/olaparib/), [Rucaparib](https://onco.cc/drugs/rucaparib/), [Talazoparib](https://onco.cc/drugs/talazoparib/), [Veliparib](https://onco.cc/drugs/veliparib/)
- terms: [Checkpoint (two meanings)](https://onco.cc/terms/checkpoint/), [Enabling characteristic: genome instability and mutation](https://onco.cc/terms/genome-instability-mutation/), [Genome-wide loss of heterozygosity (gLOH)](https://onco.cc/terms/genome-wide-loss-of-heterozygosity/), [Germline BRCA mutation (gBRCA)](https://onco.cc/terms/gbrca-mutation/), [Homologous recombination deficiency (HRD) in breast cancer](https://onco.cc/terms/hrd-in-breast-cancer/), [Inhibitor](https://onco.cc/terms/inhibitor/), [Maintenance therapy](https://onco.cc/terms/maintenance-therapy/), [Residual disease after neoadjuvant therapy in triple-negative breast cancer: the decision point](https://onco.cc/terms/tnbc-residual-disease-decision/), [Somatic mutation theory of cancer](https://onco.cc/terms/somatic-mutation-theory/), [Synthetic lethality](https://onco.cc/terms/synthetic-lethality/), [Targeted therapy](https://onco.cc/terms/targeted-therapy-term/), [What follows what in castration-resistant prostate cancer](https://onco.cc/terms/prostate-crpc-sequencing/), [Who is eligible for a PARP inhibitor in prostate cancer, and why the gene matters](https://onco.cc/terms/prostate-hrr-eligibility/)
- trials: [A Clinical Study Evaluating a Combination of Oregovomab and Niraparib in Adult Women With Platinum Sensitive Recurrent Ovarian Cancer.](https://onco.cc/trials/nct05335993/), [A Comparison of Platinum-based Therapy With TSR-042 and Niraparib Versus Standard of Care (SOC) Platinum-based Therapy as First-line Treatment of Stage III or IV Nonmucinous Epithelial Ovarian Cancer](https://onco.cc/trials/nct03602859/), [A Long-term Treatment Extension Study of Niraparib in Participants Who Completed a Prior GlaxoSmithKline/TESARO-sponsored Niraparib Study](https://onco.cc/trials/nct04641247/), [A Phase I/II Study of MEDI4736 in Combination With Olaparib in Patients With Advanced Solid Tumors.](https://onco.cc/trials/nct02734004/), [A Study of Durvalumab Alone and Durvalumab+Olaparib in Advanced, Platinum-Ineligible Bladder Cancer (BAYOU)](https://onco.cc/trials/nct03459846/), [A Study of Niraparib Combination Therapies for the Treatment of Metastatic Castration-Resistant Prostate Cancer](https://onco.cc/trials/nct03431350/), [A Study of Niraparib in Combination With Abiraterone Acetate and Prednisone Versus Abiraterone Acetate and Prednisone for the Treatment of Participants With Deleterious Germline or Somatic Homologous Recombination Repair (HRR) Gene-MutatedProstatic Neoplasms (mCSPC)](https://onco.cc/trials/nct04497844/), [A Study of Radiation Therapy With Pembrolizumab and Olaparib or Other Radiosensitizers in Women Who Have Triple-Negative or Hormone-Receptor Positive/Her2 Negat](https://onco.cc/trials/nct04683679/), [A Study to Investigate the Safety, Tolerability, Pharmacokinetics (PK), and Preliminary Anticancer Activity of GSK4524101 Alone or With Niraparib in Participants With Solid Tumors](https://onco.cc/trials/nct06077877/), [APOLLO: A Randomized Phase II Double-Blind Study of Olaparib Versus Placebo Following Curative Intent Therapy in Patients With Resected Pancreatic Cancer and a](https://onco.cc/trials/nct04858334/), [ATHENA-MONO / GOG-3020](https://onco.cc/trials/athena-mono/), [BROCADE3](https://onco.cc/trials/brocade3/), [Clinical Study of QL1706 in Combination With Olaparib for the Treatment of Patients With Previously Treated Homologous Recombination Repair-Deficient Recurrent](https://onco.cc/trials/nct07005583/), [Combination Therapy of AK112 With Chemotherapy and/or Olaparib in Platinum-sensitive Ovarian Cancer](https://onco.cc/trials/nct06686030/), [CUPISCO](https://onco.cc/trials/cupisco/), [D9319C00001- 1L OC Mono Global RCT](https://onco.cc/trials/nct04884360/), [Efficacy and Safety Comparison of Niraparib to Placebo in Participants With Human Epidermal Growth Factor 2 Negative (HER2-) Breast Cancer Susceptibility Gene Mutation (BRCAmut) or Triple-Negative Breast Cancer (TNBC) With Molecular Disease](https://onco.cc/trials/nct04915755/), [Efficacy and Safety of Olaparib (MK-7339) in Participants With Previously Treated, Homologous Recombination Repair Mutation (HRRm) or Homologous Recombination Deficiency (HRD) Positive Advanced Cancer (MK-7339-002 / LYNK-002)](https://onco.cc/trials/nct03742895/), [EMBRACA](https://onco.cc/trials/embraca/), [FPI-2265 (225Ac-PSMA-I&T) and Olaparib for Patients With Metastatic Castration-Resistant Prostate Cancer (mCRPC)](https://onco.cc/trials/nct06909825/), [I-SPY 2](https://onco.cc/trials/i-spy-2/), [Lung-MAP (SWOG S1400 and S1900)](https://onco.cc/trials/lung-map/), [MAGNITUDE](https://onco.cc/trials/magnitude/), [Maintenance Durvalumab (MEDI4736) and Olaparib (AZD2281) After Standard 1st Line Treatment (Carboplatin/Cisplatin, Etoposide, Durvalumab) in HRD Positive Extens](https://onco.cc/trials/nct06419179/), [Maintenance Niraparib Plus Ipilimumab in Patients With Metastatic Pancreatic Adenocarcinoma Whose Disease Has Not Progressed on Platinum-Based Chemotherapy](https://onco.cc/trials/nct06747845/), [Niraparib Added to Anti-PD-L1 Antibody Maintenance in SLFN11-positive, Extensive-disease SCLC](https://onco.cc/trials/nct05718323/), [Novel Neoadjuvant and Adjuvant Strategy for Germline BRCA 1/2 Mutated Triple Negative Breast Cancer](https://onco.cc/trials/nct05485766/), [Olaparib in the Treatment of BRCA1/2 Unmutated and BRCA1 Promoter Methylated Recurrent and Metastatic Triple-negative Breast Cancer](https://onco.cc/trials/nct05522491/), [Olaparib in Treating Patients With Metastatic Biliary Tract Cancer With Aberrant DNA Repair Gene Mutations](https://onco.cc/trials/nct04042831/), [Olaparib Treatment in BRCA Mutated Ovarian Cancer Patients After Complete or Partial Response to Platinum Chemotherapy](https://onco.cc/trials/nct01874353/), [Olaparib With or Without Durvalumab for DDR Gene Mutated Biliary Tract Cancer Following Platinum-based Chemotherapy](https://onco.cc/trials/nct05222971/), [OlympiA](https://onco.cc/trials/olympia/), [OlympiAD](https://onco.cc/trials/olympiad/), [PAOLA-1 / ENGOT-ov25](https://onco.cc/trials/paola-1/), [PARTNER](https://onco.cc/trials/partner/), [Pembrolizumab Adjuvant in Patients With Early-stage Triple Negative Breast Cancer With Residual Disease After Neoadjuvant Pembrolizumab Plus Chemotherapy](https://onco.cc/trials/nct07486687/), [Pembrolizumab and Olaparib Treatment of Extensive Small Cell Lung Cancer (ES-SCLC)](https://onco.cc/trials/nct05623319/), [Pembrolizumab With Olaparib as Combined Therapy in Metastatic Pancreatic Cancer](https://onco.cc/trials/nct05093231/), [PET Dynamics to Response-Adapted Neoadjuvant Therapy in TNBC](https://onco.cc/trials/nct06245889/), [PHOENIX DDR/Anti-PD-L1](https://onco.cc/trials/phoenix/), [Placebo-controlled, Study of Concurrent Chemoradiation Therapy With Pembrolizumab Followed by Pembrolizumab and Olaparib in Newly Diagnosed Treatment-](https://onco.cc/trials/nct04624204/), [plasmaMATCH](https://onco.cc/trials/plasmamatch/), [POLO](https://onco.cc/trials/polo/), [PRIMA / ENGOT-OV26](https://onco.cc/trials/prima/), [PROfound](https://onco.cc/trials/profound/), [PROpel](https://onco.cc/trials/propel/), [QLS5132 Combination Therapy in Advanced Solid Tumors](https://onco.cc/trials/nct07453394/), [Roll Over StudY for Patients Who Have Completed a Previous Oncology Study With Olaparib](https://onco.cc/trials/nct04421963/), [SAFIR-ABC10](https://onco.cc/trials/safir-abc10/), [Selinexor & Talazoparib in Advanced Refractory Solid Tumors; Advanced/Metastatic Triple Negative Breast Cancer (START)](https://onco.cc/trials/nct05035745/), [SOLO-1](https://onco.cc/trials/solo-1/), [Study of ART6043 in Advanced/Metastatic Solid Tumors Patients (POLKA)](https://onco.cc/trials/nct05898399/), [Study of Durvalumab+Olaparib or Durvalumab After Treatment With Durvalumab and Chemotherapy in Patients With Lung Cancer (ORION)](https://onco.cc/trials/nct03775486/), [Study of Neoadjuvant Olaparib Monotherapy and Olaparib and Durvalumab Combination in HER2 Negative BRCAm Breast Cancer](https://onco.cc/trials/nct05498155/), [Study of Pembrolizumab With Concurrent Chemoradiation Therapy Followed by Pembrolizumab With or Without Olaparib in Stage III Non-Small Cell Lung Cancer (NSCLC) (MK-7339-012/KEYLYNK-012)](https://onco.cc/trials/nct04380636/), [Study of Talazoparib With Enzalutamide in Men With DDR Gene Mutated mCSPC](https://onco.cc/trials/nct04821622/), [Study on Olaparib Plus Abiraterone as First-line Therapy in Men With Metastatic Castration-resistant Prostate Cancer (China Cohort)](https://onco.cc/trials/nct05171816/), [Study to Compare the Efficacy and Safety of Olaparib When Given in Combination With Carboplatin and Paclitaxel, Compared With Carboplatin and Paclitax](https://onco.cc/trials/nct01081951/), [TALAPRO-2](https://onco.cc/trials/talapro-2/), [TAPUR (Targeted Agent and Profiling Utilization Registry)](https://onco.cc/trials/tapur/), [Temozolomide Monotherapy or in Combination With Olaparib in Patients With Triple Negative Breast Cancer (TNBC)](https://onco.cc/trials/nct05128734/), [To Assess Safety and Efficacy of Agents Targeting DNA Damage Repair With Olaparib Versus Olaparib Monotherapy.](https://onco.cc/trials/nct03330847/), [TRITON3](https://onco.cc/trials/triton3/), [WoO: Window of Opportunity Trial of Olaparib and Durvalumab in Histologically Proven EOC](https://onco.cc/trials/nct04644289/)
- ideas: [A functional test for homologous recombination deficiency validated across laboratories](https://onco.cc/ideas/idea-tr2-hrd-functional-standard/), [ctDNA-guided duration of PARP maintenance](https://onco.cc/ideas/idea-ctdna-guided-parp-duration/), [Start low and step up: individualised titration of oral cancer drugs, randomised](https://onco.cc/ideas/idea-tr1-start-low-titrate-up-oral-agents/), [Which patients' blood clones will become leukaemia after treatment?](https://onco.cc/ideas/idea-chip-risk-modifiers/)
- key papers: [Long-term efficacy and safety of addition of carboplatin with or without veliparib to standard neoadjuvant chemotherapy in triple-negative breast cancer: 4-year follow-up data from BrighTNess, a randomized phase III trial](https://onco.cc/key-papers/paper-geyer-brightness-4-year-follow-up-ann-oncol-2022/), [Management of Hereditary Breast Cancer: American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology Guideline](https://onco.cc/key-papers/paper-asco-hereditary-breast-cancer-guideline-jco-2020/), [OlympiA: a year of olaparib after surgery for BRCA-mutated, high-risk early breast cancer](https://onco.cc/key-papers/paper-olympia-nejm-2021/), [Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high-risk, early breast cancer](https://onco.cc/key-papers/paper-olympia-overall-survival-ann-oncol-2022/), [PAOLA-1: olaparib added to bevacizumab maintenance in newly diagnosed ovarian cancer, with benefit confined to HRD-positive tumours](https://onco.cc/key-papers/paper-paola-1-nejm-2019/), [SOLO-1: two years of olaparib maintenance after first-line chemotherapy for BRCA-mutated ovarian cancer](https://onco.cc/key-papers/paper-solo-1-nejm-2018/), [Sustained benefit of adjuvant olaparib in women with germline BRCA1- and BRCA2-associated high-risk HER2-negative early breast cancer: updated results from the OlympiA phase III trial](https://onco.cc/key-papers/paper-olympia-6-year-update-ann-oncol-2026/), [TRITON2: rucaparib in men with metastatic castration-resistant prostate cancer harbouring a BRCA1 or BRCA2 alteration](https://onco.cc/key-papers/paper-abida-triton2-rucaparib-brca-jco-2020/)
- roadmaps: [Pancreatic cancer roadmap: from Whipple's operation to gemcitabine, FOLFIRINOX, adjuvant chemotherapy, PARP inhibition, KRAS inhibition, vaccines and the surveillance question](https://onco.cc/roadmaps/pancreatic-roadmap/), [Targeted therapy roadmap: imatinib → designed for resistance → the undruggable drivers fall](https://onco.cc/roadmaps/targeted-therapy-roadmap/), [Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem](https://onco.cc/roadmaps/tnbc-roadmap/)
- people: [Alan Ashworth](https://onco.cc/people/alan-ashworth/), [Alan D. D'Andrea](https://onco.cc/people/alan-dandrea/), [Andrew Tutt](https://onco.cc/people/andrew-tutt/), [Christopher Lord](https://onco.cc/people/chris-lord/), [Isabelle Ray-Coquard](https://onco.cc/people/isabelle-ray-coquard/), [Jean Abraham](https://onco.cc/people/jean-abraham/), [Jennifer K. Litton](https://onco.cc/people/jennifer-litton/), [Johann de Bono](https://onco.cc/people/johann-de-bono/), [Jonathan A. Ledermann](https://onco.cc/people/jonathan-ledermann/), [Kathleen N. Moore](https://onco.cc/people/kathleen-moore/), [Kim N. Chi](https://onco.cc/people/kim-chi/), [Maha Hussain](https://onco.cc/people/maha-hussain/), [Mansoor Raza Mirza](https://onco.cc/people/mansoor-raza-mirza/), [Mary-Claire King](https://onco.cc/people/mary-claire-king/), [Robert L. Coleman](https://onco.cc/people/robert-coleman/), [Talia Golan](https://onco.cc/people/talia-golan/), [Thomas Helleday](https://onco.cc/people/thomas-helleday/)
- biomarkers: [Homologous recombination repair gene mutation in prostate cancer](https://onco.cc/biomarkers/hrr-gene-mutation/)
- technologies: [ATR and CHK1 inhibitors](https://onco.cc/technologies/atr-chk1-inhibitors/), [HRD genomic scar scores (GIS, LOH, HRDetect)](https://onco.cc/technologies/hrd-genomic-scar-scores/), [RAD51 foci assay (functional HRD test)](https://onco.cc/technologies/rad51-foci-assay/), [Radioligand plus DNA-repair inhibitor combinations](https://onco.cc/technologies/radionuclide-parp-combination/), [STRIDE DNA break detection (intoDNA)](https://onco.cc/technologies/stride-dna-break-detection/)
- institutions: [Breast Cancer Research Foundation](https://onco.cc/institutions/bcrf/), [European Society of Gynaecological Oncology](https://onco.cc/institutions/esgo/), [Guy's and St Thomas' NHS Foundation Trust / King's Health Partners Cancer Centre](https://onco.cc/institutions/guys-st-thomas/), [Huntsman Cancer Institute, University of Utah](https://onco.cc/institutions/huntsman/), [Newcastle Cancer Centre / Northern Centre for Cancer Care](https://onco.cc/institutions/newcastle-cancer-centre/), [Sheba Medical Center](https://onco.cc/institutions/sheba/), [Society of Gynecologic Oncology](https://onco.cc/institutions/sgo/), [Stephenson Cancer Center, OU Health](https://onco.cc/institutions/stephenson-oklahoma/), [The Royal Marsden](https://onco.cc/institutions/royal-marsden/)
- pathways: [Base excision repair, PARP & alkylation damage](https://onco.cc/pathways/base-excision-repair-parp/), [cGAS-STING innate sensing](https://onco.cc/pathways/cgas-sting/), [Clonal haematopoiesis (CHIP)](https://onco.cc/pathways/clonal-haematopoiesis/), [DNA damage response & homologous recombination](https://onco.cc/pathways/ddr/), [DNA replication stress](https://onco.cc/pathways/replication-stress/), [Double-strand break repair: HR versus end joining](https://onco.cc/pathways/homologous-recombination-repair/), [Synthetic lethality: paired dependencies](https://onco.cc/pathways/synthetic-lethality-map/)
- pairings: [Germline BRCA test → adjuvant PARP inhibitor](https://onco.cc/pairings/germline-to-parp/), [PARP inhibitor + AR pathway inhibitor (prostate)](https://onco.cc/pairings/parp-plus-arpi/)
- collections: [Ovarian Cancer Research Alliance (OCRA)](https://onco.cc/collections/ovarian-cancer-research-alliance/)
- companies: [ARCAGY-GINECO](https://onco.cc/companies/arcagy-gineco/), [Breast Cancer Trials](https://onco.cc/companies/breast-cancer-trials/), [IMPACT Therapeutics](https://onco.cc/companies/impact-therapeutics/)

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JSON: https://onco.cc/api/v1/entities/parp-inhibitor.json