PARP Inhibitor Maintenance in Ovarian Cancer: What the Trials Found

Table of Contents

1. How PARP Inhibitors Work
2. The Words the Trials Use
3. First-Line Maintenance: SOLO-1 and Olaparib
4. First-Line Maintenance: PRIMA and Niraparib
5. First-Line Maintenance: PAOLA-1, Olaparib With Bevacizumab
6. First-Line Maintenance: ATHENA-MONO and Rucaparib
7. Maintenance After a Relapse: NOVA, SOLO-2 and ARIEL3
8. The Overall-Survival Signals Behind the 2022–2023 Changes
9. What the Current FDA Labels State
10. Side Effects and Their Measured Rates
11. Myelodysplastic Syndrome and Acute Myeloid Leukaemia
12. Mirvetuximab Soravtansine and Later Lines of Treatment
13. What Is Not Known
14. Key Research Papers
15. Connections
16. Featured Videos

How PARP Inhibitors Work

Every cell suffers small breaks in its DNA every day. PARP1 is an enzyme that sits on single-strand breaks and calls repair proteins to the spot. A second, more exact repair system called homologous recombination fixes the more dangerous double-strand breaks. The BRCA1 and BRCA2 genes are needed for homologous recombination to work.

Two laboratory studies published side by side in 2005 showed what happens when both systems fail at once. Bryant and colleagues reported that when PARP is blocked, unrepaired single-strand breaks collapse the forks where DNA is being copied, and the cell then needs homologous recombination to recover. Cells lacking BRCA2 cannot do that, and they proved acutely sensitive to PARP inhibitors. Farmer and colleagues found in cells that loss of BRCA1 or BRCA2 function made them profoundly sensitive to PARP inhibition, leading to chromosome damage, a halt in cell division and cell death. Researchers call this pairing — two defects that a cell survives one at a time but not together — synthetic lethality.

The logic explains the pattern in the trials below. In a woman with an inherited BRCA mutation, her normal cells still keep one working copy of the gene, while the tumour has usually lost both. Bryant and colleagues wrote that treatment with PARP inhibitors was likely to be highly tumour specific for this reason. Tumours without a BRCA mutation can still have a weak homologous-recombination system for other reasons; such tumours are labelled homologous recombination deficient (HRD-positive). Tumours with a working system are called homologous recombination proficient, or HRD-negative. The broader biology of DNA repair is shown step by step in the DNA repair animation.

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The Words the Trials Use

• Maintenance means treatment given after chemotherapy has worked (a complete or partial response), while there is little or no visible cancer, to delay its return. Every maintenance trial on this page compared a PARP inhibitor with a placebo tablet.
• First-line means right after the first round of treatment for a new diagnosis. Recurrent or relapsed means the cancer came back after earlier treatment.
• Platinum-sensitive describes a cancer that came back long enough after platinum chemotherapy (carboplatin or cisplatin) to be treated with platinum again. The trials grouped this by the platinum-free interval: under 6 months counted as platinum-resistant, 6 to 12 months as partially sensitive and 12 months or more as fully sensitive.
• Progression-free survival is the time until scans show the cancer growing, or death. It is the main result in almost every trial here.
• Overall survival is the time until death from any cause. It is the harder measure to move and the one the FDA reviews leaned on.
• Hazard ratio compares the rate of an event between two groups. A hazard ratio of 0.30 for progression means progression happened at about 30% of the placebo rate; 1.00 means no difference; above 1.00 means the event was more frequent in the drug group. The 95% confidence interval shows the range the true value plausibly falls in — an interval that crosses 1.00 means the trial could not rule out no difference.
• Germline BRCA mutations are inherited and present in every cell; somatic mutations arose only in the tumour.

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First-Line Maintenance: SOLO-1 and Olaparib

SOLO-1 enrolled 391 women with newly diagnosed stage III or IV high-grade serous or endometrioid ovarian, fallopian-tube or primary peritoneal cancer and a BRCA1 or BRCA2 mutation, all with a response to platinum chemotherapy. Of these, 388 had a confirmed germline mutation and 2 a somatic one. The trial gave olaparib tablets 300 mg twice daily (260 women) or placebo (131 women) for up to 2 years.

• Progression-free survival, first report (2018): after a median follow-up of 41 months, the risk of progression or death was 70% lower with olaparib (hazard ratio 0.30, 95% CI 0.23–0.41). At 3 years, 60% of the olaparib group and 27% of the placebo group were free of progression.
• Progression-free survival at 5 years (2021): in a post-hoc update, median progression-free survival was 56.0 months with olaparib and 13.8 months with placebo (hazard ratio 0.33, 95% CI 0.25–0.43). The median time on olaparib was 24.6 months, so the gap continued well after the tablets were stopped.
• Overall survival at 7 years (2023): the hazard ratio for death was 0.55 (95% CI 0.40–0.76; P = 0.0004). The trial had set a stricter threshold of P < 0.0001 for this analysis, so the authors described the gain as clinically meaningful but not statistically significant by the prespecified criteria. At 7 years, 67.0% of the olaparib group and 46.5% of the placebo group were alive, and 45.3% versus 20.6% were alive without having needed another cancer treatment.

The authors of the 7-year report wrote that the potential for cure may be enhanced. That is their interpretation; the trial did not measure cure. They also reported that myelodysplastic syndrome and acute myeloid leukaemia stayed uncommon and that new cancers were balanced between the two groups.

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First-Line Maintenance: PRIMA and Niraparib

PRIMA asked whether a PARP inhibitor helps after first-line chemotherapy regardless of BRCA status. It assigned 733 women with newly diagnosed advanced ovarian cancer and a response to platinum chemotherapy to niraparib once daily or placebo, in a 2:1 ratio. The trial population was described as being at high risk of recurrence. Of the 733, 373 (50.9%) had HRD-positive tumours.

• Progression-free survival, HRD-positive group: median 21.9 months with niraparib versus 10.4 months with placebo (hazard ratio 0.43, 95% CI 0.31–0.59).
• Progression-free survival, whole trial: 13.8 versus 8.2 months (hazard ratio 0.62, 95% CI 0.50–0.76).
• Progression-free at 5 years: 22% versus 12% in the whole trial and 35% versus 16% in the HRD-positive group.
• Overall survival, early look (2019): at 24 months, 84% of the niraparib group and 77% of the placebo group were alive (hazard ratio 0.70, 95% CI 0.44–1.11).
• Overall survival, final (2024): after a median follow-up of 73.9 months there was no difference. The hazard ratio was 1.01 (95% CI 0.84–1.23) in the whole trial, 0.95 (0.70–1.29) in the HRD-positive group and 0.93 (0.69–1.26) in the HRD-negative group. The current niraparib label gives the HRD-positive medians as 71.9 months with niraparib and 69.8 months with placebo.

One complication runs through the survival numbers: many women in the placebo group received a PARP inhibitor later, once their cancer came back — 37.8% of the placebo group overall and 48.4% in the HRD-positive group, against 11.7% and 15.8% of the niraparib group. A trial in which the comparison group later gets the same kind of drug measures the effect of taking it early rather than taking it at all.

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First-Line Maintenance: PAOLA-1, Olaparib With Bevacizumab

Bevacizumab is an antibody that blocks a signal tumours use to grow new blood vessels. PAOLA-1 enrolled 806 women with newly diagnosed advanced high-grade ovarian cancer who were responding to first-line platinum–taxane chemotherapy given with bevacizumab. All continued bevacizumab (15 mg per kilogram every 3 weeks, up to 15 months in total); in addition, 537 received olaparib 300 mg twice daily for up to 24 months and 269 received placebo. BRCA status and the result of surgery did not affect eligibility.

• Progression-free survival, whole trial: median 22.1 months with olaparib plus bevacizumab versus 16.6 months with placebo plus bevacizumab (hazard ratio 0.59, 95% CI 0.49–0.72).
• HRD-positive, including BRCA mutations: 37.2 versus 17.7 months (hazard ratio 0.33, 95% CI 0.25–0.45).
• HRD-positive without a BRCA mutation: 28.1 versus 16.6 months (hazard ratio 0.43, 95% CI 0.28–0.66).
• HRD-negative: the olaparib label reports a progression-free survival hazard ratio of 1.00 (95% CI 0.75–1.34) and an overall-survival hazard ratio of 1.18 (95% CI 0.87–1.60) for the 277 women (34%) in this group, and states that the clinical benefit was mainly due to the HRD-positive group.
• Overall survival, final (2023): after about 62 months of follow-up, median overall survival in the whole trial was 56.5 versus 51.6 months (hazard ratio 0.92, 95% CI 0.76–1.12; P = 0.41), not a significant difference. In the HRD-positive group, in an analysis the authors call prespecified and exploratory, the hazard ratio was 0.62 (95% CI 0.45–0.85): 65.5% of the olaparib group and 48.4% of the placebo group were alive at 5 years, and 46.1% versus 19.2% were still free of relapse.

As in PRIMA, many women in the placebo group took a PARP inhibitor later: 45.7%, against 19.6% in the olaparib group.

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First-Line Maintenance: ATHENA-MONO and Rucaparib

ATHENA-MONO tested rucaparib after first-line surgery and platinum chemotherapy in a broad group, including women without BRCA mutations or other signs of HRD. It assigned 427 women to rucaparib 600 mg twice daily and 111 to placebo, a 4:1 ratio. Its HRD group was defined as a BRCA mutation, or no BRCA mutation but a high level of a genetic scar called loss of heterozygosity.

• HRD-positive: median progression-free survival 28.7 months versus 11.3 months (hazard ratio 0.47, 95% CI 0.31–0.72).
• Whole trial: 20.2 versus 9.2 months (hazard ratio 0.52, 95% CI 0.40–0.68).
• HRD-negative: 12.1 versus 9.1 months (hazard ratio 0.65, 95% CI 0.45–0.95).
• Serious side effects: grade 3 or higher anaemia in 28.7% of the rucaparib group versus 0% on placebo, and neutropenia (low white-cell count) in 14.6% versus 0.9%.

The 2022 report gave no overall-survival result. The rucaparib label read for this page lists only an ovarian-cancer use after a relapse; it does not include first-line maintenance.

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Maintenance After a Relapse: NOVA, SOLO-2 and ARIEL3

These three trials came first. All enrolled women whose cancer had come back, was platinum-sensitive and had responded again to platinum chemotherapy.

NOVA (niraparib)

553 women were split into a germline BRCA cohort (203) and a non-germline-BRCA cohort (350) and assigned niraparib 300 mg once daily or placebo, 2:1.

• Progression-free survival: 21.0 versus 5.5 months in the germline BRCA cohort (hazard ratio 0.27); 12.9 versus 3.8 months in HRD-positive tumours without a germline BRCA mutation (hazard ratio 0.38); 9.3 versus 3.9 months in the whole non-germline-BRCA cohort (hazard ratio 0.45).
• Overall survival, final: 40.9 versus 38.1 months in the germline BRCA cohort (hazard ratio 0.85, 95% CI 0.61–1.20) and 31.0 versus 34.8 months in the non-germline-BRCA cohort (hazard ratio 1.06, 95% CI 0.81–1.37). The authors reported that overall survival did not differ significantly between the groups.

SOLO-2 (olaparib)

295 women with a BRCA mutation who had already had at least two courses of platinum chemotherapy received olaparib 300 mg twice daily (196) or placebo (99).

• Progression-free survival: 19.1 versus 5.5 months (hazard ratio 0.30, 95% CI 0.22–0.41).
• Overall survival, final: 51.7 versus 38.8 months (hazard ratio 0.74, 95% CI 0.54–1.00; P = 0.054), a 12.9-month difference in medians that did not reach statistical significance. The figure was not adjusted for the 38% of placebo patients who later received a PARP inhibitor.

ARIEL3 (rucaparib)

564 women received rucaparib 600 mg twice daily (375) or placebo (189). Results were tested step by step in three nested groups.

• Progression-free survival: 16.6 versus 5.4 months with a BRCA mutation (hazard ratio 0.23); 13.6 versus 5.4 months in HRD-positive tumours (hazard ratio 0.32); 10.8 versus 5.4 months in the whole trial (hazard ratio 0.36).
• Overall survival, final (median follow-up 77.0 months): 45.9 versus 47.8 months in the BRCA group (hazard ratio 0.83, 95% CI 0.58–1.19). The authors reported no overall-survival benefit with rucaparib in the HRD-positive group or the whole trial, and wrote that overall survival was similar between the arms. Of 168 placebo patients who received a later treatment, 77 (46%) received one containing a PARP inhibitor.
• Time to a second progression: in the BRCA group, 26.1 versus 18.4 months (hazard ratio 0.67), suggesting the head start was not simply lost on the next treatment.

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The Overall-Survival Signals Behind the 2022–2023 Changes

PARP inhibitors were also approved, for a time, as a treatment for recurrent ovarian cancer in place of chemotherapy, not only as maintenance after it. Two randomised trials compared that use head to head with chemotherapy in women with BRCA mutations.

• ARIEL4 randomised 349 women with BRCA-mutated ovarian cancer who had had at least two earlier chemotherapy regimens to rucaparib (233) or chemotherapy (116). Rucaparib lengthened progression-free survival, the main goal. In the final analysis, median overall survival was 19.4 months with rucaparib versus 25.4 months with chemotherapy (hazard ratio 1.3, 95% CI 1.0–1.7; P = 0.047). Of the chemotherapy group, 69% later crossed over to rucaparib.
• SOLO3 randomised 266 women with BRCA-mutated, platinum-sensitive relapsed cancer to olaparib (178) or non-platinum chemotherapy (88). Overall survival was similar overall (hazard ratio 1.07, 95% CI 0.76–1.49; medians 34.9 and 32.9 months). In a post-hoc split, it favoured olaparib after two earlier chemotherapy lines (hazard ratio 0.83; 37.9 versus 28.8 months) but pointed the other way after three or more (hazard ratio 1.33, 95% CI 0.84–2.18; 29.9 versus 39.4 months). The authors suggested BRCA reversion mutations — changes that restore the gene's function in the tumour — might have contributed: none of the 6 olaparib patients (3.5%) with a reversion mutation detected at the start had a tumour response.

Together with the maintenance results above, these findings led to regulatory action. An FDA review published in 2025 states that from 2014 through 2019 the agency approved six PARP inhibitor uses in advanced epithelial ovarian cancer, and that from 2022 through 2023 all six were withdrawn or narrowed after a potential harmful effect on overall survival was seen in four randomised trials. According to that review:

• The uses of niraparib, olaparib and rucaparib as treatment for BRCA-mutated or HRD-positive advanced ovarian cancer were withdrawn.
• The uses of all three as maintenance after a relapse were narrowed to patients with BRCA mutations only.

A 2024 review gives the dates: between June and September 2022 all three treatment uses for recurrent ovarian cancer were withdrawn, and between November 2022 and September 2023 all three maintenance uses in recurrent disease were restricted. At the time that review was written, the three first-line maintenance uses were unchanged. The niraparib label in force in 2026 lists first-line maintenance only for HRD-positive cancers, although PRIMA had reported a progression-free benefit regardless of HRD status.

The FDA review describes the agency's reasoning about overall-survival results that are not statistically significant and about subgroup findings. The general point it illustrates is that a drug can delay progression on scans and still fail to lengthen life, or, in some groups, may shorten it.

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What the Current FDA Labels State

The labels read through the FDA's openFDA service for this page (olaparib, effective July 2025; niraparib, July 2026; rucaparib, December 2025) list these ovarian-cancer uses, all for adults:

• Olaparib: first-line maintenance for a germline or somatic BRCA mutation; first-line maintenance together with bevacizumab for HRD-positive cancer (a BRCA mutation and/or genomic instability); maintenance after a relapse for a germline or somatic BRCA mutation. Each requires a response to platinum chemotherapy and selection with an FDA-approved companion test.
• Niraparib: first-line maintenance for HRD-positive cancer; maintenance after a relapse for a germline BRCA mutation only.
• Rucaparib: maintenance after a relapse for a germline and/or somatic BRCA mutation.

None of the three labels lists a use as a stand-alone treatment for ovarian cancer that has come back. The labels' warnings sections list these safety facts:

• All three: myelodysplastic syndrome and acute myeloid leukaemia, some cases fatal (details in the next sections), and harm to an unborn baby, with effective contraception advised in the label.
• Olaparib: monthly blood counts; pneumonitis (lung inflammation) in 1.0% of patients, some cases fatal; blood clots in the veins and lungs, including fatal pulmonary embolism; drug-induced liver injury.
• Niraparib: blood counts weekly for the first month, monthly for the next 11 months and periodically after that; high blood pressure and heart effects, with blood pressure and heart rate checked at least weekly for the first 2 months and monthly for the first year; posterior reversible encephalopathy syndrome, a rare brain-swelling condition.
• Rucaparib: blood counts at the start and monthly; treatment not started until blood counts have recovered from earlier chemotherapy.

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Side Effects and Their Measured Rates

The most frequent serious side effects of all three drugs fall on the blood. The trial reports give these rates of grade 3 or higher events (severe enough to need treatment or a change of dose), with the placebo rate where reported:

• Olaparib, SOLO-1 (5-year report): anaemia 22% versus 2%; neutropenia 8% versus 5%; serious adverse events of any kind 21% versus 13%.
• Olaparib, SOLO-2 (final): anaemia 21% versus 2%; serious adverse events 26% versus 8%. Eight women on olaparib (4%) had adverse events ending in death, six of them judged treatment-related: three myelodysplastic syndrome and three acute myeloid leukaemia.
• Niraparib, PRIMA: anaemia 31.0%, low platelets (thrombocytopenia) 28.7%, neutropenia 12.8%. No treatment-related deaths.
• Niraparib, NOVA: thrombocytopenia 33.8%, anaemia 25.3%, neutropenia 19.6%.
• Rucaparib, ARIEL3: any grade 3 or higher event 56% versus 15%; anaemia or low haemoglobin 19% versus 1%; raised liver enzymes (ALT or AST) 10% versus none.
• Rucaparib, ATHENA-MONO: anaemia 28.7% versus 0%; neutropenia 14.6% versus 0.9%.

Across five niraparib trials, a 2023 safety review found side effects of some kind in at least 99% of patients and grade 3 or higher events in 51–74%. Treatment was paused in 62–80% and the dose lowered in 47–71%. Gut symptoms were common but usually mild (under 5% grade 3 or higher); fatigue and trouble sleeping were also reported. A starting dose set by body weight and platelet count was followed by fewer severe events, pauses and dose cuts than a fixed starting dose.

For olaparib in SOLO-1, a detailed tolerability analysis found that the common side effects — anaemia, neutropenia, low platelets, nausea, fatigue and vomiting — usually began within the first 3 months. A first episode of anaemia, neutropenia, low platelets, nausea or vomiting lasted a median of under 2 months, and a first episode of fatigue a median of 3.48 months. Of the 162 women still taking olaparib at month 24, 64.2% were on the full starting dose.

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Myelodysplastic Syndrome and Acute Myeloid Leukaemia

Myelodysplastic syndrome is a failure of the bone marrow to make normal blood cells; it can turn into acute myeloid leukaemia, a fast-growing blood cancer. Both are known late effects of chemotherapy, and every woman in these trials had already had platinum chemotherapy. The question is how much PARP inhibitors add.

A 2021 meta-analysis pooled 18 placebo-controlled trials with 7,307 patients. PARP inhibitors raised the odds of myelodysplastic syndrome or acute myeloid leukaemia compared with placebo (Peto odds ratio 2.63, 95% CI 1.13–6.14). The incidence was 0.73% in the PARP inhibitor groups and 0.47% in the placebo groups. In the World Health Organization's drug-safety database, the same team found 178 reported cases; the median time on a PARP inhibitor was 9.8 months, the median time from first dose to diagnosis was 17.8 months, and 45% of the 104 cases with a recorded outcome ended in death.

The labels give trial-by-trial figures, which run higher in the relapse trials, where women had already had more chemotherapy:

• Olaparib: about 1.2% (26 of 2,219) across clinical studies, 54% of them fatal. SOLO-1: 1.9% versus 0.8% on placebo. PAOLA-1, HRD-positive: 1.6% versus 2.3% in the control arm. SOLO-2: 8% versus 4%.
• Niraparib: PRIMA, HRD-positive, with 6.1 years of follow-up: 3.3% versus 2.4%. NOVA, germline BRCA cohort: 7% versus 3%. The final PRIMA report gives 2.3% versus 1.6% for the whole trial.
• Rucaparib: 1.6% (34 of 2,141) across ovarian and prostate cancer studies. ARIEL3, BRCA group: 7% versus 6%. The final ARIEL3 report gives 4% versus 3% for the whole trial.

The labels state that all patients who developed these conditions had earlier platinum chemotherapy and/or other DNA-damaging treatment, and that the drug is stopped if the diagnosis is confirmed.

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Mirvetuximab Soravtansine and Later Lines of Treatment

When ovarian cancer comes back within 6 months of platinum chemotherapy, it is called platinum-resistant, and maintenance is no longer the question. Mirvetuximab soravtansine is an antibody–drug conjugate: an antibody that seeks out folate receptor alpha, a protein on the surface of many ovarian cancer cells, carrying a chemotherapy payload attached to it.

The MIRASOL trial enrolled 453 women with platinum-resistant high-grade serous ovarian cancer who had had one to three earlier lines of treatment and whose tumours showed high levels of folate receptor alpha (at least 75% of cells staining at 2+ or more). They received mirvetuximab soravtansine or the doctor's choice of single-agent chemotherapy.

• Median progression-free survival: 5.62 versus 3.98 months.
• Tumour shrinkage (objective response): 42.3% versus 15.9%.
• Median overall survival: 16.46 versus 12.75 months (hazard ratio for death 0.67, 95% CI 0.50–0.89).
• Grade 3 or higher adverse events: 41.7% versus 54.1%; events leading to stopping treatment: 9.2% versus 15.9%.

MIRASOL is context, not a PARP inhibitor trial. It applies to a different, later stage of the disease and to tumours selected by a different test. Its report does not address how earlier PARP inhibitor use affects the result.

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What Is Not Known

• Whether first-line PARP inhibitors lengthen life for most women. The clearest overall-survival gain is in BRCA-mutated cancer in SOLO-1, and even that missed its prespecified significance threshold. PRIMA found no difference in overall survival in any group. PAOLA-1 showed a gain only in the HRD-positive group, in an exploratory analysis.
• How much later PARP inhibitor use in the placebo groups blurred the results. In PRIMA, PAOLA-1, SOLO-2 and ARIEL3, between roughly a third and nearly half of placebo patients received one later. The trials compared early versus later use more than use versus none.
• The value for HRD-negative tumours. ATHENA-MONO reported a modest progression-free gain in this group (hazard ratio 0.65) without overall-survival data in its report; in PAOLA-1 the HRD-negative hazard ratios were 1.00 for progression and 1.18 for survival, according to the olaparib label.
• Who is cured. The SOLO-1 and PAOLA-1 authors raised the possibility that first-line maintenance may enhance cure. Neither trial was designed to show cure, and longer follow-up is the only way to answer it.
• The best sequence after a PARP inhibitor stops working. The ARIEL4 authors called for a better understanding of the most appropriate treatment after progression on a PARP inhibitor and of the order of chemotherapy and PARP inhibitors. The SOLO3 findings point to BRCA reversion mutations as one possible factor.
• The long-term blood-cancer risk in the first-line setting. The 2021 meta-analysis described myelodysplastic syndrome and acute myeloid leukaemia as delayed and often lethal and called for more study, particularly in front-line maintenance, where women may live many years after treatment.

The trial numbers above describe groups of women, not what will happen to any one person.

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Key Research Papers

1. Bryant HE, Schultz N, Thomas HD, Parker KM, Flower D, Lopez E, et al. Specific killing of BRCA2-deficient tumours with inhibitors of poly(ADP-ribose) polymerase. Nature. 2005;434(7035):913-7. PubMed PMID: 15829966
2. Farmer H, McCabe N, Lord CJ, Tutt AN, Johnson DA, Richardson TB, et al. Targeting the DNA repair defect in BRCA mutant cells as a therapeutic strategy. Nature. 2005;434(7035):917-21. PubMed PMID: 15829967
3. Moore K, Colombo N, Scambia G, Kim BG, Oaknin A, Friedlander M, et al. Maintenance Olaparib in Patients with Newly Diagnosed Advanced Ovarian Cancer. N Engl J Med. 2018;379(26):2495-2505. PubMed PMID: 30345884
4. Banerjee S, Moore KN, Colombo N, Scambia G, Kim BG, Oaknin A, et al. Maintenance olaparib for patients with newly diagnosed advanced ovarian cancer and a BRCA mutation (SOLO1/GOG 3004): 5-year follow-up of a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol. 2021;22(12):1721-1731. PubMed PMID: 34715071
5. DiSilvestro P, Banerjee S, Colombo N, Scambia G, Kim BG, Oaknin A, et al. Overall Survival With Maintenance Olaparib at a 7-Year Follow-Up in Patients With Newly Diagnosed Advanced Ovarian Cancer and a BRCA Mutation: The SOLO1/GOG 3004 Trial. J Clin Oncol. 2023;41(3):609-617. PubMed PMID: 36082969
6. Colombo N, Moore K, Scambia G, Oaknin A, Friedlander M, Lisyanskaya A, et al. Tolerability of maintenance olaparib in newly diagnosed patients with advanced ovarian cancer and a BRCA mutation in the randomized phase III SOLO1 trial. Gynecol Oncol. 2021;163(1):41-49. PubMed PMID: 34353615
7. González-Martín A, Pothuri B, Vergote I, DePont Christensen R, Graybill W, Mirza MR, et al. Niraparib in Patients with Newly Diagnosed Advanced Ovarian Cancer. N Engl J Med. 2019;381(25):2391-2402. PubMed PMID: 31562799
8. Monk BJ, Barretina-Ginesta MP, Pothuri B, Vergote I, Graybill W, Mirza MR, et al. Niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer: final overall survival results from the PRIMA/ENGOT-OV26/GOG-3012 trial. Ann Oncol. 2024;35(11):981-992. PubMed PMID: 39284381
9. Ray-Coquard I, Pautier P, Pignata S, Pérol D, González-Martín A, Berger R, et al. Olaparib plus Bevacizumab as First-Line Maintenance in Ovarian Cancer. N Engl J Med. 2019;381(25):2416-2428. PubMed PMID: 31851799
10. Ray-Coquard I, Leary A, Pignata S, Cropet C, González-Martín A, Marth C, et al. Olaparib plus bevacizumab first-line maintenance in ovarian cancer: final overall survival results from the PAOLA-1/ENGOT-ov25 trial. Ann Oncol. 2023;34(8):681-692. PubMed PMID: 37211045
11. Monk BJ, Parkinson C, Lim MC, O'Malley DM, Oaknin A, Wilson MK, et al. A Randomized, Phase III Trial to Evaluate Rucaparib Monotherapy as Maintenance Treatment in Patients With Newly Diagnosed Ovarian Cancer (ATHENA-MONO/GOG-3020/ENGOT-ov45). J Clin Oncol. 2022;40(34):3952-3964. PubMed PMID: 35658487
12. Mirza MR, Monk BJ, Herrstedt J, Oza AM, Mahner S, Redondo A, et al. Niraparib Maintenance Therapy in Platinum-Sensitive, Recurrent Ovarian Cancer. N Engl J Med. 2016;375(22):2154-2164. PubMed PMID: 27717299
13. Matulonis UA, Herrstedt J, Oza A, Mahner S, Redondo A, Berton D, et al. ENGOT-OV16/NOVA trial of niraparib in recurrent ovarian cancer: Survival and long-term safety. Gynecol Oncol. 2025;195:192-199. PubMed PMID: 40139026
14. Pujade-Lauraine E, Ledermann JA, Selle F, Gebski V, Penson RT, Oza AM, et al. Olaparib tablets as maintenance therapy in patients with platinum-sensitive, relapsed ovarian cancer and a BRCA1/2 mutation (SOLO2/ENGOT-Ov21): a double-blind, randomised, placebo-controlled, phase 3 trial. Lancet Oncol. 2017;18(9):1274-1284. PubMed PMID: 28754483
15. Poveda A, Floquet A, Ledermann JA, Asher R, Penson RT, Oza AM, et al. Olaparib tablets as maintenance therapy in patients with platinum-sensitive relapsed ovarian cancer and a BRCA1/2 mutation (SOLO2/ENGOT-Ov21): a final analysis of a double-blind, randomised, placebo-controlled, phase 3 trial. Lancet Oncol. 2021;22(5):620-631. PubMed PMID: 33743851
16. Coleman RL, Oza AM, Lorusso D, Aghajanian C, Oaknin A, Dean A, et al. Rucaparib maintenance treatment for recurrent ovarian carcinoma after response to platinum therapy (ARIEL3): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2017;390(10106):1949-1961. PubMed PMID: 28916367
17. Ledermann JA, Oza AM, Lorusso D, Aghajanian C, Oaknin A, Dean A, et al. Rucaparib for maintenance treatment of platinum-sensitive, recurrent ovarian carcinoma: Final results of the phase 3, randomized, placebo-controlled ARIEL3 trial. Eur J Cancer. 2025;225:115584. PubMed PMID: 40580808
18. Scambia G, Villalobos Valencia R, Colombo N, Cibula D, Leath CA 3rd, Bidziński M, et al. Olaparib as Treatment Versus Nonplatinum Chemotherapy in Patients With Platinum-Sensitive Relapsed Ovarian Cancer: Phase III SOLO3 Study Final Overall Survival Results. J Clin Oncol. 2025;43(12):1408-1416. PubMed PMID: 39668137
19. Oza AM, Lisyanskaya A, Fedenko A, de Melo AC, Shparyk Y, Rakhmatullina I, et al. Rucaparib versus chemotherapy for treatment of relapsed ovarian cancer with deleterious BRCA1 or BRCA2 mutation (ARIEL4): final results of an international, open-label, randomised, phase 3 trial. Lancet Oncol. 2025;26(2):249-264. PubMed PMID: 39914419
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22. Morice PM, Leary A, Dolladille C, Chrétien B, Poulain L, González-Martín A, et al. Myelodysplastic syndrome and acute myeloid leukaemia in patients treated with PARP inhibitors: a safety meta-analysis of randomised controlled trials and a retrospective study of the WHO pharmacovigilance database. Lancet Haematol. 2021;8(2):e122-e134. PubMed PMID: 33347814
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24. Moore KN, Angelergues A, Konecny GE, García Y, Banerjee S, Lorusso D, et al. Mirvetuximab Soravtansine in FRα-Positive, Platinum-Resistant Ovarian Cancer. N Engl J Med. 2023;389(23):2162-2174. PubMed PMID: 38055253

Label facts on this page (current ovarian-cancer uses, warnings and trial-by-trial blood-cancer rates, the PAOLA-1 HRD-negative hazard ratios and the PRIMA HRD-positive survival medians) come from the FDA prescribing information for olaparib, niraparib and rucaparib, read through openFDA and published on DailyMed.

PubMed Topic Searches

1. PubMed: PARP inhibitor maintenance and overall survival in ovarian cancer
2. PubMed: homologous recombination deficiency and PARP inhibitors
3. PubMed: PARP inhibitors, myelodysplastic syndrome and acute myeloid leukaemia
4. PubMed: BRCA reversion mutations and PARP inhibitor resistance

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Connections

• Ovarian Cancer — the main topic page
• Oncology — the cancer section
• CA-125 Test — the blood marker followed during and after treatment
• How DNA Is Repaired — the repair systems PARP inhibitors exploit
• Breast Cancer — the other cancer most tied to BRCA mutations
• Prostate Cancer — where olaparib and rucaparib are also labelled
• Pancreatic Cancer — another BRCA-linked cancer studied with olaparib
• Acute Myeloid Leukemia — the rare late blood cancer listed in the labels

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