Olaparib Maintenance Monotherapy in Patients With BRCA Mutated Ovarian Cancer Following First Line Platinum Based Chemotherapy.

Patterns of genomic instability in > 2000 patients with ovarian cancer across six clinical trials evaluating olaparib

Abstract Background The introduction of poly(ADP-ribose) polymerase (PARP) inhibitors represented a paradigm shift in the treatment of ovarian cancer. Genomic data from patients with high-grade ovarian cancer in six phase II/III trials involving the PARP inhibitor olaparib were analyzed to better understand patterns and potential causes of genomic instability. Patients and methods Homologous recombination deficiency (HRD) was assessed in 2147 tumor samples from SOLO1, PAOLA-1, Study 19, SOLO2, OPINION, and LIGHT using next-generation sequencing technology. Genomic instability scores (GIS) were assessed in BRCA1 and/or BRCA2 (BRCA)-mutated (BRCAm), non-BRCA homologous recombination repair-mutated (non-BRCA HRRm), and non-HRRm tumors. Results BRCAm was identified in 1021/2147 (47.6%) tumors. BRCAm tumors had significantly higher GIS than non-BRCAm tumors (P < 0.001) and high biallelic loss (815/838; 97.3%) regardless of germline (658/672; 97.9%) or somatic (101/108; 93.5%) BRCAm status. In non-BRCA HRRm tumors (n = 121) a similar proportion were HRD-positive (GIS ≥ 42: 55/121; 45.5%) relative to HRD-negative (GIS < 42: 52/121; 43.0%). GIS was highly variable in non-BRCA HRRm (median 42 [interquartile range (IQR) 29–58]) and non-HRRm (n = 1005; median 32 [IQR 20–55]) tumors. Gene mutations with high GIS included HRR genes BRIP1 (median 46 [IQR 41–58]), RAD51C (median 58 [IQR 48–66]), RAD51D (median 62 [IQR 54–69]), and PALB2 (median 64 [IQR 58–74]), and non-HRR genes NF1 (median 49 [IQR 25–60]) and RB1 (median 55 [IQR 30–71]). CCNE1-amplified and PIK3CA-mutated tumors had low GIS (CCNE1-amplified: median 24 [IQR 18–29]; PIK3CA-mutated: median 32 [IQR 14–52]) and were predominantly non-BRCAm. Conclusions These analyses provide valuable insight into patterns of genomic instability and potential drivers of HRD, besides BRCAm, in ovarian cancer and will help guide future research into the potential clinical effectiveness of anti-cancer treatments in ovarian cancer, including PARP inhibitors as well as other precision oncology agents. Trial registration The SOLO1 trial was registered at ClinicalTrials.gov (NCT01844986) on April 30, 2013; the PAOLA-1 trial was registered at ClinicalTrials.gov (NCT02477644) on June 18, 2015 (retrospectively registered); Study 19 was registered at ClinicalTrials.gov (NCT00753545) on September 12, 2008 (retrospectively registered); the SOLO2 trial was registered at ClinicalTrials.gov (NCT01874353) on June 7, 2013; the OPINION trial was registered at ClinicalTrials.gov (NCT03402841) on January 3, 2018; the LIGHT trial was registered at ClinicalTrials.gov (NCT02983799) on November 4, 2016.

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

PURPOSE In SOLO1/GOG 3004 (ClinicalTrials.gov identifier: NCT01844986 ), maintenance therapy with the poly(ADP-ribose) polymerase inhibitor olaparib provided a sustained progression-free survival benefit in patients with newly diagnosed advanced ovarian cancer and a BRCA1 and/or BRCA2 (BRCA) mutation. We report overall survival (OS) after a 7-year follow-up, a clinically relevant time point and the longest follow-up for any poly(ADP-ribose) polymerase inhibitor in the first-line setting. METHODS This double-blind phase III trial randomly assigned patients with newly diagnosed advanced ovarian cancer and a BRCA mutation in clinical response to platinum-based chemotherapy to maintenance olaparib (n = 260) or placebo (n = 131) for up to 2 years. A prespecified descriptive analysis of OS, a secondary end point, was conducted after a 7-year follow-up. RESULTS The median duration of treatment was 24.6 months with olaparib and 13.9 months with placebo, and the median follow-up was 88.9 and 87.4 months, respectively. The hazard ratio for OS was 0.55 (95% CI, 0.40 to 0.76; P = .0004 [ P < .0001 required to declare statistical significance]). At 7 years, 67.0% of olaparib patients versus 46.5% of placebo patients were alive, and 45.3% versus 20.6%, respectively, were alive and had not received a first subsequent treatment (Kaplan-Meier estimates). The incidence of myelodysplastic syndrome and acute myeloid leukemia remained low, and new primary malignancies remained balanced between treatment groups. CONCLUSION Results indicate a clinically meaningful, albeit not statistically significant according to prespecified criteria, improvement in OS with maintenance olaparib in patients with newly diagnosed advanced ovarian cancer and a BRCA mutation and support the use of maintenance olaparib to achieve long-term remission in this setting; the potential for cure may also be enhanced. No new safety signals were observed during long-term follow-up.

Poly(ADP-ribose) polymerase (PARP) inhibitors for the treatment of ovarian cancer

Ovarian cancer is the sixth most common cancer in women world-wide. Epithelial ovarian cancer (EOC) is the most common; three-quarters of women present when disease has spread outside the pelvis (stage III or IV). Treatment consists of a combination of  surgery and platinum-based chemotherapy. Although initial responses to chemotherapy are good, most women with advanced disease will relapse. PARP (poly (ADP-ribose) polymerase) inhibitors (PARPi), are a type of anticancer treatment that works by preventing cancer cells from repairing DNA damage, especially in those with breast cancer susceptibility gene (BRCA) variants. PARPi offer a different mechanism of anticancer treatment from conventional chemotherapy. To determine the benefits and risks of poly (ADP-ribose) polymerase) inhibitors (PARPi) for the treatment of epithelial ovarian cancer (EOC). We identified randomised controlled trials (RCTs) by searching the Cochrane Central Register of Controlled Trials (Central 2020, Issue 10), Cochrane Gynaecological Cancer Group Trial Register, MEDLINE (1990 to October 2020), Embase (1990 to October 2020), ongoing trials on www.controlled-trials.com/rct, www.clinicaltrials.gov, www.cancer.gov/clinicaltrials, the National Research Register (NRR), FDA database and pharmaceutical industry biomedical literature. We included trials that randomised women with EOC to PARPi with no treatment, or PARPi versus conventional chemotherapy, or PARPi together with conventional chemotherapy versus conventional chemotherapy alone. We used standard Cochrane methodology. Two review authors independently assessed whether studies met the inclusion criteria. We contacted investigators for additional data. Outcomes included overall survival (OS), objective response rate (ORR), quality of life (QoL) and rate of adverse events. We included 15 studies (6109 participants); four (3070 participants) with newly-diagnosed, advanced EOC and 11 (3039 participants) with recurrent EOC. The studies varied in types of comparisons and evaluated PARPi. Eight studies were judged as at low risk of bias in most of the domains. Quality of life data were generally poorly reported. Below we present six key comparisons.  The majority of participants had BRCA mutations, either in their tumour (sBRCAmut) and/or germline (gBRCAmut), or homologous recombination deficiencies (HRD) in their tumours. Newly diagnosed EOC Overall, four studies evaluated the effect of PARPi in newly-diagnosed, advanced EOC. Two compared PARPi with chemotherapy and chemotherapy alone. OS data were not reported. The combination of PARPi with chemotherapy may have little to no difference in progression-free survival (PFS) (two studies, 1564 participants; hazard ratio (HR) 0.82, 95% confidence interval (CI 0).49 to 1.38; very low-certainty evidence)(no evidence of disease progression at 12 months' 63% with PARPi versus 69% for placebo).  PARPi with chemotherapy likely increases any severe adverse event (SevAE) (grade 3 or higher) slightly (45%) compared with chemotherapy alone (51%) (two studies, 1549 participants, risk ratio (RR) 1.13, 95% CI 1.07 to 1.20; high-certainty evidence). PARPi combined with chemotherapy compared with chemotherapy alone likely results in little to no difference in the QoL (one study; 744 participants, MD 1.56 95% CI -0.42 to 3.54; moderate-certainty evidence).  Two studies compared PARPi monotherapy with placebo as maintenance after first-line chemotherapy in newly diagnosed EOC. PARPi probably results in little to no difference in OS (two studies, 1124 participants; HR 0.81, 95%CI 0.59 to 1.13; moderate-certainty evidence) (alive at 12 months 68% with PARPi versus 62% for placebo). However, PARPi may increase PFS (two studies, 1124 participants; HR 0.42, 95% CI 0.19 to 0.92; low-certainty evidence) (no evidence of disease progression at 12 months' 55% with PARPi versus 24% for placebo). There may be an increase in the risk of experiencing any SevAE (grade 3 or higher) with PARPi (54%) compared with placebo (19%)(two studies, 1118 participants, RR 2.87, 95% CI 1.65 to 4.99; very low-certainty evidence), but the evidence is very uncertain. There is probably a slight reduction in QoL with PARPi, although this may not be clinically significant (one study, 362 participants; MD -3.00, 95%CI -4.48 to -1.52; moderate-certainty evidence).  Recurrent, platinum-sensitive EOC Overall, 10 studies evaluated the effect of PARPi in recurrent platinum-sensitive EOC. Three studies compared PARPi monotherapy with chemotherapy alone. PARPi may result in little to no difference in OS (two studies, 331 participants; HR 0.95, 95%CI 0.62 to 1.47; low-certainty evidence) (percentage alive at 36 months 18% with PARPi versus 17% for placebo). Evidence is very uncertain about the effect of PARPi on PFS (three studies, 739 participants; HR 0.88, 95%CI 0.56 to 1.38; very low-certainty evidence)(no evidence of disease progression at 12 months 26% with PARPi versus 22% for placebo). There may be little to no difference in rates of any SevAE (grade 3 or higher) with PARPi (50%) than chemotherapy alone (47%) (one study, 254 participants; RR 1.06, 95%CI 0.80 to 1.39; low-certainty evidence). Four studies compared PARPi monotherapy as maintenance with placebo. PARPi may result in little to no difference in OS (two studies, 560 participants; HR 0.88, 95%CI 0.65 to 1.20; moderate-certainty evidence)(percentage alive at 36 months 21% with PARPi versus 17% for placebo). However, evidence suggests that PARPi as maintenance therapy results in a large PFS (four studies, 1677 participants; HR 0.34, 95% CI 0.28 to 0.42; high-certainty evidence)(no evidence of disease progression at 12 months 37% with PARPi versus 5.5% for placebo). PARPi maintenance therapy may result in a large increase in any SevAE (51%) (grade 3 or higher) than placebo (19%)(four studies, 1665 participants, RR 2.62, 95%CI 1.85 to 3.72; low-certainty evidence). PARPi compared with chemotherapy may result in little or no change in QoL (one study, 229 participants, MD 1.20, 95%CI -1.75 to 4.16; low-certainty evidence). Recurrent, platinum-resistant EOC Two studies compared PARPi with chemotherapy. The certainty of evidence in both studies was graded as very low. Overall, there was minimal information on the QoL and adverse events. PARPi maintenance treatment after chemotherapy may improve PFS in women with newly-diagnosed and recurrent platinum-sensitive EOC; there may be little to no effect on OS, although OS data are immature. Overall, this is likely at the expense of an increase in SevAE. It is  disappointing that data on quality of life outcomes  are relatively sparse. More research is needed to determine whether PARPi have a role to play in platinum-resistant disease.

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

There is a high unmet need for treatment regimens that increase the chance of long-term remission and possibly cure for women with newly diagnosed advanced ovarian cancer. In the primary analysis of SOLO1/GOG 3004, the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib significantly improved progression-free survival versus placebo in patients with a BRCA mutation; median progression-free survival was not reached. Here, we report an updated, post-hoc analysis of progression-free survival from SOLO1, after 5 years of follow-up. SOLO1 was a randomised, double-blind, placebo-controlled, phase 3 trial, done across 118 centres in 15 countries, that enrolled patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-1 and with BRCA-mutated, newly diagnosed, advanced, high-grade serous or endometrioid ovarian cancer with a complete or partial clinical response after platinum-based chemotherapy. Patients were randomly assigned (2:1) via a web-based or interactive voice-response system to receive olaparib (300 mg twice daily) or placebo tablets orally as maintenance monotherapy for up to 2 years; randomisation was by blocks and was stratified according to clinical response after platinum-based chemotherapy. Patients, treatment providers, and data assessors were masked to group assignment. The primary endpoint was investigator-assessed progression-free survival. Efficacy is reported in the intention-to-treat population and safety in patients who received at least one dose of treatment. The data cutoff for this updated, post-hoc analysis was March 5, 2020. This trial is registered with ClinicalTrials.gov (NCT01844986) and is ongoing but closed to new participants. Between Sept 3, 2013, and March 6, 2015, 260 patients were randomly assigned to olaparib and 131 to placebo. The median treatment duration was 24·6 months (IQR 11·2-24·9) in the olaparib group and 13·9 months (8·0-24·8) in the placebo group; median follow-up was 4·8 years (2·8-5·3) in the olaparib group and 5·0 years (2·6-5·3) in the placebo group. In this post-hoc analysis, median progression-free survival was 56·0 months (95% CI 41·9-not reached) with olaparib versus 13·8 months (11·1-18·2) with placebo (hazard ratio 0·33 [95% CI 0·25-0·43]). The most common grade 3-4 adverse events were anaemia (57 [22%] of 260 patients receiving olaparib vs two [2%] of 130 receiving placebo) and neutropenia (22 [8%] vs six [5%]), and serious adverse events occurred in 55 (21%) of 260 patients in the olaparib group and 17 (13%) of 130 in the placebo group. No treatment-related adverse events that occurred during study treatment or up to 30 days after discontinuation were reported as leading to death. No additional cases of myelodysplastic syndrome or acute myeloid leukaemia were reported since the primary data cutoff, including after the 30-day safety follow-up period. For patients with newly diagnosed advanced ovarian cancer and a BRCA mutation, after, to our knowledge, the longest follow-up for any randomised controlled trial of a PARP inhibitor in this setting, the benefit derived from 2 years' maintenance therapy with olaparib was sustained beyond the end of treatment, extending median progression-free survival past 4·5 years. These results support the use of maintenance olaparib as a standard of care in this setting. AstraZeneca; Merck Sharpe & Dohme, a subsidiary of Merck & Co, Kenilworth, NJ, USA.

Patient-centred outcomes and effect of disease progression on health status in patients with newly diagnosed advanced ovarian cancer and a BRCA mutation receiving maintenance olaparib or placebo (SOLO1): a randomised, phase 3 trial

In the phase 3 SOLO1 trial, maintenance olaparib provided a significant progression-free survival benefit versus placebo in patients with newly diagnosed, advanced ovarian cancer and a BRCA mutation in response after platinum-based chemotherapy. We analysed health-related quality of life (HRQOL) and patient-centred outcomes in SOLO1, and the effect of radiological disease progression on health status. SOLO1 is a randomised, double-blind, international trial done in 118 centres and 15 countries. Eligible patients were aged 18 years or older; had an Eastern Cooperative Oncology Group performance status score of 0-1; had newly diagnosed, advanced, high-grade serous or endometrioid ovarian cancer, primary peritoneal cancer, or fallopian tube cancer with a BRCA mutation; and were in clinical complete or partial response to platinum-based chemotherapy. Patients were randomly assigned (2:1) to either 300 mg olaparib tablets or placebo twice per day using an interactive voice and web response system and were treated for up to 2 years. Treatment assignment was masked for patients and for clinicians giving the interventions, and those collecting and analysing the data. Randomisation was stratified by response to platinum-based chemotherapy (clinical complete or partial response). HRQOL was a secondary endpoint and the prespecified primary HRQOL endpoint was the change from baseline in the Functional Assessment of Cancer Therapy-Ovarian Cancer Trial Outcome Index (TOI) score for the first 24 months. TOI scores range from 0 to 100 (higher scores indicated better HRQOL), with a clinically meaningful difference defined as a difference of at least 10 points. Prespecified exploratory endpoints were quality-adjusted progression-free survival and time without significant symptoms of toxicity (TWiST). HRQOL endpoints were analysed in all randomly assigned patients. The trial is ongoing but closed to new participants. This trial is registered with ClinicalTrials.gov, NCT01844986. Between Sept 3, 2013, and March 6, 2015, 1084 patients were enrolled. 693 patients were ineligible, leaving 391 eligible patients who were randomly assigned to olaparib (n=260) or placebo (n=131; one placebo patient withdrew before receiving any study treatment), with a median duration of follow-up of 40·7 months (IQR 34·9-42·9) for olaparib and 41·2 months (32·2-41·6) for placebo. There was no clinically meaningful change in TOI score at 24 months within or between the olaparib and placebo groups (adjusted mean change in score from baseline over 24 months was 0·30 points [95% CI -0·72 to 1·32] in the olaparib group vs 3·30 points [1·84 to 4·76] in the placebo group; between-group difference of -3·00, 95% CI -4·78 to -1·22; p=0·0010). Mean quality-adjusted progression-free survival (olaparib 29·75 months [95% CI 28·20-31·63] vs placebo 17·58 [15·05-20·18]; difference 12·17 months [95% CI 9·07-15·11], p<0·0001) and the mean duration of TWiST (olaparib 33·15 months [95% CI 30·82-35·49] vs placebo 20·24 months [17·36-23·11]; difference 12·92 months [95% CI 9·30-16·54]; p<0·0001) were significantly longer with olaparib than with placebo. The substantial progression-free survival benefit provided by maintenance olaparib in the newly diagnosed setting was achieved with no detrimental effect on patients' HRQOL and was supported by clinically meaningful quality-adjusted progression-free survival and TWiST benefits with maintenance olaparib versus placebo. AstraZeneca and Merck Sharp & Dohme.