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

BACKGROUND: 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. OBJECTIVES: To determine the benefits and risks of poly (ADP-ribose) polymerase) inhibitors (PARPi) for the treatment of epithelial ovarian cancer (EOC). SEARCH METHODS: 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. SELECTION CRITERIA: 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. DATA COLLECTION AND ANALYSIS: 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. MAIN RESULTS: 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. AUTHORS' CONCLUSIONS: 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.

Epidermal growth factor receptor blockers for the treatment of ovarian cancer.

BACKGROUND: This is an update of a previously published version of the review (Issue 10, 2011).Epithelial ovarian cancer (EOC) is the seventh most common cause of cancer death among women worldwide. Treatment consists of a combination of surgical debulking and platinum-based chemotherapy. Between 55% and 75% of women who respond to first-line therapy experience relapse within two years. Second-line chemotherapy is palliative and aims to reduce symptoms and prolong survival. Improved understanding about the molecular basis of EOC has led to the development of novel agents, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and anti-EGFR antibodies. OBJECTIVES: To compare the effectiveness and harmful effects of interventions that target the epidermal growth factor receptor in the treatment of epithelial ovarian cancer (EOC). SEARCH METHODS: We searched the Cochrane Gynaecological Cancer Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL; 2010, Issue 4), MEDLINE, and Embase up to October 2010. We also searched registers of clinical trials, abstracts of scientific meetings, and reference lists of included studies, and we contacted experts in the field. This update includes further searches up to September 2017. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing anti-EGFR agents with or without conventional chemotherapy versus conventional chemotherapy alone or no treatment in women with histologically proven EOC. DATA COLLECTION AND ANALYSIS: Two review authors independently abstracted data, assessed risk of bias, and performed GRADE assessment. MAIN RESULTS: From 6105 references obtained through the literature search and an additional 15 references derived from grey literature searches, we identified seven RCTs that met our inclusion criteria and included 1725 participants. Trial results show that after first-line chemotherapy is provided, maintenance treatment with erlotinib (EGFR tyrosine kinase inhibitor (TKI)) probably makes little or no difference in overall survival (hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.81 to 1.20; one study; 835 participants; low-certainty evidence) and may make little or no difference in progression-free survival (HR 1.05, 95% CI 0.90 to 1.23; one study; 835 participants; very low-certainty evidence). Less than 50% of participants provided quality of life data, and study authors reported these results incompletely. The certainty of evidence is very low, but treatment may reduce quality of life compared to observation.Treatment with an EGFR TKI (vandetanib) for women with relapsed EOC may make little or no difference in overall survival (HR 1.25, 95% CI 0.80 to 1.95; one study; 129 participants; low-certainty evidence) and may make little or no difference in progression-free survival (HR 0.99, 95% CI 0.69 to 1.42; one study; 129 participants; very low-certainty evidence). In treating patients with relapse, giving EGFR TKI may slightly increase some toxicities, such as severe rash (risk ratio (RR) 13.63, 95% CI 0.78 to 236.87; one study; 125 participants; very low-certainty evidence). Quality of life data were not available for meta-analysis.Anti-EGFR antibody treatment in relapsed EOC may or may not make a difference to overall survival (HR 0.93, 95% CI 0.74 to 1.18; four studies; 658 participants; moderate-certainty evidence) and may or may not have any effect on progression-free survival (HR 0.90, 95% CI 0.70 to 1.16; four studies; 658 participants; low-certainty evidence). Anti-EGFR antibody treatment may or may not increase side effects, including severe nausea and/or vomiting (RR 1.27, 95% CI 0.56 to 2.89; three studies; 503 participants; low-certainty evidence), severe fatigue (RR 1.06, 95% CI 0.66 to 1.73; I² = 0%; four studies; 652 participants; low-certainty evidence), and hypokalaemia (RR 2.01, 95% CI 0.80 to 5.06; I² = 0%; three studies; 522 participants; low-certainty evidence). Severe diarrhoea rates were heterogeneous across studies (RR 2.87, 95% CI 0.59 to 13.89; four studies; 652 participants; low-certainty evidence), and subgroup analysis revealed that severe diarrhoea was more likely with pertuzumab (RR 6.37, 95% CI 1.89 to 21.45; I² = 0%; three studies; 432 participants; low-certainty evidence) than with seribantumab treatment (RR 0.38, 95% CI 0.07 to 2.23; I² = 0%; one study; 220 participants; very low-certainty evidence). Quality of life data were incompletely reported, and we were unable to combine them in a meta-analysis. AUTHORS' CONCLUSIONS: Current evidence suggests that an anti-EGFR single-agent biological treatment (EGFR TKI or anti-EGFR antibody) makes little or no difference to survival, either as maintenance treatment after first-line chemotherapy or in association with chemotherapy in recurrent cancer. Anti-EGFR therapy may increase some side effects and may or may not reduce quality of life.

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

BACKGROUND: Ovarian cancer is the sixth most common cancer and seventh most common cause of cancer death in women world-wide. Three-quarters of women present when the disease has spread throughout the abdomen (stage III or IV) and treatment consists of a combination of debulking surgery and platinum-based chemotherapy. Although initial responses to chemotherapy are good, most women will relapse and require further chemotherapy and will eventually develop resistance to chemotherapy.PARP (poly (ADP-ribose) polymerase) inhibitors, are a novel type of medication that works by preventing cancer cells from repairing their DNA once they have been damaged by other chemotherapy agents. It is not clear how PARP inhibitors compare to conventional chemotherapy regimens for the treatment of ovarian cancer, with respect to survival, side effects and quality of life. OBJECTIVES: To determine the benefits and risks of PARP inhibitors for the treatment of epithelial ovarian cancer (EOC). SEARCH METHODS: We identified randomised controlled trials (RCTs) by searching the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 4), the Cochrane Gynaecological Cancer Group Trial Register, MEDLINE (1990 to May 2014), EMBASE (1990 to May 2014), ongoing trials on www.controlled-trials.com/rct, www.clinicaltrials.gov, www.cancer.gov/clinicaltrials and the National Research Register (NRR), the FDA database and pharmaceutical industry biomedical literature. SELECTION CRITERIA: Women with histologically proven EOC who were randomised to treatment groups in trials that either compared PARP inhibitors with no treatment, or PARP inhibitors versus conventional chemotherapy, or PARP inhibitors together with conventional chemotherapy versus conventional chemotherapy alone. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. Two review authors independently assessed whether studies met the inclusion criteria. We contacted investigators for additional data, where possible. Outcomes included survival, quality of life and toxicity. MAIN RESULTS: We included four RCTs involving 599 women with EOC. Data for veliparib were limited and of low quality, due to small numbers (75 women total). Olaparib, on average, improved progression-free survival (PFS) when added to conventional treatment and when used as maintenance treatment in women with platinum-sensitive disease compared with placebo (hazard ratio (HR) 0.42, 95% confidence interval (CI) 0.29 to 0.60; 426 participants ; two studies), but did not improve overall survival (OS) (HR 1.05, 95% CI 0.79 to 1.39; 426 participants; two studies). We graded this evidence as moderate quality using the GRADE approach. Olaparib was associated with more severe adverse events (G3/4) during the maintenance phase compared with controls (risk ratio (RR) 1.74, 95% CI 1.22 to 2.49; 385 participants, two studies; moderate quality evidence). Quality of life data were insufficient for meta-analysis. We identified four ongoing studies. AUTHORS' CONCLUSIONS: PARP inhibitors appear to improve PFS in women with recurrent platinum-sensitive disease. Ongoing studies are likely to provide more information about whether the improvement in PFS leads to any change in OS in this subgroup of women with EOC. More research is needed to determine whether PARP inhibitors have any role to play in platinum-resistant disease.