Introduction
Challenges in treating EOC
Utility of laboratory markers in the diagnosis of EOC recurrence
Recurrent EOC and common genetic mutations
Importance of platinum free interval in platinum sensitive relapsed ovarian Cancer
PFI and treatment responses in platinum sensitive relapsed EOC
Current status of selecting patients based on platinum sensitivity
Treatment options for platinum sensitive versus platinum resistant recurrent EOC
Chemotherapy
Targeted therapies
Approved therapies
Therapies under clinical development
Maintenance therapy in recurrent EOC
Trial name [ClinicalTrials. gov identifier] | Drug | Mono/Combo; Phase | Patient population and key eligibility | N | Treatment arms | Primary endpoint | Results |
---|---|---|---|---|---|---|---|
GOG 212 [42] | Paclitaxel | Mono; Phase III | Advanced EOC in complete response | 1157 | Pac IV or CT-2103 (PP) | OS | No improvement in OS; increased toxicities |
ICON 7 [44] | Bevacizumab | Combo; Phase III | Newly diagnosed early or advance EOC, first line | 1528 | C + Pac vs C + Pac + bev | PFS and OS | No improvement in PFS. No improvement in OS: restricted mean survival time chemo vs bev group 44.6 months (95% CI 43.2–45.9) vs 45.5 months (CI 44.2–46.7); log-rank (p = 0.85) Benefit only in high-risk subset: mean OS 34.5 months (95% CI 32.0–37.0) vs 39.3 months (37.0–41.7) (log-rank p = 0.03). |
GOG 218 [43] | Bevacizumab | Combo; Phase III | Newly diagnosed advance EOC | 1873 | C + Pac (TC group) vs C + Pac + bev (TCP group) vs C + Pac + bev followed by bev maintenance | PFS and OS | PFS improvement of 3.8 months (10.3 for standard chemotherapy, 14.1 months for the maintenance regimen), Median OS was not significantly different between arms |
NCT02022917 [43] | Bevacizumab | Combo; Phase II | Extensive stage IIIC or IV EOC | 27 | Postoperative PBC + adjuvant and maintenance bev | AEs | Ongoing; study completion Dec 2018 |
ATALANTE (NCT02891824) | Atezolizumab | Combo; Phase III | Late relapse EOC | 405 | Atezolizumab in combination with PBC + bev administered concurrent to chemotherapy and in maintenance | PFS | Ongoing; study completion 2023 |
Pazopanib | Mono; Phase III | Platinum-sensitive maintenance in EOC | 940 | Pazopanib 800 mg OD maintenance in EOC patients who did not progress after one line of chemotherapy | PFS | Improved median PFS vs placebo 17.9 vs 12.3 months, respectively (HR: 0.77; 95% CI, 0.64–0.91; p = 0.0021) |
Application of PARP inhibitors in the treatment of recurrent ovarian Cancer
Olaparib SOLO2/ENGOT-Ov21 (n = 195) [51] | Niraparib NOVA/ENGOT-OV16 (n = 367) [52] | Veliparib (n = 50) [55] | |||
---|---|---|---|---|---|
Grade 3 and 4 Adverse Events | Hematological | Anemia 38 (18%) Neutropenia 8 (4%) Thrombocytopenia 2 (1%) | Anemia 93 (25.3%) Neutropenia 72 (19.6%) Thrombocytopenia 124 (33.8%) | Anemia 45 (22%)/70 (19%) Neutropenia 16 (7%)/25 (7%) Thrombocytopenia 5 (2%)/19 (5%) | Leukopenia 1 (2%) Neutropenia 1 (2%) Thrombocytopenia 1 (2%) |
Non-hematological | Fatigue 8 (4%) Abdominal pain 5 (3%) Nausea 5 (3%) Vomiting 5 (3%) | Hypertension 30 (8.2%) Fatigue 30 (8.2%) Abdominal pain 4 (1.1%) Nausea 11 (3.0%) | Elevated AST/ALT 25 (13%)/39 (10%) Fatigue 18 (9%)/25 (7%) Abdominal pain 5 (2%)/9 (2%) Nausea 9 (4%)/14 (4%) | Nausea 2 (4%) Metabolism/nutrition 1 (2%) Other investigations 6 (12%) | |
Serious Adverse Events | Total | 35 (18%) | Total 110 (30%) [16] | ARIEL2: total 50 (25%) ARIEL3: total 78 (21%) | Total 12 (24%) |
Individual | Anemia 7 (4%) Abdominal pain 3 (2%) Intestinal obstruction 3 (2%) | ARIEL2: Intestinal obstruction 10 (5%) Anemia 9 (4%) ARIEL3: Anemia 16 (4%) Pyrexia 6 (2%) Vomiting 6 (2%) Intestinal obstruction 3 (1%) | |||
Dose Changes due to Adverse Events | Dose reductions 49 (25%) Discontinuations 21 (11%) | Dose reductions: 244 (66.5%) Discontinuations: 54 (14.7%) | ARIEL2: Dose reductions: 80 (39%) Discontinuations: 19 (9%) ARIEL3: Dose reductions: 203 (55%) Discontinuations: 50 (13%) | Dose Reductions: 31 (62%) Discontinuations: 31 (62%)a |
PARP inhibitor Monotherapy in recurrent EOC (Table 3)
Approved therapies
Trial name [ClinicalTrials.gov identifier]s | PARPi (approval status) | Mono/Combo; Phase; PARP enzyme targeted | Patient population and key eligibility | N | Treatment arms | Primary endpoint | Results/Trial status |
---|---|---|---|---|---|---|---|
Study 42 (NCT01078662) [56] | Olaparib (approved) | Mono; PARP 1 > PARP2> > PARP3 | Confirmed genetic BRCA1 and/or BRCA2 mutation | 298 | Olaparib 400 mg (8 × 50 mg capsules), oral BID until progression of the disease | Tumor response rate | ORR was 34% (46/137; 95% CI: 26–42) and median DoR was 7.9 (95% CI 5.6–9.6) months |
LIGHT study (NCT02983799) [57] | Olaparib (approved) | PARP 1 > PARP2> > PARP3 | gBRCAm and wt PSROC HGS | 260 | Olaparib 300 mg after ≥1 L PBC | ORR | Ongoing; study completion 2020 |
SOLO3/ NCT02282020 [11] | Olaparib (approved) | Mono; Phase III; PARP 1 > PARP2> > PARP3 | gBRCAm PSROC | 411 | Olaparib vs. physician’s choice of single agent standard of care non-platinum based chemotherapy (TPC) after ≥2 L PBC | ORR | ORR 72% olaparib vs 51% TPC OR 2.53 (1.40, 4.58) p = 0.002 PFS 13.4 vs 9.2 mo HR 0.62 (0.43, 0.91); P = 0.013 |
NCT01081951 | Olaparib (approved) | Combo; Phase II; PARP 1 > PARP2> > PARP3 | PSROC (both germline BRCA and sporadic) | 162 | 200 or 400 mg BID olaparib + C + Pac vs C + Pac as first line | PFS | Prelim results: Median PFS 12.2 (olaparib arm) versus 9.6 mos (no olaparib) p = 0.0012; study completion Dec 2018 |
NRG-GY005 (NCT0250226) | Olaparib (approved) | Combo; Phase II/III; PARP 1 > PARP2> > PARP3 | Platinum resistant recurrent high-grade OC | 680 | Olaparib/cediranib versus single agent chemotherapy | PFS (phase II) OS (phase III) | Ongoing; study completion 2023 |
NCI-OVM1403/NRG-GY004 (NCT0244660) | Olaparib (approved) | Combo; Phase III; PARP 1 > PARP2> > PARP3 | PSROC HGS; BRCA stratified | 549 | Olaparib versus olaparib/cediranib versus platinum doublet | PFS | Ongoing; study completion Dec 2019 |
ENGOTOV24/AVANOVA (NCT02354131) | Niraparib (investigational; approved only for maintenance) | Combo; Phase I/II; PARP1 and PARP2 | PSROC | 108 | Niraparib versus niraparib-bevacizumab | PFS | Ongoing; study completion 2020 |
ARIEL 2 (Part 1: results available; Part 2 ongoing) (NCT01891344) [53] | Rucaparib (approved) | PARP 1>>>> > PARP2 | PSROC HGS | 493 | 600 mg BID rucaparib | PFS | Prelim results: PFS in the BRCAm (HR 0.27, 95% CI 0.16–0.44, p < 0.0001) LOH high (0.62, 0.42–0.90, p = 0.011) |
ARIEL4/NCT02855944 | Rucaparib (approved) | Mono; Phase III; PARP 1>>>> > PARP2 | BRCAm HGSOC (platinum sensitive and resistant) | 345 | Rucaparib vs PBC | PFS | Ongoing; study completion 2024 |
NCT01113957 | Veliparib (investigational) | Combo; PARP 1 and PARP2 | Recurrent HGSOC (both germline BRCA and sporadic allowed) | 168 | [1] Veliparib and temozolomide vs. [2] PLD | ORR | Results not available |
NCT01306032 [58] | Veliparib (investigational) | Combo; PARP 1 and PARP2 | Recurrent HGSOC (both germline BRCA and sporadic allowed) | 75 | Oral cyclophos 50 mg + veliparib 60 mg daily vs. Oral cyclophos 50 mg daily | ORR | Well tolerated with some clinical activity; addition of veliparib at 60 mg daily did not improve either the response rate or the median PFS |
PARP inhibitors combination therapy in recurrent EOC (Table 3)
Trial name [ClinicalTrials. gov identifier] | Drug (approval status) | Mono/Combo; Phase; PARP enzymes targeted | Patient population; newly diagnosed/recurrent and key eligibility | N | Treatment arms | Primary endpoint | Results/Trial status |
---|---|---|---|---|---|---|---|
SOLO-2 (NCT01874353) [51] | Olaparib (approved) | Mono; Phase III; PARP 1 > PARP2> > PARP3 | PSROC HSG; ≥2 PBC BRCAm only, gBRCAmut BRCA1: Ola:132 (67%) PBO: 61 (62%) BRCA2: Ola: 58 (30%) PBO: 35 (35%) | 295 | Olaparib 300 mg bid vs placebo maintenance after ≥2 PBC | PFS | Ola vs PBO: 19.3 months (95% CI 16.5–27.3) vs 5.5 months (5.0–5.8); HR [in favor of ola] 0.33, 95% CI 0.24–0.44; p < 0.0001).; study completion 2021 |
Olaparib (approved) | Mono; Phase III; PARP 1 > PARP2> > PARP3 | Germline BRCA mutant only, newly diagnosed HGSOC or endometrioid stage III and IV Of 391 patients at interim analysis, centrally confirmed gBRCA1/2 m: 388 somatic BRCA1/2 m: 2 | 451 | Olaparib 300 mg bid vs placebo maintenance after 1 L PBC | PFS | Primary analysis: 60% vs. 27% in ola vs PBO (HR for disease progression or death, 0.30; 95% CI, 0.23 to 0.41; p < 0.001) Ongoing; study completion 2023 | |
PAOLA1/ENGOT/GCIG (NCT02477644) [66] | Olaparib (approved) | Combo; Phase III; PARP 1 > PARP2> > PARP3 | Newly diagnosed HGSOC | 612 | Bev or bev/olaparib maintenance after 1 L platinum/taxane/bev | PFS | Ongoing; study completion 2022 |
ICON 9 trial (NCT03278717) | Olaparib (approved) | Combo; Phase III; PARP 1 > PARP2> > PARP3 | PSROC | 618 | Olaparib or olaparib/cediranib maintenance after 1 L PBC | PFS and OS | Ongoing; study completion 2023 |
ENGOT-OV26/PRIMA (NCT02655016) [67] | Niraparib (approved) | Mono; Phase III; PARP1 and PARP2 | HRD positive, stage III and IV | 305 | Niraparib vs placebo maintenance after 1 L PBC with PR or CR | PFS | Ongoing; study completion August 2019 |
GOG-3005 (NCT02470585) [11] | Velaparib (investigational) | Combo; Phase III; PARP 1and PARP2 | Advanced HGSOC, both BRCA germline mutation carriers and BRCA wild types | 1140 | Veliparib vs placebo maintenance after 1 L (C + Pac) or (C + Pac + veliparib) | PFS | Ongoing; study completion 2020 |
Third-line and beyond in EOC – the unmet need
Study | Phase | Patient population | Treatment arms | HR classification | PFS/OS/ORR |
---|---|---|---|---|---|
II | Platinum-sensitive recurrent serous ovarian cancer; ≥2 PBC with PR or CR to most recent PBC | olaparib 400 mg bid vs PBO | Germline or tumor BRCA Ola: 74 (56%) vs PBO 62 (50%) | PFS: ola: 11.2 months (BRCAm)/7.4 months (wt) p < 0.00001, For PBO: 4.3 months (BRCAm)/5.5 months (wt); p = 0.007 OS: BRCAm ola vs PBO 34.9 months (95% CI 29.2–54.6) vs 30.2 months (23.1–40.7); HR 0.62 (95% CI 0.41–0.94) nominal p = 0.025BRCAwt in11 (15%) of 74 patients with BRCAm who received ola maintenance for ≥5 years: ola vs PBO: 24.5 months (19.8–35.0) vs 26.6 months (23.1–32.5); HR 0.83 (95% CI 0.55–1.24); nominal p = 0.37 | |
III | Newly diagnosed HGSOC or endometrioid stage III and IV | olaparib 300 mg bid vs PBO | Of 391 patients at interim analysis, centrally confirmed gBRCA1/2 m: 388 somatic BRCA1/2 m: 2 | PFS: Primary analysis: 60% vs. 27% in ola vs PBO (HR for disease progression or death, 0.30; 95% CI, 0.23 to 0.41; p < 0.001) | |
SOLO-2 [51] | III | PSROC HSG; ≥2 PBC | olaparib 300 mg bid vs PBO | gBRCAmut BRCA1: Ola:132 (67%); PBO: 61 (62%) BRCA2: Ola: 58 (30%); PBO: 35 (35%) | In 286 patients with BRCA1/2 (Ola: 190; PBO: 96). median PFS Ola vs PBO (19.3 months [95% CI 16.5–27.3] vs 5.5 months [5.0–5.8]; HR [in favor of ola] 0.33, 95% CI 0.24–0.44; p < 0.0001). |
ENGOT-OV16/NOVA [52] | III | PSROC | Niraparib 300 mg vs. PBO o.d | BRCA1/2 positive & BRCA1/2 negative gBRCA cohort: 203 (niraparib: 138,PBO: 65) non-gBRCA cohort: 350 (niraparib: 234, PBO: 116 | Median PFS gBRCAm 21 mo (nira) vs 5.5 months (PBO) (HR, 0.27; 95% confidence interval [CI], 0.17 to 0.41), p < 0.00001; Non-gBRCAm HRD+ 12.9 months (nira) versus 3.8 months (PBO) (HR 0.38 95% CI, 0.24 to 0.59), p < 0.00001; All Non-gBRCAm 9.3 months (nira) versus 3.9 months (PBO) (HR .45; 95% CI, 0.34 to 0.61), p < 0.00001 |
Ongoing; completion June 2020 | III | PSROC- HSGOC, ≥2 prior PBC with PR or CR to most recent PBC | Rucaparib maintenance therapy 600 mg p.o. b.i.d. vs. PBO | HRD stratification at the time of enrollment (BRCAmut; BRCAwt/ LOH high; BRCAwt/ LOH low) BRCAm ruca: 130 [35%] vs PBO: 66 [35%] HRD carcinoma ruca: 236 [63%] vs PBO: 118 [62%]) | Median PFS in BRCA-mut rucaparib vs PBO 16.6 mo (95% CI 13.4–22.9) vs. 5.4 mo (95% CI 3.4–6.7) (HR 0.23 [95% CI 0.16–0.34]; p < 0.0001) HRD carcinoma ruca vs PBO: 13.6 mo (10.9–16.2) vs 5.4 mo (5.1–5.6; 0.32 [0.24–0.42]; p < 0.0001) |