SOLO2/ENGOT-Ov21: trial | Bending the Curve: Trial by Trial

SOLO2/ENGOT-Ov21

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

Phase 3N = 295NCT01874353

Population

Platinum-sensitive relapsed high-grade serous or endometrioid ovarian cancer with a BRCA1/2 mutation, at least two previous platinum-based regimens, in response to the latest

Design

International, multicentre, double-blind, randomised, placebo-controlled phase 3 trial. Patients with platinum-sensitive relapsed high-grade serous or endometrioid ovarian cancer (including primary peritoneal and fallopian tube cancer) and a BRCA1/2 mutation, ECOG performance status 0-1 and at least two previous platinum regimens, who responded to the latest platinum, were randomised 2:1 to olaparib tablets 300 mg twice daily or placebo. Primary end point investigator-assessed PFS.

Primary endpoint

PFS

Arms

Olaparib tablets (experimental, n = 196): Olaparib 300 mg (two 150 mg tablets) twice daily
Placebo (control, n = 99): Matching placebo tablets

People

Pujade-Lauraine E

PFSHR 0.30 (95% CI 0.22–0.41)Δ median PFS+13.6 monthsOSHR 0.74 (95% CI 0.54–1.00)Δ median OS+12.9 months

Show the numbers

Results reported for SOLO2/ENGOT-Ov21
Endpoint	Analysis	Olaparib tablets	Placebo	Effect
PFS	primaryPujade-Lauraine 2017	median 19.1 months (16.3–25.7)	median 5.5 months (5.2–5.8)	HR 0.30 (95% CI 0.22–0.41)P<0.0001Investigator-assessed. One olaparib patient was randomised in error.
OSAll randomised patients (analysed as randomly allocated)	finalPoveda 2021	median 51.7 months (41.5–59.1)	median 38.8 months (31.4–48.6)	HR 0.74 (95% CI 0.54–1.00)P=0.054Unadjusted for the 38% of patients in the placebo group who received subsequent PARP inhibitor therapy. Median follow-up 65.7 months with olaparib and 64.5 months with placebo. The authors state that statistical significance was not reached.

Results reported for SOLO2/ENGOT-Ov21
Endpoint	Analysis	Olaparib tablets	Placebo	Effect
PFS	primaryPujade-Lauraine 2017	median 19.1 months (16.3–25.7)	median 5.5 months (5.2–5.8)	HR 0.30 (95% CI 0.22–0.41)P<0.0001Investigator-assessed. One olaparib patient was randomised in error.
OSAll randomised patients (analysed as randomly allocated)	finalPoveda 2021	median 51.7 months (41.5–59.1)	median 38.8 months (31.4–48.6)	HR 0.74 (95% CI 0.54–1.00)P=0.054Unadjusted for the 38% of patients in the placebo group who received subsequent PARP inhibitor therapy. Median follow-up 65.7 months with olaparib and 64.5 months with placebo. The authors state that statistical significance was not reached.

Hazard ratio (95% CI) by endpoint. Values below 1 favour the experimental arm.

Data table

Endpoint	HR	95% CI
PFS	0.3	0.22–0.41
OS	0.74	0.54–1

Illustrative — modelled from reported values, not trial data. PFS, primary.

Show curves

Olaparib tablets (experimental)
Placebo (control)

Median-only curves assume a constant hazard (exponential) and fit plateaus, as seen with some immunotherapies, poorly.

Data table (modelled values)

Months	Olaparib tablets	Placebo
0	100.0%	100.0%
12	64.7%	22.0%
24	41.9%	4.9%
36	27.1%	1.1%
48	17.5%	0.2%

Illustrative — modelled from reported values, not trial data. OS, final.

Show curves

Olaparib tablets (experimental)
Placebo (control)

Median-only curves assume a constant hazard (exponential) and fit plateaus, as seen with some immunotherapies, poorly.

Data table (modelled values)

Months	Olaparib tablets	Placebo
0	100.0%	100.0%
32	65.1%	56.5%
65	41.8%	31.3%
97	27.2%	17.7%
129	17.7%	10.0%

Appears in

2012 Olaparib maintenance in platinum-sensitive relapse: Study 19 and SOLO2

Sources

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 DOI
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 DOI