@article {GaoA10, author = {Y Gao and X Wu and J Zhu and R Yin and J Yang and J Liu and J Wang and L Wu and Z Liu and D Wang and G Lou and H Yang and Q Zhou and B Kong and Y Huang and L Chen and G Li and R An and T Tan and J Dong}, title = {O017/$\#$15 Efficacy and safety of niraparib maintenance treatment in platinum-sensitive recurrent ovarian cancer after shorter or longer chemotherapy: a post hoc subgroup analysis}, volume = {31}, number = {Suppl 4}, pages = {A10--A11}, year = {2021}, doi = {10.1136/ijgc-2021-IGCS.17}, publisher = {BMJ Specialist Journals}, abstract = {Objectives Traditionally >=6 cycles of platinum-containing chemotherapy (Pt-chemo) are recommended for platinum-sensitive recurrent ovarian cancer (PSROC). PARP inhibitor maintenance treatment (MT) can be initiated upon clinical complete/partial response (CR/PR) after >=4 cycles of chemotherapy. Shorter chemotherapy may improve patient experience without compromising efficacy. This study aims to compare the efficacy and safety of niraparib to placebo as MT administered after <=4 or \>4 cycles of Pt-chemo.Methods This is a post hoc analysis of the published NORA phase III study (NCT03705156). Adults with PSROC and CR/PR to most recent Pt-chemo were randomized 2:1 to niraparib or placebo. Primary endpoint was PFS by BICR. Subgroups comprised patients with <=4 or \>4 cycles of most recent Pt-chemo.Results Table 1 summarizes key baseline characteristics which were overall balanced between groups. Median (95\% CI) PFS was 18.37 months (8.54{\textendash}not estimable [NE], <=4-cycle/niraparib) versus 3.88 months (3.68{\textendash}7.43, <=4-cycle/placebo; HR=0.36 [p=0.0016]), and was 18.33 months (10.28{\textendash}NE, \>4-cycle/niraparib) versus 5.49 months (3.71{\textendash}5.75, \>4-cycle/placebo; HR=0.33 [p\<0.0001]) (figure 1). Overall safety profiles were comparable between <=4-cycle/niraparib and \>4-cycle/niraparib, with similar percentages of patients experiencing neutrophil count decrease (60.4\%; 58.1\%), anemia (50.0\%; 55.0\%), and platelet count decrease (45.8\%; 58.1\%). Composition of grade >=3 TEAEs was consistent with the overall NORA results.View this table:Abstract O017/$\#$15 Table 1 Key baseline characteristics for subgroups with <=4 or \>4 treatment cycles of most recent PT-chemoAbstract O017/$\#$15 Figure 1 PFS by blinded independent central review (interaction-to-treat)Conclusions Similar niraparib-versus-placebo PFS benefits were observed after <=4-cycle or \>4-cycle Pt-chemo in CR/PR patients. The efficacy and safety of niraparib MT after shorter Pt-chemo remain to be verified in larger samples.}, issn = {1048-891X}, URL = {https://ijgc.bmj.com/content/31/Suppl_4/A10.2}, eprint = {https://ijgc.bmj.com/content/31/Suppl_4/A10.2.full.pdf}, journal = {International Journal of Gynecologic Cancer} }