Mature survival data from the Gynecological Cancer InterGroup ICON8 trial, presented in a Proffered Paper Session today at ESMO Virtual Congress 2020, confirmed the previously published primary progression-free survival (PFS) analysis: weekly dose-dense chemotherapy is a well-tolerated alternative to 3-weekly (q3w) chemotherapy for epithelial ovarian cancer (EOC) but it provides no PFS or overall survival (OS) advantage (Abstract 805O).
In the study, 1,566 patients with FIGO stage IcG3–IV EOC were randomised 1:1:1 to standard chemotherapy (q3w carboplatin AUC 5/6 + q3w paclitaxel 175 mg/m2 [n=522]), weekly paclitaxel (q3w carboplatin AUC 5/6 + q1w paclitaxel 80 mg/m2 [n=523]) or weekly carboplatin/paclitaxel (q1w carboplatin AUC2 + q1w paclitaxel 80 mg/m2 [n=521]). Before entering ICON8, patients had undergone immediate primary surgery (IPS) (48%) or were considered inoperable/had neoadjuvant chemotherapy with planned delayed primary surgery (DPS) (52%) during chemotherapy. The co-primary outcomes were PFS and OS.
As of 01 April 2020, there was no difference in the death rate between standard chemotherapy (61%) and either weekly paclitaxel (57%; p=0.14; hazard ratio [HR] 0.89; 97.5% confidence interval [CI] 0.74–1.06) or weekly carboplatin/paclitaxel (58%; p=0.27; HR 0.91; 97.5% CI 0.76–1.09). The median OS did not differ between the standard q3w chemotherapy arm (47.4 months) and the weekly chemotherapy arms (54.1 months with paclitaxel and 53.4 months with carboplatin/paclitaxel). The surgical approach (IPS or DPS) had no impact on the survival findings.
The updated PFS results, presented nearly three years after the primary results were reported and following an additional 153 events, support the original analysis, with no significant difference between the PFS observed in the standard q3w chemotherapy arm and either the weekly paclitaxel (p=0.37) or the weekly carboplatin/paclitaxel (p=0.48) arms. The restricted mean PFS durations in the standard q3w chemotherapy, weekly paclitaxel and weekly carboplatin/paclitaxel arms were 25.0 months, 25.5 months and 25.9 months, respectively.
This final analysis of ICON8 provides conclusive evidence that although weekly dose-dense chemotherapy with paclitaxel or paclitaxel/carboplatin can be successfully administered as first-line treatment for EOC, it has no OS or PFS benefits over standard q3w chemotherapy.
Abstract and session details
- Clamp AR et al. ICON8: Overall survival results in a GCIG phase III randomised controlled trial of weekly dose-dense chemotherapy in first line epithelial ovarian, fallopian tube or primary peritoneal carcinoma treatment. ESMO Virtual Congress 2020, Abstract 805O
Proffered Paper - Gynaecological cancers 2, 21.09.2020, h. 16:20 – 18:00, Channel 3