Survival Benefits of Carboplatin Plus Paclitaxel and Immunotherapy in Patients With Advanced Endometrial Cancer

Shannon Westin, MD, University of Texas MD Anderson Cancer Center, Houston, Texas, and colleagues presented results from the phase 3 DUO-E/GOG-3041/ENGOT-EN10 trial at the 2023 ESMO Congress. The study examined the effectiveness of the combination of immunotherapy with carboplatin/paclitaxel (CP) on progression-free survival (PFS) for patients with newly diagnosed advanced or recurrent endometrial cancer (EC).

Participants in the trial included patients with newly diagnosed FIGO stage III/IV or recurrent EC who had not previously received systemic treatment. The patients were randomized in a 1:1:1 ratio in three treatment groups: CP, which consisted of CP + durvalumab placebo for 6 cycles followed by maintenance durvalumab placebo + olaparib placebo; CP + durvalumab, which consisted of CP + durvalumab (1120 mg administered intravenously every 3 weeks) for 6 cycles followed by maintenance durvalumab (1500 mg administered intravenously every 4 weeks) + olaparib placebo; or CP + durvalumab + olaparib, which consisted of CP + durvalumab for 6 cycles followed by maintenance durvalumab + olaparib (300 mg tablets twice per day).

The researchers used RECIST v1.1 to measure dual primary endpoints of PFS in the intent-to-treat (ITT) populations in the CP + durvalumab vs CP treatment groups and the CP + durvalumab + olaparib vs CP treatment groups. They also performed a subgroup analysis for PFS by patients’ mismatch repair (MMR) status. The secondary endpoint of the trial was overall survival (OS).

The results from the study showed that within the ITT population (N = 718), patients who only received CP had a median follow-up duration of 12.6 months, a PFS event rate of 71.8%, a median PFS of 9.6 months, and a 12-/18-month PFS rate of 41.1%/21.7%. Patients who received the treatment combinations of CP + durvalumab and CP + durvalumab + olaparib had a lower PFS event rate of 58.4%, a slightly lower median PFS of 10.2 months, and a higher 12-/18-month PFS rate of 48.5%/37.8%. In addition, the CP + durvalumab + olaparib combination reduced the PFS event rate to 52.7%, increased the median PFS to 15.1 months, and increased the 12-/18-month PFS rate to 61.5%/46.3%.

Overall, the study found that within the ITT population, patients who received the treatment combinations of CP + durvalumab and CP + durvalumab + olaparib experienced significant improvements in PFS vs those who received CP alone. Although the interim OS data were immature, there was a trend toward the combination treatment being beneficial (CP + durvalumab vs CP: HR 0.77; 95% CI, [0.56-1.07]; P = 0.120; CP + durvalumab + olaparib vs CP: HR 0.59 [0.42-0.83]; P = 0.003). Furthermore, the PFS subgroup analysis showed that patients with deficient MMR (n = 143) and patients who were MMR proficient (n = 545) also saw improvement in the median PFS and 12-/18-month PFS rates when treated with both CP + durvalumab and CP + durvalumab + olaparib.

SN Westin, KN Moore, HS Chon, et al. Durvalumab (durvalumab) plus carboplatin/paclitaxel (CP) followed by maintenance (mtx) durvalumab ± olaparib (olaparib) as a first-line (1L) treatment for newly diagnosed advanced or recurrent endometrial cancer (EC): Results from the phase III DUO-E/GOG-3041/ENGOT-EN10 trial. Presented at: the 2023 ESMO Congress 2023; October 20-24, 2023; Madrid, Spain, and virtual; Abstract LBA41