Randomized phase II study of chemoradiotherapy with cisplatin + S-1 versus cisplatin + pemetrexed for locally advanced non-squamous non-small cell lung cancer: SPECTRA study

Abstract Objectives SPECTRA is a multicenter, randomized phase II study of chemotherapy with cisplatin (CDDP) plus S-1 versus CDDP plus pemetrexed (PEM) in combination with thoracic radiotherapy (TRT) for locally advanced non-squamous non-small cell lung cancer, in order to determine which of these two regimens might be preferable for comparison with standard therapies in a future phase III study. Materials and methods Patients were randomly assigned to receive CDDP + S-1 (CDDP 60 mg/m2 on day 1 and S-1 80 mg/m2 on days 1–14, every 4 weeks, up to 4 cycles) or CDDP + PEM (CDDP 75 mg/m2 + PEM 500 mg/m2 on day 1, every 3 weeks, up to 4 cycles) combined with TRT (60 Gy in 30 fractions). The primary endpoint was the 2-year progression-free survival (PFS) rate. The sample size had been set at 100 patients. Results A total of 102 patients were randomized to receive CDDP + S-1 or CDDP + PEM (CDDP + S-1, n = 52; CDDP + PEM, n = 50) between January 2013 and October 2016. The results in the CDDP + S1 group and CDDP + PEM group were as follows: completion rates of TRT (60 Gy)/chemotherapy (4 cycles) was 92 %/73 % and 98 %/86 %, respectively; the response rates were 60 % and 64 %, respectively; median PFS after a median follow-up of 32.1 months, 12.7/13.8 months (hazard ratio [HR] = 1.16; 95 % confidence interval [CI], 0.73–1.84); 2-year PFS rate, 36.5 % (95 % CI, 23.5–49.6)/32.1 % (95 %CI, 18.9–45.4); median OS, 48.3/59.1 months (HR = 1.05; 95 %CI, 0.58–1.90); 2-year OS rate, 69.2 % (95 %CI, 56.7–81.8)/66.4 % (95 %CI, 53.0–79.9); Grade 3 toxicities: febrile neutropenia (12 %/2 %), anorexia (8 %/16 %), diarrhea (8 %/0 %), esophagitis (6 %/8 %), and neutropenia (35 %/50 %); Grade 2 or worse radiation pneumonitis, 15 % (8 patients)/4 % (2 patients). Conclusion The 2-year PFS rate in the CDDP + S-1 arm was higher than that in the CDDP + PEM arm. Both treatments were safe, with manageable toxicities.