Six versus eight cycles of bi-weekly CHOP-14 with or without rituximab in elderly patients with aggressive CD20+ B-cell lymphomas: a randomised controlled trial (RICOVER-60)

SummaryBackgroundCyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) is used to treat patients with non-Hodgkin lymphoma. Interval decrease from 3 weeks of treatment (CHOP-21) to 2 weeks (CHOP-14), and addition of rituximab to CHOP-21 (R-CHOP-21) has been shown to improve outcome in elderly patients with diffuse large B-cell lymphoma (DLBCL). This randomised trial assessed whether six or eight cycles of R-CHOP-14 can improve outcome of these patients compared with six or eight cycles of CHOP-14.Methods1222 elderly patients (aged 61–80 years) were randomly assigned to six or eight cycles of CHOP-14 with or without rituximab. Radiotherapy was planned to sites of initial bulky disease with or without extranodal involvement. The primary endpoint was event-free survival; secondary endpoints were response, progression during treatment, progression-free survival, overall survival, and frequency of toxic effects. Analyses were done by intention to treat. The trial is registered on National Cancer Institute website, number NCT00052936 and as EU-20243.Findings3-year event-free survival was 47·2% after six cycles of CHOP-14 (95% CI 41·2–53·3), 53·0% (47·0–59·1) after eight cycles of CHOP-14, 66·5% (60·9–72·0) after six cycles of R-CHOP-14, and 63·1% (57·4–68·8) after eight cycles of R-CHOP-14. Compared with six cycles of CHOP-14, the improvement in 3-year event-free survival was 5·8% (−2·8–14·4) for eight cycles of CHOP-14, 19·3% (11·1–27·5) for six cycles of R-CHOP-14, and 15·9% (7·6–24·2) for eight cycles of R-CHOP-14. 3-year overall survival was 67·7% (62·0–73·5) for six cycles of CHOP-14, 66·0% (60·1–71·9) for eight cycles of CHOP-14, 78·1% (73·2–83·0) for six cycles of R-CHOP-14, and 72·5% (67·1–77·9) for eight cycles of R-CHOP-14. Compared with treatment with six cycles of CHOP-14, overall survival improved by −1·7% (−10·0–6·6) after eight cycles of CHOP-14, 10·4% (2·8–18·0) after six cycles of R-CHOP-14, and 4·8% (−3·1–12·7) after eight cycles of R-CHOP-14. In a multivariate analysis that used six cycles of CHOP-14 without rituximab as the reference, and adjusting for known prognostic factors, all three intensified regimens improved 3-year event-free survival (eight cycles of CHOP-14: RR [relative risk] 0·76 [0·60–0·95], p=0·0172; six cycles of R-CHOP-14: RR 0·51 [0·40–0·65], p<0·0001; eight cycles of R-CHOP-14: RR 0·54 [0·43–0·69], p<0·0001). Progression-free survival improved after six cycles of R-CHOP-14 (RR 0·50 [0·38–0·67], p<0·0001), and eight cycles of R-CHOP-14 (RR 0·59 [0·45–0·77], p=0·0001). Overall survival improved only after six cycles of R-CHOP-14 (RR 0·63 [0·46–0·85], p=0·0031). In patients with a partial response after four cycles of chemotherapy, eight cycles were not better than six cycles.InterpretationSix cycles of R-CHOP-14 significantly improved event-free, progression-free, and overall survival over six cycles of CHOP-14 treatment. Response-adapted addition of chemotherapy beyond six cycles, though widely practiced, is not justified. Of the four regimens assessed in this study, six cycles of R-CHOP-14 is the preferred treatment for elderly patients, with which other approaches should be compared.