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Prolonged maintenance with rituximab in indolent NHL
A
B
Figure 3. Survival outcomes during the randomized Maintenance II period. Kaplan-Meier analysis of progression-free (A) and overall survival (B) during the random- ized Maintenance II period. R-SC: subcutaneous rituximab.
84.6) for other regimens (including FCM and MCP). All but one patient per arm among the 276 who were randomized in Maintenance II were responders after Induction (Online Supplementary Table S5). Proportions of patients in com- plete response or partial response at the end of Maintenance I were also comparable between arms among the 276 patients who were randomized (Online Supplementary Table S5).
Of the 357 patients who achieved a partial response at the end of Induction, 77 achieved a complete response by the end of Maintenance I, providing a conversion rate of 21.6% (95% CI: 17.4–26.2).
The MabCute study was unable to address its primary endpoint (investigator-assessed PFSrand) because the number of events reported was insufficient: 129 PFSrand events were needed for 80% power at 5% significance, with approxi- mately 700 patients needed initially to yield the 330 required for randomization. There were 46 PFSrand events at the end of study: 19 and 27 in the rituximab and observa- tion arms, respectively: P=0.410 by log-rank test stratified by FLIPI risk category and NHL subtype; HR 0.76 (95% CI: 0.37–1.53), estimated using a Cox regression model with
FLIPI risk category and NHL subtype as stratification fac- tors. PFSrand rates at 6, 9, 12, 15 and 18 months (Kaplan-Meier estimates) were similar for both arms (between 0.97 at 6 months and 0.88 at 18 months for rituximab, and between 0.96 at 6 months and 0.87 at 18 months for observation). The median PFSrand was not reached in either arm (Figure 3A).
One patient, randomized to observation, discontinued from the study and subsequently died 2 months later. This event was not taken into consideration in the primary analysis due to a recording issue. It had no effect on the overall results or conclusions of the study.
The median PFSreg (from enrollment to end of Maintenance I) (Figure 4A) was 46.32 months (95% CI: 42.87–60.02) in patients receiving bendamustine, 39.62 months (95% CI: 27.86–not reached) in patients receiving CHOP, and 37.03 months (95% CI: 33.87–74.12) in patients receiving CVP. Three-year PFS estimates for patients receiving bendamustine, CHOP, and CVP were 0.63 (95% CI: 0.57–0.69), 0.58 (0.46–0.68), and 0.59 (0.28– 0.80), respectively. The median OSreg (from enrollment to end of Maintenance I) (Figure 4B) was not reached in patients receiving bendamustine (95% CI: 66.86–not
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