Treatment with obinutuzumab-chlorambucil or rituximab-chlorambucil , as compared with chlorambucil monotherapy , increased response rates and prolonged progression-free survival ( median progression-free survival , @ months with obinutuzumab-chlorambucil vs. @ months with chlorambucil alone ; hazard ratio for progression or death , @ ; @ % confidence interval -LSB- CI -RSB- , @ to @ ; P < @ ; and @ months with rituximab-chlorambucil vs. @ months with chlorambucil alone ; hazard ratio , @ ; @ % CI , @ to @ ; P < @ ) .