In case of discontinuation of study treatment, the patient will be considered as withdrawn from study treatment, and will be followed as planned for at least 30 days after the last administration of study treatment for safety purpose. In case of study treatment discontinuation without disease progression, efficacy data will be collected every 6 weeks until disease progression, death or end of study whatever comes first. After disease progression, the patient will be followed-up every 12 weeks (3 months) for overall survival until death or end of study.