The stability of the monoclonal antibody Ipilimumab, the active ingredient of Yervoy®, used for the treatment of different types of cancer, has been investigated. Shaking/temperature, light exposure and dilution, protein drug renowned stressors, were applied on a 30-45-day series of experiments to observe the physicochemical and biological behavior of the molecule. Ipilimumab demonstrated stability under shaking and heat up to 45 days, without any unfolding during the induced combined stressors. Under artificial sunlight, the mAb showed to be sensitive even under the minimum dose tested (720 kJ/m