This phase II, single-arm, multicenter study will evaluate efficacy and toxicity of administration of pembrolizumab following cyclophosphamide therapy, in advanced stage triple-negative breast cancer.~Duration of Therapy~Treatment may continue until one of the following occurs:~Disease progression~Inter-current illness that prevents further administration of treatment~Unacceptable adverse event(s)~Pregnancy~Patient decides to withdraw from study treatment,~General or specific changes in the patient's condition render the patient unacceptable for further treatment in the judgment of the investigator~Completed 24 months of uninterrupted treatment with pembrolizumab or 35 administrations of study medication, whichever is later~Duration of Follow Up~Subjects will be followed for up to 3 years after removal from study treatment or until death, whichever occurs first.~Patients removed from study for unacceptable adverse events (AEs) will be followed until resolution or stabilization of the event(s).
The purpose of this study is to evaluate pembrolizumab therapy in patients with triple-negative breast cancer (TNBC) who have received at least one prior line of therapy.