Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumadin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed as long as patient has adequate coagulation defined as: activated partial thromboplastin time (aPTT) international normalized ratio (INR) =< 1.5 x upper limit of normal Participants may not be currently receiving anticoagulation with coumadin for treatment or prophylaxis; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed Currently receiving warfarin or other warfarin-derived anticoagulant for treatment, prophylaxis or otherwise; Note: Therapy with heparin, direct oral anticoagulants, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other Coumadin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, direct thrombin inhibitors, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumadin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed for subjects receiving anticoagulant, the subjects must, in the investigator's opinion, be clinically stable with no evidence of active bleeding while receiving anticoagulant therapy. The INR for subjects on warfarin should be in the therapeutic range. Low molecular weight heparin (LMWH) is allowed. Patient is currently receiving warfarin or other coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), fondaparinux, or other oral anticoagulants is allowed OR for subjects receiving warfarin or low molecular weight heparin (LMWH), the subjects must, in the Investigator's opinion, be clinically stable with no evidence of active bleeding while receiving anticoagulant therapy. The INR for these subjects may exceed 1.5 × ULN if that is the goal of anticoagulant therapy. Subject is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise. Therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed. Patient is currently receiving warfarin or other coumadin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Receiving warfarin (or other coumarin derivatives) and is unable to switch to low molecular weight heparin (LMWH) before the first dose of study drug International normalized ratio (INR) =< 1.5\r\n* Use of rivaroxaban, apixaban, edoxaban or warfarin is an exclusion criteria; therapy with heparin, low molecular weight heparin (LMWH), dabigatran or fondaparinux is allowed Currently receiving rivaroxaban, apixaban, endoxaban, warfarin or other warfarin derived anticoagulant; therapy with heparin, low molecular weight heparin (LMWH), dabigatran or fondaparinux is allowed; if transitioning from a prohibited anticoagulant, a minimum washout of 7 days from last dose of the prohibited medication is required prior to ribociclib start Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed administration of therapeutic doses of LMWH, fondaparinux, or unfractionated heparin (UFH) for more than 72 hours before randomization; Patient is currently receiving warfarin or other Coumarin-derived anticoagulant for treatment, prophylaxis, or other reasons. Therapy with heparin, low molecular weight heparin, or fondaparinux is allowed. Patient is currently receiving warfarin or other coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Subject is currently receiving warfarin or other coumarin-derived anti-coagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed Subject is currently receiving warfarin or other Coumarin derived anti-coagulant for treatment; therapy with heparin, low molecular weight heparin (LMWH), factor Xa, or fondaparinux is allowed Patient is currently receiving warfarin or other Coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; NOTE: therapy with apixaban, dabigatran, heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumadin-derived anticoagulant for treatment, prophylaxis or otherwise. Therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise. Therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed. Patient is currently receiving warfarin or other vitamin K antagonist; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed Patient is currently receiving warfarin or other coumarin-derived anticoagulant for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH) or fondaparinux is allowed The subject is receiving warfarin (or other coumarin derivatives) and is unable to switch to low molecular weight heparin (LMWH) before the first dose of study drug Patient is currently receiving warfarin or other coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed OR for subjects receiving warfarin or low molecular weight heparin (LMWH), the subjects must, in the Investigator's opinion, be clinically stable with no evidence of active bleeding while receiving anticoagulant therapy. The INR for these subjects may exceed 1.5 × ULN if that is the goal of anticoagulant therapy. Patient is currently receiving warfarin or other coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise. Therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed. Patient is currently receiving warfarin or other Coumarin derived anti-coagulant, for treatment, prophylaxis or otherwise; therapy with heparin, low molecular weight heparin (LMWH), or fondaparinux is allowed