Despite the combined actions of maintenance triple immunotherapy, most transplanted organs do eventually fail. Immunotherapy is truly a treatment that delays the inevitability of graft rejection. However, when an acute rejection episode does finally occur, transplant patients still have good therapy options. In the vast majority of rejection episodes, the temporary treatment of high doses of corticosteroid is used to combat rejection by severely depressing the immune system. For those rejection episodes which are resistant to corticosteroid treatment, polyclonal and monoclonal antibodies are often employed as a rescue therapy. The more recently explored monoclonal antibodies, such as Muromonab-CD3 and Basiliximab, are more specific than their polyclonal counterparts; this is important because medications with higher specificity have less pathways by which to induce serious medical complications. Finally, antiproliferatives have also been found to be effective in treating rejection episodes. When utilized for rescue therapy, antiproliferatives are delivered at much higher dosages relative to maintenance immunosuppressive levels, and gastrointestinal intolerance can be a severe side effect (for Mycophenolate Mofetil).

In the future, immunotherapy will seek to find more effective ways to prevent rejection episodes rather than treat them. As a general rule, any therapy that utilizes less medication is ultimately a better treatment for the patient.