The European APL91 and the North American Intergroup study I0129 reported in the 1990s that ATRA combined with chemotherapy markedly improves the outcome of APL. Large randomized and single-arm studies from around the world with both short and relatively long-term follow-up confirm the impact of ATRA, while optimizing their mode of administration. However, the incidence and outcome of late relapses have not been well established.
Leader of the Acute Lymphoblastic Leukemia Program Dan Douer discusses a recent study that examined late relapses among APL patients enrolled in the North American Intergroup study I0129 conducted between April 1992 and February 1995. The research concludes that late relapses are very rare after four years; at that time, patients are most likely cured. If the high rate of early death can be reduced, more patients will benefit from the high cure rate reported by this and other studies.