- Pregnant women are excluded from this study because there is an unknown but potential risk for adverse events in the developing fetus with SL-401 and azacitidine (negative urine or serum pregnancy test required within 14 days of Cycle 1, Day 1). Because nursing infants have unknown potential for adverse events secondary to treatment of the mother, breastfeeding should be discontinued if the mother is treated with SL-401 and azacitidine.