A Safety Study of SGN-CD33A in Combination With Standard-of-care in Patients With AML

The study will be conducted in the following distinct parts:

Part A: Induction dose escalation - 7+3 combined with SGN-CD33A (Day 1 and Day 4 dosing)

Part B: Consolidation dose escalation - consolidation combined with SGN-CD33A; up to 4 cycles
of consolidation therapy will be administered after SGN-CD33A (Day 1 of each cycle).

Part C: Maintenance - SGN-CD33A Monotherapy; Up to 24 patients with and up to 24 patient
without prior allogeneic stem cell transplant will be treated with SGN-CD33A. Both arms will
enroll simultaneously. SGN-CD33A will be administered on Day 1 of each 6-week cycle for up to
8 cycles.

Part D: Induction plus consolidation - induction/consolidation combined with SGN-CD33A;
patients who achieve a CR/CRi (with or without a second induction) will receive up to 4
cycles of consolidation therapy administered after SGN-CD33A (Day 1 of each cycle).

Part E: Induction dose escalation - 7+3 combined with SGN-CD33A (Day 1 dosing)

Inclusion Criteria:

- All subtypes of Acute Myeloid leukemia (except for acute promyelocytic leukemia)

- Eastern Cooperative Oncology Group status of 0 or 1

- Adequate baseline renal and hepatic function

- Central venous access

- Part specific requirements: eligible to receive induction; achieved CR/CRi with
standard induction and eligible to receive consolidation; in CR with documented blood
count recovery for maintenance

Exclusion Criteria:

- Previous treatment for MDS or MPN for dose escalation cohorts

- Inadequate lung function

- Inadequate heart function