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Acute Promyelocytic Leukaemia APML4 Protocol

APML4 Protocol: A phase II trial in patients with previously untreated acute promyelocytic leukaemia to evaluate the effect on time to molecular relapse and early death rate as a result of: (i) adding arsenic trioxide to all-trans retinoic acid and idarubicin for remission induction, (ii) adding arsenic trioxide to all-trans retinoic acid as consolidation, (iii) the obligatory use of prednisone (or prednisolone) and aggressive haemostatic support during induction.

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ANZCTR
Registry ID
ACTRN12605000070639
Enrollment
129
Registered
2005-08-04
Start date
2004-11-10
Completion date
2009-09-23
Last updated
2023-08-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Acute promyelocytic leukemia (APL) is a unique subtype of acute myeloid leukemia that is characterized by distinct clinical and laboratory abnormalities. It is associated with a striking risk of early death due to bleeding. Fortunately, the outcome for patients with APL has improved dramatically following the introduction of all-trans retinoic acid (ATRA) and its combination with chemotherapeutic drugs such as idarubicin. Patients with a white cell count > 10 x 109/L at diagnosis are at particularly increased risk of early death and of relapse (disease recurrence). Arsenic trioxide (ATO) has proved to be even more effective than ATRA as a single agent, and is now routinely used for the treatment of the 20%–30% of patients who relapse after initial treatment with ATRA and chemotherapy. ATO has a side-effect profile that is substantially different from both ATRA and chemotherapy. In the APML4 trial, members of the Australasian Leukaemia and Lymphoma Group (ALLG) combined the 3 most active drugs used for APL (ATRA, idarubicin, and ATO) in induction, and then consolidated the responses with 2 cycles of ATRA and ATO without chemotherapy. This strategy helped reduce the total amount of chemotherapy compared with many other protocols available, in the hope of reducing long-term side effects such as bone marrow damage and heart damage. Two years of maintenance was used as per the ALLG standard practice for APL. The results were very impressive. One hundred and twenty-four evaluable patients were enrolled between Nov 2004 and Sep 2009, and the outcomes were reported in 2 publications (Blood 2012, Lancet Haematology 2015). The early death rate was 3%, and 95% of patients achieved complete remission after induction with ATRA, ATO and idarubicin. All 112 patients who started consolidation achieved molecular remission (no detectable leukaemia by a very sensitive molecular assay). The long term results that were reported in Lancet Haematology showed that the relapse rate at 5 years was only 5%. Patients traditionally regarded as at very high risk of relapse had the same low relapse rate as patients who were in the standard risk category, and this was a major achievement of the APML4 treatment plan. Overall, 94% of patients were still alive at 5 years. When the results were compared with the ALLG’s previous APML3 trial (which did not include ATO), the results were substantially better with less relapses and better overall survival. Although side effects occurred, as in every clinical trial for leukaemia, the overall side effect profile was widely acknowledged as acceptable (ie. not excessive).

Interventions

A single arm phase II study of all-trans retinoic acid (ATRA), idarubicin and arsenic trioxide (As2O3) over 36 days as induction therapy for acute promyelocytic leukaemia, followed by two cycles of consolidation with ATRA and As2O3 (over 28 days and 35 days respectively). Prednisone is administered during induction for all patients. Consolidation is followed by 2 years of maintenance therapy with daily 6-mercaptopurine, once weekly methotrexate, and 2 weeks of ATRA every 3 months. Bone marrow sa

A single arm phase II study of all-trans retinoic acid (ATRA), idarubicin and arsenic trioxide (As2O3) over 36 days as induction therapy for acute promyelocytic leukaemia, followed by two cycles of consolidation with ATRA and As2O3 (over 28 days and 35 days respectively). Prednisone is administered during induction for all patients. Consolidation is followed by 2 years of maintenance therapy with daily 6-mercaptopurine, once weekly methotrexate, and 2 weeks of ATRA every 3 months. Bone marrow sampling for molecular monitoring is performed after each cycle of induction and consolidation, and then every 3 months for 2 years.

Sponsors

Australasian Leukaemia and Lymphoma Group
Lead SponsorOther Collaborative groups

Study design

Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)

Eligibility

Sex/Gender
All
Age
1 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Morphological diagnosis of APL, either classical FAB-M3 or variant FAB-M3v. The leukaemia must have occurred de novo, with no previous history of preleukaemia, myelodysplasia, or myeloproliferative disorder. 2. Demonstration of PML-RARA fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR). 3. ECOG performance status 0-3. 4. Absence of previous history of serious cardiac, pulmonary, hepatic or renal disease, and absence of history of grand mal seizures. A serum creatinine >200umol/L or serum bilirubin >50umol/L precludes entry into the study, unless medically correctable. 5. A left ventricular ejection fraction of at least 50% as demonstrated by gated heart pool scan (preferably) or cardiac ultrasound. 6. ECG showing sinus rhythm and Q-Tc interval <500msec. Prolongation of Q-Tc due to medication or electrolyte disturbance must be corrected before registration. 7. No previous treatment for APL, or history of cancer (other than basal cell skin cancer, or carcinoma of cervix in situ). 8. No contra-indication to use of any of the study drugs. 9. A negative pregnancy test in females of child-bearing age. 10. Written informed consent

Exclusion criteria

No exclusion criteria

Outcome results

None listed

Source: ANZCTR · Data processed: Mar 26, 2026