Acute promyelocytic leukemia
ICD-10 C92.4 · ICD-11 2A60.0&XH1A50

Low/Intermediate-Risk APL (WBC ≤10,000/ml) When ATRA/ATO-Based Consolidation Fails to Achieve Molecular Remission

This protocol applies to patients with low/intermediate-risk acute promyelocytic leukemia who do not reach the required molecular endpoint at the end of ATRA/ATO-based consolidation and require a next-line approach.

Patient Scenario

A white blood cell count at or below 10,000/ml places this patient in the low/intermediate-risk APL category. Most clinicians today use this two-tier classification — high risk (>10,000/ml) versus low/intermediate risk — to guide therapy selection at each line.

Why This Protocol Is Needed

Previous line did not reach its goal

The prior treatment — chemotherapy-free ATRA/ATO-based consolidation (following ATRA/ATO-based induction) — did not achieve PML-RARA negative status by PCR at the end of consolidation. Failure to reach this molecular target is the trigger for escalation to the current protocol.

Treatment Approach (Overview Only)

Salvage strategies in this relapsed/refractory setting centre on arsenic trioxide-based combinations. Several agent combinations have shown activity in regaining molecular response; the specific options, their sequencing, and individualised considerations are detailed in the full structured protocol.

Clinical goal: Regaining of molecular complete remission (PML-RARA negative).
Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.3389/fonc.2022.1062524
In the era of ATRA, APL has been stratified into three categories of risk with regards to relapse-free survival (RFS): WBC >10,000/ml (high-risk), WBC ≤10,000 ml with platelet count ≤40,000/ml (intermediate-risk), and WBC ≤10,000/ml with platelet count >40,000/ml (low-risk).
Today, most clinicians will categorize APL within two categories, high risk (>10,000/ml) and low/intermediate risk.
The activity of ATO in relapsed disease has been demonstrated in multiple studies.
The combination of ATO and other agents such as idarubicin and GO have also shown efficacy in regaining molecular CR.
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