Waldenström with adverse molecular biology: MYD88-wildtype (poor BTKi response — ibrutini...

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`RF-WM-HIGH-RISK-BIOLOGY`
Type	Red flag
Status	reviewed 2026-04-27 \| pending_clinical_signoff
Diseases	`DIS-WM`
Sources	`SRC-ESMO-WM-2024` `SRC-NCCN-BCELL-2025`

Red Flag Origin

Definition	Waldenström with adverse molecular biology: MYD88-wildtype (poor BTKi response — ibrutinib/zanubrutinib substantially less active), CXCR4-mutated (delayed BTKi response, may benefit zanubrutinib > ibrutinib per ASPEN trial), TP53-mutated (chemo-resistance), or IPSSWM intermediate-high / high risk. Drives selection of fixed-duration chemoimmuno (BR or Dex-R-Cyclo) over continuous BTKi when MYD88-wildtype.
Clinical direction	intensify
Category	high-risk-biology

Trigger Logic

{
  "any_of": [
    {
      "finding": "myd88_status",
      "value": "wildtype"
    },
    {
      "finding": "cxcr4_mutation",
      "value": true
    },
    {
      "finding": "tp53_mutation",
      "value": true
    },
    {
      "finding": "ipsswm_high_risk",
      "value": true
    }
  ],
  "type": "biomarker"
}

Notes

MYD88-L265P mutation present in ~95% WM and is the predictive biomarker for BTKi efficacy — MYD88-wildtype WM (~5%) responds poorly to ibrutinib (ORR ~30% vs ~90% for MYD88-mut per Treon series). For MYD88-WT or BTKi-ineligible: BR (bendamustine + rituximab) is preferred fixed-duration regimen. CXCR4 mutations (~30-40% MYD88-mut WM) delay BTKi response and are partially overcome by zanubrutinib (ASPEN trial showed deeper responses vs ibrutinib in CXCR4-mut subset). TP53-mut WM: avoid chemoimmuno; BTKi-based or BCL2-based (venetoclax — Castillo emerging data) preferred.

Used By

Algorithms

ALGO-WM-2L - ALGO-WM-2L