Waldenström Macroglobulinemia
New Waldenström macroglobulinemia research, summarized each month in plain language.
2026 so far: From January 2026 to September 2026, evidence on BTK inhibitors became more specific about response and safety differences. Real-world first-treatment comparisons and POD24 studies (progression within 24 months) also helped set expectations for how long disease control may last. Read the 2026 review
We also cover clinical trials.
Yearly update
2026 so far
- BTK inhibitor differences. Comparative and longer follow-up data clarified BTK trade-offs.
- First treatment comparisons. Retrospective cohorts compared frontline regimens using response and durability.
- Beyond standard BTK. Newer agents and non-BTK regimens showed activity with caveats.
- Managing complications. Reports repeatedly highlighted infections and IgM-driven complications.
- Tracking disease activity. Mutation and imaging measures often diverged from IgM on BTK.
New
September 2026
- Upfront treatment outcomes. First treatments differed in major response rates and time to next treatment.
- Early relapse risk. Relapse within 24 months after one regimen linked to worse later outcomes.
- Nerve and anemia symptoms. Rituximab-based treatment was linked to improved neuropathy and anemia symptoms.
August 2026
- First treatment options. Rituximab combinations were linked with longer time before worsening.
- BTK pill therapy. BTK inhibitor pills looked active, but data were from a small study.
- Beta-2 microglobulin. Higher beta-2 microglobulin at diagnosis was tied to worse survival.
- ICU infection risk. In ICU patients, infections were a leading cause of death.
July 2026
- BTK treatment response. BTK inhibitors often worked well in routine care.
- Infection risk. Infections were common during BTK inhibitor treatment.
- New BTK safety data. A newer BTK inhibitor reported early dosing and safety data.
- Heart and infection links. Studies linked monoclonal proteins with heart amyloid and severe infections.
June 2026
- Post-BTK treatment. Bortezomib-based treatment often worked after BTK inhibitors.
- First-line treatment. Obinutuzumab plus bendamustine had high response rates as first treatment.
- Free light chain tests. Two free light chain blood tests mostly agreed overall.
May 2026
- Pirtobrutinib in relapsed WM. In a trial of relapsed or refractory WM, pirtobrutinib showed high response rates, but serious side effects were also reported.
- Zanubrutinib vs ibrutinib safety. In real-world data that included WM, zanubrutinib was linked to lower rates of new atrial fibrillation or flutter, major bleeding, and death within 12 months than ibrutinib, though this type of study cannot fully control for differences between patient groups.
- PET/CT vs blood response tracking. A PET/CT-based method matched blood-based response categories after chemoimmunotherapy, but often did not match during BTK inhibitor treatment.
April 2026
- Longer disease control. With longer follow-up, acalabrutinib responses continued to last for many patients.
- Long-term safety signals. Longer follow-up added detail on heart-related side effects and a rare severe bleeding event.
- Bleeding can worsen. Case reports suggest bleeding may worsen in some people on certain BTK inhibitors.
- Diagnosis from unusual clues. Some diagnoses started after unusual lab results or rare tissue involvement prompted further testing.
March 2026
- BTK inhibitor results and safety. BTK inhibitors continued to show responses, but side effects and differences between patient subgroups affected how results were interpreted.
- IgM rebound during switches. Some reports noted an IgM rebound during certain treatment switches, especially when stopping a BTK inhibitor.
- Kidney function at diagnosis. Lower kidney filtering (reduced eGFR) at diagnosis was linked to shorter survival in reported datasets.
- Risk scores in the BTK era. Several studies suggested older risk scores predicted outcomes less well when BTK inhibitor–based treatment was used.
February 2026
- Zanubrutinib vs ibrutinib outcomes. With longer follow-up, zanubrutinib continued to show faster and deeper responses than ibrutinib, and fewer people stopped zanubrutinib because of side effects.
- Different long-term side effects. Long-term side effects differed by drug rather than one being side effect-free, with heart rhythm problems reported more with ibrutinib and low neutrophil counts more common with zanubrutinib.
- Diagnosis and lab testing issues. Reports described WM being found during workup for persistent unexplained anemia and noted that very high IgM can interfere with a common lab method unless the sample is specially handled.
- Early signals on BTK resistance. Bone marrow testing during ibrutinib treatment suggested possible patterns linked to longer control versus progression, but these findings are early and not used for routine decisions.
January 2026
- BR long-term control. Many people had long-lasting control after bendamustine-rituximab.
- Early relapse risk. Return within 24 months was linked to shorter survival.
- Mutation level monitoring. Mutation levels may track bone marrow disease better than IgM.
- Infection-related deaths. Infections remained a major reported cause of death.
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