Chemotherapy induced thrombocytopenia

CIT Key points

1.  Rule out other causes of low plt, even if the cause is most likely CIT

2.  Two types: persistent CIT, and nadir CIT

3. Persistent CIT: typically plt count < 50K, requiring dose reduction or dose delays.

4. N-plate has most data compared to oral thrombopoietin agonists.

Starting dose 2-4microgram per week gives best results, compared to intracycle dosing. Can titrate dose up or down by 1 microgram per week depending on plt level. If plt level > 200K, dose down.

5. N plate is not useful for nadir thrombocytopenia if plt count recovers before the next cycle spontaneously.

6. The issue with nadir thrombocytopenia is need to hold anticoagulants that the patient is on for VTE or Afib.

7. Persistent CIT found 3 main predictors of nonresponse to romiplostim treatment: known bone marrow involvement by tumor, prior pelvic irradiation, and prior receipt of temozolomide therapy

8. There is a risk of VTE because of romiplostim, but ok to ct it if patient is on therapeutic anticoagulation.

9. No role for use of romiplostim to manage CIT in myeloid malignancies

 Reference: ASH education book 2022