Mechanism of action: Pirtobrutinib balliculeVisual mnemonic: Pirtobrutinib mascot “Jay (ap)Pears to brutally nibble”
What it isNoncovalent BTK inhibitor; relapsed or refractory mantle-cell lymphoma and chronic lymphocytic leukemia.
Why this oneBecause it does not depend on the C481 cysteine, it keeps working after the C481S mutation that defeats ibrutinib, acalabrutinib and zanubrutinib.
What limits itSerious infection, bleeding, cytopenias, atrial arrhythmia, and second malignancies require surveillance.
200 mg QD until progression or unacceptable toxicity
200 mg QD
CLL/SLL, previously treated
adults
200 mg QD
200 mg QD until progression or unacceptable toxicity
200 mg QD
Renal Severe (eGFR 15–29): reduce 200→100 mg QD (otherwise reduce by 50 mg; discontinue if on 50 mg). Mild–moderate (eGFR 30–89): no adjustment
Hepatic No adjustment needed
Instructions
Swallow whole with water; do not cut, crush, or chew
With or without food; take at the same time each day
Missed dose >12 h: skip — take next dose as scheduled
Toxicity (Grade ≥3 non-heme, defined cytopenias): interrupt until recovery to Grade 1/baseline, restart 200→100→50 mg QD by occurrence; discontinue on 4th occurrence
If strong CYP3A inhibitor unavoidable: reduce dose by 50 mg (interrupt if on 50 mg); if moderate CYP3A inducer unavoidable: increase 200→300 mg (or +50 mg if on 50/100 mg)
Available strengths
tab 50, 100 mg
Cautions
Fatal/serious infections incl. opportunistic (Grade ≥3 in 25%, most commonly pneumonia); consider vaccination/antimicrobial prophylaxis
Hemorrhage incl. fatal; consider withholding 3–7 days pre/post surgery
Pregnancy Can cause fetal harm (animal data at ~3x human exposure); verify pregnancy status before starting; advise of fetal risk
Lactation Do not breastfeed during treatment and for 1 week after last dose
Cost
Pirtobrutinib (JAYPIRCA)
Strength
#/mo
generic $/mo
CostPlus
50 mg
tab
30 qd
not offered
100 mg
tab
30 qd
not offered
NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Pirtobrutinib is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.
NO BOXED WARNINGS
Principal riskInfections, hemorrhage and cytopenias