Pirtobrutinib (Jaypirca, Eli Lilly) is a non-covalent, third-generation BTK inhibitor. 

When is Pirtobrutinib Used for CLL?

To be eligible for pirtobrutinib treatment, patients must have previously received at least two lines of therapy, including a BTK inhibitor and a BCL-2 inhibitor. 

How is Pirtobrutinib Administered?

This medication is taken orally at a recommended dosage of two 100 mg tablets a day. 

How Does Pirtobrutinib Work?

Pirtobrutinib is a non-covalent Bruton's tyrosine kinase (BTK) inhibitor, which means it binds to BTK in a reversible manner. This contrasts with covalent BTK inhibitors that form a permanent bond with BTK.

In people with CLL who have developed resistance to covalent BTK inhibitors (like ibrutinib, acalabrutinib, or zanubrutinib) due to BTK mutations, pirtobrutinib's reversible binding allows it to maintain efficacy. This is because pirtobrutinib can still inhibit BTK even if certain mutations have altered the protein structure, whereas covalent inhibitors might lose effectiveness. Over time, additional mutations in the CLL cell may occur, which can cause pirtobrutinib to stop working. 

How Effective is Pirtobrutinib for CLL?

A 2023 study of pirtobrutinib in CLL showed the following data on how long pirtobrutinib helps achieve a duration of response (DoR), meaning the length of time CLL signs and symptoms are decreased either partially or fully. 

• Patients who have previously taken a covalent BTK inhibitor and then take pirtobrutinib: DoR 18.4 months
• If you have not taken venetoclax or other BCL-2 inhibitors and then take pirtobrutinib: DoR 24.9 months
• If you have previously taken venetoclax and then take pirtobrutinib: DoR 14.8 months

Side Effect Profile of Pirtobrutinib for CLL

The percentage of people with CLL who experience mild-moderate versions of common side effects from pirtobrutinib is shown below. 

You can visit the Side Effects Management section of this guide for more information on these side effects. 

For more information on this therapy, check out Jaypirca Prescribing Information.

Financial Resources for Pirtobrutinib

To locate financial resources for pirtobrutinib, click here to visit the financial support section of the guide.