How it is administered

Pirtobrutinib is taken by mouth as a tablet. The recommended dose is 200 mg once daily, swallowed whole with water, with or without food. Tablets should not be cut, crushed, or chewed. If you miss a dose by more than 12 hours, skip the missed dose and take the next dose as scheduled.

How it works

Pirtobrutinib is a small molecule that works by blocking a protein called Bruton tyrosine kinase (BTK). BTK is important for the survival and growth of certain types of B-cells, which are a kind of white blood cell. In blood cancers like mantle cell lymphoma and chronic lymphocytic leukemia, these B-cells grow uncontrollably. By inhibiting BTK, pirtobrutinib helps to stop the signals that make these cancerous B-cells grow and survive.

Pirtobrutinib is unique because it can block both the normal form of BTK and forms that have certain mutations, which means it may work even if other BTK inhibitors have stopped working. This makes it a valuable option for patients whose disease has come back or did not respond to previous treatments, especially those who have already tried other BTK inhibitors.

Who Should take it

Pirtobrutinib is approved for adults with certain blood cancers who have already tried other treatments. Specifically, it is indicated for:

• Adults with mantle cell lymphoma (MCL) whose cancer has come back or did not respond to at least two previous treatments, including a BTK inhibitor.
• Adults with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) who have received at least two prior lines of therapy, including a BTK inhibitor and a BCL-2 inhibitor.

If you have marginal zone lymphoma, pirtobrutinib may be considered if other options have been exhausted, but its main approvals are for MCL and CLL/SLL. Your doctor will decide if this medication is suitable for you based on your treatment history and current health.

Who should not take it

There are no absolute contraindications listed for pirtobrutinib, but it should be used with caution in certain situations:

• If you are pregnant or planning to become pregnant, as pirtobrutinib can harm an unborn baby.
• If you have severe liver problems or a history of drug-induced liver injury, your doctor will need to monitor you closely.
• If you have active infections, bleeding problems, or significant heart rhythm issues, your doctor may need to adjust your treatment or monitor you more closely.

Always inform your healthcare provider about all your medical conditions and medications before starting pirtobrutinib.

Commonly used with

Pirtobrutinib is often used as a single agent, especially in patients who have already tried other therapies. In clinical studies, patients had previously received other treatments such as chemoimmunotherapy, other BTK inhibitors, and BCL-2 inhibitors. Your doctor may use pirtobrutinib after these treatments, but it is not typically combined with other cancer drugs at the same time.

Commonly tested with

Pirtobrutinib has been tested in clinical trials as a single agent in patients with relapsed or refractory mantle cell lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma who have received prior treatments, including other BTK inhibitors and BCL-2 inhibitors. It is being studied in various combinations and settings, but its main approval is as a single agent after other therapies have failed.