New FDA approval brings a targeted therapy option to initial CLL treatment

The U.S. Food and Drug Administration (FDA) recently approved pirtobrutinib for adults with previously untreated chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) who don’t have a genetic change called del(17p).

This approval gives some people newly diagnosed with CLL or SLL another option for their initial treatment. It is especially notable because pirtobrutinib is a targeted therapy that works differently from traditional chemotherapy-based treatment.

What is pirtobrutinib?

Pirtobrutinib is a type of targeted treatment called a noncovalent Bruton tyrosine kinase (BTK) inhibitor. BTK is a protein that helps certain blood cancer cells grow and survive. By blocking BTK, pirtobrutinib can help slow the growth of CLL or SLL.

Pirtobrutinib was previously approved for people with CLL or SLL whose disease had returned or stopped responding to earlier treatments. With this new FDA approval, it can now also be considered as an initial treatment for certain people with CLL or SLL.

What is del(17p)?

del(17p), short for deletion of the short arm of chromosome 17, is a genetic change found in some people with CLL. It involves the loss of a region of chromosome 17 that includes the TP53 gene, which normally helps control abnormal cell growth.

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CLL with del(17p) can behave differently and may be more difficult to treat with some therapies. That’s why knowing whether you have this genetic change can be an important part of treatment planning.

Your doctor can check for it using a blood test called fluorescence in situ hybridization (FISH). The test looks for specific chromosome changes in your CLL cells. Your care team may also order other genetic or molecular tests to help determine which treatments may be most appropriate for you.

What did the clinical trial show?

The FDA’s decision was based on results from the phase 3 BRUIN CLL-313 trial, which included 282 people with previously untreated CLL or SLL who didn’t have del(17p).

Participants were randomly assigned to receive either pirtobrutinib or a combination of two medicines, bendamustine and rituximab (BR), for six treatment cycles.

Researchers looked at progression-free survival (PFS), which measures how long people live without their cancer getting worse or dying from any cause.

After a median follow-up of about 28 months, the median PFS had not yet been reached for people who received pirtobrutinib. This means that more than half of the people in this group had not experienced disease progression by the time of the analysis.

In comparison, the median PFS was 33.5 months for people who received bendamustine plus rituximab. Overall, people who received pirtobrutinib had a significantly lower risk of their disease progressing or death during the study period.

Why is this approval important?

For people newly diagnosed with CLL or SLL, the first treatment decision can be especially important. Today’s targeted therapies can work for long periods, and some people may only need one or two lines of treatment.

This approval adds another targeted therapy option to the choices doctors can consider when deciding on an initial treatment plan. It also gives patients and their care teams another option to weigh alongside factors such as the cancer’s genetic features, overall health, age, other medical conditions, and potential side effects.

Importantly, this approval applies specifically to adults with previously untreated disease who don’t have del(17p). Your treatment options may also depend on other features of your cancer and your overall health.

What does this mean if you have CLL or SLL?

If you have recently been diagnosed with CLL or SLL, this approval is another example of how treatment options are expanding beyond traditional chemotherapy-based approaches.

Ask your oncologist whether pirtobrutinib could be an option for you and how it compares with other available initial treatments. Understanding the specific features of your CLL or SLL can help you and your care team choose a treatment approach that fits your individual situation.

Disclaimer: The information provided in this article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Outcomes4Me is not acting as your caregiver, and any suggestions or guidance offered should not replace the advice of your healthcare provider or qualified medical professional. Always seek the guidance of your physician or other qualified health provider with any questions you may have regarding a medical condition.