Idelalisib (Zydelig)

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Gilead Sciences, Inc.

In light of recently reported safety concerns, the European Medicines Agency’s (EMA) Pharmacovigilance Risk Assessment Committee (PRAC) has issued provisional advice for doctors and patients using idelalisib (Zydelig).

The EMA recently began reviewing the safety of idelalisib because of serious adverse events, most of which were infection-related, that were reported in 3 clinical trials investigating idelalisib in combination with other drugs.

These trials have since been stopped.

Now, the PRAC is making provisional recommendations to ensure idelalisib is used as safely as possible outside of clinical trials.

These recommendations will be forwarded to the European Commission, which will issue a provisional legally binding decision applicable in all European Union (EU) member states.

In the EU, idelalisib is approved as monotherapy for adults with follicular lymphoma that is refractory to 2 prior lines of treatment.

Idelalisib is also approved for use in combination with rituximab to treat adults with chronic lymphocytic leukemia (CLL) who have received at least 1 prior therapy or as first-line treatment in the presence of 17p deletion or TP53 mutation in CLL patients considered unsuitable for chemo-immunotherapy.

Recommendations

The PRAC is recommending that previously untreated CLL patients with 17p deletion or TP53 mutation do not begin treatment with idelalisib. In addition, doctors should re-evaluate each patient taking idelalisib as first-line treatment for CLL and only continue treatment if the benefits outweigh the risks.

Idelalisib can continue to be used in combination, only with rituximab, in CLL patients who have received at least 1 prior therapy and as monotherapy in patients with follicular lymphoma that is refractory to 2 lines of treatment.

Patients with any evidence of ongoing systemic infection should not be started on treatment with idelalisib.

And patients should be informed about the risk of serious infections with idelalisib.

All patients who do receive idelalisib should take antibiotics to prevent Pneumocystis jirovecii pneumonia, and they should be monitored for respiratory signs and symptoms. Regular clinical and laboratory monitoring for cytomegalovirus infection is also recommended.

Patients should have regular blood tests to detect neutropenia. In case a patient has moderate or severe neutropenia, treatment with idelalisib may have to be interrupted, in line with the updated summary of product characteristics.

The EMA said further details on these provisional measures will be provided in writing to healthcare professionals, and the product information will be updated accordingly.

Likewise, further information on the review of idelalisib will be provided as necessary and once the review is finished.

About the review

The EMA’s review of idelalisib started after a higher rate of serious adverse events, including deaths, was seen in 3 clinical trials evaluating the addition of idelalisib to standard therapy in first-line CLL and relapsed indolent non-Hodgkin lymphoma (NHL).

Most of the deaths were related to infections such as Pneumocystis jirovecii pneumonia and cytomegalovirus infection. Other excess deaths were related mainly to respiratory events.

The NHL studies (NCT01732926 and NCT01732913) included patients with disease characteristics different from those covered by the currently approved indication for idelalisib and investigated combinations of drugs that are not currently approved in the EU—idelalisib plus rituximab for NHL and idelalisib plus bendamustine and rituximab for NHL.

The CLL trial (NCT01980888) involved patients who had not received previous treatment, some of whom had the 17p deletion or TP53 mutation. However, the trial also investigated a combination of drugs not currently approved in the EU—idelalisib plus bendamustine and rituximab.

At present, the PRAC is conducting the review. Once the PRAC is finished, its recommendations will be forwarded to the EMA’s Committee for Medicinal Products for Human Use, which will adopt a final opinion.

The European Commission will take this opinion into account and adopt a legally binding decision that is applicable in all EU member states.

EMA recommends safety measures for idelalisib