Regulatory

FDA reduces initial monitoring time for Amgen’s Imdelltra

The revised prescribing information cuts post-infusion observation from 22–24 hours to six–eight hours for the first two doses to adults with extensive-stage small cell lung cancer

The US Food and Drug Administration (FDA) has approved an update to the prescribing information for Amgen’s Imdelltra (tarlatamab-dlle), reducing the recommended monitoring period following the first two infusions for adults with extensive-stage small cell lung cancer (ES-SCLC) whose disease has progressed after platinum-based chemotherapy.

Under the revised guidance, patients should be monitored for six to eight hours in an appropriate healthcare setting after each of the first two doses, replacing the earlier requirement for 22 to 24 hours of observation. A follow-up assessment, including vital signs, is also required the day after each of these doses.

Monitoring requirements for subsequent doses remain unchanged, with six to eight hours required for the third dose and throughout Cycle 2, three to four hours for Cycles 3 and 4, and two hours for Cycle 5 and beyond.

The updated label continues to recommend that patients remain within one hour of suitable medical facilities for 48 hours from the start of the first and eighth day infusions, accompanied by a caregiver.

Amgen said the regulatory update could reduce the time patients need to spend in healthcare settings during the early stages of treatment and help address practical barriers to treatment access.

“This approval is an important step in simplifying care for people living with and treating ES-SCLC,” said Jay Bradner, Executive Vice-President, Research and Development, Amgen. “Reducing monitoring to six to eight hours for the initial doses may help address practical barriers associated with administering Imdelltra and enable more patients to receive care closer to home.”

Imdelltra is a targeted immunotherapy designed to bind to DLL3 proteins on tumour cells and CD3 on T cells, activating the immune system to target small cell lung cancer cells. The monitoring update applies only to the first two doses.

In January 2025, Amgen received conditional approval from the UK Medicines and Healthcare products Regulatory Agency for Imdelltra for the treatment of ES-SCLC.