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 time for patients with extensive-stage small cell lung cancer (ES-SCLC) after their first two infusions.

The revised guidance is intended for adults whose ES-SCLC has progressed after treatment with platinum-based chemotherapy.

It recommends a monitoring period ranging between six and eight hours in an appropriate healthcare setting following the initial two doses of Imdelltra. This replaces the previous requirement for 22 to 24 hours of observation.

Additionally, patients will receive a follow-up assessment, including vital signs, the day after each of these first two doses.

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

The updated label also continues to advise 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 highlighted that this regulatory decision could cut the need for patients to spend extended periods in healthcare settings during the early stages of treatment.

Amgen AI and data research and development executive vice-president Jay Bradner said: “This approval is an important step in simplifying care for people living with and treating ES-SCLC.

“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.

“We continue to work closely with the healthcare community to ensure appropriate educational support for navigating Imdelltra treatment is available to providers, patients and care partners.”

Imdelltra is described as a targeted immunotherapy designed to bind to DLL3 proteins on tumour cells and CD3 on T cells, activating the immune system to target SCLC cells.

The update to monitoring procedures is limited to the first two doses of Imdelltra.

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