Radiation Combined With BIspecific T-Cell Engager in DLL3 Expressing Tumors

Tarlatamab will be administered at a step-up dose of 1mg on Cycle 1 Day 1 and then 10 mg on Cycle 1 Day 8 and Cycle 1 Day 15 and every 2 weeks thereafter. For cycle 2 onwards, tarlatamab infusion will occur every 2 weeks on days 1 and 15 of each cycle.

Standard of care RT can begin as early as Cycle 1 Day 16 and as late as Cycle 2 Day 28, assuming there is no ongoing CRS (extracranial)/ICANS (cranial).

Standard of care radiation therapy can occur prior to Cycle 1 Day 1 (if radiation treatment is completed \<7 days prior to the start of tarlatamab) or be interdigitated with tarlatamab with a 7-day washout between RT and infusion, with RT to begin as early as Cycle 1 Day 22 and as late as cycle 2 Day 28, assuming no ongoing CRS (extracranial)/ICANS (cranial).