Part 1 is a dose-escalation phase with a 3+3 sequential-group design in which patients will receive a dosimetry dose followed by maximum of five 5-week cycles of treatment doses of intracerebroventricular 177Lu-DTPA-omburtamab.
Part 2 is a cohort-expansion phase in which patients will receive a treatment at the recommended dose determined in Part 1, until confirmed LM progression, unacceptable toxicity, or for maximum of 5 cycles, whichever comes first; however, the total number of cycles will be determined based upon data from Part 1 (e.g., the dosimetry data) to minimize the risk of radiation necrosis and decreased neurological function End of treatment will take place within 5 weeks after the last cycle and thereafter the patients will be enter the follow-up period. The patients will be followed for up until one year after first dose (Part 1) and 2 years after first dose (Part 2).
