Phase 1 study of intraventricular 131I-omburtamab targeting B7H3 (CD276)-expressing CNS malignancies

Table 1 Demographics and dose escalation for the phase I study

¹³¹I-omburtumab dose (MBq)	Number planned in the absence of DLT	Number of patients enrolled	No. receiving at least one Rx dose	Number of NB	Number of other diagnoses**	Median actual dose received (mCi/MBq)	Number of patients treated with 2 cycles
370	3	5^c^,d	3	1	2	10/370	1
740	3	3	3	1	2	20.6/762.2	3
1110	3	6¹	6^b	5	1	30.3/1121.1	4
1480	3	3	3	1	2	40/1480	2
1850	3	6^c^,e	6	3	3	49.6/1835.2	3
2220	3	4^e	4	3	1	58.1/2149.7	1
2590	6	6^a	6	1	5	69.9/2586.3	2
2960	6	5	5	0	5	79.4/2937.8	1
Total	30	38	36	15	21		17

DLT dose-limiting toxicity, NB neuroblastoma
^aOne patient at this dose level received age-based dose reduction per protocol
^bOne patient at this dose level with DLT
^cOne patient replaced because treatment dose was not administered due to rapid disease progression after the first imaging dose
^dOne patient replaced because treatment dose was not administered due to non-compliance after the first imaging dose
^eAdditional patients treated on compassionate basis after IRB approval
^**Other diagnoses (n = 21) included medulloblastoma (n = 6), ependymoma, (n = 3), melanoma and rhabdomyosarcoma (n = 3 each), choroid plexus carcinoma (n = 2), and atypical rhabdoid teratoma, chordoma, pineoblastoma and retinoblastoma (n = 1 each)

ISSN: 1756-8722