STI-6129

STI-6129 binds to different CD38 epitopes than daratumumab. While neurotoxicity or ocular toxicity were not observed with STI-6129 in animal models, including non-human primates, such event will be considered as adverse events of special interest (AESI) and comprehensive neurology and ocular (including slit lamp) examinations will be performed at baseline and study completion, and at any AESI. STI-6129 will be administered intravenously once in a 4-week cycle, with the intention being to treat patients until disease progression or unacceptable toxicity.

Daratumumab is the first anti-CD38 mAb drug approved by the FDA for use as single agent and in combination with standard therapies for MM. In cynomolgus monkey, the PK profiles of STI-6129 and STI-5171 were nearly identical, further confirming the stability of the ADC in monkey blood circulation.In summary, STI-6129 exhibits potent in vitro and in vivo anti-tumor activities in multiple CD38-positive hematological models. These results warrant further development of STI-6129, potentially as a better or alternative agent for treatment of multiple myeloma.