ALX Oncology Holdings Inc., ("ALX Oncology" or "the Company") (NASDAQ:ALXO), an immuno-oncology company developing therapies that block the CD47 immune checkpoint pathway, announced the first patients have been dosed in an arm of the randomized UMBRELLA phase 1/2 clinical study partnered with Sanofi that is evaluating evorpacept in combination with SARCLISA (isatuximab-irfc). Evorpacept is ALX Oncology's investigational CD47-blocking therapeutic that uniquely combines a high-affinity CD47-binding domain with an inactivated Fc domain and SARCLISA is Sanofi's approved CD38 monoclonal antibody in patients with relapsed or refractory multiple myeloma (RRMM).

SARCLISA binds to a specific epitope on the CD38 receptor on multiple myeloma (MM) cells, inducing distinct antitumor activity. CD38 is highly and uniformly expressed on the surface of MM cells and after first-line treatment, some relapsed or recurred patients have shown resistance to CD38 agents. CD47 expression increases as multiple myeloma progresses, suggesting that evorpacept may have the potential to re-sensitize tumors to CD38 treatment or overcome anti-CD38 resistance. This novel therapeutic combination has demonstrated synergistic anti-tumor activity in preclinical models.