A First-In-Human Phase 1/2 Open-Label Study of Intravenous ST-067, Subcutaneous ST-067 with or Without Obinutuzumab Pre-Treatment, and ST-067 in Combination with Pembrolizumab in Subjects with Advanced Solid Malignancies
This is a multiphase, multicenter study, which includes a Phase 1a open-label, dose escalation monotherapy study of ST-067 given as an SC injection with or without obinutuzumab \[Gazyva®\] pre-treatment, by IV infusion, and in combination with pembrolizumab. A Phase 2 monotherapy arm is also planned; the exact design of the Phase 2 study elements with respect to formulation and pre-treatment will be determined after completion of the Phase 1 study portion of the trial.
• Male and female patients aged ≥18 years
• Must provide written informed consent and any authorizations required by local law
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Have histologically or cytologically confirmed diagnosis of advanced/metastatic solid tumor
• For Phase 1a, the following solid tumors are allowed: Melanoma, Merkel cell, RCC, urothelial, NSCLC,TNBC, SCCHN, microsatellite instability high, high tumor mutation burden (Hi TMB) or mismatch repair deficient, gastric, cervical, endometrial, cutaneous squamous, small cell lung, esophageal, hepatocellular carcinoma and platinum resistant ovarian cancer.
⁃ For patients who have developed disease progression through standard therapy, or
⁃ For patients whom standard of care therapy that prolongs survival is unavailable or unsuitable (according to the investigator and after consultation with the Medical Monitor) For Phase 1 combination therapy dose escalation, the following solid tumors are allowed: Melanoma, Merkel cell, RCC, urothelial, NSCLC (with no EGFR, TRK receptor, or ALK positive mutations/fusions), TNBC, SCCHN, MSI-Hi tumors, Hi TMB or mismatch repair deficient, gastric, cervical, endometrial, cutaneous squamous, small cell lung, esophageal, and HCC
∙ TNBC is diagnosed in a tumor which does not express estrogen receptor or progesterone receptor, is not human epidermal growth factor receptor 2 (HER2) 3+ on IHC or is negative by fluorescence in situ hybridization (FISH).
‣ MSI high tumor should have mutations in 30% or more microsatellites by PCR or be negative for MSH1/2/6 or PMS-2 by IHC.
‣ Hi-TMB high tumor has 10 mut/Mb or greater calculated from whole genome sequencing or whole exome sequencing
• For Phase 2, the following solid tumors are allowed:
• Melanoma, RCC, TNBC, NSCLC, SCCHN, and MSI-Hi tumors
• Has at least 1 measurable lesion per RECIST 1.1 criteria which has not been biopsied or received prior irradiation
• Has an accessible tumor for biopsy pre- and on-treatment (mandatory).