Safety Study of SEA-CD40 in Cancer Patients

The study will be conducted in the following parts: Part A: Intravenous (IV) monotherapy dose-regimen finding for solid tumors -- Dose-escalation, and possible dose-interval modification to lengthen the treatment cycle, to define the IV SEA-CD40 monotherapy maximum tolerated dose (MTD) and/or the optimal biological dose (OBD) regimens in patients with solid tumors. The ability to increase the dose intensity (to give additional doses within a treatment cycle) may be evaluated. Part B: IV monotherapy solid tumor expansion cohorts -- Disease-specific solid tumor expansion cohorts may be enrolled where patients will be treated with doses at or below the IV SEA-CD40 monotherapy MTD and/or OBD determined in Part A. Part C: IV monotherapy dose-regimen finding for lymphomas -- Dose-escalation, and possible dose-interval modification to lengthen the treatment cycle, to define the IV SEA-CD40 monotherapy MTD and/or the OBD regimens in patients with lymphomas. The ability to increase the dose intensity (to give additional doses within a treatment cycle) may be evaluated. Part D: IV monotherapy lymphoma expansion cohorts -- Disease-specific lymphoma expansion cohorts may be enrolled where patients will be treated with doses at or below the IV SEA-CD40 monotherapy MTD and/or OBD determined in Part C. Part E: Combination therapy dose-regimen finding for solid tumors -- IV SEA-CD40 dose-escalation to define the MTD and/or the OBD regimen to be administered in combination with standard approved dose of pembrolizumab in patients with solid tumors. Part F: Combination therapy solid tumor expansion cohorts -- Disease-specific solid tumor expansion cohorts may be enrolled where patients will be treated with IV SEA-CD40 and pembrolizumab combination therapy; doses of SEA-CD40 will be at or below the MTD and/or OBD determined in Part E. Part G: Subcutaneous (SC) injection (injected under the skin) monotherapy dose-regimen finding for solid tumors -- Dose-escalation, and possible dose-interval modification to lengthen the treatment cycle, to define the SC SEA-CD40 monotherapy maximum tolerated dose (MTD) and/or the optimal biological dose (OBD) regimens in patients with solid tumors. Part H: SC monotherapy solid tumor expansion cohorts -- Disease-specific solid tumor expansion cohorts may be enrolled where patients will be treated with doses at or below the SC SEA-CD40 monotherapy MTD and/or OBD determined in Part G. (Note: There is no Part I) Part J: SC monotherapy dose-regimen finding for lymphomas -- Dose-escalation, and possible dose-interval modification to lengthen the treatment cycle, to define the SC SEA-CD40 monotherapy MTD and/or the OBD regimens in patients with lymphomas. Part K: SC monotherapy lymphoma expansion cohorts -- Disease-specific lymphoma expansion cohorts may be enrolled where patients will be treated with doses at or below the SC SEA-CD40 monotherapy MTD and/or OBD determined in Part J. Part L: Combination therapy in pancreatic cancer -- Patients will be treated with SEA-CD40 doses at or below MTD and/or OBD. An established dose of pembrolizumab and a standard regimen of gemcitabine and nab-paclitaxel will be used. In Parts A, C, E, G, and J, a maximum feasible dose (MFD) will be defined if an MTD and/or OBD cannot be identified. Parts B, D, F, H, K. and L will explore the recommended dosing regimen once the MTD and/or OBD, or MFD (if the MTD and/or OBD cannot be identified) has been determined.