The study consists of 2 parts:~Part 1: Phase 1 dose-escalation with 2 parallel staggered escalation cohorts: one cohort of patients treated with OMTX705 as monotherapy and one cohort of patients receiving escalating doses of OMTX705 in combination with standard pembrolizumab. The combination arm will start once OMTX705 monotherapy safety has been evaluated.~Part 2: Up to 4 cohort expansions to confirm the safety of OMTX705 as monotherapy and in combination with pembrolizumab and will provide additional efficacy information.~The classical 3+3 design will be followed to establish the maximum tolerated dose (MTD) or the provisional recommended dose for the expansion phase. Three to six patients per treatment cohort will be assigned to receive sequentially higher doses of OMTX705 on Days 1 and 8 in cycles of 21 days. The OMTX705 starting dose is 1.0 mg/kg~Dose escalation will be based on a review of all parameters critical to subject safety from C1D1 to the start of C2D1. A safety report will be reviewed by the safty review committee (SRC) to determine if progression to the next planned dose level should occur or if additional subjects or lower dose levels are needed.~Expansion phase (Part 2): Once MTD is identified, or if another dose is identified because observed efficacy, non-DLT safety, or because a dose is supported by the PK/PD model under development, a provisional recommended Phase 2 dose (RP2D) will be selected by the sponsor and SRC for cohort expansion. Up to 4 cohort expansions of up to 15 patients each will proceed to confirm the safety and for initial assessment of anti-tumor activity. Each expansion cohort can be enriched with patients with advanced/metastatic cancer with no therapeutic standard alternative indications in which antitumor activity has been observed during the escalation phase. The final decision on the expansion cohort enrichment will be made by the sponsor with the support of the SRC.~After treatment discontinuation, patients will have the EoT visit 30 (±2) days after the last dose of any component of the treatment for the evaluation of new AEs or recovery from previous ones. EoT visit can be anticipated for patients scheduled to receive the next line of systemic treatment to the day of the start of the new therapy if this happens less than 30 days after the last dose of study treatment.~Subjects who discontinue study treatment for reasons other than progressive disease (PD) will continue to attend PFS Follow-up (FU) Visits every 12 (±1) weeks from the EoT Visit until the occurrence of PD, loss to follow up, consent withdrawal, death, the start of subsequent systemic antineoplastic therapy, or study termination, whichever occurs first.~Only patients enrolled in Part 2 will be followed for survival. To assess survival status, subjects will be contacted (which may be by phone or hospital visit, whichever is preferable) every 3 months from the first dose of OMTX705.
Open-label, two parallel arm, multicenter, Phase 1 dose-escalation study to evaluate the safety and tolerability of OMTX705, both as monotherapy or in combination with pembrolizumab in the treatment of patients with advanced or metastatic cancer in whom there is no available standard therapeutic option.