SYS-6090

The goal of this clinical trial is to test JMT108, a type of drug called a bispecific antibody in adult patients with locally advanced or metastatic solid tumors.
The main questions it aims to answer are:
* To assess the safety and tolerability of JMT108 at increasing doses and determine the dose and schedule to be used in the second part of the study (Phase 1a)
* To assess effectiveness of JMT108 in participants with locally advanced or metastatic tumors (Phase 1b)
* To evaluate how quickly JMT108 is metabolized by the body (pharmacokinetics or PK)
* To evaluate if antibodies to the study drug develop (immunogenicity)
* To evaluate preliminary efficacy to the drug
* To explore the pharmacodynamic (PD) characteristics of JMT108
* To explore the correlation between biomarker levels and preliminary efficacy
Participants will:
* Provide written informed consent
* Undergo screening tests to ensure they are eligible for study treatment
* Attend all required study visits and receive JMT108 by intravenous injection every 2 weeks until the study doctor determines study treatment should be stopped, based on how well a participant is doing on treatment
* Be followed for progression every 3 months for up to 2 years

This study is designed as an open-label, multi-center Phase 1 clinical study in participants with advanced malignant tumors to evaluate the safety, tolerability, PK characteristics, and preliminary anti-tumor activity of JMT108 injection, and to determine the RP2D/schedule for subsequent studies.