This is an open-label, dose-escalation and dose-expansion Phase I /II clinical study divided into Phase I and Phase II to evaluate the safety and tolerability of JCXH-211 combined with anti-PD-1 antibody in patients with malignant solid tumors.

Phase I: Dose escalation study of intratumoral injection of JCXH-211 combined with anti-PD-1 antibody IV infusion A dose escalation study of intratumoral injection of JCXH-211 combined with anti-PD-1 antibody IV infusion will be planned in 2 dose groups . Three to six patients will be enrolled in each dose group.

Phase II:Dose Expansion Study of JCXH-211 Combined with Anti-PD-1 Antibody In this part of the study, the sponsor and investigator select the optimal dose based on the safety, PK, PD and preliminary efficacy results of the dose escalation phase, and select 1 to 2 of the tumors for JCXH-211 combined with anti-PD-1 antibody dose expansion study with reference to the approved indications of anti-PD-1 antibody (Toripalimab ) in China, and planned to enroll 15 to 30 patients in each cohort of combination therapy.

Tumor response assessments will be performed using RECIST1.1 and iRECIST at the end of study treatment/early withdrawal visit and every 6 weeks during treatment.

All patients will be followed for safety and survival. The data cut-off date for study is defined as 6 months after the last patient is enrolled.

Inclusion Criteria:

1. Male or female patients, aged 18 to 75 years;
2. patients with malignant solid tumors confirmed by pathology and/or cytology who have progressed or are intolerant to standard treatment (except best supportive care); Including patients who have received prior anti-PD-1 antibody therapy; patients who have been approved as eligible for Toripalimab:
3. General condition score ECOG 0 ~ 1;
4. Expected survival of more than 3 months;

Exclusion Criteria:

1. Known or suspected allergy to the ingredients of the study drug or its analogues; allergic history to another monoclonal antibody;
2. patients who have previously received IL-12 therapy (alone or as part of a treatment regimen), except those who have participated in tolerance to a single intratumoral injection;
3. patients who have previously received treatment with anti-PD-1, anti-PD-L1, or anti-PD-L2 agents, or have received treatment directed at another stimulatory or coinhibitory T-cell receptor (e.g., CTLA-4, OX-40, CD137), and discontinued treatment due to Grade 3 or higher immune-related adverse events (irAEs);