The preclinical pharmacological mechanism of YH02 injection is well established. By constructing a vector expressing MMP13, introducing a human S promoter, and genetically modifying the capsid protein, the virus's permeability, tumor targeting capability, and infection efficiency were significantly enhanced. Preclinical pharmacodynamic studies demonstrated that YH02 exhibits potent tumor growth inhibitory effects in various human-and murine-derived solid tumor models (including breast cancer, liver cancer, and melanoma). Given that oncolytic virus therapies already have approved products with demonstrated safety and efficacy worldwide, this study may offer potential clinical benefits for patients with advanced solid tumors who have failed standard treatments.

YH02 injection has undergone an open-label, dose-escalating, and expanded Phase I clinical study in China aimed at evaluating the safety, tolerability, biodistribution characteristics, viral clearance, and immunogenicity of intratumoral administration of YH02 injection in patients with advanced solid tumors who have failed adequate standard therapy and lack effective treatment options, while preliminarily investigating its efficacy. No high-grade adverse drug reactions (ADRs) have been observed to date, nor were there any serious adverse events (SAEs), severe adverse drug reactions (SUSARs), or fatal events. The clinical safety and tolerability of this product for intratumoral administration are favorable.

Cancer is a disease that poses a serious threat to human health and social development. The International Agency for Research on Cancer (IARC) of the World Health Organization released the latest global cancer burden data for 2020. In 2020, there were 19.29 million new cancer cases worldwide, among which China accounted for 4.57 million cases, representing 23.7% globally. The number of cancer-related deaths worldwide reached 9.96 million in 2020, with China contributing 3 million deaths, accounting for 30% of total cancer-related fatalities. Data indicate that malignant tumor deaths account for 23.91% of all causes of death among residents, and annual medical expenditures due to malignant tumors exceed $220 billion, imposing a significant burden on patients and their families, healthcare systems, and society as a whole. Over the past decade, the cancer burden has shown a sustained upward trend, with the incidence rate of malignant tumors increasing by approximately 3.9% annually and the mortality rate rising by 2.5% annually. Furthermore, globally, due to accelerating population aging, the cancer burden is projected to increase by 50% by 2040 compared to 2020, with the number of new cancer cases reaching nearly 30 million.

In recent years, tumor immunotherapy has become a pivotal approach in cancer treatment, standing alongside chemotherapy, targeted therapy, surgery, and radiotherapy. Particularly, immune checkpoint inhibitors (ICIs) have achieved remarkable clinical success. However, overall, the response rates to these therapies remain limited and require further improvement. Tumors that respond to ICI are termed immunologically "hot tumors," whereas those that do not respond are referred to as "cold tumors." Since German scientist Jean Rommelaere first described oncolytic virus therapy as tumor immunotherapy in a 2011 publication, oncolytic viruses have gained widespread acceptance as a key branch of tumor immunotherapy. The use of oncolytic viruses to convert "cold tumors" into "hot tumors" is recognized as an effective strategy .

Oncolytic viruses possess multiple functions, including direct killing of tumor cells, induction of immune responses, and enhancement of the efficacy of other antitumor agents. Compared to conventional treatment approaches, they offer distinct advantages such as high specificity, minimal side effects, and broad efficacy against various tumor types. Oncolytic viruses are a class of naturally occurring or genetically engineered viruses capable of targeting and destroying tumor cells. The primary oncolytic viruses currently employed in cancer research include herpes simplex virus, adenovirus, and vaccinia virus. These viruses achieve specific targeting of tumor cells and self-replication by leveraging various mechanisms: abnormal expression of surface receptors, defects in surface molecules, alterations in signaling pathways within tumor cells, deletion of genes essential for viral replication in normal cells but non-essential in tumor cells, and placement of replicative genes under the control of specific promoters. This enables tumor cell lysis and death, with released viruses initiating new infection cycles. Additionally, lysed tumor cells release abundant tumor antigens, activating specific antitumor immunity to recognize and attack uninfected tumor cells. Furthermore, upon entering the body, oncolytic viruses stimulate antiviral immunity, reverse the suppressive state of immune cells in the tumor microenvironment, and redirect immune attacks toward tumor cells. Finally, oncolytic viruses can deliver therapeutic molecules or be combined with other therapies to enhance antitumor efficacy.

Human adenovirus was first isolated in 1953 from the tonsils of infants with respiratory infections. Adenoviruses can infect various mucosal tissues, including the gastrointestinal tract, respiratory system, urogenital tract, and conjunctiva [14]. Adenoviral vectors are widely used in research on prevention and treatment of genetic disorders, cancers, and infectious diseases; in addition to the commonly employed adenovirus type 5 vector, multiple other serotype adenovirus vectors have been developed. Adenovirus is an envelope-free, twenty-faced symmetrical linear double-stranded DNA virus classified by the International Commission on Viral Classification into groups A-G7 comprising 52 serotypes .Oncolytic adenoviruses, also known as conditionally replicating adenoviruses (CRADs), are genetically engineered adenoviruses capable of selectively replicating within tumor cells, ultimately causing their lysis while causing minimal damage to normal cells. The most widely used oncolytic adenoviruses belong to subtypes 2 and 5 of the Adenovirus genus within the Adenoviridae family , both classified serologically as Group C. These are enveloped double-stranded DNA viruses with a twenty-faced symmetrical structure, featuring fibrin-based cilia on their capsid surface whose size and quantity are species-specific, playing a role in receptor cell adhesion and binding. The infection process involves several key steps: first, viral particles bind to specific receptors on the host cell membrane, primarily the Coxsackievirus receptor (CAR); subsequently, they interact with integrins, enter cells via endocytosis, and shed their capsids; finally, viral DNA is released into the nucleus through nuclear pores for transcription and replication. Due to their ability to selectively replicate in tumor cells and deliver exogenous genes for expression therein, oncolytic adenoviruses have garnered significant attention in oncology therapy and represent a promising novel approach for cancer treatment. However, the use of recombinant oncolytic adenoviruses alone did not achieve the expected therapeutic efficacy; consequently, further modification of oncolytic adenoviruses has become a new research focus.

In clinical research on oncolytic adenovirus-based cancer gene therapy, the United States leads the world in this field, with several of its oncolytic adenovirus products having entered the clinical stage. Clinical studies have demonstrated that oncolytic adenovirus-based therapies will become a highly promising area of focus for future cancer gene therapy. In 2003 and 2005, China's National Medical Products Administration approved two adenovirus-based products for market release: "Jinyousheng" by Shenzhen Sainuo and "Ankerui" by Shanghai Sanwei Biotech. Clinical trials conducted with Ankerui across various solid tumors indicated favorable safety profiles and certain therapeutic efficacy when administered via intratumoral injection or pleural perfusion for treating nasopharyngeal carcinoma, hepatocellular carcinoma, pancreatic cancer, among others . Currently, most oncolytic virus drug development in China relies primarily on purchased or imported generic versions, with few companies possessing comprehensive independent design capabilities or robust R&D capacities; overall, the design quality remains relatively low, and most products exhibit insufficient therapeutic efficacy.The preclinical pharmacological mechanism of YH02 injection is well established. By constructing a vector expressing MMP13, introducing a human S promoter, and genetically modifying the capsid protein, the virus's permeability, tumor targeting capability, and infection efficiency were significantly enhanced. Preclinical pharmacodynamic studies demonstrated that YH02 exhibits potent tumor growth inhibitory effects in various human-and murine-derived solid tumor models (including breast cancer, liver cancer, and melanoma). Given that oncolytic virus therapies already have approved products with demonstrated safety and efficacy worldwide, this study may offer potential clinical benefits for patients with advanced solid tumors who have failed standard treatments.

YH02 injection has undergone an open-label, dose-escalating, and expanded Phase I clinical study in China aimed at evaluating the safety, tolerability, biodistribution characteristics, viral clearance, and immunogenicity of intratumoral administration of YH02 injection in patients with advanced solid tumors who have failed adequate standard therapy and lack effective treatment options, while preliminarily investigating its efficacy. No high-grade adverse drug reactions (ADRs) have been observed to date, nor were there any serious adverse events (SAEs), severe adverse drug reactions (SUSARs), or fatal events. The clinical safety and tolerability of this product for intratumoral administration are favorable.

Inclusion Criteria:

• Age: ≥18 years.
• Resectable malignant solid tumors confirmed by histology or cytology (including head and neck cancer, breast cancer, melanoma, cervical cancer, skin malignancies, salivary gland carcinoma, oropharyngeal carcinoma, etc.) should prioritize treatment options for head and neck cancer, breast cancer, and melanoma.
• After complete failure of standard treatment (disease progression or intolerance to therapy) and in the absence of effective therapeutic options.
• There must be at least one measurable lesion (according to the RECIST 1.1 criteria), and the lesion must be suitable for intratumoral injection.
• ECOG score ≤2.
• The expected survival period is ≥12 weeks.
• The subject must demonstrate adequate hematological and organ function, with all laboratory parameters evaluated within 7 days prior to the initial administration and meeting the following criteria: Hematologic system (no recent transfusion or hematopoietic stimulation therapy within 14 days): ANC ≥ 1.5 × 10⁹/L; PLT ≥ 80 × 10⁹/L; Hemoglobin (Hb) ≥ 85 g/L; Liver function: Total bilirubin (TBIL) ≤ 2 × upper limit of normal (ULN) (≤ 3.0 × ULN for patients with Gilbert syndrome or liver metastases/hepatocellular carcinoma); Alanine aminotransferase (ALT) ≤ 2.5 × ULN; For patients with liver metastases or hepatocellular carcinoma: ALT ≤ 5 × ULN; Aspartate aminotransferase (AST) ≤ 2.5 × ULN; Albumin ≥ 2.8 g/dL; Renal function: Creatinine ≤ 1.5 × ULN; or Creatinine clearance (Ccr) ≥ 30 mL/min (calculated using the Cockcroft-Gault formula, only when creatinine> 1.5 × ULN); Coagulation function: Activated partial thromboplastin time (APTT) ≤ 1.5 × ULN; International normalized ratio (INR) or Prothrombin time (PT) ≤ 1.5 × ULN.
• The subject has voluntarily signed an informed consent form and demonstrates good compliance.

Exclusion Criteria:

• Patients had received antitumor therapy for the first time within 4 weeks prior to initial administration, including endocrine therapy, chemotherapy, radiotherapy, targeted therapy, immunotherapy, or traditional Chinese medicine-based antitumor treatment; or had participated in other clinical trials within 4 weeks before enrollment.

Development of any other malignant tumor other than the study tumor within 5 years prior to first use of the investigational drug, excluding locally advanced cancers that have been completely cured or are disease-free for at least 5 consecutive years, such as basal or squamous cell skin cancer, superficial bladder cancer, prostate carcinoma in situ, cervical carcinoma in situ, or breast ductal carcinoma in situ.

• The adverse effects of previous antitumor treatments have not yet been classified as Grade ≤1 on the NCI CTCAE v5.0 grading scale (excluding toxicities such as alopecia and grade 2 neurotoxicity induced by prior platinum-based therapy, which researchers consider to pose no safety risks).
• Receiving systemic glucocorticoids (prednisone>10 mg/day or equivalent doses of similar agents) or other immunosuppressive therapies within 2 weeks prior to initial use of the study drug, excluding the following: topical, ocular, intra-articular, intranasal, or inhaled glucocorticoid therapy; short-term (≤1 week) prophylactic use of glucocorticoids (e.g., for contrast agent allergy) or for treatment of non-autoimmune diseases (e.g., delayed hypersensitivity reactions induced by contact allergens).
• Immuno-modulatory drugs, including but not limited to thymosin, IL-2, and interferon (IFN), were administered within 2 weeks prior to the first administration of the study drug.
• A syndrome characterized by clinically significant autoimmune diseases (excluding well-controlled hypothyroidism). Patients with vitiligo, type 1 diabetes mellitus, or psoriasis who do not require systemic treatment and have no history of recurrence in the absence of external triggers are eligible for inclusion.
• A live attenuated vaccine was administered within 4 weeks prior to the first use of the study drug.
• Has previously received oncolytic virus therapy or other gene-based therapies.
• Patients had undergone major surgical procedures or suffered severe trauma within 4 weeks prior to enrollment, or were expected to undergo significant surgery during the study period; furthermore, before the first administration of the investigational drug, all adverse events (AEs) related to surgery or major trauma had not resolved to CTCAE level ≤1 or baseline levels.
• Patients with clinical manifestations of CNS metastasis or meningeal metastasis, or other evidence indicating that the patient's CNS or meningeal metastatic lesions are not under control, shall be deemed unsuitable for enrollment by the investigator. Patients with clinical symptoms suggestive of brain or meningeal disease require computed tomography (CT) or magnetic resonance imaging (MRI) examination.
• For patients with previously treated brain metastases, inclusion may be considered if their clinical condition is stable within 4 weeks prior to enrollment, there is no evidence of new lesions or lesion progression, and they have not received glucocorticoid therapy within 1 week before the first administration.
• Has a medical history of leptomeningitis.
• Patients with a history or evidence of high-risk cardiovascular disease are eligible, including but not limited to: severe cardiac rhythm or conduction abnormalities (e.g., ventricular arrhythmias requiring clinical intervention, grade II-III atrioventricular block), a Fridericia formula-corrected QT interval (QTcF) ≥ 470 msec; acute coronary syndrome (including acute myocardial infarction and unstable angina), stroke, or other grade 3 or higher cardiovascular events occurring within 6 months prior to first administration; stent implantation within 6 months before initial use of the study drug; congestive heart failure classified as grade ≥ II according to the New York Heart Association (NYHA) criteria; echocardiographic findings of valvular morphological abnormalities (grade ≥ 2); note: patients with grade 1 valvular morphological abnormalities (e.g., mild regurgitation/stenosis) may be enrolled, but those with moderate valve thickening are excluded; left ventricular ejection fraction (LVEF) <the institutional lower limit (or LVEF <50% if no such limit exists); or poorly controlled blood pressure despite antihypertensive therapy (i.e., systolic blood pressure ≥ 160 mm Hg and/or diastolic blood pressure ≥ 100 mm Hg).
• Virological tests: Positive for hepatitis B virus surface antigen (HBsAg); positive for hepatitis B core antibody (HBcAb) with hepatitis B virus (HBV) DNA level> upper limit of detection (ULN); positive for hepatitis C virus antibody (HCV-Ab) with hepatitis C virus (HCV) RNA level> ULN; positive for anti-human immunodeficiency virus antibody (Anti-HIV). Meeting any of the above criteria.
• Had an active infection requiring systemic treatment (intravenous administration) within 2 weeks prior to the first use of the investigational drug, excluding local treatments.

Patients known to have allergic reactions to any component of the YH02 injection formulation.

• Individuals with known mental disorders that may affect research compliance or substance abuse.
• Patients who have undergone or plan to undergo organ transplantation (e.g., liver transplantation).
• Patients who, according to the investigators' assessment, have other severe systemic diseases, abnormal laboratory findings, or other reasons that make them unsuitable for participation in this clinical study.