A Study to Evaluate Efficacy and Safety of Lenvatinib Combined With Tislelizumab in Patients With FHRCC

Inclusion Criteria:

1. Fully understand and voluntarily sign the informed consent form and agree to receivetreatment, examination and follow-up as required by the study protocol;
2. Age ≥ 18, < 80 years, male or female;
3. ECOG score ≤2;
4. unresectable or recurrent metastatic FH-deficient renal cell carcinoma not previouslytreated with systemic antitumor therapy, as confirmed by histology. Prior cytokinetherapy is allowed;
5. At least 1 measurable tumor lesion according to RECIST 1.1 criteria. The lesion thathas received prior radiotherapy and progressed again is allowed as a target lesion;
6. agree to provide blood and urine samples and previous archived or fresh tumor tissuesamples.
7. Demonstrates adequate organ function.
8. Female subjects of childbearing potential must have a negative serum pregnancy testresult within 7 days prior to the first dose. participants of childbearing potentialmust be willing to use an adequate method of contraception for the course of the studythrough 180 days after the last dose of study drug.

Exclusion Criteria:

1. Prior treatment with agents targeting VEGF, VEGFR, or mTOR, including but not limitedto sunitinib, axitinib, pazopanib, sorafenib, cabozantinib, lenvatinib, bevacizumab,anlotinib, or everolimus;
2. Prior treatment with anti-PD-1, PD-L1 or CTLA-4 antibodies;
3. Participants who are using other investigational agents or who had receivedinvestigational drugs <=4 weeks prior to study treatment start;
4. Received major surgery or is recovering from surgery (as judged by the investigator)within 4 weeks;
5. Received Chinese herbal or proprietary Chinese medicine preparation with an antitumorindication within 2 weeks;
6. Requirement of adrenocorticosteroids (>10 mg prednisone or equivalent daily) or otherimmunosuppressive systemic therapy within 2 week; inhalation of >10 mg prednisone orequivalent daily, but without active autoimmune disease may participate in this study;
7. History of organ transplantation or conditions requiring long-termadrenocorticosteroid or immunosuppressive therapy
8. Hypothyroidism, adrenal or pituitary gland function that can be controlled withhormone replacement therapy, type I diabetes mellitus, psoriasis or vitiligo that donot require systemic therapy may be enrolled in the study;
9. Didn't recover from prior antineoplastic therapy, grade 0 to 1 as defined by NCI-CTCAE 5.0 (except alopecia), or levels specified in the inclusion/exclusion criteria.Irreversible toxicity that is not expected to be exacerbated by the study drug can beenrolled;
10. The presence of other malignancies that have progressed or require treatment within 5years (excluding basal cell carcinoma of the skin, squamous cell carcinoma of theskin, superficial bladder cancer or cured carcinoma in situ, such as carcinoma in situof the breast, prostate cancer: subjects with limited low-risk prostate cancer (≤ T2a,Gleason score ≤ 6, PSA < 10ng/ml) who have received radical treatment and no PSAbiochemical (those with recurrence may participate in this study);
11. History of active central nervous system (CNS) metastases or baseline phase imagingshowing CNS metastases within 30 days prior to the first dose. Subjects with priorsurgical or radiation treatment for brain or meningeal metastases who have maintainedclinical stability for ≥ 3 months by screening and have discontinued systemic hormonetherapy (dose > 10 mg/day of prednisone or other equivalent hormone) for > 4 weeks maybe enrolled. Subjects may be enrolled in this study if the subject's CNS metastasescan be treated to meet the requirements of the enrollment criteria and if thesubject's CNS symptoms have returned to ≤ grade 1 for at least 2 weeks prior toenrollment (except for residual signs or symptoms related to CNS treatment);
12. Poorly controlled hypertension: SBP ≥ 150 mmHg and/or DBP ≥ 90 mmHg;
13. Any one or more of the following cardiovascular disease states within the last 6months: myocardial infarction; unstable angina; endoluminal angioplasty or coronarystenting; coronary/peripheral artery bypass graft; NYHA cardiac function class 3-4;congestive heart failure; cerebrovascular accident including transient ischemicattack;
14. Heart rate corrected QT interval (QTc) ≥ 480 ms;
15. History of active bleeding or other severe bleeding within 1 month;
16. Deep vein thrombosis or pulmonary embolism within 6 months;
17. Arterial embolism within the last 12 months;
18. Clinically significant gastrointestinal abnormalities, including: malabsorption, totalgastrectomy, or any condition that may interfere with the absorption of oralmedications; active ulcers treated within 6 months; active gastrointestinal bleeding (vomiting blood, blood in stool, or black stool) within 3 months by endoscopy;metastatic lesions in the gastrointestinal tract suspected of bleeding, inflammatorybowel disease, ulcerative colitis Gastrointestinal perforation or othergastrointestinal disorders that increase the risk of perforation;
19. The presence of (non-infectious) pneumonia/interstitial lung disease requiringadrenocorticosteroid therapy, either previously or currently
20. Presence of active infection requiring systemic therapy, presence of humanimmunodeficiency virus (HIV) infection (known HIV antibody positivity), presence ofactive HBV infection (HBsAg positive, or HBcAb positive but HBsAg negative, additionalDNA quantification is required and results that do not exceed the upper limit ofnormal laboratory values can be enrolled), presence of active HCV infection (previousHCV infected patients with negative HCV RNA test results during the screening periodcan be enrolled);
21. Live virus vaccinations within the last 1 month, including but not limited to mumps,rubella, measles, varicella/zoster, yellow fever, rabies, BCG, and typhoid vaccines,excluding inactivated virus vaccines;
22. A history of severe drug allergy, including but not limited to antibody drugs andsmall molecule targeted drugs;
23. Known psychiatric illness or history of substance abuse;
24. Presence of unhealed wounds;
25. The presence of any medical history or current evidence of disease, treatment orlaboratory abnormality that, in the investigator's judgment, could confound theresults of the trial, interfere with the subject's participation in the full trial, oris not in the subject's best interest to participate in the trial.