Background: Cancer immunotherapies targeting PD-1 or PD-L1 have been proven effective in causing durable antitumor immune responses with less toxicity in many types of tumors. However, the response rate of anti-PD-1/PD-L1 treatments is far from satisfactory and most patients show primary or acquired resistance to the treatments. Tim-3, one of the next generation of immune checkpoint targets, co-expressed on exhausted T cells with PD-1. It is also expressed by innate immune populations, including NK and DC. Dual blocking PD-1 and Tim-3 not only on T cells but also on DC, NK cells may achieve better clinical benefit. LB1410 is a recombinant humanized anti-PD-1/TIM-3 bispecific antibody (BsAb) developed by L&L Biopharma Co., Ltd. for the patients who are resistant to or refractory from PD-1/PD-L1 treatments. It blocked the immune checkpoint PD-1 and TIM-3-mediated immunosuppressive signal pathways simultaneously, showed better T/DC cell activity and in vivo anti-tumor efficacy compared to Tim-3 and PD-1 antibody combination in preclinical studies. Methods: This is a FIH, multicenter, non-randomized, open label, phase 1 study of LB1410 in Participants With Advanced Solid Tumor or Lymphoma（Keyplus-001）. The planned sample size is approximately 100 patients in two parts: part 1 dose escalation will evaluate safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and determine the maximum tolerated dose (MTD) and/or the recommended phase 2 dose (RP2D), and Part 2 dose expansion will further characterize the safety profile and preliminary tumor response in several cohorts including NSCLC, CRC, EC etc. Enrollment criteria include adults with life expectancy of > 3 months, ECOG performance status 0-1，histologically or cytologically confirmed advanced and/or metastatic solid tumor malignancies or lymphoma for which standard treatment fails, or no standard treatment is available, or standard treatment is not applicable at this stage. Exclusion criteria include pregnancy, lactation, or breastfeeding, ongoing or recent evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments. The primary endpoints are incidence of dose limiting toxicities and adverse events, MTD, and recommended phase 2 dose. Secondary objectives will evaluate PK parameters, preliminary antitumor activity, and immunogenicity of LB1410. Besides, the pharmacodynamics (PD) biomarkers related to LB1410 treatment, clinical activity will be explored. This clinical trial is in progress; cohorts 1 to 5 in dose escalation part have been completed. Clinical trial information: NCT05357651.