Evaluate the Safety and Clinical Activity of HH2853

Phase I: Phase I dose escalation The accelerated titration (ATD) incorporated with Bayesian Optimal Interval design (BOIN) will be used to assess the DLT, safety, tolerability, MTD and furthermore, to establish the RP2D. DLT assessment is only applicable to phase I dose escalation. Eligible patients will be enrolled in the ascending dose until MTD/RP2D is established. Phase I dose extension During the dose escalation phase, a dose extension with additional patients will be included in order to further evaluate the tolerability, pharmacokinetics, and efficacy at doses that have been evaluated as safe. The number of patients to be enrolled in each dose extension cohort is up to 15, but the final number of dose level can be determined and the final patient number at each dose level can be adjusted slightly based on available safety, efficacy, PK, and PD data upon agreement from sponsor and investigators (e.g. safety evaluation meeting). For phase I dose extension, approximately 30 patients will be enrolled based on initial estimate, but the final total number of patients will depend on the number of dose levels extended and patient number at each dose level. The total number of patients is estimated to be approximately 60 patients for phase I dose escalation and dose extension, but the final total number of patients will depend upon the number of dose cohorts to reach MTD/RP2D, and patient number at each dose level. Phase II（China Only）: Phase II is planned after the completion of phase I. Up to approximately 193 patients will be enrolled as outlined below: * Cohort 1: Relapsed/Refractory FL (n≈56) * Cohort 2: Epithelioid sarcoma (n≈77) * Cohort 3: Relapsed/Refractory PTCL, other relapsed/refractory Non-Hodgkin's lymphomas with EZH2 mutation, or advanced solid tumors with specific genetic alterations, including EZH2 mutation, INI1 deficiency, BAP1 deficiency, ARID1A mutation, or/and SMARCA4 mutation (n≈60)