The goal of this clinical trial is to study ISM8207 in participants with advanced solid tumors and relapsed/refractory B-cell lymphoma. The primary objective is to evaluate the safety and tolerability of ISM8207 orally administered in participants with advanced solid tumors and relapsed/refractory B-cell lymphoma

Inclusion Criteria:

1. Male or female participants with age ≥18 years at the time of signing the informed consent.

2. Advanced solid tumors: Histologically confirmed advanced or metastatic solid tumors who have disease progression after standard therapy, intolerable to standard therapy, or for whom no standard therapy exists.

   B-cell lymphoma: Histologically confirmed B-cell lymphoma who had received at least one prior line of standard therapy and were relapsed after or refractory to the standard therapy.

3. Have measurable or evaluable lesions in Part 1 and at least one measurable target lesion in Part 2 as defined by Response Evaluation Criteria in Solid Tumors (RECIST) criteria or Lugano 2014.

4. ECOG PS (Eastern Cooperative Oncology Group Performance Status)≤1.

5. Life expectancy of ≥12 weeks as judged by the investigator.

6. Adequate organ function as determined by medical assessment.

7. Capable of providing signed ICF and complying with the requirements and restrictions listed in the ICF and in this study protocol.

8. Female subjects of childbearing potential and male subjects must agree to use an effective method of contraception during the treatment period and for 90 days after the last dose of ISM8207.

Exclusion Criteria:

1. Prior treated with other QPCTL, CD47 or SIRPα inhibitors.
2. Burkitt lymphoma/leukemia, plasma cell myeloma, plasmablastic lymphoma.
3. Participation in other therapeutic clinical studies within 28 days or 5 half- lives (whichever is shorter) prior to first dose of study treatment.
4. Anti-tumor therapy (chemotherapy, immunotherapy, targeted therapy, biologic therapy, or other anti-tumor therapy) within 28 days or 5 half-lives, whichever is shorter prior to first dose of study treatment.
5. Previous allogeneic stem cell transplantation or autologous stem cell. transplantation within 3 months prior to first receiving study treatment.
6. Unresolved toxicity of Grade >1 attributed to any prior therapies (excluding alopecia).
7. Received antitumor steroid therapy within 7 days prior to the first study treatment administration.
8. A serious illness or medical condition(s)