This is an open-label, multicenter, single-arm phase 2 clinical study designed to evaluate the efficacy, safety, tolerability, patient-reported outcomes (PROs), pharmacokinetics (PK), anti-drug antibody (ADA) and pharmacodynamics (PD) of ES014 in adult desmoid tumor patients.

Inclusion Criteria:

• 1) Histologically confirmed desmoid tumor.
• 2)Within 12 months prior to enrollment, meeting any of the following: Tumor target lesion growth ≥ 20% or appearance of new lesions;Desmoid tumor-related pain not adequately controlled by non-opioid medications.
• 3)Meeting any of the following conditions: Subjects with recurrence or disease progression after at least one line of treatment (including surgery, radiotherapy, or systemic therapy, etc.); Treatment-naive subjects who are deemed suitable for the study drug by the investigator.
• 4)Presence of at least one measurable lesion (according to RECIST v1.1).
• 5)Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score of 0-2.
• 6)Life expectancy of at least 12 weeks.
• 7)Adequate hematologic, hepatic, renal and coagulation functions per protocol.
• 8)Male and female subjects of childbearing potential must be willing to completely abstain or agree to use a highly effective method of contraception.

Exclusion Criteria:

• 1)Any prior therapy targeting CD39, CD73, adenosine A2A receptor, or TGF-β.

• 2)Receipt of any investigational agents or devices within 4 weeks prior to the first dose of study drug.

• 3)Prior treatment with any of the following:

  1. Anticancer therapy, including chemotherapy, tyrosine kinase inhibitors (TKIs), etc., within 28 days or 5 half-lives (whichever is shorter, but not less than 14 days) prior to the first dose of study drug.
  2. For subjects who have received radiotherapy, a washout period of at least 2 weeks (limb radiation) or 4 weeks (chest, brain, or visceral organ radiation) is required before the start of study drug administration.
  3. Traditional Chinese medicine (TCM) and proprietary Chinese medicines: if the package insert or investigator deems them to have clear anti-tumor effects, a 14-day washout is required. Other TCM and proprietary Chinese medicines do not require a washout.

• 4)Prior allogeneic or autologous bone marrow transplantation or solid organ transplantation.

• 5)Previous treatment-related toxicities unresolved to ≤ Grade 1, with the exception of alopecia (any grade), ≤ Grade 2 peripheral sensory neuropathy, and long-standing irreversible toxicities at the investigator's discretion.

• 6)Major surgery within 4 weeks prior to the first dose of study treatment.

• 7)Live vaccination therapies within 4 weeks prior to the first dose of study treatment.