Please assess the completion status of the following clinical trial:

Trial Title: Sintilimab or Placebo With Chemotherapy in Esophageal Squamous Cell Carcinoma ( ORIENT-15 )

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE3
- Number of Arms: 3.0

Eligibility Criteria:
Key Inclusion Criteria:~* Histopathologically confirmed unresectable, locally advanced, recurrent or metastatic ESCC (excluding mixed adenosquamous carcinoma and other histological subtypes)~* ECOG PS of 0 or 1~* Subject must be unsuitable for definitive treatment, such as definitive chemoradiotherapy and/or surgery. For subjects who have received (neo)adjuvant or definitive chemotherapy/radiochemotherapy, time from the completion of last treatment to disease recurrence must be \> 6 months Could provide archival or fresh tissues for PD-L1 expression analysis with obtainable results~* Have at least one measurable lesion as per RECIST v1.1~Key exclusion Criteria:~* ESCC with endoscopy-confirmed near-complete obstruction requiring interventional therapy~* Post stent implantation in the esophagus or trachea with risk of perforation~* Received systemic treatment for advanced or metastatic ESCC.~* Received a cumulative dose of cisplatin ≥ 300 mg/m2 and the last cisplatin dose was within 12 months of randomization or the first dose of study treatment in the open-label phase.~* High risk of hemorrhage or perforations due to tumor invasion in adjacent organs (aorta or trachea), or have fistula formation.~* Hepatic metastasis \> 50% of the total liver volume.~* Received palliative therapy for a local lesion within 2 weeks prior to the first dose.~* Received systemic treatment with Chinese traditional medicines with anti-cancer indications or immunomodulators (including thymosins, interferons, and interleukins) within 2 weeks prior to the first dose of study treatment.~* Received systemic immunosuppressants within 2 weeks prior to randomization, excluding local use of glucocorticoids administered by nasal, inhaled, or other routes, and systemic glucocorticoids at physiological doses (no more than 10 mg/day of prednisone or equivalents), or glucocorticoids to prevent allergies to contrast media.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 75 Years
- Healthy Volunteers: f

Study Arms:
- Randomized Part: Experimental: Sintilimab + chemotherapy (Type: EXPERIMENTAL): Sintilimab in combination with investigator's choice of chemotherapy~TP regimen: Cisplatin + paclitaxel~or~CP regimen: Cisplatin + fluorourcil
- Randomised Part: Active Comparator: Placebo + chemotherapy (Type: ACTIVE_COMPARATOR): Placebo in combination with investigator's choice of chemotherapy TP regimen: Cisplatin + paclitaxel or CP regimen: Cisplatin + fluorourcil
- Open-label part: Sintilimab+ chemotherapy (Type: EXPERIMENTAL): Sintilimab in combination with investigator's choice of chemotherapy TP regimen: Cisplatin + paclitaxel or CP regimen: Cisplatin + fluorourcil

Based on this trial design, predict the completion outcome and termination type (if applicable).