Please assess the completion status of the following clinical trial:

Trial Title: A Study of Palbociclib (PD-0332991) + Letrozole vs. Letrozole For 1st Line Treatment Of Postmenopausal Women With ER+/HER2- Advanced Breast Cancer (PALOMA-2)

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE3
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Adult women with locoregionally recurrent or metastatic disease not amenable to curative therapy.~* Confirmed diagnosis of ER positive breast cancer~* No prior systemic anti-cancer therapy for advanced ER+ disease.~* Postmenopausal women~* Measurable disease as per Response Evaluation Criterion in Solid Tumors \[RECIST\] or bone-only disease~* Eastern Cooperative Oncology Group \[ECOG\] 0-2~* Adequate organ and marrow function~* Patient must agree to provide tumor tissue~Exclusion Criteria:~* Confirmed diagnosis of HER2 positive disease~* Patients with advanced, symptomatic, visceral spread that are at risk of life threatening complication in the short term~* Known uncontrolled or symptomatic CNS metastases~* Prior (neo)adjuvant treatment with letrozole or anastrozole with DFI ≤ 12-months from completion of treatment.~* Prior treatment with any CDK 4/6 inhibitor.

- Gender: FEMALE
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- PD-0332991 + Letrozole (Type: EXPERIMENTAL): PD-0332991, 125mg, orally once daily on Day 1 to Day 21 of every 28-day cycle followed by 7 days off treatment in combination with Letrozole, 2.5mg, orally once daily (continuously).
- Placebo + Letrozole (Type: ACTIVE_COMPARATOR): Placebo, 125mg, orally once daily on Day 1 to Day 21 of every 28-day cycle followed by 7 days off treatment in combination with Letrozole, 2.5mg, orally once daily (continuously).

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