Inclusion Criteria:

• Subjects and/or their parent or legally authorized representative must have an understanding, ability, and willingness to fully comply with study procedures and restrictions.
• Subjects must be able to voluntarily provide written, signed, and dated (personally or via a legally authorized representative) informed consent and/or assent, as applicable, to participate in the study.
• Subjects must have completed the 16-week induction treatment period from study SHP647-305 or SHP647-306 and met the following criteria at baseline in maintenance Study SHP647-307:
  • Meet endoscopic response criteria of a reduction in SES-CD from induction study (SHP647-305 or SHP647-306) baseline by ≥ 25% at Week 16 of induction study (SHP647-305 or SHP647-306); OR
  • Meet at least 1 of the following 4 criteria at baseline in maintenance study SHP647-307, in addition to no worsening of endoscopic score as measured by SES-CD relative to induction study (SHP647-305 or SHP647-306) baseline:
    • Achieving clinical remission as determined by meeting the criteria for clinical remission using the 2-item PRO; i.e., 2-item PRO subscores of average worst daily abdominal pain ≤ 3 (based on 11-point numerical rating scale [NRS]) over the 7 most recent days* and average daily stool type frequency ≤ 2 of type 6/7 (very soft stools/liquid stools) as shown in the BSFS over the 7 most recent days*
    • A decrease of at least 100 points in CDAI score (CDAI-100) from induction study (SHP647-305 or SHP647-306) baseline.
    • A decrease of ≥ 30% and at least 2 points from induction study (SHP647-305 or SHP647-306) baseline in the average daily worst abdominal pain over the 7 most recent days*, with the average daily stool frequency of type 6/7 (very soft stools/liquid stools) either:
      • not worsening from induction study (SHP647-305 or SHP647-306) baseline; and/or
      • meeting the criteria for clinical remission; i.e., 2-item PRO subscore of average daily stool frequency ≤ 2 of type 6/7 (very soft stools/liquid stools) as shown in the BSFS over the 7 most recent days*.
    • A decrease of ≥ 30% from induction study (SHP647-305 or SHP647-306) baseline in the average daily stool frequency of type 6/7 (very soft stools/liquid stools) as shown in the BSFS over the 7 most recent days*, with the average daily worst abdominal pain either:
      • not worsening from induction study (SHP647-305 or SHP647-306) baseline; and/or
      • meeting the criteria for clinical remission; i.e., 2-item PRO subscore of average worst daily abdominal pain ≤3 (based on 11-point NRS) over the 7 most recent days*.
  • Note: The 7 days may or may not be contiguous during the 10 days of data collection before colonoscopy preparation, depending on days to be excluded because of missing data. If fewer than 7 days are available, the criterion will be calculated on all available most recent 6 or 5 days. If fewer than 5 days are available, the criterion will be treated as missing.
• Subjects receiving any treatment(s) for CD are eligible provided they have been, and are anticipated to be, on a stable dose for the designated period of time.

Exclusion Criteria:

• Subjects who had major protocol deviation(s) (as determined by the sponsor) in induction study SHP647-305 or SHP647-306.
• Subjects who permanently discontinued investigational product because of an AE, regardless of relatedness to investigational product, in induction study SHP647-305 or SHP647-306.
• Subjects who are likely to require surgery for CD during the study period, except minor interventions (e.g., seton placement for anal fistulas).
• Subjects are females who became pregnant during induction study SHP647-305 or SHP647-306, females who are planning to become pregnant during the study period, or males or females of childbearing potential not agreeing to continue using appropriate contraception methods through the conclusion of study participation.
• Subjects who do not agree to postpone donation of any organ or tissue, including male subjects who are planning to bank or donate sperm, or female subjects who are planning to harvest or donate eggs, for the duration of the study and through 16 weeks after last dose of investigational product.
• Subjects who, in the opinion of the investigator or the sponsor, will be uncooperative or unable to comply with study procedures.
• Subjects who have developed obstructive colonic stricture, or enterovesical or enterovaginal fistulae during the induction study (SHP647-305 or SHP647-306).
• Subjects who have a newly diagnosed malignancy or recurrence of malignancy (other than resected cutaneous basal cell carcinoma, squamous cell carcinoma, or carcinoma in situ of the uterine cervix that has been treated with no evidence of recurrence).
• Subjects who have developed any major illness/condition or evidence of an unstable clinical condition (e.g., renal, hepatic, hematologic, gastrointestinal [except disease under study], endocrine, cardiovascular, pulmonary, immunologic [e.g., Felty’s syndrome], or local active infection/infectious illness) that, in the investigator’s judgment, will substantially increase the risk to the subject if he or she participates in the study.
• Subjects with any other severe acute or chronic medical or psychiatric condition or laboratory or electrocardiogram (ECG) abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study.
• Subjects with known exposure to Mycobacterium tuberculosis since testing at screening in induction study SHP647-305 or SHP647-306 and who have been advised to require treatment for latent or active disease but who are without a generally accepted course of treatment.
• Subjects with any of the following abnormalities in hematology and/or serum chemistry profiles during the evaluation of the last visit in the SHP647-305 or SHP647-306 studies.  If the results are considered by the investigator to be transient and inconsistent with the subject’s clinical condition, may be repeated once prior to enrolment in Study SHP647-307:
  • Alanine aminotransferase and aspartate aminotransferase levels ≥ 3 × the upper limit of normal (ULN);
  • Total bilirubin level ≥ 1.5 × ULN or > 2 × ULN if the subject has a known documented history of Gilbert’s syndrome;
  • Hemoglobin level ≤ 80 g/L (8.0 g/dL);
  • Platelet count ≤ 100 × 109/L (100,000 cells/mm^3) or ≥ 1000 × 109/L (1,000,000 cells/mm^3)*;
  • White blood cell count ≤ 3.5 × 109/L (3500 cells/mm^3);
  • Absolute neutrophil count< 2 × 109/L (< 2000 cells/mm^3);
  • Serum creatinine level > 1.5 × ULN or estimated glomerular filtration rate < 30 mL/min/1.73 m^2 based on the abbreviated Modification of Diet in Renal Disease Study Equation.
  • *Note: If platelet count is < 150,000 cells/mm^3, a further evaluation should be performed to rule out cirrhosis, unless another etiology has already been identified.
• Subjects who are investigational site staff members or relatives of those site staff members or subjects who are sponsor employees directly involved in the conduct of the study.
• Subjects who are participating in other investigational studies (other than induction study SHP647-305 or SHP647-306) or plan to participate in other investigational studies during Study SHP647-307.
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