Inclusion Criteria: Subjects must satisfy the following criteria to be enrolled in the study: 1. Subject fulfilled the inclusion criteria at time of entry into the Induction Study (RPC01-3201 or RPC01-3202) and have completed the Week 12 efficacy assessments of the Induction Study. 2. Subject is in clinical response (a reduction from baseline in Crohn's Disease Activity Index (CDAI) of ≥ 100 points or CDAI score of < 150 points) and/or clinical remission (CDAI score of < 150 points) and/or has an average daily stool frequency score ≤ 3 and an average abdominal pain score ≤ 1 with abdominal pain and stool frequency no worse than baseline at Week 12 of the Induction Study. Exclusion Criteria: The presence of any of the following will exclude a subject from enrollment: Exclusions Related to General Health: 1. Subject has undergone a colectomy (partial or total), small bowel resection, or an ostomy (ie, temporary colostomy, permanent colostomy, ileostomy, or other enterostomy) since Day 1 of the Induction Studies or has developed symptomatic fistula (enterocutaneous or entero-enteral). Exclusions Related to Medications: 2. Subject has received any of the following therapies during the Induction Study: a. rectal steroid therapy (ie, steroids administered to the rectum or sigmoid via foam or enema) b. post-baseline initiation of, or increase in, corticosteroids to treat worsening CD to a dose greater than the maximum daily dose taken between the screening and baseline visits c. rectal 5-ASA (ie, 5-ASA steroids administered to the rectum) d. parenteral corticosteroids e. total parenteral nutrition therapy f. antibiotics for the treatment of CD g. immunomodulatory agents (6-MP, azathioprine, including but not limited to cyclosporine, mycophenolate mofetil, tacrolimus, and sirolimus) h. immunomodulatory biologic agents as well as other treatments for CD such asetrasimod, filgotinib, and upadacitinib I. investigational agents j. apheresis