Place the diced chicken in the slow cooker. Pour the Italian dressing over the chicken, then add the garlic, pepper, and Parmesan cheese. Stir to evenly coat the chicken.
Cover and cook on low for 5–6 hours or on high for 3 hours.
During the last 30 minutes of cooking, cut the cream cheese into cubes and place it on top of the chicken mixture. Cover and cook until the cream cheese melts.
Cook the pasta separately according to the package directions.
Stir the cooked pasta into the chicken mixture just before serving.