The U.S. has been among the most sought-after pharmaceutical markets in the world for decades, however accessing this enormous market is not easy. Not only must entrants gain marketing approval from the Food and Drug Administration, they must also ensure access to patients by gaining prescriber and payer acceptance. Meeting the combined challenges of marketing approval, payer acceptance, assured reimbursement and access to patients is the result of a studied and deliberate approach to product development and launch. This studied approach is particularly important in rare disease product categories with low numbers of patients, high development costs and managed care plans focused on controlling spend.