Novartis AG (NYSE:NVS) has filed a lawsuit to block a Maryland law requiring drugmakers to offer discounts on drugs dispensed by third-party pharmacies contracting with hospitals and clinics serving low-income populations. The law, set to take effect on July 1, conflicts with the federal 340B drug discount program. Novartis argues that the law attempts to regulate interstate commerce outside of Maryland and complicates recordkeeping and transparency.