Is Patent “Evergreening” Restricting Access to Medicine/Device Combination Products?

Is Patent “Evergreening” Restricting Access to Medicine/Device Combination Products?

Source: 
Drug Patent Watch
snippet: 

Not all new drug products are truly new. Some are the result of marginal innovation and incremental patenting of existing products, but in such a way that confers no major therapeutic improvement. This phenomenon, pejoratively known as “evergreening”, can allow manufacturers to preserve market exclusivity, but without significantly bettering the standard of care.