In Australia, they're reviewing this area of patent law to see if the parameters are right http://www.ipaustralia.gov.au/about-us/public-consultations/...

Novartis said in their submission "Generic companies should be able to compete with the original version of the product after expiry of the earlier filed patents. Thus, the scope of those improvement patents must always be narrower than the earlier filed patents so that third parties are normally in a situation to use the older technology after expiry of the earlier filed patents without infringing the follow-on patents" http://pharmapatentsreview.govspace.gov.au/files/2013/01/201...