Sanofi's decision to offer a 50% discount on Zaltrap ziv-aflibercept would appear to address oncologists' objections to the colorectal cancer drug's cost, but it is not clear whether the move will improve either patient access or physician uptake.

The reason is some doctors simply don't see enough improvement over Avastin bevacizumab to try the new drug even if they cost the same - and the ones who do try it could choose to pocket the discount without passing it on to patients.