When it comes to filing patent applications, timing is everything: applications must be filed before any disclosures of the technology are made, as prior disclosures could undermine the validity of any subsequent patents.
Although some countries, notably the US, operate a short grace period for inventor disclosures, key jurisdictions, including Europe, do not. A single filing (as an international application) will usually be made to eventually cover all territories of commercial interest, so the lack of a grace period in Europe will often determine when the application is filed.
Therefore, it is important that your patent attorneys are alerted before any disclosure so they can file an application if necessary. However, it is not necessarily best to file simply as early as possible. Provided that disclosures are controlled, it can be advantageous to wait as long as possible before filing any applications.
In the vast majority of countries, patent term is 20 years from filing – not a huge amount of time when considering it takes roughly 10-15 years for a drug to be brought to market. Thankfully, there are various ways in which the overall protection for therapeutic products can be extended. These require close coordination between in-house or external patent attorneys and researchers at every stage of drug development.