Opposing Competitive Patents
You have a number of options when a competitor files a patent application for a key technology before you file. One of the best is patenting technology that is incremental to and necessary for the competitor to practice its patent. This encourages the competitor to cross license with you and keeps you from being at a competitive disadvantage.
If the application was recently published, you can file a pre-grant submission with the United States Patent and Trademark Office (USPTO) to reduce the scope of the competitor patent or even prevent it from issuing as a patent. Filing a timely and effective pre-grant submission sharply reduce your risk of infringing the competitor patent or of patent litigation, and is very cost effective.
You may influence PCT applications by filing third party observations.