To get a drug approved for market, it's vital that companies (or their CMOs) comply with current GMPs and ensure that the documentation is in place. If regulatory bodies don't believe a company is complying, they can refuse to grant approval, and if a facility isn't ready for inspection, this can delay approval.
As an example of this, approval of Cialis (tadalafil) and a number of other drugs was delayed because of manufacturing concerns at Eli Lilly's ($LLY) plants in Indianapolis. In some cases, regulatory rigor has varied depending on the stage of development, e.g., before Phase IIb, the GMP requirements have traditionally been less arduous than after, but the trend is now toward increasing rigor, particularly where Phase III trials for chronic diseases are concerned.
In some regions, the regulators seem to be getting more cautious, asking for bigger trials, which need more clinical material, adding more cost and time. This caution over requirements for clinical trials may stem from the case of Vioxx (rofecoxib), which was used to treat arthritis. The drug was linked with an estimated 27,785 heart attacks and sudden cardiac deaths in the 5 years it was on the market between its launch in 1999 and September 2004, when it was pulled. Problems were first detected in 2000, but Merck ($MRK) did not react immediately, and the drug remained on sale until late 2004.
This incident led regulators and the public to question the rigor and appropriateness of clinical trial design and execution in chronic drugs, and by extension, the manufacturing and supply of products for clinical trials.