Such studies are relatively short. If they were not, there would be no reason for companies to use the “import” route (rather than the “full development” route) to obtain approval in China.
Yes. The bridge studies, even though called registration trial, are not as rigorous as FDA/EMA's registration trial. The approval by SFDA to conduct such studies take 12-14 months on average however. For example, AMAG's partner in China 3SBio applied for such studies in China in Dec. 2009 following Feraheme approval in US June 2009, still has not received approval for conducting such study yet.
This is what you expect from import route from Bayer's press release about Betaferon approval in China - Bayer has the most experience getting their drugs approved in China:
Berlin, December 1, 2009 – Bayer Schering Pharma AG announced today that the Chinese State Food and Drug Administration (SFDA) has approved Betaferon® (interferon beta-1b) therapy for patients with relapsing-remitting multiple sclerosis (MS). Bayer plans to launch Betaferon in China by mid 2010. Betaferon is available in more than 100 countries around the world.
“This approval is good news for MS patients in China, allowing them access to Betaferon, that has been demonstrated to modify the course of MS,” said Habib Dable, Global Head, Neurology/Ophthalmology of Bayer Schering Pharma AG. “The approval of Betaferon in China underscores Bayer’s ongoing commitment to address the unmet medical needs of people around the world. With the foundation of a research and development center in Beijing in February 2009, Bayer has strengthened its engagement in the Region. In the upcoming five years, a total of 100 million Euro is planned to be invested in a center for clinical research in Beijing.
The approval is based on established efficacy and safety data from pivotal Betaferon clinical trials, along with findings from a single-arm study designed to demonstrate the efficacy and safety of Betaferon among Chinese patients with relapsing-remitting MS. During the multi-center six-month study, Betaferon significantly decreased the number of newly active lesions on MRI in Chinese patients. The data in MS patients from China is comparable with data from Betaferon studies in different patient populations and with Bayer’s post-marketing experience.