Chinese groups develop most of the world's in vivo CAR-T drug candidates

Boston Consulting Group's count of 140 in vivo CAR-T drugs includes candidates being tested in animals as well as in people ^[1]. At 82%, Chinese groups account for roughly 115 of them, which leaves about 25 for everyone else ^[1]. Nature's report does not say how many of the 140 have been given to a patient.

The appeal of the approach is practical. Ex vivo CAR-T, already used for blood cancers, means collecting a patient's immune cells, editing them in a laboratory and infusing them back ^[4]. In vivo versions instruct the body to make the change itself. The altered immune cells then attack cancer cells or, in autoimmune disease, remove the cells that attack healthy tissue ^[3]. Nature describes these therapies as cheaper and easier to develop ^[4].

The researchers Nature spoke to give overlapping reasons for China's position. Xiaoyuan Chen, a chemist at Shandong Cancer Hospital and Institute in Jinan, is developing an in vivo therapy for cancer and fibrosis ^[11]. He points to institutional investment and close ties between academia, hospitals and industry. China also has a large population of people with autoimmune disease and few treatment options, and many of them are willing to enrol, he said ^[13]. Emily Blyth, a cellular therapy researcher at The Westmead Institute for Medical Research in Sydney, said the work has been building for at least five years ^[5]. "There's a huge volume of work, a lot of it supported by the Chinese government," she said ^[6].

John Wu, who led the analysis, puts most of the weight on the trial route ^[14]. Investigator-initiated trials shorten the step from animal studies to a first patient. They also mean the earliest human data in this field are collected outside the process that eventually decides approval ^[14][12].

Those data are small so far. The published cohorts have five and 16 people, and the five-patient lupus result was read at three months ^[8][9]. The thing these studies don't tell you is whether the benefit lasts, or whether the toxic side effects seen with ex vivo CAR-T turn up as more patients are treated. Researchers told Nature that developers will need data on both before regulators approve the therapies for widespread use ^[12].

The FDA's clearance of a Chinese blood cancer candidate for clinical trials is the first move of this work into a US-supervised setting ^[10]. "Successful clinical development in China could also accelerate innovation, reduce treatment costs and generate valuable clinical evidence that benefits patients worldwide," Chen said ^[11].

In my view the Chinese lead is real on two measures: the number of programmes and the speed of first-in-human work ^[1][14]. It depends on the investigator-initiated route staying as it is. The durability and safety data that regulators require have not yet been produced by Chinese groups or anyone else ^[12].