XellSmart Biopharmaceutical (Suzhou/Shanghai) Co., Ltd. said Oct. 18 it completed enrollment in a China-based Phase II trial of its experimental Parkinson’s therapy while presenting Phase I data from a nine-person study in Seoul.
The company reported that the Phase I participants had an average improvement of more than 30 points in OFF-state MDS-UPDRS Part III motor scores at six months. The International Parkinson and Movement Disorder Society’s public abstract gives results by dose group: at six months, the lowest-dose group had a median improvement of 28 points, ranging from 11 to 35. At three months, the low- and middle-dose groups had median improvements of 28 and 39 points, respectively.
The abstract describes three dose groups, with XS411 administered at 4.5 million, 9 million or 18 million cells. Its longest follow-up, six months, covers only the lowest dose; follow-up reached three months for the middle dose and one month for the highest. The abstract also reports a 22% rise from baseline in left-putamen ¹⁸F-DOPA PET uptake at six months for the lowest-dose group, and describes the findings as preliminary, with longer-term follow-up continuing.
The abstract recorded no dose-limiting toxicities, serious adverse events or graft-related adverse events among the nine participants. XellSmart separately reported no events it considered related to XS411, no abnormal cell growth or tumors in serial MRI scans, and no graft-induced dyskinesia. The Phase I study used donor-derived induced pluripotent stem cell progenitors implanted in the putamen, with the aim of replenishing dopamine-producing cells.
XellSmart’s Phase II plan calls for 30 participants randomized 2-to-1 between XS411 and standard anti-Parkinson’s medication. The company described the trial as open-label, with blinded endpoint assessment. Its plan specifies an assessment at 12 months and follow-up for the treatment group for up to 24 months after transplantation.
A Pharnex mirror of China’s CTR20261463 registry lists recruitment as complete and a target enrollment of 30; it marks actual-enrollment information as not entered. XellSmart’s Phase II plan sets out follow-up periods but does not specify a results-release date.
