The days of gene therapy companies making huge gains off data in very small numbers of patients might be over. Axovant today put out ostensibly promising results with its Parkinson’s gene therapy, AXO-Lenti-PD, but these only came from two patients in a cohort of four. The markets were not impressed: Axovant’s stock initially rose in premarket trading, but was down 20% in morning trade. On the plus side, AXO-Lenti-PD cleared the bar set by Axovant, at least in the two evaluable patients from the second cohort of the Sunrise-PD phase II trial. At six months, they had a 21-point mean improvement in the UPDRS Part III “off” score; the target had been at least 10-15 points, in line with deep brain stimulation. The results look similar to those from the lower-dose cohort one of Sunrise-PD, but better than those seen with Voyager/Neurocrine’s VY-AADC in its 15-patient phase Ib study. However, the usual caveats about cross-trial comparisons are even more relevant with such small patient numbers. Axovant will need to show more to convince investors – it will test a higher volume and flow rate in cohort three of Sunrise-PD, and start the sham-controlled Explore-PD study next year.
|Cross-trial comparison of Parkinson's gene therapy candidates|
|Company||Project||Trial details||N||Improvement in UPDRS Part III “off” score|
|Axovant Gene Therapies||AXO-Lenti-PD||Sunrise-PD (NCT03720418), cohort 1 (4.2x106 TU)||2||22 points at 1yr|
|Sunrise-PD (NCT03720418), cohort 2 (1.4x107 TU)||2||21 points at 6mo|
|Voyager Therapeutics/ Neurocrine Biosciences||NBIb-1817 (VY-AADC)||PD-1101, NCT01973543||15||10-19 points at 3yrs across cohorts|
|PD-1102, NCT03065192||7||12 points at 2yrs|
|Source: Company presentations, clinicaltrials.gov.|