The PI-2620 retention in an AD patient
(58 years; MMSE 23) above follows the known distribution of pathological Tau aggregates in the brain (higher in posterior areas
than frontal) and is associated with glucose hypometabolism, grey matter atrophy and cognitive impairment.
Figure 29: Cortical update
of PI-2620 in amyloid positive patients
Ref: Mormino, EC. et. al., AAIC 2018;
The PI-2620 data (60-90 min p.i.) above
indicates strong differences in the cortical uptake of amyloid positive, cognitive impaired, patients compared to age-matched cognitive
normal (CN) subjects. Differences in PI-2620 uptake between cognitive normal subjects with or without amyloid are detected in medial
temporal lobe regions. This suggests promise for PI-2620 to detect pathological Tau aggregates throughout the course of AD.
Figure 30: Uptake of PI-2620
in the Globus pallidus of PSP subjects
Ref: Bullich, S, et. al., HAI 2019
The data in the figure above shows PI-2620
PET data of 5 PSP subjects at the level of the pallidum (inferior cerebellar cortex as reference region). Four out of five PSP
subjects show clearly increased uptake of PI-2620 in the globus pallidus in SUVr images obtained from 30-60 min p.i.. In contrast
to AD, the optimal PET imaging window of PI-2620 in PSP patients is 30-60 min. The AD and PSP data demonstrate the ability to PI-2620
to bind to both 3R and 4R Tau aggregates in AD and non-AD tauopathy subjects, which is a distinct feature of PI-2620 compared to
other Tau-PET tracers.
Data from the Tau-PET imaging program were
presented at multiple conferences in 2018 and early 2019 including, the HAI conference in Miami (January 17-19, 2018), the AD/PD
conference in Torino (March 15-18, 2018), the EMIM conference in San Sebastian (March 20-23, 2018), the SNMMI conference in Philadelphia
(June 23-26, 2018), the ESMEC conference in Urbino (July 01-05, 2018), the AAIC conference in Chicago (July 22-26, 2018), and the
CTAD conference in Barcelona (October 24-27, 2018), and the Human Amyloid Imaging conference in Miami (January 16-18, 2019).