A new drug out of the gates

My post on December 19 mentioned that an early-phase trial of a drug called TPN-101 in PSP was about to start recruiting participants at two sites – one in Florida and one in Michigan.  I just learned that recruitment has begun and there are now five sites.  They’re in Boca Raton, Florida; Gainesville, Florida; Farmington Hills, Michigan; Las Vegas, Nevada; and Englewood, Colorado.  Contact information is available here.

The drug, whose new generic name is “censavudine,” is an inhibitor of the enzyme reverse transcriptase.  As you’d guess, it was originally developed for the treatment of AIDS.  The mechanism of action against PSP is via reducing levels of hyperphosphorylated tau.  It’s administered as an oral tablet.  This trial is designed to test safety.  With only 40 participants and less than six months of placebo-controlled treatment (followed by the same period of open-label observation), it isn’t large/long enough to assess benefit unless the magnitude of that benefit is improbably huge.

Figure that it will take six months to fully recruit, which means that the last patient will finish in mid-2023.  So I’d expect results in late 2023.  Let’s hope that this is safe and well-tolerated and that a Phase 2b or Phase 3 trial of hundreds of patients at dozens of sites will start soon thereafter.

Short stuff

Most of my posts are long — maybe too long. The charitable explanation is that I can’t resist my instincts as a professor to explain stuff so my learners can understand it. The less charitable explanation is that I’m just a windbag. So here are a bunch of very brief items of news, ideas and opinion about PSP and CBD in the style of Twitter. In fact, I’ll even limit my character count to 280, including spaces. Here goes.


A group in Bologna did skin biopsies to look for a phosphorylated form of α-synuclein in PD, PSP or CBD, and controls – 26 subjects in each group. They found it in all 26 with PD, in no controls, and in 24 with PSP/CBD. (The other two had PD-like features.) Now: how about MSA?

You’ve noticed that CurePSP’s publicity materials call PSP, CBD and MSA “prime of life” diseases because those conditions’ usual decades, the 50s, 60s and 70s, are when life can otherwise be lived to the fullest. Do you agree? Let me know.


A group called the PSP Research Roundtable was formed in 2017 to help speed the process of testing promising drugs. It’s run by CurePSP and has membership from academia, the FDA, the NIH, drug companies, biotech, philanthropy and patient advocacy groups.


Transposon Therapeutics has started a Phase 2 trial of TPN-101 in PSP at private clinical trial sites in Boca Raton, FL and Farmington Hills, MI. Like many available HIV drugs, TPN-101 inhibits the enzyme reverse transcriptase, but otherwise, details are sparse.

About the mechanism of action of TPN-101: I can tell you that another reverse transcriptase inhibitor routinely used for HIV called efavirenz (trade names Sustiva and Stocrin) reduces tau aggregation. CurePSP is currently supporting a study of it in a mouse tauopathy model in The Netherlands.

Enough for now. No windbag, I.