Monday, July 9, 2018

Regulus Therapeutics Declares MicroRNA Therapeutics Bankrupt

Once considered a new star on the biotech firmament, the most prominent microRNA Therapeutics company is going from bad to worse fast.  

Last week, Regulus Therapeutics announced that both of its clinical programs in Alport’s Syndrome and autosomal dominant polycystic kidney disease (AKPKD) had been voluntarily halted for financial and preclinical reasons. Instead, the company will now try to renegotiate the Alport deal with Sanofi and use its remaining resources to focus on a preclinical program for HBV.

Management not in control

The program pauses follow a string of other setbacks over the last 3 or so years. Most prominently, it discontinued a highly promising candidate for the treatment of HCV due to safety questions and having been a few years too late to a highly competitive game.  A slow early advancement of that miR-122 program was partly to blame for this.

After that, it has been one delay after another for various programs.  Partner AstraZeneca e.g. returned a liver-targeted metabolic program and the Alport's program has been hit by multiple delays and trial reconfigurations.

If this was not sufficient proof that managing a biotech company has been well above the paygrades of the multiple executive teams that have come and gone over the years, running out of cash in this genetically-focused biotech bull environment is simply unacceptable.  Even if microRNAs may have lost its early luster as targets for particularly complex diseases, I had thought that having exclusive access to the huge IP portfolios of parent companies Ionis and Alnylam for microRNA Therapeutics purposes would provide a powerful backstop when it came to accessing fresh capital.

With a market cap of less than $40M and last week’s ‘we’ve-run-out-of-cash news’ I was obviously wrong…

Chasing a 'safe' target

Since microRNAs which typically have a range of biologically meaningful targets are thus promising for treating particularly diseases of complex causes and manifestations, I would have thought that with the genetics gold-rush that we are now witnessing in neurology, not least because of antisense drug SPINRAZA, there would be much interest in Regulus Therapeutics there.

I understand that HBV is becoming a hot area again, with the skyrocketing valuations of Arrowhead, Dicerna, and Arbutus suggesting that high rates of functional cures are just around the corner.  Going after HBV with a microRNA, however, would seem like a surprising choice though given that in terms of direct antiviral activity, a microRNA approach should pale in comparison to the RNAi competition.  You would therefore think that Regulus is considering a immune reactivation-related microRNA target for HBV, but it is not clear to me which model they would be basing this on.  

Hey, management, at least show us some data to hang our hats on when you sell a preclinical concept as your future.

Or does choosing HBV betray that they have lost all confidence in their ability to deal with the biological complexity of microRNAs, instead seeking safety in just measuring simple viral knockdowns?

After the quasi-demise of microRNA diagnostics leader Rosetta Genomics, there is now the real prospect that the therapeutics counterpart will equally go belly-up soon.  In order to avoid that, Regulus needs new, confident management first and foremost as the main task now is to make the case for microRNAs as therapeutic targets.  Where are all the boastful biotech executives when you need them?

Monday, July 2, 2018

Arrowhead Achieves Robust Alpha-1 Antitrypsin Lowering As Grounds for Trial Termination Still Shrouded in Mystery

Last Friday, Arrowhead Pharmaceuticals presented first data from its phase I study of ARO-AAT being developed for addressing liver disease in people with certain mutations in the alpha-1 antitrypsin gene.  Based on the selective data release, Arrowhead has assumed the lead in this indication as Alnylam struggles to regain its footing following apparent off-target-related liver toxicity almost 2 years ago.

The press release can be found here, the actual presentation here

With a mean maximal target gene knockdown of -87% between 6 to 8 weeks following a single subcutaneous injection of 100mg dose of the GalNAc-enabled ARO-AAT, Arrowhead has shattered the previous AAT knockdown record by Alnylam’s ALN-AAT of -80% at a ~4x dose of ARO-AAT.  The dynamics of the knockdown also suggests that infrequent dosing should be feasible with ARO-AAT, although without seeing the multi-dose data from this study, it is difficult to predict whether we are talking about quarterly or semi-annual dosing here.

It will also be interesting to find out whether the variation of knockdown in the 4 patients- ~-70% knockdown at 4 weeks for the 2 weaker responders and ~-90% for the 2 better responders- had to do the polymorphism issues similar to those encountered by Alnylam before.

Safety mystery remains

When Arrowhead announced on June 18 that it would terminate the healthy volunteer trial prematurely given that it had escalated above doses at which maximal knockdown can be observed, I was hesitant in taking it at face value or whether this decision also had something to do with the safety profile of ARO-AAT.

The Alpha-1 National Education Conference update only added to the impression.  Firstly, because Arrowhead must already know the knockdown from the 200mg and perhaps also the 300mg open-label cohorts since at least June 18, why didn’t the company simply show the data?   

Regarding safety, the company chose a cut-off date of June 11, that is a week before the June 18 decision.  By June 11, there were only 2 drug-related injection site reactions among the 32 subjects that had received at least 1 dose of either ARO-AAT (n=20) or placebo (n=12) per slide 17 of the presentation.  Those happened to be in the 2 of 4 100mg open-label subjects, the only subjects for which the knockdown had been reported.  

Confusingly, the company also reported that 44 subjects had received at least 1 dose (at least as of the trial termination decision date of 18/6), meaning that 8 subjects had further received 300mg of ARO-AAT (4 open-label, 4 blinded) and 4 placebo (all blinded).  Adding to the confusion, a company representative emailed me in a response to a tweet of mine on the ISR frequency that the safety update referred to those 40 subjects that had received at least 1 injection as of 11/6, but- as I said- contrary to this statement the table on slide 17 only included 32 subjects.  For all those others, the safety data were missing entirely.

The question now is whether the omission was intended as a teaser for the Liver Meeting presentation in November, a minor math issue, or whether there was something more nefarious to it.  The speed with which the company will move into patients (which already have or are at risk for liver disease) will be an important indication whether liver toxicity or the like has been observed subsequent to June 11.

By Dirk Haussecker. All rights reserved.

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