Thursday, November 28, 2019

One Pitfall to Look Out for in RNAi Therapeutics

RNAi Therapeutics have turned the corner to being a generally accepted drug modality.  Following years of ridicule and benign neglect, the industry just celebrated the FDA approval of a 2nd drug, Givlaari for the treatment of acute hepatic porphyria. This was followed in short order by the $9.7B acquisition of The Medicines Company by Novartis for its cholesterol-lowering RNAi drug candidate, Inclisiran, a harbinger for how RNAi medicines will change the game in cardiovascular risk management.

Amid all the understandable investor excitement, it is probably a good time to reflect on the potential pitfalls as we move into a world where RNAi Therapeutics dominate liver-related diseases and advance into new big areas such as the CNS and ocular disease.  Remember, investor, it takes one safety event for the most highly valued programs like HBV RNAi candidate AB-729 by Arbutus Biopharma, Arrowhead Pharmaceutical’s ARO-AAT, or the Lpa program by Silence Therapeutics to decimate your investment by half or more.

Off-targeting safety, off-targeting safety, off-targeting safety

When the discovery of RNAi was rewarded with the Nobel Prize in 2006, the Andy Fire and Craig Mello hammered home a message that would resonate for the years to come: to make RNAi Therapeutics, it’s all about the delivery!

Delivery, delivery, delivery

But as the liver has been conquered and the industry is chewing on a number of liver-related therapeutic opportunities and opening up opportunities in new areas, we still have to fully understand the odds of seeing program failures due to the difficult to predict consequences of off-targeting.

Off-targeting is the moderate knockdown of sometimes dozens of genes sharing sequence homology to the target gene.  This was shown over a decade ago and soon thereafter shown to be addressed by using simple modification strategies.

This, however, was at a time when the delivery mantra was practiced and nobody wanted to risk reducing knockdown efficacy by simultaneously considering off-targeting in their RNAi trigger designs.  I was therefore upset, as it turned out rightfully so, that Alnylam let Nastech essentially go bankrupt a decade ago when it should have acquired rights to Nastech's then industry-leading off-target-mitigation technology.

Alpha-1 Antitrypsin as testbed

Alnylam would have to pay dearly for its pride in never treating a smaller competitor well, even if it served its own interest, with off-targeting manifesting itself in markers of liver toxicity in first-generation clinical programs like chronic HBV and alpha-1 antitrypsin-related liver disease.

These two indications, unlike the now approved AHP indication for Givlaari which addresses symptoms outside of the liver, represent the most exacting off-targeting challenge as they affect liver health directly and any further exacerbation of liver stress should be avoided.  

As a result, Alnylam dug out the old off-targeting literature and in their incarnation added a GNA modification at position 7 of the guide strand while, for experimental purposes, leaving the rest of the first-generation molecule unchanged. Translational science at its best (!) and the industry can be thankful for it.

Indeed, for both the ESC+ chemistry ALN-AAT02 and ALN-HBV02 no liver enzyme elevations (above 3x ULN) were observed in 49 subjects tested, whereas 3 of 33 had such elevations with the ESC-only versions.

In Arrowhead’s case, there also were no ALT elevations >3x ULN.  However, 3 treatment-emergent grade 1 ALT elevations not exceeding 2x ULN were reported in the 28 normal healthy volunteers receiving ARO-AAT.  I am curious to see the individual time curves and the doses at which they occurred.  It is certainly an area to watch for that program as it only now moves into patients. 
Add to this considerable uncertainty about patient selection, dose and duration required to have an impact on AAT liver disease, increasingly analysts topping their price targets by the day may have to re-think how they value this program (see disclosure below).

Further behind, we have to see how Silence Therapeutics and Arbutus have addressed off-targeting with first data expected in 2020.  While Silence has avoided indications directly affecting liver health (iron overload, cardiovascular disease), Arbutus with its HBV indication will have a steeper hill to climb, although the pay-off for investors in this $80 market cap company should be considerable should it climb it come Q1 2020.

Personally, my guesstimate for non-optimized GalNAc designs would be a 50% chance of off-targeting success, also depending on preclinical vetting (after all, the very clean $9.7B Inclisiran is such a design); a 85% off-targeting success for optimized designs. 

Disclosures: long Silence Therapeutics, Arbutus Biopharma; short Arrowhead Pharmaceuticals; no position in Alnylam.

Monday, October 7, 2019

Open Letter to Arbutus Biopharma Board and Management

HBV RNAi or Nothing

It is now 4 years that Wunderkind Vivek Ramaswamy handed you a bag of worthless small molecules for half of what was then one of the premier nucleic acid therapeutics companies with a strategically valuable position in RNAi Therapeutics and bright prospects in mRNA Therapeutics and genome editing.

To this day, I wonder what he put into your drinks that you would agree to such a deal.

Today, your actions have destroyed almost all of that value as close to a dozen clinical candidates, one after the other, have failed in development revealing shocking deficiencies in evaluating preclinical safety.  Meanwhile, shareholders have lost almost everything as the share price has been decimated from around $15 to less than a dollar as I type.

But instead of dwelling on the past, I want to look to the future and make it very clear to you that with your in-house capsid inhibitor having been abandoned last week, you have no choice, but to now try and extract as much value as possible from your HBV RNAi candidate ABUS-729 with the goal of selling the company. $5 per share (~$400M) for a compound backed by phase I clinical data showing it to be safe, potent, and fairly long-lasting in knocking down its targets would seem reasonable given the interest in the space for RNAi assets and achievable before 2021.

Waiting for in-house candidates to mature enough to combine them with 729 would leave you too far behind the competition and cause you to waste your other main current asset: the $100M in cash balance (don't even think of in-licensing yet another poorly validated small molecule!).  $100M meanwhile would allow you to comfortably develop 729 to clinical validation.  This, of course, also means that you need to cut your functions to what is strictly necessary to achieve that goal, including eliminating all of pre-clinical research.

Further cash could be raised by monetizing your stake in Genevant.

The time to act decisively is now. 

Tuesday, October 30, 2018

RNAi is the Future of Cardiovascular Disease

At least, this is what Big Pharma and Biotech is saying right now following deals between pure-play RNAi companies Arrowhead Pharmaceuticals and Dicerna with Amgen and Eli Lilly, respectively, and the sale of The Medicines Company with its lead PCSK9 RNAi asset really being only a matter of timing.  Besides its new relationship with Eli Lilly announced yesterday, Dicerna has an ongoin CVD-related NASH/NAFLD collaboration with Boehringer-Ingelheim.  In addition, Wave Life Sciences and Akcea, the commercial Ionis spin-out, have been pursuing cardiovascular targets along with Pfizer and Novartis, respectively, using the competitive RNaseH antisense gene knockdown technology.

Drugging the undruggable

Part of the attraction of RNAi for CVD for the pharmaceutical industry is because the targets that come from large genetic studies (e.g. ApoCIII, Apo(a), ANGPTL3) based on chance alone are not readily druggable.  To make matters worse, amorphous lipid macromolecular aggregates are particularly difficult to target with either small molecules or antibodies.

Infrequent dosing

What a difference 10 years can make.  When Protiva (now Arbutus) was one of the first to enter a systemically administered RNAi therapeutic against LDLc-related ApoB into the clinic a decade ago, it often found itself ridiculed for using RNAi in such an indication.  Systemic RNAi back then required relatively frequent (1-3 weeks) intravenous administration which would make it an unlikely modality for widespread diseases that ideally require decade-long preventive treatment strategies.

Fast-forward to the present and now we have subcutaneously delivered RNAi with potential dosing frequencies of up to once-a-year as evidenced by the lead candidate of this crop, phase III asset Inclisiran by The Medicines Company.  If the remarkable safety profile holds up following about 2000 patient years of clinical experience, such a drug should be very widely prescribed, not least because it should enjoy great adherence, one of the major impediments of treatment success in cardiovascular disease.   

Undoubtedly, it has been the Inclisiran performance so far that has attracted the attention of players like Eli Lilly and Amgen, the latter of which, of course, should know particularly well about the competitive threat from RNAi having an antibody-based PCSK9 agent on the market (Repatha).  Beyond the upcoming slew of phase III read-outs with Inclisiran, it will equally be interesting to see the types of new targets being pursued and the clinical validation of targets like Apo(a) by the antisense competition.

Friday, October 12, 2018

AASLD Abstract Continues to Support Promise of ARO-HBV, but with a Twist

Yesterday, Arrowhead revealed the abstract for data on its new HBV RNAi drug candidate to be presented at the big annual Liver Meeting in November (AASLD).  The data continue to support highly potent knockdown of not only the surface antigen (HBsAg), but also other HBV components.

Dose response issues

When Arrowhead announced initial first-in-patient knockdown data from its 3rd generation HBV RNAi candidate ARO-HBV, I found it suspicious for them to only reveal data for the 100mg and 200mg cohorts although more data was available at the time.  Curiously, the new data seem to suggest that there was no apparent benefit from going higher than 100mg in dose, at least when dosed with the current monthly frequency. 

Whether there is significantly worsening safety with increasing dose remains to be seen.

HBeAg positive/negative dichotomy

Similarly (but not as earth-shattering for sure) to the history of a prior HBV RNAi candidate by the company before, ARC-520, however, Arrowhead was able to learn more about its drug candidate as they went along in the study.  In particular, the first dose escalation cohorts (100, 200, 300, and 400mg monthly x3) encompassed a mix of HBeAg positive and negative patients, with 13 out of 16 being HBeAg negative.    

When Arrowhead then decided the last 2 cohorts to be just HBeAg positive, a remarkable increase in drug response was observed: whereas it took the predominantly HBeAg-negative patients 70-90 days to achieve 1.5log reductions in HBsAg, it looks like the pure HBeAg-positive patients only take 30-40 days to achieve the same.

Ergo, the reason why no clean dose response had been seen in the first cohorts is best explained by the fact that they were mixed and at that small cohorts.

Trigger choice likely explanation

ARO-HBV comprises 2 RNAi triggers: one that targets all (intact) HBV mRNA (X trigger) and one that makes sure the surface antigen is hit (S trigger) even in those patients with integrated HBV.  These typically lose the corresponding DNA element targeted by the X trigger during integration.

In the early days of RNAi, there was some controversy about the usefulness of using 2 or more triggers against the same target in terms of knockdown potency and specificity.  When I first started to practice RNAi in the lab in 2003, it was my experience that when you combined a very potent trigger with a less potent one, the knockdown was less than with the highly potent one alone.  As a result, I am a firm believer in the concept of RNAi trigger competition.

In the case of ARO-HBV it means that in HBeAg negative patients that have lost the X-trigger DNA, there will be one sterile/inactive trigger somewhat blunting the potency of the active one.

HBV biology is certainly complex and downstream events could also account for final knockdown differences.  Accordingly, in the HBeAg-only cohorts  it appears from the early observations that the nuc-experienced patients that in previous studies corresponded to patients that had lost the X-trigger-targeted elements by study enrollment not only responded as well, but in fact slightly better than the nuc-naïve patients.  It will therefore be important to learn more about their HBV integration status at AASLD to confirm or disprove the competition theory.

Wednesday, October 10, 2018

Review of Recent RNAi-Related Developments

The last 2 weeks have been busy ones in the lands of RNAi Therapeutics.  Here, I would therefore like to offer my take on the most important developments.

Alnylam’s Primary Hyperoxaluria Drug Breezes Through Clinic

With 20 subjects on Lumasiran, a GalNAc-RNAi targeting glycolate oxidase, for a median of 7 months, the investigational treatment for type I primary hyperoxaluria (PH1) ismore and more looking like a solid drug.  If the data presented last week at a Paediatric meeting in Turkey hold up in another 30 patients, it should fly through approval onto the market by the end of 2019.

While the relatively small numbers in each cohort has caused a bit statistical noise, it seemed like 3mg/kg monthly gives you an advantage over 1mg/kg monthly or 3mg/kg monthly in terms of the key biomarker urinary oxalate.  Interestingly, the company has chosen 3 times 3mg/kg monthly as the loading dose regimen in the now ongoing pivotal ILLUMINATE-A trial to be followed by dosing every 3 months. , the initiation of which the company has just announced.    

The core double-blind portion of the trial runs for only 6 months, so I am a bit puzzled how much the trial can inform on the value of the loading dose regimen and whether quarterly maintenance doses are sufficiently effective.   In any case, the trial design apparently was blessed by the FDA (incl. the urinary oxalate lowering primary endpoint), so surely they will know (e.g. based on preclinical animal data).

Regarding the competition with the primary hyperoxaluria drug candidate from Dicerna, the approximately 2/3 lowering of urinary oxalate and essentially all patients getting into a range considered safe and an unremarkable safety profile sets a high hurdle for the upcoming data presentation of DCR-PHXC at ASN later this month.

Arbutus HBV-RNAi Drug About to Die   

Yesterday, Arbutus provided an update on its LNP-enabled RNAi drug candidate for the treatment of chronic HBV (ARB-1467) and it does not bode well.  Similar to most other drug candidates attempted and barely tried, ARB-1467 should be canned in the not-too-distant future. 

In a combination study testing ARB-1467 in chronic HBV patients on nucleoside reverse transcriptase inhibitor tenofovir, probably only 1 in 6 patients hit a pre-defined criteria in terms of HBsAg lowering that would allow the patient to then receive immune booster PEG-Interferon.  The not very forthcoming revelation and the fact that the data was mentioned even after dropping another shoe that its small molecule HBV RNA destabilizer is also biting the dust makes it clear that not even the company sees much value in ARB-1467.

What an utter disaster this company has been since its inception as a HBV solutions entity.

Arrowhead Early HBV Deal Further Validates

Last week, shareholders in Arrowhead Pharmaceuticals got a lesson in biotech investing as it shares have given up ~1/3 of its value following a nice deal with Johnson&Johnson for the leading HBV knockdown asset in the space, ARO-HBV.

The deal gives Arrowhead a solid $250M in financing, including a $175M upfront fee and a $75M investment in company stock at a premium of ~50% to current trading.  While this avoids an imminent dilutive secondary share issuance- the company had been running low of cash- the ‘up to 15%’ in royalties from future sales of early phase II-stage ARO-HBV is clearly disappointing.  The relatively low royalty despite of it having confirmed strong HBsAg knockdown in patients can be explained with the fact that Arrowhead has avoided bearing the full risk of having to show proof-of-concept of HBV control.  This despite of having earlier paraded results obtained with an earlier DPC-based RNAi candidate (ARC-520) as strong evidence that RNAi can achieve such immune control.

While Arrowhead got punished for playing it safely, it can now focus on commercial home-run indications with highly validated targets and transition to being a broad platform company with a wholly owned attractive lead candidate in ARO-AAT.  Indeed, Arrowhead may emerge as the leading RNAi company as Alnylam, with a market cap ~8x that of Arrowhead, is still burdened by late-stage RNAi drugs with suboptimal specificity.

While humiliating, this serves Alnylam as a good reminder to also value innovation by the direct competition (note: specificity-enhancing technology now adopted by Alnylam has been available for a decade and could have been had for peanuts, e.g. from now defunct RNAi play mdRNA/Nastech).  Fittingly, today long-time archrival Silence Therapeutics issued a press release indicating that Alnylam is playing hard-ball with regard to Silence-owned IP purportedly covering ONPATTRO.

My guess is that Alnylam would rather risk an injunction and deprive patients of a very good medicine than to submit to what appear to me legitimate demands of a competitor.

Akcea’s antisense drug for TTR amyloidosis gets FDA nod

Last Friday, Akcea’s TTR drug TEGSEDI (licensed from Ionis) finally got FDA marketing approval for patients suffering from TTR-related polyneuropathy.  As expected from the delay in the approval process, TEGSEDI’s approval is accompanied by hefty black box warnings highlighting thrombocytopenia and renal risks of the (non-GalNAc) phosphorothioate oligonucleotide.  

Furthermore, the REMS program calls for frequent blood monitoring, essentially negating the claimed at-your-home convenience advantage over competing RNAi drug ONPATTRO.  Add to the poor safety profile clear efficacy disadvantages and pricing at parity with ONPATTRO, ONPATTRO should clearly win out in the marketplace.

Having said that, the TTR community is relatively small and key opinion leaders with relationships to a given drug company tend to support the drugs from the same company.

Friday, September 28, 2018

Another Second-Generation GalNAc-RNAi Rocked by Off-Target Concerns

With the approval of ONPATTRO and the current overall clinical picture, in particular the highly encouraging safety profile seen with PCSK9-targeting Inclisiran in well over a 1000 subjects (à The Medicines Company and Alnylam), the RNAi mechanism can be considered a clinically validated  new drug modality. 

Liver enzyme elevations, however, have been seen across a few clinical programs.  This includes ALN-AAT for alpha-1 antitrypsin-related liver disease, ALN-AT3 for hemophilia, and now also Givosiran (ALN-AS1).  The most likelyreason for these observations is that the minimization of off-targeting had been neglected for these ‘2nd-generation GalNAc-RNAi triggers’, thereby raising the risk that the relatively high off-target noise (dozens of off-targets) can be detrimental to target cell health. 

To wit, the spectrum of off-target genes varies tremendously from RNAi trigger sequence to RNAi trigger sequence and affects biologically unrelated genes.  This makes it very hard to predict whether the off-target noise will have adverse effects or will be just irrelevant noise to the cell.  Not helping is the fact that lab animals due to their genome sequence differences cannot model the safety around off-targeting.  The hope is that perhaps organ explants or mice with humanized organs (e.g. humanized mouse livers) will be better predictors since the target cell is almost the same as in the clinical setting.

Marked liver enzyme elevation in Givosiran pivotal trial

This week, Alnylam provided an interim read-out from the ENVISION trial, the registrational study with GalNAc-siRNA Givosiran for acute hepatic porphyria (AHP).  AHP is a rare disease caused by defects in heme synthesis.  This results in the accumulation of toxic intermediates such as PBG and ALA which can cause a range of symptoms, including severe pain attacks.

The study envisioned an interim biomarker read-out in a first cohort of patients that had been treated for at least 3 months with study drug.  It had been agreed before with the FDA that if lowering of ALA could be found in this read-out, it might form the basis for an accelerated approval.

Unsurprisingly, urinary ALA levels were reported to be statistically significantly lower in patients treated with Givosiran compared to placebo- in-line with the phase I/II experience (p<0 .001="" span="" style="mso-spacerun: yes;"> 

Unfortunately, there were numerically more than twice as many Givosiran-treated sujects (5/23) that experienced a serious adverse event (SAE) than in the placebo group (2/20).  One of the Givosiran-treated subjects had to discontinue treatment due to liver enzyme levels above the pre-specified threshold (>8x upper limit of normal).  While no liver enzyme elevations had been reported in a similar number of patients in the earlier-stage studies, I wished the company could have talked more about the presence of other liver enzyme increases of less than 8x ULN to get a better sense of the magnitude of the problem and whether such incidence would be compatible with giving the drugs in a chronic fashion.

Having said that, with 5 SAEs in 23 subjects treated a little more than 3 months on average (on top of a case of drug-related anaphylaxis in the phase I/II open-label extension study), SAEs that might be drug-related, would already seem to invalidate Givosiran being used in those with the same genetic condition, but not necessarily with recurrent pain attacks.  This would have tremendously extended the market opportunity of Givosiran.   

In the same vein, with the present safety questions, an accelerated approval that would shave off a few months before the full dataset will be available in early 2019, can now be ruled out with high certainty.

To add insult to injury, Akcea reported earlier this week that a GalNAc-version of the competitive RNaseH antisense technology did not suffer from thrombocytopenia as unconjugated ASOs typically do, thus putting ASOs back in the race for liver targets.  Still, in the long-term and in particular with the more specific new GalNAc-RNAi trigger chemistries, RNAi should win for most liver targets, but for some targets where either RNAi has inherent difficulties achieving high potencies or in cases where off-targeting toxicity still strikes (albeit at a much lower rate), RNaseH ASOs may emerge victorious.

Disclosure: long ALNY, but have taken some off the table following these data and questions around cardiac issues with ONPATTRO; it is important now for Inclisiran to re-instill confidence in the safety of RNAi Therapeutics; short AKCA as I do not believe that their current TTR and triglyceride-lowering drugs TEGSEDI and WAYLIVRA, respectively, can be commercially successful drugs and its artificially bloated market cap is a result of the low float and short interest in this stock and not a reflection of the value that the market sees in Akcea.

Monday, September 10, 2018

Second-Tier RNAi Therapeutics Companies Starting to Deliver Clinically

Alnylam has had a 3 year head-start on the competition with GalNAc RNAi Therapeutics, but now additional companies are populating the field with actual clinical data.  While the knockdowns appear robust and the chemistries well tolerated, therapeutic utility and the potential of liver toxicity from off-targeting will have to be demonstrated in upcoming longer-term studies.

Dicerna clinically validates new target for primary hyperoxaluria

Dicerna used to be the leader in applying RNAi Therapeutics to primary hyperoxaluria (PH), an orphan genetic condition caused by dangerously high levels of oxalate in the blood.  Oxalate crystallization and deposition may then poison first the kidneys and then various organs leading to premature death.  Unfortunately, as its old LNP technology proved to be impractical, Alnylam's directly competing program targeting glycolate oxidase (GO) assumed the lead.

When Dicerna then came up with a GalNAc-based follow-up candidate (DCR-PHXC), it also chose a new target: hepatic lactate dehydrogenase (LDHA), a target which may have be applicable also for forms of PH beyond the most frequently diagnosed PH1 and for which GO is a suitable target.  Cynics may suspect that the new target was not chosen because it is the better one, but in an effort to provide differentiation over more advanced competition.  To wit, first-mover advantage can be significant in the orphan drug arena.

Perhaps due to its long-standing, deep relationship with the PH community, Dicerna has been able to recruit patients more quickly than I had suspected (in light of Alnylam's parallel recruitment efforts) in its first-in-patient study.  First data from this study (PHYOX) were revealed last week.  To their relief, LDHA knockdown resulted in oxalate lowering in all 9 subjects (8 PH1, 1 PH2) tested.

Following a single-dose of either 1.5mg/kg or 3.0mg/kg, at least 30% reductions in urinary oxalate were seen and all or almost all subjects got to urinary oxalate levels at or below 1.1mmol/24hrs/1.73m2, a level predictive of end-stage-renal-disease freedom.

More detailed data will be presented later this year where we will get a better sense in how the results stack up with those of Alnylam.  Earlier this summer, Alnylam reported 64% mean urinary oxalate reductions relative to baseline before following more than one dose.  Another area of concern is that it appears that 3 out of the 9 injections resulted in injection site reactions (ISR).  To see ISRs is not surprising per se, but the frequency appears to be on the high end based on early experience and could be a competitive disadvantage.  Similarly, no word was said about liver enzymes.

Given that Dicerna has been rushing the PHYOX trial without so much as testing multi-dose regimens, I expect the regulatory agencies to demand at least 2 dosing schemes in the upcoming pivotal trials.  A nightmare scenario would see Dicerna being sent back to phase II to test the safety of multi-dosing, a fate that Regulus Therapeutics had suffered before in Europe.

Disclosure: Over the last few months, I have been largely playing the volatility of DRNA- both on the long and short side.  Looking ahead to the end of the year, I would be hesitant of taking a substantial long position due to a market cap approaching $1B with the potential of negative surprises both on safety and efficacy when more detailed PHYOX data will be presented.  On the other hand, a deal (such as on the IND-ready mystery candidate) could provide a catalyst to the upside at least in the short-term.

Arrowhead sees best HBsAg knockdowns so far with new GalNAc candidate

When similar to Dicerna Arrowhead had to retool its lead programs with the GalNAc technology, one question was whether they could achieve knockdowns as potent as with DPC delivery which employed explicit cell penetrating chemistries.  It was therefore cause for celebration when the company reported -2log HBV surface antigen (HBsAg) knockdowns at the World Gastroenterologists Summit, better than with ARC520 and ARC521 before (slides here).  Also, the knockdown was observed regardless of e-antigen status, but that was to be expected with the new sequence design.

Intriguingly, following 3 monthly injections, the knockdown curves still kept coming down, making it almost look like HBV can be beaten into submission by the knockdown effect alone and without the help of an immune boosting effect.

Unfortunately, only HBsAg results from the 100mg and 200mg monthly dosing cohorts were disclosed even though the company had dosed 9 other dosing and patient cohorts.  Based on cohorts 8-11, it appears that best results may in fact have been obtained with the 300mg monthly regimen which will probably be disclosed in the run-up to this year’s AASLD meeting.

Similar to Alnylam in 2014, after showing impressive RNAi target knockdowns in the clinic, the wait is now on to show that the knockdowns will translate into therapeutic benefits.  Given the speed of the company’s execution in general, I would expect pertinent data to emerge from the HBV program in late 2019/early 2020.

Disclosure: similar to Dicerna, I have been recently playing the volatility of ARWR stock, getting long as it had been consolidating around the $14 level, then selling and going short into last week’s 50% spike to a $2B market cap.  With the puts I then sold ($21 and $20 September strikes), I have a ~10% cushion should the stock zoom past $21 by the September options expiration and my max gain is ~13%.  This is intended as a short-term trade

By Dirk Haussecker. All rights reserved.

Disclaimer: This blog is not intended for distribution to or use by any person or entity who is a citizen or resident of, or located in any locality, state, country or other jurisdiction where such distribution, publication, availability or use would be contrary to law or regulation or which would subject the author or any of his collaborators and contributors to any registration or licensing requirement within such jurisdiction. This blog expresses only my opinions, they may be flawed and are for entertainment purposes only. Opinions expressed are a direct result of information which may or may not be accurate, and I do not assume any responsibility for material errors or to provide updates should circumstances change. Opinions expressed in this blog may have been disseminated before to others. This blog should not be taken as investment, legal or tax advice. The investments referred to herein may not be suitable for you. Investments particularly in the field of RNAi Therapeutics and biotechnology carry a high risk of total loss. You, the reader must make your own investment decisions in consultation with your professional advisors in light of your specific circumstances. I reserve the right to buy, sell, or short any security including those that may or may not be discussed on my blog.