+Timos Papagatsias

Sunday, 26 June 2011

"Profecting" vaccines for HIV?

Leave a Comment
Profectus Biosciences develops novel vaccine approaches, primarily focussing on HIV and HCV. Formed in 2003, as a spinout of the Institute of Human Virology (IHV) at the University of Maryland, Profectus includes amongst its founders well-known names in the field of virology research: Dr Robert Gallo, Dr William Blattner and Dr Robert Redfield; the same group are also members of the company's scientific advisory board


In 2008, Profectus has in-licensed Wyeth's HIV, HCV HepB and HSV vaccine programs which allowed it access to Wyeth's proprietary DNA and vectored vaccine technologies. According to the company's website, focus is placed on therapeutic vaccination and on development of immunotherapeutics


The therapeutic vaccination protocols are based on "prime-boosting" approaches. Profectus uses modified plasmid DNA (pDNA) vectors for priming the immune system against HIV antigens and then "boosts" the generated responses through vaccination with a Vesicular Stomatitis Vector (VSV). The priming process is enhanced by the simultaneous expression of interleukin-12 (from a different co-administered plasmid) and the use of electroporation for delivery of the pDNA. The company has already completed a set of experiments in non-human primates, demonstrating strong immunogenicity and safety. 


Some more information on Profectus' exciting and pioneering technology of "transition-state vaccines" and genetic adjuvants being developed by the company can be found here. The "transition-state vaccine" approach (a quite promising approach, however, still in its infancy) basically aims on targeting key antigenic regions and their structural conformations presented to the immune system only for small amounts of time during an infection process; characteristic example is the interaction of HIV's gp120 with the CD4 receptor. In terms of adjuvant systems in development, Profectus is combining the enzymatically-active region of cholera toxin (CTA1) with a number of cytokines. Although the use of adjuvants in vaccine products is widely considered to be necessary for augmenting vaccine efficacy, extremely stringent FDA regulations have resulted in no adjuvanted vaccines being approved for almost 80 years (apart from vaccines containing alum), other than the recent approval of GSK's Cervarix in 2009.


Where things become really interesting is the immunotherapeutics approach that Profectus has chosen to follow. In short the company is developing NF-κB inhibitors, and more specifically, inhibitors of p65 (one of the components of the NF-κB heterodimer). As the company states on its website, inhibition of NF-κB will result in suppression of the immune activation caused by certain viral infections, which will in turn lead to a better prognosis and slower disease progression. In my opinion, this is quite a risky strategy and has to be coupled with a targeted delivery approach. NF-κB is involved in the majority of cellular pathways and shutting those pathways down could simply cause more problems rather than solve them. However, targeted delivery of such inhibitors could well be extremely useful, especially in certain forms of cancers (solid tumours) where NF-κB inhibition-induced apoptosis would slow down tumour growth. Additionally, in cells infected by viral pathogens, shutting down NF-κB would result in apoptosis, decreased virus production and spread, and would additionally generate a good source of antigen for generation of antiviral immune responses.


Since its incorporation, Profectus Biosciences has received a substantial amount of money in terms of grants and private investments (approximately $44 million; a breakdown of this funding  is shown on the table below).

Date Funds received ($M) 
01-Feb-05Incorporation 
30-Mar-063
15-Jun-073
19-Jun-070.3
19-Jul-070.2
08-Dec-0821.6
22-Jul-095
04-Oct-104.4
06-Oct-106.25
Total 43.75
25-May-11Phase I start


You can find some more information on the Phase I trial by Profectus here. Briefly, the company is testing the effect of IL-12 on the immunogenicity of their HIV vaccine candidate, MAG pDNA. The vaccine will be delivered via electroporation and the trial will recruit 60 individuals. As this is developed as a therapeutic vaccine, subjects enrolled in the trial will be HIV-infected with CD4 counts of greater or equal to 500 cells/μl of blood and will remain on antiretroviral therapy throughout the study duration. The study duration is anticipated to be 36 weeks, which puts a publication of results likely to take place in Q2 2012.


Profectus appears to be a strong investment proposal, however, a more informed opinion could be formed towards the middle of next year, with Phase I results available, and that period could constitute a possible investment entry point. Strong Phase I results will lead to increased interest from potential biotech/pharma partners, something that will push the company's value upwards; nevertheless, the risk associated with HIV vaccine development is still high.


Below you can find a graphic depicting estimated rNPV for Profectus Biosciences and its HIV-vaccine candidate (data to 2031). Calculations are based on a heavily modified version of BioGenetic Ventures' previously published model.



PV of RevenueNPV of Cash FlowRisk-Adjusted NPV
$ 710,247,523$ 160,799,596 $ 20,216,720

The following table highlights some of the key assumptions used to "feed" the model. A very modest estimate has been used for the price of a potentially successful HIV vaccine; HIV infections growth rate should also be viewed with caution, as the increased use of ARVs will slow down the epidemic spread over the next 10 years-in fact signs of reduction are already evidentAdditionally, the incorporation of ARVs into HIV vaccine clinical trials (which makes it more difficult for a vaccine candidate to show efficacy) has not been calculated in this model, as not enough data is currently available. 

ParameterEstimate
Total number of HIV-infected individuals33,000,000*
HIV infections growth rate8.997%*
Peak market penetration (years) 3
Revenue per unit ($)150
Revenue Years12
Number of Subjects Phase I60
Number of Subjects Phase II600
Number of Subjects Phase III5,000
* UNAIDS Report 2010≠ Very modest estimate

Profectus is an interesting company with a significant potential for profit generation, should its technology and vaccination approaches show promising results in the clinic. Competition from other HIV vaccine development companies is expected to be fierce but Profectus is definitely a company to watch closely.

Read More...

Sunday, 20 March 2011

"Shaping" new vaccines

Leave a Comment
On March 8th 2011, Liquidia Technologies announced that it has received $10 million from the Bill and Melinda Gates Foundation, in order to develop new vaccine candidates utilizing its proprietary PRINT (Particle Replication In Non-Wetting Templates) technology. For those that have been following the activities of the Gates Foundation, it will immediately be evident that this type of activity, i.e. akin to a VC firm, is quite different to the normal grant process that the Foundation was, and still is, employing when financing a project. One can refer to the Collaboration for AIDS Vaccine Discovery (CAVD), a network of research teams that the Foundation set up and funded with $355 million in order to work towards development of an HIV vaccine, to understand the scope and basic functions of this charity organization.

Liquidia Technologies was founded in 2004 and is currently being backed up (besides the Gates Foundation) by New Enterprise Associates, Canaan Partners, Pappas Ventures, Firelake Capital Management, the Wakefield Group as well as private investors. This is a strong group of investors that, in theory, could assist Liquidia in its plans for rapid growth. Canaan Partners are well known and active investors in companies such as VaxInnate (recently in the news for receiving $117.9 million over three years-potentially rising to $196.6 million over five years- by the HHS, for development of influenza vaccine candidates) and Chimerix, a company that develops orally available antiviral agents, using its Phospholipid Intramembrane Microfluidization (PIM) technology.

What is really exciting about Liquidia's PRINT technology is the ability to control and modify at will the shape, size, chemical composition and, in general, most parameters that play a role in the immunomodulatory properties of a vaccine candidate. The company proposes formulating a vaccine agent or a drug, on a PRINT-produced dissolvable particle. Making use of the ability of the immune system to recognize and distinguish between 3D shapes of proteins and pathogenic/self structural components, such a particle could possess the shape of a bacterial component that triggers a specific immune response, or the structural conformation of a cytoplasm-localized protein, that would facilitate transport of the active ingredient through the cell membrane.

From an investor's perspective, Liquidia constitutes an attractive case. PRINT technology should generally increase the efficacy of a vaccine and could be employed to generate an adjuvant effect; these features will drive costs of vaccine production down and discard the need for use of non-approved adjuvant agents (the FDA is known for its reluctance to approve novel adjuvants). PRINT particles can also be combined with existing vaccines, and this opens up a wealth of opportunities for Liquidia. The company has recently announced the initiation of its first clinical trial, testing its lead seasonal flu vaccine candidate, LIQ001. A quick look at the clinicaltrials.gov website reveals that LIQ001 is being tested as a combination with sanofi's Fluzone; the trial has finished recruitment and is expected to complete in late 2011 with results available in early 2012. As this trial constitutes the company's first attempt of progressing the PRINT-based technology from proof-of-concept into the clinic, we are waiting impatiently to see the results. Liquidia has also signed an agreement with the PATH Malaria Vaccine Initiative (MVI) for the use of PRINT technology in the development of a new generation of malaria vaccines; we believe this is a strategic step, crucial for the company's further development and a collaboration that should yield large amounts of clinical trial data, necessary for further evaluation of PRINT.

Looking into the future, a company such as Liquidia, constitutes an attractive target for acquisition/partnership from a larger biotech or pharma company. Despite the company's recent investment influx and collaborative agreements, it still remains very interesting to see how PRINT technology will navigate the regulatory path and to pressure-test its limitations and advantages.
Read More...

Tuesday, 8 February 2011

Immune Design steps up and gets noticed…again...and again!

Leave a Comment
Back in July, Immune Design raised $32 million in a Series B financing; that’s quite a bit of money and brings the total up to $50 million since 2008. Amongst the leading investors we can see ProQuest Investments (who also have in their portfolio companies like Aerovance, who develops asthma-combating drugs, and  Somalogic, who develops novel diagnostics tools for oncology, neurology and CV diseases), The Column Group, Versant Ventures and Alta Partners.
Now the company is making waves once again by licensing out its proprietary GLA (Glucopyranosyl Lipid Adjuvant) to MedImmune, for it to be used as an immunomodulating agent in vaccines for select infectious diseases. GLA is a TLR-4 agonist and is considered to be the next generation of MPL (Monophosphoryl Lipid A), an adjuvant originally developed by Corixa and currently being used in vaccines produced by GSK, following the latter's acquisition of Corixa. GLA was originally licensed to Immune Design by the Infectious Disease Research Insitute, IDRI, of Seattle.
Immune Design's approach to vaccine design and development is pretty straightforward: targeting of dendritic cells (DC) with their proprietary vector (DC-NILV, Dendritic Cell targeting Non-Integrating Lentivirus Vector)  coupled with GLA.  Not surprisingly, and given their “talent” for attracting investment, Immune Design had already been identified as an emerging drug developer by FierceBiotech in 2008.
The company has some big names on its Scientific Advisory board. Lary Corey is heavily involved in HIV vaccine clinical trials, Rafi Ahmed is involved in HIV vaccine research as well, David Baltimore developed the prototype lentivirus vector that Immune Design are now using (and of course has received the Nobel prize for the discovery of reverse transcriptase!), Philip Greenberg who works on modulating T-cell responses to viruses, Inder Verma, who develops gene therapy vectors and Ralph Steinman who is credited with the discovery of dendritic cells. Throw in the mix someone like Richard Klausner who was an Executive Director for Global Health at the Bill and Melinda Gates foundation and Director of the National Cancer Institute and you end up with a pretty strong team. David Baltimore and Richard Klausner are also on the board of Directors. Immune Design also has a strong executive team; you can find more info here. Given the structure of the Scientific and Exec boards, Immune Design venturing into the world of HIV vaccines pretty soon looks a real possibility.
Although the company appears a promising and investable package, it lacks in variety of antigen delivery systems and adjuvants. Looking at their technology, as shown on their website page, the company seems to have been built around a single vector-adjuvant system, not a particularly "safe" approach-a profitable one so far though, as the GLA licensing deal with MedImmune will give Immune Design $212 million. The ability, however, to directly and specifically target DC is a major advantage and should yield exciting results in the years to come. It can be expected that they will seek to partner with companies that are quite geared towards antigen modification for enhancement of immune responses, such as SEEK (formerly known as PepTcell) a company with universal flu and HIV vaccines in Phase II clinical trials.


Read More...