Now Emerging: A Natural Alternative To Drug Delivery

Heptune Emergent Biologics make up one of the most promising drug categories. Biologics are being used to treat diabetes, lymphomas, breast cancer, and challenging autoimmune conditions like arthritis and psoriasis.

But biologics pose their own challenges, especially because of their short resonance time in the bloodstream and potential negative effects within the body.  Safe and effective delivery systems are critical for biologics.

One existing gold standard delivery solution has been polyethylene glycol (PEG), but since PEG isn’t a natural compound, it lacks a safe degradation pathway, accumulates in some tissues, and has some immunogenicity issues. Moreover, PEG compounds can contribute to drugs being less effective over time.

That’s where Emergent Technologies and our portfolio company, Cassion Biotech, brings uniqueness to the drug delivery market with its approach of using a naturally occurring sugar polymer (heparosan) to conjugate, coat or complex to a drug.

Heparosan ([-4-N-acetylglucosamine-a1,4-glucuronic acid-b1-]n) is generated within the body and is degraded by a natural process. It naturally occurs in all animals and is biodegradable via normal pathways in the body. Heparosan advantages include the following:


It’s inert.  The body produces no extracellular enzymes that degrade heparosan, and there are no known receptors or binding proteins for heparosan.

It’s stealthy.  It is proposed the immune system does not see heparosan, thus does not make antibodies against it (certain pathogens actually employ heparosan as a camouflage).

It’s biocompatible.  Heparosan is made and turned-over by the body, thus causing no harm when eventually degraded inside the lysosomes.

It’s flexible. A variety of customizable heparosan polymers can be made in a uniform monodisperse manner allowing pharmacokinetic customization for each drug.


Cassion Biotech’s delivery solution, the HEPtune® Technology, builds upon these advantages, creating a new, natural alternative to PEG.

Pre-clinical studies have supported positive advantages of heparosan in the body. The polymer is stable in the plasma and has shown increased resonance time of drug conjugates compared to drug alone. Accumulation has not been shown in tissues observed. Over time, the metabolites of the probe linker are excreted in urine and feces. The polymer does not cross the blood-brain barrier, which may be important for ensuring the safety of some therapeutics. No detrimental toxicological effects were observed from the heparosan with acute doses of 100 mg/kg in a rodent model. Additionally, a repeated-dose (7 months) drug conjugate toxicology study showed no specific antibody response (no IgG or IgM was found present) to heparosan.

A variety of biologics have been modified with heparosan, with retention of activity and improvement of pharmacokinetics. HEPtune offers a quite immunologically effective an biodegradable delivery system without affecting long-term effectiveness of drugs.

There are also business benefits: HEPtune is customizable and adaptable, making it easy to improve existing drugs and extend their patent life. Caisson’s patented syntheses also offer greater quality and control of manufacturing.  And, although the system is still in development, its cost is not significantly higher than current systems in the marketplace for high potency actives.

And HEPtune is on a fast track:  Cassion pursues commercial partnerships out licensing its HEPtune drug delivery system on a drug by drug basis, granting worldwide licensing and marketing rights to its partner. One of the first such global licensing deals with a major healthcare partner was publically announced in 2012.

So HEPtune promises to make a big impact in the marketplace. And it promises to change the way people think about drug delivery systems.

Changing perceptions about what is possible is always one of our goals at Emergent Technologies.

What do you want to build today?