Biotech Strategy Blog

Commentary on Science, Innovation & New Products with a focus on Oncology, Hematology & Cancer Immunotherapy

Posts tagged ‘osteoporosis drug development’

Contrary to popular opinion, innovation is not dead in the biomedical industry, as evidenced by news of a novel drug-delivery system published as a Rapid Publication in Science Translational Medicine (STM) on February 16, 2012.

The paper from Robert Farra of MicroCHIPS, Inc. and research collaborators, describes a first-in-human testing of a wirelessly controlled drug delivery microchip.

Farra et al., report the results of a clinical trial with 8 women in whom microchips were implanted for 103 days. The data showed that the pharmacokinetic profile of microgram-quantities of the anti-osteoporosis drug, teriparatide (FORSTEO), delivered by the microchip was similar to subcutaneous injections.  However, the device did fail in one of the 8 women, so data is only reported for 7 patients, a very small patient sample.

Picture Credit: MicroCHIPS, Inc.

The drug delivery device is an array of 600-nL micro reservoirs in which the drug is stored, that is associated with a 13.0 mm x 5.4mm x 0.5mm silicon chip.

The microchip was implanted beneath the skin (subcutaneously) in the abdomen by creating a 2.5cm incision, performed during an outpatient visit.

This paper is also interesting for its use of telemedicine. A remote operator was able to establish a wireless link and send instructions directly to the implant on dosing schedule as well as receive information back on operation of the chip.

John T. Watson, Professor of Bioengineering at the University of California San Diego  commented in the accompanying editorial that:

“The microchip represents more than 10 years of engineering design and development efforts to arrive at a programmable, implantable device for subcutaneous release of a therapeutic agent in discrete doses.”

Multiple engineering design advances were made along the way.

He also noted the results from the quality-of-life surveys administered during the trial; the majority of women stating they often forgot they had the device implanted and would readily consent to a fresh implant if needed.

Innovations in drug delivery offer hope of an improved quality of life to patients with chronic disease who require daily injections.  In 2010, there were approximately 50,000 teriparatide users, not an insignificant market opportunity.  People with diabetes who require daily injection of insulin is another potential market that springs to mind.

The first-in-human results reported in Science Translational Medicine show promise and the potential of a novel implanted wireless drug delivery system.

However, many questions remain unanswered by this research including the reliability & durability of the microchip device, given that it failed in 1 out of 8 women implanted.

Further work on validating the technology, and confirming its safety, reliability and efficacy in a larger sample size will be needed before it can obtain regulatory approval.


ResearchBlogging.orgFarra, R., Sheppard, N., McCabe, L., Neer, R., Anderson, J., Santini, J., Cima, M., & Langer, R. (2012). First-in-Human Testing of a Wirelessly Controlled Drug Delivery Microchip Science Translational Medicine DOI: 10.1126/scitranslmed.3003276

Watson, J. (2012). Re-Engineering Device Translation Timelines Science Translational Medicine DOI: 10.1126/scitranslmed.3003687

Bone is a tissue in constant state of remodeling by osteoclasts (cells responsible for bone resorption) and osteoblasts (cells responsible for new bone formation).

Osteoporosis is a disease of progressive bone loss that is associated with increase risk of fractures.  Particularly debilitating are hip fractures in the elderly that are costly to treat and also lead to increased death and reduction in quality of life.  It’s estimated that osteoporosis affects 44 million people in the United States over the age of 50.

Most treatments for osteoporosis inhibit bone resorption e.g. bisphosphonates (alendronate, risedronate, ibandronate, zoledronic acid).  By inhibiting or reducing bone resorption, there is a lower amount of bone loss.

Recent research published in the November 2011 issue of the journal Nature Medicine has highlighted a new potential target for osteoporosis drug development that acts on osteoblasts and promotes bone formation.

In a series of elegant experiments, Takako Negishi-Koga and colleagues found that osteoclast-derived Semaphorin 4D (Sema4D) inhibits bone formation.

They found that the transmembrane protein Sema4D is expressed by osteoclasts and inhibits osteoblastic bone formation. In other words, Sema4D is a critical mediator of osteclast-osteoblast communication. 

They reported that:

In osteoblastic cells, Sema4D stimulation decreased the expression of cadherin-11 at the cell-cell contact region suggesting that Sema4D stimulates cell motility through an impairment of cell-cell adhesion, which in turn results in the reduction in bone-forming activity.

Osteoclast-derived Sema4D inhibits bone formation: 

The binding of Sema4D to its receptor Plexin-B1 on osteoblasts resulted in the activation of the small GTPase RhoA, which inhibits bone formation by suppressing insulin-like growth factor-1 (IGF-1) signaling and by modulating osteoblast motility. 

The implication of these findings is that blocking Sema4D could promote osteoblastic bone formation without affecting osteoclastic bone resorption.  The researchers successfully tested this hypothesis using an antibody to Sema4D.

They concluded that:

These results suggest that the blocking Sema4D–Plexin-B1 interaction is a new and potentially effective strategy for increasing bone formation in humans.

This preclinical work using an animal model is highly promising and suggests that as we learn more about the bone microenvironment, new therapeutic and molecular targets for drug development may emerge.

ResearchBlogging.orgNegishi-Koga, T., Shinohara, M., Komatsu, N., Bito, H., Kodama, T., Friedel, R., & Takayanagi, H. (2011). Suppression of bone formation by osteoclastic expression of semaphorin 4D Nature Medicine, 17 (11), 1473-1480 DOI: 10.1038/nm.2489

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