Futuristic “Human-on-Chip” Models Will Help Drug Development
The pharmaceutical industry needs better scientific models for testing drugs before they get to the proving ground of human clinical trials. Current lab dish models and animal testing models are time-consuming, expensive and chronically unable to predict which drugs are going to work in clinical trials. The industry is crying out for new modes of early testing that can shorten the timelines, reduce the cost and increase the odds of success in clinical trials.
Both lab dish models and animal models have run into serious limitations. Cell culture (“in vitro”) assays offer some real advantages. Many can provide true, “human” answers to fairly simple questions. But they lack complexity.
Therefore, due both to regulatory requirements and convention, pharmaceutical companies have for decades progressed their testing from cells into animals, where the testers can see the impact on an entire organism with all its interconnecting systems.
But animal models are in some ways even worse. As Dylan Walsh pointed out in his timely New Yorker blog post, most animal testing—the kind done in rodents—is crude and ineffective, not to mention how it feels for the mice.
Fortunately, the reliance on this unfortunate patchwork might be about to crack. If cell models could be shown to predict efficacy in a reliable way, ineffective therapeutic candidates would fail faster – and cheaper. Better safety testing would drastically reduce the sacrifice of animals while yielding more predictive results. Here, though, any changes there would likely take many years because of the immense difficulty of making regulatory agencies like the U.S. Food and Drug Administration comfortable with new regulations.
In fact, futuristic models are beginning to appear. Walsh’s New Yorker post features Harvard luminary Don Ingber, who has been working, organ by organ, on establishing better in vitro models since the founding of his Wyss Institute (whose delightful full name is the “Wyss Institute for Biologically Inspired Engineering”). His strong academic work in sophisticated in vitro tissue engineering reaches back to the early 1990s. As Walsh writes, “Recent efforts have led to fully functioning “organs-on-a-chip,” named with a nod to their roots in microchip manufacturing. A critical and deceptively simple benefit of these organs-on-a-chip is that they simulate, in a rudimentary way, the mechanical motion essential to organ function.”
Ingber’s lab is in the lead in this area, especially in lung models. I wrote about Ingber’s work here in 2010. Walsh writes:
“The physical mechanics of organs-on-a-chip—the lung-on-a-chip can “breathe” like a normal lung—provide an essential advantage over inert cells grown in a petri dish. For instance, in a recent experiment conducted by Ingber’s lab, when a set of the lungs-on-a-chip that could “breathe” were dosed with the cancer medication interleukin-2, they were afflicted by a well-documented side effect of the medication in humans, severe pulmonary edema; only mild symptoms appeared in a model of the lungs-on-a-chip that didn’t breathe. ‘We’ve ignored mechanics for a century,’ Ingber said.”
These single-organ models are impressive. Last month, the Wyss Institute signed a collaboration at undisclosed terms on the development of human and animal “organs-on-chips” for safety testing.
In some cases, less sophisticated models in tissues such as liver and skin have already become industry standards. I wrote about these models, and the likely future of this field, here in 2009.
More ambitious models are on the way. As Walsh’s post mentions in a brief aside, there are a few efforts from “a handful of labs worldwide [that] have so far constructed a system with more than one organ.”
One of these is in Berlin, Germany, where TissUse, a CBT Advisors client, is pioneering perhaps the most advanced of these efforts. Recognizing that the secret to mimicking complex biology in culture lies in a combination of organ architecture and live circulation, TissUse, spun out of Berlin’s Technical University in 2010. It has built its platform around organoids, the minimal functional units of organs. These include liver lobules, skin segments, kidney nephrons and the lining of the intestine. These organoids can be bathed in appropriate nutrients, and have waste products taken away, at the same scale at which they are served by capillaries in the body. Scale is extremely important in biology. This effort to mimic the natural scale of organ biology makes the TissUse system both robust and modular.
It’s not a perfect analogy, but organoids can be thought of as similar to the transistors that started to replace vacuum tubes in the 1950s. Transistors made modern electronics – laptops, mobile phones, tablets – possible. Similarly, organoids open up vast possibilities. The technologies for first creating them and then packing them optimally onto chips are still in their infancy. For more on TissUse and their organoid-based approach, please go to the longer version of this post on my blog Boston Biotech Watch.
Besides TissUse, the most advanced company that we found to be working on multi-organ models is Hurel, founded in 2006 by Michael Shuler of Cornell University. Hurel raised Series A funds from hedge fund Spring Mountain Capital in April. The Hurel web site talks about “products under development for future release” that involve “fluidically mediated metabolic interaction of different cell-based models drawn from or representing different bodily organs, such as liver-with-heart and liver-with-kidney combinations.”
Hemoshear of Charlottesville, VA, has set an emerging industry standard for “vascular pharmacology” by including the impact of dynamic blood flow on cells in culture. Founded in 2008 out of the nearby University of Virginia, Hemoshear was reported in 2012 to have 10 biopharmaceutical industry customers. The company puts cells of different organs, most recently liver, into their dynamic systems that push blood past the liver cells. That allows them to get a high-quality look at liver toxicity, drug metabolism and drug-drug interactions. Aside from the useful combination of different organs with vasculature, the company has not reported multi-organ approaches.
Forward-minded venture investor Founders Fund of San Francisco laments the “medieval” approach used in traditional pharmaceutical discovery. The right sources of capital combined with the right industry partnerships, both currently emerging, might give TissUse, Hurel, Hemoshear and other companies a path to preclinical testing that is both more accurate and more humane.
[Disclosure: TissUse is a client of CBT Advisors.]