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Seizing the Reins

From translational science to manufacturing, PDPs have significantly expanded their mandates and built labs that they believe fill an important niche in global health research. Is this a good idea?

By Regina McEnery

Three decades ago, three researchers from Seattle concerned about poor access to birth control options in developing countries put their heads together and created the nonprofit organization known today as PATH. Since then PATH—the current name derives from Program for Appropriate Technology in Health—has far exceeded its initial mandate. It has grown to become a major participant in global health research and a leading force for the development of vaccines of relevance to people in developing countries. A leader or member of many product-development partnerships (PDPs), PATH isn’t just a sponsor of other people’s ideas. It also has a sophisticated laboratory of its own that has grown steadily since it opened its doors in 1979. Today, the PATH lab has one team working on a variety of vaccine stabilization and formulation problems, and another dedicated to diagnostics.

In the world of PDPs, PATH is far from unique in this regard. Other organizations of its kind, such as the Infectious Disease Research Institute (IDRI), Aeras and IAVI have also built their own sophisticated laboratories to speed the translation of scientific discovery into global health solutions or to address specific problems of vaccine development, from formulation to assay development to heat stability. These labs don’t come cheap. Nor are they easy to manage. They are dependent on flexible funding, which isn’t always easy to get, and are often difficult to staff due to their specialized functions. On the other hand, they have generated a fair number of technical breakthroughs of potentially great relevance to global health. That is of course what they’re supposed to do. What is less clear, though, is just how much of this they should be doing on their own.

PDPs are meant to serve as bridges between the public and private sector, harnessing the expertise of each sector to tackle a problem of relevance to economic development or global health. The idea is that academic and other non-industry researchers—who might have splendid ideas and high ideals but little product development experience—can work through PDPs to tap the resources and expertise of manufacturers. To make that proposition attractive to the private sector, the typical biomedical PDP will take on much of the financial risk of developing products to deal with complex diseases that aren’t likely to generate much profit.

PATH’s Malaria Vaccine Initiative (MVI), for example, in partnership with GlaxoSmithKline (GSK), is supporting the development and clinical testing of the RTS,S vaccine candidate against the malaria parasite. In 2001, MVI forged an agreement with GSK to develop RTS,S for African infants and children, offering technical assistance and alleviating much of the risk of the venture for the drug company by providing funding through a grant from the Bill & Melinda Gates Foundation to MVI. A large-scale Phase III efficacy and safety trial has been underway at 11 sites in seven African countries. The latest set of results, published in the New England Journal of Medicine in November, suggests that the candidate is only modestly effective in preventing severe and clinical malaria in infants (see Vaccine Briefs, this issue). Final results from this trial are anticipated by the end of 2014.

But PATH also does a good deal of its own research, operating a biosafety level-2 (BSL-2) lab at its headquarters in downtown Seattle. A Vaccine Formulation and Stabilization Team at the lab has, with a number of external technical collaborators, formulated a vaccine candidate against enterotoxigenic E. coli (ETEC) and a veterinary vaccine against Newcastle disease as fast-dissolving tablets for oral immunization. The tablet technology PATH has advanced could support the creation of inexpensive, heat-stable and easy-to-use vaccine products that can be dissolved in water and swallowed or administered under the tongue—all of which are of significant value to public health in developing countries. Just this summer, PATH’s lab in partnership with several other collaborators launched a project to expand global access to adjuvants of special relevance to vaccines made from highly purified antigens, which tend to be less immunogenic than whole-organism varieties.

PATH  

The Program for Appropriate Technology in Health (PATH) was founded in 1975 with a focus on family planning. Its mission has evolved significantly over time to include other global health causes, such as the development of vaccine candidates and diagnostics for an array of diseases. In its lab, which doubled in size when PATH moved to its current headquarters in 2010, teams are advancing innovative work in diagnostics and vaccine formulation and stabilization.

Location of lab: Seattle

Square footage: 5,465, which is used by the Vaccine Technologies Group’s stabilization and formulation team and the Diagnostic Development Group.

Lab workforce: 13

Post-docs: 5

Graduate students: PATH currently does not employ any graduate students


Indeed, since it opened its doors more than three decades ago, the size and scope of the laboratory has expanded dramatically. While the non-profit’s mission extends to nutrition, maternal and child health and improving health systems technology, its in-house staff of vaccine scientists primarily concentrate on solving the technical problems of vaccine development, effectiveness and ease-of-use in low-resource settings. The direct involvement of PATH’s scientists in such efforts, the organization argues, has allowed it to monitor and maintain the quality of projects and products with which it is closely associated. According to Debbie Kristensen, who leads the Vaccine Technologies group at PATH, this soup-to-nuts approach is unusual in the PDP world. “We are involved in every aspect of vaccine development and introduction, so we have an understanding of all the pieces of the puzzle.”

Other PDPs that operate BSL-2 labs include PATH’s neighbor in Seattle, IDRI, which focuses on diagnostics, vaccines, and therapeutics for neglected tropical diseases, such as leishmaniasis and schistosomiasis, as well as AIDS, malaria, and tuberculosis. Aeras, which is based in Rockville, Md., and dedicated to developing better tuberculosis vaccines, has its own laboratories and manufacturing facilities. IAVI, which publishes this independent magazine, has its AIDS Vaccine Design and Development Laboratory (DDL) at the 95-acre Brooklyn Army Terminal, which was built in 1918 and recently converted into a bioscience park.

Infectious Disease Research Institute  

The Infectious Disease Research Institute (IDRI) was founded in 1993 by Steven Reed to apply advances in immunology to the development of novel diagnostics, vaccines, and therapeutic products for diseases that disproportionately affect developing countries, including leishmaniasis, tuberculosis, malaria, leprosy, and AIDS. IDRI occupies several floors of a 1960s-style building in Seattle that once housed the Fred Hutchinson Cancer Research Center.

Location of lab: Seattle

Square footage: 50,000. Space includes biosafety level 1 and 2 labs, a GMP production lab, and a vivarium. The lab will expand to 58,000 square feet when IDRI moves to a new facility in Seattle in 2013.

Lab workforce: 89

Post-docs: 7

Graduate students: 2 beginning in 2013


IDRI’s research presence has grown substantially in recent years with the development of a glucopyranosyl lipid adjuvant, or GLA. The novel toll-like receptor 4 (TLR4) agonist has since been added to candidate vaccines for AIDS, influenza, malaria, tuberculosis, visceral leishmaniasis, schistosomiasis, and hookworm. The adjuvant stimulates innate and adaptive immune responses by inducing dendritic cell maturation and the release of pro-inflammatory cytokines and chemokines associated with cell trafficking (PLoS One 6, e16333, 2011).

The DDL, which opened in 2008, turned its attention early to systematically and briskly devising and testing potential HIV immunogens. This is precisely the kind of thing biotech and pharmaceutical companies do to develop novel vaccines and IAVI felt it was largely lacking in the AIDS vaccine field. “The idea for the DDL was to go into that space that is often occupied by biotech and supplement it with capacity to test immunogens rapidly and efficiently,” says Rick King, IAVI’s vice president of research and development. That work was facilitated by its access to a nearby animal testing facility owned by the State University of New York Downstate Medical Center.

Aeras, meanwhile, has focused on manufacturing, most recently for its own live recombinant tuberculosis vaccine candidate that was evaluated in a Phase I trial by researchers from St. Louis University in Missouri. The vaccine candidate, called Aeras-422, is a modernized version of the bacille Calmette-Guerin (BCG) vaccine, which is derived from an avirulent bovine strain of the TB bacterium and is primarily given to children in the developing world. Aeras-422 was dropped from further development after two of the participants in the 22-person trial developed shingles. But the PDP manufacturing facility, which adheres to good manufacturing practices (GMP) enforced by the US Food and Drug Administration, has kept itself busy on other projects. It is currently engaged in process development, fermentation, protein purification, and fill-and-finish—the filling, sealing, and labeling of bulk vaccine product in vials—for vaccine candidates against not only TB, but other diseases as well.

This represents a bit of a change from the initial vision for the manufacturing facility. Aeras initially restricted the facility to upstream manufacturing of the rBCG vaccine candidate—mostly for recombination BCG fermentations, which are particularly difficult because the bacterium is so fragile and unstable. Eventually, however, it added a second facility to build its capabilities in downstream manufacturing, including the standard lyophilization or spray-drying of vaccine candidates for longer shelf-life.

PATH’s in-house lab, for its part, focuses on improving the formulation of vaccines, which is complicated because vaccines often have large, complex biomolecules as active ingredients. Funded by a US$5.2 million contract awarded in 2010 by the Biomedical Advanced Research and Development Authority (BARDA), a branch of the US Health and Human Services, PATH scientists are busy these days stabilizing influenza vaccines. They are investigating heat-stable formulations for existing inactivated and live-attenuated seasonal and pandemic influenza vaccines. They’re also developing freeze-drying, foam-drying, and spray-drying technologies to improve the shelf-life of both types of vaccines.

Ties that bind

There has lately been much cross-fertilization between various PDPs or the nonprofits that created them. PATH and IDRI, for example, teamed up two years ago to see whether IDRI’s oil-in-water emulsions boosted immune responses to pandemic flu vaccines. PATH sponsored the research, and IDRI conducted the emulsion analysis, focusing on a model antigen representing the main components of a vaccine candidate against the virulent H5N1 influenza virus. The study, which evaluated the influence of oils, surfactants, and excipients on stability as well as antigen structure and immunogenicity of the influenza antigen, found the adjuvant activity by the different oil-in-water emulsions varied quite a bit. But IDRI scientists attributed the differences to the biological activity of the oil composition rather than physical interactions of the antigen with the emulsion (Influenza Other Respi. Viruses, doi: 10.1111/irv.12031, 2012).

Likewise, IAVI and Aeras, which have worked together in the past, announced this summer a “collaboration agreement” that will enable the PDPs to share clinical research center capacity for early phase clinical trials and leverage each organization’s expertise in the design development and production of vaccine candidates. IAVI also forged a partnership with PATH’s MVI this year to provide interferon-gamma ELISpot and multi-color flow cytometry assays as MVI moves malaria vaccine candidates into clinical trials. The T-cell assays were refined and validated at IAVI’s Human Immunology Lab at Imperial College London.

For its TB candidate, IDRI manufactured the adjuvant and collaborated with a group in Iowa to manufacture the antigen, while IDRI and Aeras joined forces to execute the clinical testing for the Phase I trial. Aeras’ manufacturing facility, meanwhile, has collaborated with the Sabin Vaccine Institute in Washington, whose PDP on the campus of Baylor College of Medicine in Houston focuses on vaccine candidates for neglected tropical diseases, such as Chagas disease and schistosomiasis.

Aeras completed a master services agreement with PATH earlier this year, which enables Aeras to contract with each of the various PATH organizations focusing on vaccine development for emerging and epidemic diseases. Aeras and PATH have already engaged on two projects this year and expect to pursue additional projects in the future.

Aeras  

A biotech with a social mission, Aeras was established to find better vaccines to fight tuberculosis. Its vaccine discovery and immunology laboratories opened in 2003. Aeras also established an upstream manufacturing facility in 2006 and a downstream manufacturing facility three years later.

Location of lab: Rockville, Md.

Square footage: 28,858, which includes its labs and two manufacturing facilities

Lab and manufacturing workforce: 55

Post-docs: 13

Graduate students: 12


Aeras’ facilities have also manufactured the first pilot-scale lot of Sabin’s Na-GST-1 vaccine candidate that is now being tested in a Phase I study in Brazil. The antigen in the vaccine candidate is the glutathione S-transferase (GST) protein found in the human hookworm Necator americanus, which is critical for blood feeding and survival of the parasite and therefore represents a good target for vaccination. Sabin’s PDP also contracted with Aeras to make a pilot-scale lot for its vaccine candidate against schistosomiasis, which afflicts more than 200 million people around the world. Taken together, hookworm and schistosomiasis represent the most common of the seven major neglected tropical diseases, and the second highest burden of parasitic disease behind malaria.

“From our standpoint, in terms of cost and availability for producing Phase I clinical material, we have found PDPs together with developing country manufacturers work well for us because they have a unique commitment to public health,” says Sabin’s president Peter Hotez. “We have found the interactions have been easier and there is more give and take.” Still, working with other PDP labs has drawbacks. “For one, there’s the availability of time—they have their own projects to work on,” he says. “The other is experience with new vaccines.”

PDP labs and manufacturing facilities have turned out to be a magnet for scientists with highly specialized expertise, such as fermentation technology or vaccine formulation and delivery. They are also in some cases vital to the portfolio management of PDPs, doing the preclinical testing required to make decisions about which vaccine candidates to pursue.

Aeras’ lab, for instance, is equipped to do flow cytometry, which it uses to measure antigen-specific cellular immune responses that some TB vaccine candidates are designed to provoke. IAVI’s DDL is set up to advance vaccine candidates into clinical trials. It is capable of standardized protein production and purification, which is needed to make protein-based experimental vaccine candidates for preclinical studies. It also supports ongoing research at the dozen or so labs in IAVI’s neutralizing antibody consortium (NAC). In keeping with its title, the DDL, and its partners at the Bill & Melinda Gates Foundation have also poured money into a replicating viral vector vaccine program that includes replication-competent canine distemper virus (CDV) and vesicular stomatitis virus (VSV) viral vectors.

IAVI Design and Development Lab  

IAVI’s AIDS Vaccine Design and Development Laboratory (DDL) opened in 2008 at the Brooklyn Army Terminal, which city, state and private entities have been developing as a bioscience center. The DDL has functioned as a hub for IAVI’s other laboratories, which include the Human Immunology Lab in London, the Neutralizing Antibody Center in La Jolla, Calif., and the HIV Vaccine Translational Research Laboratory in India. A primary focus of the DDL has been providing translational research support for researchers designing immunogens for AIDS vaccine candidates. It also has an active replicating viral vector vaccine candidate program.

Location of lab: Brooklyn, NY

Square footage: 40,000

Lab workforce: 26

Post-docs: 1

Graduate students: 1


While other labs are developing AIDS vaccine candidates using VSV, IAVI’s is taking a slightly different tack from most. Its VSV vector strategy seeks to induce the immune system to produce an antibody response to HIV. The CDV viral vector vaccine candidate is not currently being used anywhere else, either commercially or experimentally, making the project particularly innovative. “The idea percolated that the measles virus or CDV would be good vectors to deliver a vaccine specifically to the regions [in the body] where HIV likes to infect cells and replicate,” says Chris Parks, IAVI’s senior director of viral vaccines and deputy director of the DDL. Parks says both CDV and its cousin, the measles virus, were considered as vectors because they replicate in some of the same tissues as HIV. But the DDL settled on CDV because so many people have pre-existing immunity to measles virus and because other research groups were developing measles virus vectors. “It’s not the perfect solution to pre-existing immunity because measles antibodies will cross-react with CDV,” says Parks. “But they don’t seem to be nearly as potent against the canine virus.”

Pre-clinical studies in ferrets, which are susceptible to distemper, have been encouraging. The animals showed no apparent side effects after being vaccinated intranasally or intramuscularly with a CDV vector vaccine candidate that was modified to deliver several proteins from the simian immunodeficiency virus (SIV). They also found that the live vector replicated in lymphoid tissue in the abdominal cavity of the ferrets. “So it was doing exactly what we thought it would do, and the ferrets didn’t seem to mind,” says Parks.

Importantly, the ferrets also produced antibodies against the SIV proteins showing that the CDV vector replicated enough to induce a response by the immune system. “One of the biggest hurdles we face developing live replicating vectors is balancing safety vs. replication. We need the vector to replicate enough to trigger an immune response, but not so much that it causes symptoms of an infection. In the lab, we say, is it hot enough to make a good immune response without causing adverse reactions?” The lab has grown larger batches of the CDV and VSV vaccine vectors and is now investigating different vaccination regimens in rhesus macaques. If those studies generate promising results, the lab will conduct a challenge study in macaques to see if the vaccine candidate is protective against SIV infection.

As this program illustrates, having its own lab can allow a PDP to invest in promising projects that might otherwise wither on the vine because they present too high a risk of failure. In line with the missions of their parent PDPs, the labs can also help accelerate research on novel vaccines and drugs for diseases that have a disproportionate impact on the developing world—but little commercial appeal to drug companies and biotechs.

Toughing out the rough times

On the flipside, ambitious as they are, these facilities are expensive to staff and maintain. And their financial future is largely tied up with that of the PDP, which itself is dependent upon the largesse of public and private donors. Just how dependent was all too clear when the collapse of the US economy in 2008, and then the Eurozone crisis, forced many wealthy countries—the lifeblood of many PDPs—to scale back or shelve their foreign aid commitments. The recent economic turbulence has also made it much more difficult for PDPs to find new donors and raise additional revenue. IAVI, for instance, was forced to freeze departmental budgets, reduce staff, and curtail programs, including those at its labs. This process has been particularly hard on the DDL, whose staff peaked at about 50 two years ago, but is now down to 26.

“Obviously we are in the midst of a lot of changes, and we need to think about where we’re going,” says King, in August, just days after IAVI announced a restructuring. King says the DDL will curtail the protein production work it has been doing for IAVI’s Neutralizing Antibody Center in La Jolla, as well as for other research collaborators. Some of the analytical testing will have to be done in La Jolla as well. “We will have a core mission taking technology from one stage to the next,” he says, “but we will have to be more selective about being a very broad hub for field-wide testing of immunogens. We are not going to be able to have quite as open a door and [we’ll have to] choose carefully so we fulfill our commitments to partners.”

Kristensen says PATH too has felt the effect of the economic slowdown, though this has not led to a drop in the utilization of its laboratory, which was intentionally equipped with standard equipment of relevance to many R&D processes. “While our lab is small in comparison to many, we have actually seen a slight growth in utilization over the last few years,” says Kristensen. “During this period, PATH has been fortunate to continue to attract support for our efforts, albeit in slightly different ways than in the past.” For instance, though PATH has experienced a decrease in the availability of flexible funding from donors to conduct research on new innovations, this decline has been offset by what Kristensen calls an “increased donor interest in our vaccine formulation, vaccine stabilization and diagnostic assay development capabilities.”

IDRI’s CEO Stewart Parker says, meanwhile, that because her organization has a history of being extremely frugal the economic downturn has had a relatively minor impact on its programs. “In fact, since 2008, IDRI has increased employment from 73 to 125,” she says. “That being says, we’ll continue to watch our budget closely, find creative ways to supplement grant income and continue to increase awareness of IDRI’s research achievements in order to attract additional unrestricted funding.”

One rather ironic upshot of the economic uncertainties faced by PDPs is that their scientists, who often joined the nonprofits in part to escape the daily grind of chasing grants, are now being forced to churn out grant proposals to tap funds from the US National Institutes of Health and other government agencies. Unfortunately, this kind of sponsorship is harder to secure these days, thanks to a larger pool of applicants and static funding.

Nonprofits that invest in their own labs must also contend with the vagaries of biomedical product development and the complexity its inherent unpredictability introduces to portfolio management. And, since doing the right thing—not the profitable thing—is their mission, PDPs often must grapple with how best to share their intellectual property with others and make sure that the tools and products resulting from their research are made available to those who most need them—the world’s poorest people. That is, of course, if they can be sure they will have control of the product at that point.

“The typical PDP doesn’t have the intellectual property to wheel and deal,” says Erik Iverson, IDRI’s executive vice president of business development and external affairs. “They really don’t have their own products. That is the nature of the PDPs; they are a functional unit created to manage portfolios. So they find organizations that have products in development and enter into co-development agreements to do the work. A few PDPs have their own technology and horses in the race, such as Aeras’ recombinant TB vaccine [Aeras 422], but the vast majority of the pipeline belongs to other organizations. That is the nature of the public-private partnership.”

Iverson says IDRI is an unusual player in the PDP field in that regard. It creates most of its own products in-house, including vaccine candidates for TB and leishmaniasis, and the organization’s bread and butter—oil and emulsion adjuvants. “My point is that we are not middle-men,” he says. “We create the stuff pushed forward with funding that we receive. Other PDPs usually go out and find the technology and products.”

Necessity and invention

For the longest time, vaccines were made by chemically attenuating or killing pathogens, or finding genetic variants of pathogenic organisms that were naturally attenuated, and delivering them whole to induce immunity. But as standards for both quality and safety have risen in recent decades, researchers have increasingly favored recombinant approaches to vaccine design and manufacturing. Today, those messy or time-consuming techniques have largely given way to more surgical and scientifically sophisticated strategies for vaccine design and delivery. Researchers today use such technologies as viral recombination, codon de-optimization and microRNA insertion to attenuate target organisms, and bioinformatics and protein engineering to devise immunogens. New vehicles for immunogen delivery, meanwhile, include everything from plasmids to replication-competent vectors to bacteria.

All this can complicate vaccine development, and the management of that process. Cutting-edge strategies certainly require staff with rarified skills. But so does the basic business of vaccine formulation and manufacturing, particularly if the targeted pathogen is less than amenable to laboratory cultivation and manipulation. So for all the emphasis on rational vaccine design these days—that is, using antigens, delivery systems and adjuvants that elicit predictable immune responses against specific epitopes—vaccinology remains as much an art as a science, says Pat Fast, a pediatrician and chief of medical affairs at IAVI. “If you could be perfectly rational, there wouldn’t be this art to it,” says Fast, who has been involved in numerous vaccine trials for AIDS, influenza, and other diseases. “There is a lot of art to getting a virus to grow to high titers, getting a high output of your protein to your cell line. It’s not easy and there are not a lot of people who know how to do that.”

Just ask Reginald Kidd, Aeras’ director of manufacturing and validation. “The current [BCG] vaccine that is on the market is a pretty primitive culture that is grown in not a terribly controlled way,” says Kidd. “The modern candidate is a recombinant that expresses proteins from actual mycobacterium TB. The challenge is to wean the bacteria off of the media, bank that culture, to be able to develop a fermentation process that [allows you] to grow and harvest the bacteria but genetically still have the same culture you started off with.”

If it sounds difficult, that’s because it is. Kidd, who describes himself as an “ex-fermentation guy,” came to Aeras several years ago with a background in Escherichia coli, a bacterium that multiplies profusely and is thus much easier to deal with, at least from a culturing perspective. “E. coli doubles every 20 minutes, BCG may double every 24 hours,” says Kidd. “I was amazed at how long it took. It takes a month for all the colonies to show up on the plate. And after all the manipulations you do, the harvesting and washing of the cells, then freeze-drying, it loses its viability. The challenges are growing the bacteria and keeping it alive and having it end up in a vial, freeze-dried, without contaminating it along the way.”

Kidd says the lab constructed about a dozen recombinant BCG candidates, before they were able to find one that retained its genetic stability through to the end of the fermentation process. “You get to a point where, maybe two weeks go by, and the DNA inserts are still there. Just to get one passage [subculturing cells] takes a month. So you could construct a [candidate], go through passages, and wait six-to-eight months and say this looks good or take the risk and manufacture right away.”

Fast says vaccine PDPs anticipated such difficulties and prepared for them, which explains the establishment of some PDP laboratories. “Some groups have felt that they need to have manufacturing in house, particularly when there is a specialized aspect to growing the protein, like with mycobacterium,” she says. Others, she says, have outsourced such work. But the focus a PDP laboratory can provide—at least on products of relevance to its parent organization—has its advantages. “The ideal,” says Fast, “is that the lab can do rapid, iterative work without a profit motive, and bring something that is thought to be at the point of being able to be handed over to the commercial sector, even though there may not be a huge amount of profit."