Overselling preclinical results

As part of my ongoing effort to make sure that I never run out of blogging material, I subscribe to a number of quack e-mail newsletters. In fact, sometimes I think I’ve probably overdone it. Every day, I get several notices and pleas from various wretched hives of scum and quackery, such as NaturalNews.com, Mercola.com, and various antivaccine websites. I think of it as my way of keeping my finger on the pulse of the antiscience and pseudoscience wing of medicine, but I must admit that I don’t really read them all, but they do allow me to know what the quacks are selling and what new arguments they’re coming up with without actually going to each of their websites. I can then judge by the headlines and the blurbs included in the e-mails whether I think it’s worth it to go to the website itself and, of course, whether the topic might represent fodder for a good blog post. I will admit that not all the sites I monitor are as loony as the Health Ranger’s. In fact, I monitor the blogs and websites of the National Center for Complementary and Alternative Medicine (NCCAM), various naturopath organizations, and the like in order to learn of the “respectable” arguments being used to tout various nostrums.
Sometimes—albeit rarely—I even learn about some interesting new science.

One of the most common themes (besides antivaccine hysteria, claims that diet can prevent 95% of all cancers, etc.) tends to be one of a variety of pitches for various “cures” of serious diseases like cancer and heart disease that “they” don’t want you to know about; i.e., the Kevin Trudeau gambit. Who this “they” is can range from doctors to pharmaceutical companies to universities to the government, but the central message is that someone out there doesn’t want you to know The Truth. A variation of this sort of appeal is the claim that there is a promising new therapy, a cure even, usually natural, that is languishing somewhere because it can’t be patented, because pharmaceutical companies would lose money if it were ever validated and brought into clinical use, or because it goes against current medical dogma. It doesn’t even have to be natural. After all, dichloroacetate (DCA) is not exactly “natural.” After it was shown to have promise in animal models, a pesticide salesman named Jim Tassano sold DCA bought from chemical companies to desperate cancer patients from a website that claimed to be selling it only for pets with cancer, a ruse that fooled no one. Yet the “natural treatment” crowd embraced it whole-heartedly because it looked as though sellers of DCA were sticking it to The Man.

Unfortunately, it’s not just the quacks who use this method of selling their wares. I wish it were, but it’s not. Over the years, I’ve come across scientists who have used pitches that sound disturbingly like the pitches that I’ve just described. Sometimes, as I recently discussed, these pitches are no more than overselling results in university and medical journal press releases. Sometimes, they involve direct pitches to the public to fund their research. In many of these cases, I wonder whether the scientist involved is at the heart of it or whether he’s along for the ride, having been seduced by the blandishments of fundraisers, PR people, or others whose agenda might involve promoting his science but doesn’t necessarily involve safeguarding the scientist’s reputation. In fact, even Evangelos Michelakis, the University of Alberta researcher who discovered the antitumor effects of DCA, did some of that, albeit not in a manner that bothered me. It can be very tempting, I would imagine, if one has a therapy that’s been in the news and is frustrated by the inability to obtain funding to pursue what appears to be a promising line of research. This is particularly true these days, given the exceedingly tight paylines at the NIH and private foundations. Nevertheless, it makes me uncomfortable, and I was reminded of this discomfort when recently I came across a series of articles, in which a journalist was using a variant of the sales pitches above. While I’ll grant that what he’s trying to raise money for appears to be worthwhile research (more later), I also left feeling very uncomfortable at the sales pitch he had chosen, which resulted in his article “going viral” into other articles like this:

To be fair, I must point out that this hype seems to be eminating mainly from a British writer, Alexander Masters, whose friend Dido Davies suffers from pancreatic neuroendocrine cancer, essentially the same cancer that claimed the life of Steve Jobs nearly a year ago, and not the scientist working on the project, Prof. Magnus Essand of the Uppsala University in Sweden. In fact, at several points he tries to throw out a note of caution. That doesn’t stop him from taking advantage of Masters’—shall we say?—enthusiasm, nor does it stop the usual suspects from using Prof. Essand’s work to attack big pharma, promote conspiracy theories about “natural” cancer cures “they” don’t want you to know about, and in general attack science. And no wonder. Let’s take a look at Master’s article:

On the snow-clotted plains of central Sweden where Wotan and Thor, the clamorous gods of magic and death, once held sway, a young, self-deprecating gene therapist has invented a virus that eliminates the type of cancer that killed Steve Jobs.

‘Not “eliminates”! Not “invented”, no!’ interrupts Professor Magnus Essand, panicked, when I Skype him to ask about this explosive achievement.

‘Our results are only in the lab so far, not in humans, and many treatments that work in the lab can turn out to be not so effective in humans. However, adenovirus serotype 5 is a common virus in which we have achieved transcriptional targeting by replacing an endogenous viral promoter sequence by…’

It sounds too kindly of the gods to be true: a virus that eats cancer.

‘I sometimes use the phrase “an assassin who kills all the bad guys”,’ Prof Essand agrees contentedly.

Yet, Masters tells us, this miraculous cancer cure virus (in actuality, a virus that might or might not represent a promising new treatment) is sitting in a little freezer near Prof. Essand’s office “gathering frost,” even though it is “exquisitely precise,” “only causes mild, flu-like side effects in humans,” and results in tumors in mice “melting away.” Those bastards! Why won’t they fund this science? Can’t they see that it’s so groundbreaking that it must be funded? Can’t they see that every month that this virus sits in Prof. Essand’s freezer is a month when millions of patients (OK, thousands of patients—well, maybe hundreds of patients) are dying unnecessarily?

I exaggerate a bit, of course, but that is basically the tone of Masters’ article, leavened occasionally with only the gentlest words of caution that this is all preliminary, that it might not work out. Indeed, Masters lays down an incredible piece of utter nonsense in describing how he finds potential new therapies in science that might have promise:

It was on one of those evenings that I came across a blog about a quack in Mexico who had an idea about using sub-molecular particles – nanotechnology. Quacks provide a very useful service to medical tyros such as myself, because they read all the best journals the day they appear and by the end of the week have turned the results into potions and tinctures. It’s like Tommy Lee Jones in Men in Black reading the National Enquirer to find out what aliens are up to, because that’s the only paper trashy enough to print the truth. Keep an eye on what the quacks are saying, and you have an idea of what might be promising at the Wild West frontier of medicine. This particular quack was in prison awaiting trial for the manslaughter (by quackery) of one of his patients, but his nanotechnology website led, via a chain of links, to a YouTube lecture about an astounding new therapy for neuroendocrine cancer based on pig microbes, which is currently being put through a variety of clinical trials in America.

I don’t know about you, but if I were Prof. Essand, I wouldn’t exactly be flattered that this is how Masters came across my work. In fact, I’ve actually had a couple of quacks cite my work before, and if I’m ever in the mood maybe I’ll blog about it sometime. In the meantime, all I can say about what Masters writes here is that it meets the criteria of being so wrong it’s not even wrong. What you’re more likely to find on quack cites are treatments based on prescientific understandings of cancer (in essence, humors and “imbalances”); wishful thinking like The Secret (the German New Medicine, for example); a complete misunderstanding of human physiology and science (such as Robert O. Young’s quackery claiming that all cancer is due to excess acid or, of course, homeopathy); or, if you’re lucky, maybe the sort of understanding of cancer we had 100 years ago, such as the trophoblastic hypothesis that underlies the quackery that is known as the Gerson therapy. Where you do see cutting edge science on quack websites, you will see its abuse, not its being put to use to develop promising therapies outside the mainstream. Deepak Chopra’s abuse of quantum theory comes to mind. What you are incredibly unlikely to find is any sort of cutting edge science applied to the problem of cancer or other diseases in a way that’s likely to do anything except to fleece the marks. How Masters could be so extravagantly clueless about how science works is truly astonishing.

Still, Masters’ article intrigued me enough that I did some PubMed searches for Essand’s work and any other work related to this particular viral construct, Ad5[CgA-E1A-miR122]PTD. You probably all know me well enough by now to realize that, whenever I see a story about science or medicine that piques my interest, I try to “go to the tape,” so to speak; i.e., find the original research articles in the peer-reviewed literature describing the work. The reason, of course, is obvious; what is reported in the news about science and the actual science itself are sometimes related solely by coincidence.

In any case, this article from 2011 in Gene Therapy, this article from 2010 in PLoS ONE, and this article from 2007 in Clinical Cancer Research appear to be the main articles describing this particular virus. In brief Prof. Essand appears to have done a fairly clever thing. He’s taken an adenovirus and altered it to target it to neuroendocrine tumors while at the same time decreasing its ability to replicate in other cell types. He’s done this using two strategies. First, he took a promoter that is highly active in cells of neuroendocrine origin, the chromogranin-A (CgA) promoter. A promoter is a stretch of DNA that controls the expression of a gene. Depending upon what transcription factors (proteins that control gene expression) bind to its sequences, it can turn genes off or on based on intracellular signals, cell type, and any number of factors. CgA is a protein in secretory granules of neuroendoocrine cells that serves as a precursor of several biologically active peptides made by the cells. For purposes of targeting the adenovirus, the CgA gene is highly expressed in neuroendocrine tumors and CgA is known to be a sensitive and specific tumor maker for neuroendocrine tumors. So the basic idea is to use the CgA promoter to drive the adenovirus (dubbed Ad[CgA-E1A]) infecting the neuroendocrine cancer cells to make the E1A protein, which results in replication of the virus only in cells that normally make CgA; i.e., neuroendocrine cells. The final act of the adenovirus life cycle is to lyse the cells and release all the replicated viral particles, hence the term “oncolytic” virus. These new viral particles then disperse and infect nearby cells, repeating the cycle.

This isn’t the clever part of what Prof. Essand has done. Thus far, all he’s done is to make a pretty straightforward choice of a promoter that is as tissue- or cell-specific as he can think of, stick it into an adenoviral vector, and use it to drive the adenovirus to make the genes that promote its replication. It’s a nice trick but nothing we haven’t been doing at least since the 1990s to make an oncolytic adenovirus more cell-specific. What was clever was what he did to address a major problem that adenoviral gene therapy can have, namely liver toxicity. The CgA promoter isn’t perfectly specific (no promoter is). It has some activity in liver cells (hepatocytes), which means that, especially for liver metastases (which is where neuroendocrine cancers tend to metastasize first, there is the potential for even this specific virus to replicate in hepatocytes and lyse them just as it’s lysing tumor cells, just at a lower level. The result would be liver injury, hepatitis in essence. Enough hepatocyte death, and it could mean patient death.

To lessen the chance of that, Prof. Essand took advantage of microRNAs. MicroRNAs are small RNA sequences (usually around 20-22 nucleotides long) that are complementary to (and therefore bind to) specific sequences in the messenger RNAs (mRNA) for various genes, preventing the mRNA from being turned into protein by either preventing translation or by inducing the degradation of the mRNA. In other words, microRNAs (miRs) block protein synthesis at the mRNA level. Indeed, microRNAs have become increasingly appreciated as a major mechanism regulating gene expression. (I’ve even published a couple of papers on microRNAs.) What Prof. Essand did was to take target sequences for a microRNA, miR-122, and tack six copies of this target sequence on to the 3′-untranslated region of the E1A gene. It turns out that hepatocytes make a lot of miR-122, so much miR-122 that this single microRNA makes up around 70% of the total microRNAs that hepatocytes make. What that means is that in hepatocytes miR-122 will silence (shut down) E1A before it can even be made into protein. That’s the even neater trick.

Finally, apparently Prof. Essand has made one other modification, namely adding the protein transduction domain (PTD) of the HIV-1 Tat protein (Tat-PTD) inserted into the viral fiber, hence the name Ad5[CgA-E1A-miR122]PTD. The reason to do this is to increase the ability of the virus to bind to cell types not making the coxsackievirus-adenovirus receptor (CAR), which adenovirus requires for entry into the cell. Although his methods for adding the Tat-PTD to adenoviral vectors re described in this paper, in which Prof. Essand reports the construction of Ad5-PTD vectors, I haven’t been able to find a paper reporting the construction of Ad5[CgA-E1A-miR122]PTD or a paper showing its efficacy against xenograft models of neuroendocrine cancers, although I have found a paper in which Prof. Essand fiddled with his vector some more by adding somatostatin motifs that bind to somatostatin receptors expressed by neuroendocrine cancers, comparing his previous vector Ad5[CgA-E1A-miR122] to his new, improved, more somatostatin-y virus Ad5fkFWKT[CgA-E1A-miR122] in tissue culture for their ability to infect neuroendocrine cancer cells.

Perusing Prof. Essand’s papers, I note that Ad[CgA-E1A] does a pretty good job of suppressing neuroendocrine tumor growth in mice and prolonging their survival in xenograft models. I also note that Ad5[CgA-E1A-miR122] does appear to demonstrate better targeting in that it causes less liver toxicity in mice associated with more specific silencing of E1A expression in hepatocytes in mice. What I did not see was an experiment demonstrating that either Ad[CgA-E1A], Ad5[CgA-E1A-miR122], or Ad5[CgA-E1A-miR122]PTD “melting tumors away.” What I do see are some interesting results in preclinical models. Do these results warrant following up, perhaps even in clinical trials? Sure. I’d like to see them followed up. Are they so amazing that it is a crime that the clinical trial hasn’t been funded yet? No. Funding is very, very tight right now, and there are a lot of great projects out there (mine among them, I would say at the risk of being too boastful) going unfunded because, in the US at least, the NIH is only funding at about the 7% level through the NCI. Yet that is exactly the impression that Masters gives in his article. It’s full of colorful language, such as describing the virus as surging “through the bloodstreams of test animals, rupturing cancerous cells with Viking rapacity”; a “virus that eats cancer”; and similar overblown language. Even Prof. Essand gets in on the act, calling his virus “an assassin who kills all the bad guys.” This virus, even if it works exactly as advertised in Masters’ article does not “eat cancer.” It kills cancer cells with a high degree of specificity. That’s a good thing, but far from a cure. Even though Masters does occasionally tamp down the rhetoric below 11, it doesn’t sound convincing:

The closer you get to manipulating the cellular forces of human existence, the more you sound like a schoolboy babbling about his model aeroplane. Everything in the modern genetics lab is done with kits. There are no fizzing computer lights or fractionating columns dribbling out coagulations of genetic soup in Magnus’s lab; not a single Bunsen burner. Each narrow laboratory room has pale, uncluttered melamine worktops running down both sides, wall units above and small blue cardboard cartons dotted everywhere. Even in their genetics labs, Swedes enjoy an air of flatpack-ness. The most advanced medical lab in the world, and it looks like a half-fitted kitchen.

Nothing at all against Prof. Essand. He seems like a nice enough guy and a good scientist, but I highly doubt that he has the most advanced medical lab in the world, particularly in light of his funding difficulties moving his virus to the next stage.

Besides the tone of Masters’ article, which is at its core not that far removed from a lot of articles I saw on DCA and some e-mails I get about various cancer “cures,” particularly the part where he cites that infamous Amgen study at face value claiming to find that most basic science research can’t be reproduced (hopefully you will remember my deconstruction of this article), there’s another thing that bothers me:

What costs the £1 million (less than two per cent of the price of Francis Bacon’s Triptych 1976) that Magnus needs to bring this medicine to patients is not the production, but the health-and-safety paperwork to get the trials started. Trials come in three phases. What Magnus was suggesting for his trifling £1 million (two Mont Blanc diamond-encrusted pens) was not just a phase I trial, but also a phase II, which, all being well, would bring the virus right to the point where a big pharmaceuticals company would pay 10 or 100 times as much to take it over and organise the phase III trial required by law to presage full-scale drug development.

‘So, if Calvin Klein or Elton John or… Paris Hilton stumped up a million, could they have the virus named after them?’

‘Why not?’ Magnus nodded, showing me the bacteria incubator, which looks like an industrial clothes washer, only less complicated. ‘We can make an even better one for two million.’

I don’t know about you, but I’m not sure I like the idea of wealthy donors getting to name potential cures after themselves if they fork over enough money. It’s one thing to put their name on a building (and even that can cause problems, as the Robert Wood Johnson University Hospital found out when it sold the naming rights to its new children’s hospital to Bristol Myers-Squibb. Of course, if a pharmaceutical company were to buy the rights to Prof. Essand’s adenovirus, it would be able to call it anything it wants if it turned it into a product. Be that as it may, imagine the Calvin Klein adenovirus or the Elton John cure for cancer or maybe the Lady Gaga cancer tenderizer. The possibilities are endless.

Regular readers know that I’m not someone who is somehow anti-capitalist or against pharmaceutical companies making profits on general principle. Nor am I opposed to universities doing some fundraising to try to start clinical trials on promising therapies that they don’t have funding for. In fact, I’ll even direct you to Prof. Essand’s oncolytic virus fundraising page. If you’re so inclined, donate. It looks like worthwhile research, and as a fellow biomedical researcher I’d like to see it advanced.

But remember this. Despite what Masters implies in his article and what others citing his article are saying explicitly about Prof. Essand’s virus, it is not because “they” don’t want you to know about Essand’s research that it is not being funded. It’s probably not even because pharmaceutical companies can’t profit from it. They certainly could. They could take Essand’s viruses and modify them more to make them even more specific and more oncolytic, patent the new viruses, and potentially make boatloads of money.

I’ll tell you the most likely real reason for Prof. Essand’s difficulties securing funding for his trial as someone who used to do gene therapy research himself back in the late 1990s and early 2000s and once worked in a lab that collaborated with a rather big lab looking at oncolytic viruses: Gene therapy and oncolytic viruses for cancer have fallen out of favor in the cancer research world. The primary reason is the highly publicized death of Jesse Gelsinger in a clinical trial of adenoviral-delivered gene therapy, a death that also reminds us that adenoviral vectors are not necessarily as safe as they are advertised. True, much progress has been made in the last 13 years since that horrific disaster, and it’s virtually certain that adenoviral therapies today are likely safer than they were when an idealistic 18-year-old paid the ultimate price for his altruism. But we don’t know, and scientists have become considerably more gun shy when it comes to adenovirus-based therapies, gene therapy or oncolytic viral therapy. There’s just not much interest in it anymore, and I’ve noticed a marked fall-off in the number of abstracts describing such therapies being presented at the big cancer conferences over the last decade or so.

Look at it this way. There are hundreds, if not thousands, of promising therapies out there. Using adenoviral vectors is hard. Heck, Prof. Essand shows us that. Look at all the manipulations of his adenovirus backbone he had to do to get his adenoviral vector to infect the cells he wants it to infect, replicate only in the cells in which he wants it to replicate, and, just as importantly, keep it from replicating in the cells in which he doesn’t want it to replicate. Then remember that, to eliminate cancer, this virus has to destroy virtually every cancer cell. That is the magnitude of the challenge. Add to that the various other difficulties that any sort of virus-based therapy faces in terms of manufacturing clinical grade material and assuring its safety, and it’s not too surprising that pharmaceutical companies are taking a “wait and see” attitude. This is especially true given that life-threatening neuroendocrine cancers are not that common, limiting the number of patients who would benefit from this form of gene therapy that would require a high cost to develop. Worse, there’s no a priori way to know that Prof. Essand’s treatment would be any more likely to succeed than any of the other promising experimental treatments currently in the pipeline for various cancers. From the published information, which doesn’t appear to include Ad5[CgA-E1A-miR122]PTD, I can’t even hazard a guess.

Yet the assumption is that it is. It’s human nature, after all. People who develop a new treatment always assume that it is more worthy than other people’s new treatments, and people who know someone with the disease will tend to agree because they want their loved one to live. Unfortunately, those of us in the biz have seen these “miracle cures” before that eliminate tumors in mice but don’t to nearly as much in humans. It was immunotherapy in the 1980s. Then in the 1990s it was antiangiogenic therapy and, yes, gene therapy, including therapy with oncolytic viruses. In fact, my primary research interest for a long time was antiangiogenic therapy, and I had high hopes for it. Now, having come down to earth based on clinical studies done over the last 15 years, I’m a lot more skeptical of the sorts of treatments touted by someone like Masters. I only wish that Prof. Essand hadn’t let himself be sucked into being part of the hype.