Tecfidera (BG 12) And PML

If you are currently taking Tecfidera, please take part in my Tecfidera patient poll (click here).

Over the last month or so, there’s been a rising crescendo of concern among MS patients about the possible link between the newly approved oral MS drug Tecfidera (formally known as BG 12) and the deadly brain infection PML (Progressive Multifocal Leukoencephalopathy). I’ve received many anxious emails on the subject, and Internet MS forums and Facebook pages are rife with alarm over the perceived recent spate of bad Tecfidera news.

As long-time readers of this blog know, I’m not a big fan of Big Pharma, to say the least. In fact, I hold them in regard only slightly higher than the New York Yankees, who I am convinced are the essence of evil incarnate on earth. But I am also not a big fan of fear mongering, and when reviewed objectively, the facts behind the alleged link between Tecfidera and PML simply don’t warrant the level of anxiety recent reports have fomented. In fact, it seems that rivalries in the Big Pharma sandbox may be playing a role in all the hyperbole, but more on that later.

As most MSer are aware, PML is a brain infection that most often occurs in patients experiencing severe immunosuppression, such as those suffering from HIV/AIDS. In the context of MS, the infection is most closely linked to the drug Tysabri, whose mechanism of action often reduces immune system surveillance of the central nervous system quite drastically, opening up the possibility of opportunistic infection by the JC virus, which causes PML. Of course, it is this same mechanism of action that makes Tysabri so effective (the latest figures indicate that Tysabri therapy results in an 81% reduction in relapses, a 64% reduction in disease progression, and one in three RRMS patients appear to be free of disease activity for a prolonged period of time – click here for an exhaustive breakdown of Tysabri, its effectiveness, and PML). Despite Tysabri’s efficacy, PML is a real concern for those taking it, as 347 Tysabri patients have contracted the potentially deadly infection (approximately 120,000 patients are currently taking the drug).

Recently, it was revealed that four cases of PML occurred in German patients taking the psoriasis drug Fumaderm, from which Tecfidera was derived. It’s important to note that although the two drugs are similar, they are not identical. Fumaderm is a compound of dimethyl fumarate and three other related chemicals. Tecfidera is made only of dimethyl fumarate. Fumaderm has been used to treat psoriasis in Germany and some other European countries for about 20 years, with much success (click here), and is generally considered to have a benign side effect profile.

Both Tecfidera and Fumaderm do have immunosuppressive properties. In Tecfidera’s phase 3 DEFINE trial, it was found that the drug reduced lymphocyte counts in treated patients by about 28%. Lymphocytes are immune system cells whose mission it is to combat infection. These same cells are implicated in the MS disease process, and it is this depressive effect on lymphocytes that could well account for Tecfidera’s abity to fight the symptoms of MS. However, 4% of trial subjects (1 in 25) experienced a more severe form of lymphopenia (the medical name for a reduction in lymphocyte counts) which could make them vulnerable to opportunistic infections, requiring them to cease taking the drug. Recovery of lymphocyte counts after cessation of Tecfidera should be quite robust, based on  years of experience with Fumaderm. (Click here for the entire DEFINE trial report)

A look at the four Fumaderm PML cases is quite revealing (click here.-site requires free membership, well worth it). In one case, the patient was not actually taking Fumaderm, but a version of the drug made by a compounding pharmacy which included a chemical not found in Fumaderm, which could have resulted in a formulation more potent or otherwise problematic than the factory produced drug. Another patient had sarcoidosis, a potentially deadly autoimmune disease, and had previously been treated with powerful immunosuppressive drugs. A third Fumaderm PML patient had cancer, and had been treated with Efalizumab, a drug in the same family as Tysabri that has a known risk of PML.

Two of the Fumaderm PML patients had severely depressed lymphocyte counts for two and five years respectively before developing PML. In Germany, the prescribing guidelines for Fumaderm require that patients get blood tests done to check cell counts every month for the first six months they are on the drug, and then every two months thereafter to check for depleted lymphocyte counts. If patients are found to have significant lymphopenia, the guidelines call for dosages to be adjusted or the drug stopped altogether. Apparently, this regimen was not followed in these two cases, as the patients’ lymphopenia was somehow allowed to persist until they developed PML. It’s quite likely that had the lymphopenia been addressed far earlier, neither patient would have contracted PML.

So, what should concerned patients take away from all of this? Tecfidera does depress white blood cell counts, and this effect quite likely plays a large role in its therapeutic value. However, 4% of treated patients can be expected to experience a more severe drop in lymphocyte counts, which could open them up to opportunistic infections like PML if left untreated for an extended period of time. That’s the bad news. The good news is that this drop in cell counts is easily detected by standard blood tests. Once such a decrease is detected, the drug can be stopped and any potential danger averted.

For reasons that I can’t explain, the FDA guidelines for Tecfidera only require blood tests done before treatment is initiated and then once yearly for the duration of treatment. Based on the Tecfidera trial data, as well as the experience gathered from the 20 year history of Fumaderm use in Europe, the requirement of just one blood test a year seems misguided. I’m currently waiting for my insurance company to give me the okay to start Tecfidera, and my neurologist is requiring blood tests every other month for all of his Tecfidera patients. As noted above, two of the Fumaderm PML patients had severely depressed lymphocyte counts for two and five years, so blood testing every other month should provide more than ample opportunity to catch any potential problems well before they become very real concerns.

I am by no means a doctor, just a well educated patient, but I would strongly advise all patients starting Tecfidera to insist that the neuro’s test their blood for lymphocyte counts at least every other month. Doing so should largely eliminate any chance of PML and set many a mind at ease. Despite its similarities to its cousin Fumaderm, Tecfidera is a brand-new drug, and although all signs point to it being a very safe medicine, I think it prudent to err on the side of caution. If your neuro resists, print out the DEFINE trial results and show him/her the data on lymphopenia, which can be found on the ninth page of the study. I always urge patients to educate themselves and to self advocate. Here’s the perfect opportunity to do both.

In short, all of the recent concerns about Tecfidera and PML appear to be hugely overblown. To put things in context, Tysabri has seen 347 cases of PML in approximately 260,000 patient hours of drug exposure. Fumaderm has seen four cases of PML in approximately 180,000 hours of drug exposure. It’s been noted that Fumaderm is not generally given as a long-term therapy. However, at least one study researched psoriasis patients who have taken the drug for up to 14 years, with no apparent added risk associated with long-term use (click here). Based on the DEFINE trial results, the large majority of Tecfidera patients, 96%, should experience no problems whatsoever with lymphopenia. Regular blood testing should ensure that patients who do experience clinically significant drops in lymphocyte counts avoid any potential problems.

The fact that Tecfidera is an oral drug that appears to be almost twice as effective as the injectable CRAB drugs, and may have neuroprotective properties to boot, should make it a very valuable weapon in the arsenal against MS. Like all of the current MS drugs, it is not a cure, but it will hopefully bring many patients some significant relief from this terrible disease. Using all of my self-control, I'll refrain from going on my usual rant about how the focus of pharmaceutically funded MS research on immune system suppression and modulation does absolutely nothing whatsoever in the effort to find a cure for the disease, but it doesn't. And that sucks. There, I said it. I couldn't help myself.

Oh, I almost forgot. About those shenanigans in the Big Pharma sandbox: it appears that the reports of potential problems with Tecfidera were first brought to the attention of the FDA and the general public by Teva Pharmaceuticals, makers of Copaxone, one of the CRAB drugs that are currently considered the first-line drugs given to new MS patients (click here). Guess which MS drugs are most threatened by the potential success of Tecfidera? Yup, the CRABs, of which Copaxone is currently the most prescribed. With Copaxone sales of $4 billion (yes, billion) in 2012, Teva has about 4 billion reasons to try to delay Tecfidera’s entry into the market, or to stir up concern among the drug’s potential consumers. Not that I would ever accuse any Big Pharma players of partaking in such underhanded behavior. Gee, I sure hope the Yankees win the World Series…

Not.

(For a comprehensive overview of the how's and why's of Tecfidera, please see my previous post on the topic, by clicking here)

Hype or Hope? Much Touted Oral MS Drug Tecfidera (BG 12) Approved byFDA.

If you are currently taking Tecfidera, please take part in my Tecfidera patient poll (click here).

Last week, the FDA approved Biogen’s long-awaited oral MS drug, Tecfidera (formally known as BG 12). Naturally, the news was featured most prominently in the financial sections of newspapers/websites (click here), as an uptick in shareholder value is much more newsworthy than a potentially breakthrough drug that could help hundreds of thousands of patients suffering from a heinous disease. Much was also reported about the drug's yearly price of $54,900, which is actually considered reasonable in the demented world of MS drug pricing. Such are the priorities of our whacked out society. Okay, social commentary over…

Tecfidera’s active ingredient is dimethyl fumarate (DMF – click here), a derivative of fumaric acid, a naturally occurring substance that can be found in mushrooms, lichens, and moss. DMF was first used for medicinal purposes in a highly effective anti-psoriasis drug called Fumaderm, which has been marketed in Germany since 1994. It’s important to note that Tecfidera and Fumaderm are not identical compounds, which must be kept in mind when comparing the actions and side effects of the two drugs. Much might be inferred by reviewing the history of Fumaderm, but trying to make precise, direct comparisons could well in lead to erroneous conclusions. More on that later…

The release of Tecfidera has been much anticipated in the MS community, as clinical trials showed the pill to be significantly more effective in reducing relapses and slowing the progression of multiple sclerosis disability than the current frontline MS treatments (Copaxone, Rebif, Avonex, and Betaseron – all injectables), while its side effect profile appears to be quite mild when compared to many of the other MS disease modifying treatments.

Tecfidera joins Gilenya and Aubagio as the only MS treatments currently in pill form. In clinical trials, Gilenya was more effective in terms of reducing relapse rates, but concerns about potentially serious side effects (dangerously low blood pressure and pulse rates, potential for opportunistic infections) have kept the drug from reaching "blockbuster" status. There are some indications that Gilenya may have neuroprotective properties, and it is currently undergoing trials for use against Primary Progressive Multiple Sclerosis (click here). It is one of the few drugs being tested for the progressive forms of the disease. In trials, Aubagio proved to be just about as effective as the CRAB drugs in reducing relapses, and has exhibited some potential in inhibiting disease progression, but the drug comes with two black box warnings (the strongest issued by the FDA) concerning liver toxicity and the possibility that it can cause major birth defects (click here). Tecfidera’s comparatively mild side effect profile, which is comprised primarily of flushing of the skin and gastric disturbances, its high rate of efficacy, and oral dosing have led to the expectation that it will soon be a leader in the multiple sclerosis drug market.

Tecfidera’s mechanism of action, which is not fully understood (something that is not uncommon, the action of many pharmaceuticals are not fully understood), appears to be threefold. The drug exhibits immunomodulatory, anti-inflammatory, and antioxidant properties, the combination of which theoretically affords the compound its potency. In two large-scale studies, called DEFINE and CONFIRM, Tecfidera reduced relapse rates by approximately 50% over placebo, and reduced the progression of disability by about 30%. By comparison, the CRAB drugs reduce relapse rates by about 35%, and Tysabri cuts relapses about 65%. Whether these drugs impact disease progression has yet to be firmly established.

Much of the excitement surrounding Tecfidera involves the prospect that, in addition to its disease modifying characteristics, the drug may be neuroprotective. Neuroprotection is one of the holy grails of MS research. If the cells of the central nervous system can be protected from the ravages of multiple sclerosis, then the progression of the disease can be inhibited. The notion that Tecfidera may be neuroprotective is based on the fact that one of the drug’s supposed mechanisms of action is the activation of Nrf2 pathways in the human body. Nrf2 (click here) is simply a protein that exists within every human cell, inoperative until it is kicked into action by a Nrf2 activator (think of it like a bottle rocket – until lit, it sits there doing nothing, but once lit (activated) it zooms into action). Once activated, Nrf2 migrates into the nucleus of the cell and bonds to the DNA within, initiating the production of powerful antioxidants. If Nrf2 was a bottle rocket, it’s thought that Tecfidera could initiate the process that lights its fuse.

Antioxidants (the good guys) are the body’s defense against free radicals (the bad guys), cell damaging oxygen molecules that are released during the biological process of turning food into energy, much like noxious exhaust fumes are released by an automobile engine turning gasoline into energy. Once free radicals are released they act like wrecking balls, smashing through cell walls and inflicting injury. The process by which free radicals do damage to the body’s tissues is known as oxidative stress, which is believed to be one of the primary drivers of MS disease progression, as well as a factor in many other diseases (click here). Therefore, by combating oxidative stress through Nrf2 activation, Tecfidera may protect central nervous system tissues from damage by free radicals, which would be a very good thing.

Some Facebook pages and websites, including a previous post on Wheelchair Kamikaze (click here), have mistakenly equated Tecfidera with a nutraceutical product called Protandim (click here). In laboratory tests, Protandim has proven to be a powerful Nrf2 activator, a quality it does share with Tecfidera. However, Tecfidera’s mechanism of action appears to be much more complex and wide-ranging, and not confined only to Nrf2 activation. It also effects cytokines (chemical signals that influence the inflammatory process – click here), and down regulates the immune system. This down regulation of the immune system may in fact be the primary driver of Tecfidera’s effectiveness. According to the official report detailing the results of the DEFINE trial (click here), which appeared in the New England Journal of Medicine, “It is difficult to determine whether the therapeutic effect of BG 12 stems predominantly from immunomodulatory mechanisms or from neuroprotective mechanisms.”

Now back to Fumaderm, Tecfidera’s very effective German anti-psoriasis cousin. Fumaderm's efficacy in treating psoriasis, an autoimmune disease, is well documented, with 50% of the patients taking it achieving at least 70% improvement in their condition. Since Fumaderm’s primary component, like Tecfidera, is dimethyl fumarate, its side effect profile is similar to Tecfidera’s. Through 20 years of use, the most prevalent Fumaderm side effects have been gastric disturbances (stomach ache, vomiting, and diarrhea) and flushing of the skin, which, according to a paper prepared by Britain’s NHS (click here), can lead to discontinuance and/or noncompliance in 30% to 40% of patients. In the Tecfidera drug trials, though, dropout rates were negligible, with no significant difference between those patients taking the actual drug and those on placebo. Gastric disturbances and flushing of the skin were the most commonly reported side effects in the Tecfidera trials, but appeared to be manageable and diminished significantly after one month on the therapy. This discrepancy between the patient experience with Fumaderm versus Tecfidera is likely due to the different chemical makeup of the two compounds (Tecfidera is composed only of DMF, while Fumaderm includes DMF and some other derivatives of fumaric acid), and/or to differences in dosing, as patients on Fumaderm generally take a higher dose of DMF than will be given to Tecfidera users. Still, only real world experience will tell us how troublesome these side effects prove to be.

Another effect seen in both drugs is leukopenia, a reduction in white blood cell counts. This condition is accompanied by lymphopenia, a reduction in specific white blood cells, including B and T cells, which are the targets of many of the current MS drugs (Tysabri, Rituxan, Gilenya, Aubagio). This suppression of immune system cells may play a part in the two drugs' effectiveness, but can be problematic if the cell counts get too low, as this might open the patient up to opportunistic infections, although none were seen during the clinical trials. Tecfidera induced lymphopenia and leukopenia are reversible with cessation of drug therapy.

In its 20 years on the German market, comprising over 170,000 patient hours, Fumaderm has been linked to four cases of PML (click here), the opportunistic brain infection associated with Tysabri. While this may initially seem troublesome, it’s important to keep in mind that these cases occurred over a very long time period, and at least one of these patients was using other powerful immunosuppressive drugs. Generally, opportunistic infections are not seen in patients using Fumaderm.

During the Tecfidera DEFINE trial, white cell and lymphocyte cell counts dropped an average of 10% and 28% respectively, which could very well play a role in the drug’s efficacy. Importantly, though, over the two-year run of the trial, no instances of opportunistic infections were reported. It was noted, however, that 4% of trial patients experienced a more serious drop in cell counts (this info can be found on page 1106, paragraph 3 in the NEJM article – click here). In Germany, Fumaderm patients are required to have blood tests once a month for the first six months they are on the therapy, and then every other month thereafter, to keep an eye on cell counts The FDA guidelines for Tecfidera only call for yearly blood tests, and though I’m no doctor, this recommendation seems a bit questionable. Even though no opportunistic infections were noted in the two Tecfidera trials, why not err on the side of caution? We’re only talking about simple blood tests, which could head off potential problems before they get started.

Some other rare but potentially serious side effects noted in the Tecfidera study were liver and kidney events, although most were mild and reversible. There were no reported incidences of kidney failure. Still, I would think, all the more reason for regular blood tests, especially since so many MS patients are on other drugs that can be liver or kidney toxic.

So, what do I make of all this, as an educated patient? Tecfidera seems to be a very promising new drug for MS sufferers, one which might even help those with progressive disease due to its antioxidant, neuroprotective potential. I will very likely begin Tecfidera therapy sometime in the near future, even though my diagnosis is still uncertain and none of the other MS drugs have helped me. I’m encouraged by the fact that Tecfidera is related to a drug that is very effective in treating psoriasis, and has also anecdotally been noted to have a positive effect on a host of other diseases, including sarcoidosis and alopecia. I definitely show signs of some sort of systemic autoimmune activity, a condition against which Tecfidera’s mechanisms of action suggest might make it effective.

Tecfidera’s clinical trials convincingly demonstrate it to be effective in treating RRMS. Whether you believe MS is an autoimmune disease or not, it’s indisputable that the immune system plays some significant role in the MS disease process, and Tecfidera’s combination of immunomodulation, anti-inflammatory action, and antioxidant activation should provide a potent mix to help tame the disease. We’ll have to see just how troublesome the gastric and skin flushing side effects turn out to be, although, as stated above, in the trials they appeared to drop off dramatically after the first month of therapy.

Personally, if and when I do go on Tecfidera, I am going to insist on blood tests every 4-6 weeks, based on the study data concerning leukopenia and lymphopenia, as well as renal and hepatic toxicity. I’m on so many drugs that I rattle when I move, and I’ve learned to take nothing for granted. I’d suggest patients sharing similar concerns print out the New England Journal of Medicine DEFINE trial article linked to above and show the pertinent sections to their neurologist. The 4% rate of serious lymphopenia has not been publicized, as far as I can tell, and that alone should be reason for regular monitoring of blood counts. Better safe than sorry, especially when using a drug new to the market. Of course, that’s just my humble “I'm not a doctor” opinion…

(Update: for more information on Tecfidera and PML, please see my latest post on the topic, by clicking here)

Related articles

• FDA Approves New Multiple Sclerosis Treatment: Tecfidera (fda.gov)
• UPDATED: Biogen Idec rolls up FDA OK for blockbuster multiple sclerosis drug Tecfidera (fiercebiotech.com)
• Biogen Prices New MS Pill At $55K, Prepares For Marketing Battle (forbes.com)