From Blog: The Haystack
In a blow to the Hepatitic C drug development arena, Bristol-Myers Squibb last night pulled the plug on BMS-986094, an NS5B inhibitor in mid-stage trials. The decision comes just weeks after the company reported a patient suffered from heart failure during a Phase II study of the compound. Nine patients were eventually hospitalized, with varying symptoms of kidney and heart toxicity, according to BMS’s release (See more coverage by Adam Feuerstein at The Street and by Andrew Pollack at the NYT)
BMS-986094? You might know this molecule better as Inhibitex’s former nucleoside INX-089. The molecule came to BMS through its $2.5 billion purchase of Inhibitex in 2011, as we wrote last year here at the Haystack.
The molecule belongs to a family of new nucleosides with fairly common structural motifs: a central sugar appended to a nitrogen heterocycle (usually purine- or uracil-based) and an elaborate phosphoramidate prodrug. These new drugs’ similarities may also prove to be their Achilles heel – Idenix Pharmaceuticals announced an FDA-requested partial clinical hold on their IDX-184 lead. This cautious approach aims to protect patients; though the drugs are similar, 184’s main structural difference – a thioester-based, slightly more-polar prodrug – seems to be enough to distance it from the cardiac side-effects seen with BMS-986094.
For a fairly in-depth look at the chemistry behind these inhibitors, as well as dozens of other analogues that never made it to prime time, check out US Patent 7,951,789 B2, issued to Idenix just last year.
From Blog: The Haystack
When you think of reaction screening, what comes to mind? Most would say LC-MS, the pharma workhorse, which shows changes in molecular polarity, mass, and purity with a single injection. Some reactions provide conversion clues, like evolved light or heat. In rare cases, we can hook up an in-line NMR analysis – proton (1H) usually works best due to its high natural abundance (99.9%).
Please welcome a new screening technique: 13C NMR. How can that work, given the low, low natural abundance of ~1.1% Carbon-13?
Researchers at UT-Southwestern Medical Center have the answer: rig the system. Jamie Rogers and John MacMillan report in JACS ASAP 13C-labeled versions of several common drug fragments, which they use to screen new biocatalyzed reactions.
Biocatalysis = big business for the pharma world. The recent Codexis / Merck partnership for HCV drug boceprevir brought forth an enzyme capable of asymmetric amine oxidation. Directed evolution of an enzyme made sense here, since they knew their target structure, but what if we just want to see if microbes will alter our molecules?
Enter the labeled substrates: the researchers remark that they provide an “unbiased approach to biocatalysis discovery.” They’re not looking to
accelerate a certain reaction per se, but rather searching for any useful modifications using the 13C “detector” readout. One such labeled substrate, N-(13C)methylindole, shows proof-of-concept with their bacterial library, producing two different products (2-oxindole and 3-hydroxyindole) depending on the amount of oxygen dissolved in the broth. NMR autosamplers make reaction monitoring a snap, and in short order, the scientists show biotransformations of ten more indole substrates.
This paper scratches multiple itches for various chem disciplines. Tracking single peaks to test reactions feels spookily close to 31P monitoring of metal-ligand catalysis. Organickers, no strangers to medicinally-relevant indole natural products, now have another stir-and-forget oxidation method. Biochemists will no doubt wish to tinker with each bacterial strain to improve conversion or expand scope. The real question will be how easily we can incorporate 13C labels into aromatic rings and carbon chains, which would greatly increase the overall utility.
From Blog: The Haystack
BMS is shelling out $2.5 billion dollars for Inhibitex, a small pharma company with a Phase II molecule for treatment of Hepatitis C (HCV). The deal adds to the scramble for HCV assets in recent months, with Gilead agreeing to pay almost $11 billion for Pharmasset in November, and Roche’s recent purchase of Anadys. While much has been written about the merits (and price tags) of each deal, the Haystack thought it was worth taking a closer look at the chemical composition of the multi-million dollar molecules.
So what did BMS get for their money?
INX-089, Inhibitex’s lead molecule, has a common antiviral motif: a nucleoside core (the 5-membered ring sugar attached to a nitrogen heterocycle) with an amino acid based prodrug hanging off the left-hand side. Clinically-tested antivirals sharing this basic setup include IDX-184 and NM-283, both from Idenix, and PSI-352938, from Pharmasset (For an overview of the varied structures currently in development for HCV, see Lisa’s 2010 C&EN story).
INX-089 bears a close resemblance to Pharmasset’s lead nucleotide inhibitor PSI-7977. That’s not a mistake, believes ‘089 discoverer Chris McGuigan, of the Welsh School of Pharmacy. In a recent article (J. Med. Chem. 2010, 53, 4949), McGuigan himself comments “The Pharmasset nucleoside [is] rather parallel to our early work on anti-HIV ProTides.”
Wait, what are ProTides?
Both INX-089 and PSI-7977 aren’t themselves the active viral inhibitor, but phosphoramidate “ProTide” prodrugs: compounds broken down by the body into the active drug (Chem Note: PSI-7977 has single-enantiomer Sp chirality at phosphorus, while INX-189 is a mixture of diastereomers).
Once in the body, enzymes cleave the phosphoramidate group to a phosphate (PO42-). Kinases attach two more phosphate groups, and viruses let this dressed-up molecule inside, where the nucleotide warhead inhibits HCV by interfering with RNA replication (Antimicrob. Agents Chemother. 2011, 55, 1843).
A few comments on the drug itself: The similarity of the ProTide portion (left-hand side) of the molecule to PSI-7977 really is striking: swap in an isobutyl ester and a phenyl, and it’s the same beast! The more interesting switch comes on the upper-right (“eastern”) part of the structure: a protected guanosine ring. This ring harks back to guanine, one of the four common nucleic acids found in DNA.
PSI-7977, meanwhile, shows off a uracil, a nucleic acid found in RNA, not DNA.
Although it’s tempting to think such similar compounds all dock into the NS5B polymerase at the active site (in the yellow “palm” of the hand-shaped enzyme), don’t be too sure – a recent paper by Pharmasset scientists (J. Med. Chem. 2012, Just Accepted) shows quite a few “Finger,” “Palm,” and “Thumb” sites. It’s not yet clear whether all nucleoside drugs bind to the active site in the same way. The authors also remark that, due to fast replication and mutation, potentially resistant strains of HCV pop up daily.
From Blog: The Haystack
Well, 2011 is in the books, and we here at The Haystack felt nostalgic for all the great chemistry coverage over this past year, both here and farther afield. Let’s hit the high points:
1. HCV Takes Off – New treatments for Hepatitis C have really gained momentum. An amazing race has broken out to bring orally available, non-interferon therapies to market. In October, we saw Roche acquire Anadys for setrobuvir, and then watched Pharmasset’s success with PSI-7977 prompt Gilead’s $11 billion November buyout. And both these deals came hot on the heels of Merck and Vertex each garnering FDA approval for Victrelis and Incivek, respectively, late last spring.
2. Employment Outlook: Mixed – The Haystack brought bad employment tidings a few times in 2011, as Lisa reported. The “patent cliff” faced by blockbuster drugs, combined with relatively sparse pharma pipelines, had companies tightening their belts more than normal. Traffic also increased for Chemjobber Daily Pump Trap updates, which cover current job openings for chemists of all stripes. The highlight, though, might be his Layoff Project. He collects oral histories from those who’ve lost their jobs over the past few years due to the pervasive recession and (slowly) recovering US economy.. The result is a touching, direct, and sometimes painful collection of stories from scientists trying to reconstruct their careers, enduring salary cuts, moves, and emotional battles just to get back to work.
3. For Cancer, Targeted Therapies – It’s also been quite a year for targeted cancer drugs. A small subset of myeloma patients (those with a rare mutation) gained hope from vemurafenib approval. This molecule, developed initially by Plexxikon and later by Roche / Daiichi Sankyo, represents the first success of fragment-based lead discovery, where a chunk of the core structure is built up into a drug with help from computer screening.From Ariad’s promising ponatinib P2 data for chronic myeloid leukemia, to Novartis’s Afinitor working in combination with aromasin to combat resistant breast cancer. Lisa became ‘xcited for Xalkori, a protein-driven lung cancer therapeutic from Pfizer. Researchers at Stanford Medical School used GLUT1 inhibitors to starve renal carcinomas of precious glucose, Genentech pushed ahead MEK-P31K inhibitor combinations for resistant tumors, and Incyte’s new drug Jakifi (ruxolitinib), a Janus kinase inhibitor, gave hope to those suffering from the rare blood cancer myelofibrosis.
4. Sirtuins, and “Stuff I Won’t Work With – Over at In the Pipeline, Derek continued to chase high-profile pharma stories. We wanted to especially mention his Sirtris / GSK coverage (we had touched on this issue in Dec 2010). He kept up with the “sirtuin saga” throughout 2011, from trouble with duplicating life extension in model organisms to the Science wrap-up at years’ end. Derek also left us with a tantalizing tidbit for 2012 – the long-awaited “Things I Won’t Work With” book may finally be coming out!
5. Active Antibacterial Development – In the middle of 2011, several high-profile and deadly bacterial infections (Germany, Colorado, among others) shined a spotlight on those companies developing novel antibacterials. We explored front -line antibiotics for nasty Gram-negative E.coli, saw FDA approval for Optimer’s new drug Fidiclir (fidaxomicin) show promise against C. difficile and watched Anacor’s boron-based therapeutics advance into clinical testing for acne, and a multi-year BARDA grant awarded to GSK and Anacor to develop antibacterials against bioterrorism microorganisms like Y. pestis.
6. Obesity, Diabetes, and IBS – Drugs for metabolic disorders have been well-represented in Haystack coverage since 2010. Both Carmen and See Arr Oh explored the vagaries of Zafgen’s ZGN-433 structure, as the Contrave failure threatened to sink obesity drug development around the industry. Diabetes drugs tackled some novel mechanisms and moved a lot of therapies forward, such as Pfizer’s SGLT2 inhibitors, and Takeda’s pancreatic GPCR agonist. Ironwood and Forest, meanwhile, scored an NDA for their macrocyclic peptide drug, linaclotide.
7. The Medicine Show: Pharma’s Creativity Conundrum – In this piece from October, after Steve Jobs’ passing, Forbes columnist Matt Herper both eulogizes Jobs and confronts a real ideological break between computer designers and drug developers. His emphasis? In biology and medical fields, “magical thinking” does not always fix situations as it might in computer development.
We hope you’ve enjoyed wading through the dense forest of drug development with Carmen, Aaron, Lisa, and See Arr Oh this past year. We here at The Haystack wish you a prosperous and healthy 2012, and we invite you to come back for more posts in the New Year!
From Blog: The Haystack
It’s been a busy six months for new Hepatitis C (HCV) meds: first, Merck and Vertex have their drugs approved in May, and then Pharmasset leaks PSI-7977 clinical data. Now, Anadys Pharmaceuticals has just announced Phase IIb results for its clinical candidate setrobuvir (ANA-598). The pill lowered virus levels to undetectable limits in 78% of patients after 12 weeks of combination treatment with either ribavirin or pegylated interferon. Anadys notes only one major side effect, a rash occurring in 1/3 of the ‘598-treated patients. The therapy targets patients in tough-to-treat HCV genotype 1 (gen1), unlike PSI-7977, which targets gen2 and gen3.
The data seems to have convinced Roche, which acquired Anadys last Monday in all-cash deal analysts say represented a 260% premium over Anadys’s Friday stock closing price. Roche, no stranger to the HCV battle, hopes to integrate setrobuvir into a potential oral drug cocktail with its current suite of polymerase and protease inhibitors.
Setrobuvir interacts with N5SB polymerase at the allosteric “palm” binding site, located in the center of the baseball-mitt shaped enzyme. The drug’s sulfur-nitrogen heterocycle – a benzothiadiazine – is the key to virus inhibition; Anadys has installed the motif in all their HCV inhibitors, going back to their 2005 patents.
Chemists have known about the virus-targeting properties of this heterocycle for a while, but most derivatives have been culled in pre-clinical testing (see J. Antimicrob. Chemoth. 2004, 54, 14-16 for a brief review). Interestingly, chemists initially prepared benzodiathiazines, such as those in Merck’s chlorothiazide (c. 1957, according to the Merck Index), as diuretics, which found use in diabetic treatment. Over the next 40 years, modified medicines treated conditions ranging from epilepsy and cognitive therapy to hypertension and transcriptase regulation. Tweaked benzodiathiazines first showed anti-HIV and anti-CMV activity in the mid-1990s.
One final advantageous wrinkle in this structure: unlike PSI-7977, setrobuvir is not nucleoside-derived. This feature changes its binding behavior, pharmacokinetics, and even its intellectual property strategies, since many current antiviral therapies mimic the nucleosides found in RNA and DNA chains.
From Blog: The Haystack
An announcement hinting at the possibility of an all-oral hepatitis C treatment had researchers abuzz last week. Pharmasset, a Princeton, NJ company specializing in antiviral discovery, alluded to upcoming conference data that suggested a combination of ribavirin (a generic antiviral) and Pharmasset’s experimental pill PSI-7977 lowered viral counts to near-undetectable levels in a ten-patient trial (kudos to Adam Feuerstein of The Street for initial reports. . . here at The Haystack, editor Lisa Jarvis has also tracked HCV drug development for some time now).
Hepatitis C virus (HCV) is a chronic liver virus with an estimated 180 million infected worldwide. Two relatively new extermination options are available: Merck’s Victrelis (boceprevir) and Vertex’s Incivek (telaprevir), approved by the FDA ten days apart last year. Unfortunately, though both drugs are administered orally, each requires co-administration of injected interferon, which can cause severe fatigue and flu-like symptoms. Both oral drugs inhibit the same enzyme: the NS3 protease, which drags down a patient’s immunity and helps the virus to produce new copies of its proteins.
In contrast, the ribavirin and PSI-7977 combination involves no injections, making it easier for patients to follow the appropriate medication schedule, and lessening side effects. The PSI compound also clips a different target: NS5B polymerase, an RNA enzyme that helps viral genetic replication. In addition, the PSI-7977 is “pan-genotypic,” meaning it inhibits several genetically different strains of HCV.
A 2010 article (J. Med. Chem. 2010, 53, 7202) details the full story of PSI-7977’s synthesis. Notice anything interesting? It’s really a nucleotide strapped on to a P-chiral prodrug, a “protected” substance the body later converts to the active drug species. This P-chiral motif is seen more often in asymmetric phosphine ligands (compounds that stick to metal catalysts during reactions to modify catalyst activity) than in drug development – often chemists install drug chirality at carbon or sulfur instead. The initial drug lead was actually a mixture of both phosphorus enantiomers (“Sp” and “Rp”), until process chemists realized they could selectively crystallize out the more potent “Sp” product.
In the meantime, Pharmasset scientists haven’t stopped pushing their HCV portfolio forward: a recent paper (J. Org. Chem., 2011, 76, 3782) details a new lead: PSI-352938, a cyclic phosphate prodrug attached to a purine-fluororibose nucleotide warhead. The team credits this new prodrug design with a 10-100-fold increase in potency over the “naked” adenine drug for NS5B RNA polymerase inhibition. PSI-352938 recently completed a multiple ascending dose Phase I trial, in which a daily 200 mg dose brought HCV titres down below the detection limit in 5 of 8 patients.
From Blog: The Haystack
Merck is going bare knuckles in the marketing battle for Hepatitis C patients. Just days after receiving FDA approval to market its protease inhibitor boceprevir, now known as Victrelis, it revealed Roche has signed on to co-promote the drug alongside its pegylated interferon drug Pegasys, a cornerstone of HCV treatment.
Competition in the HCV arena is expected to be fierce, as Vertex Pharmaceuticals is expected to get the FDA nod to market its own protease inhibitor for HCV telaprevir, to be marketed as Incivek, no later than Monday. Both the Merck and Vertex drugs will need to be taken in combination with the current standard of care, pegylated interferon and ribavirin.
Although the two drugs have never gone head to head in the clinic, telaprevir is widely considered to have a better dosing regimen and a slight safety and efficacy edge over Victrelis. As such, analysts have believed that Merck’s main advantage in the HCV market would be its ability to promote Victrelis alongside its own pegylated interferon PegIntron. Now, it will also have Roche’s sales force out there hawking Victrelis with Pegasys, as well.
No financials for the deal were announced, so its hard to say at this point how much Merck is giving up in its quest for a bigger piece of the HCV market. It’s also important to note that this is a non-exclusive pact, so time will tell whether Roche and Vertex establish a similar alliance.
The deal also allows Merck and Roche to “explore new combinations of investigational and marketed medicines.” As readers will recall, the ultimate goal is to eliminate the need for interferon and ribavirin, which have harsh side effects, and treat HCV using only a cocktail of pills. Roche and Merck each have promising small molecules against HCV in their pipelines: Merck has vaniprevir, an NS3/4a protease inhibitor in Phase II trials, while Roche has the polymerase inhibitor RG7128, the protease inhibitor RG7227, and the earlier-phase polymerase inhibitor RG7432.
Read here for past coverage of the race to get new HCV drugs to market.
From Blog: The Haystack
This Friday, we’re looking back at 2010′s big news in pharma and biotech, both the good and the bad. Check out our picks and be sure to weigh in on what you think we missed.
1. Provenge Approved
In April, Dendreon’s Provenge became the first approved cancer immunotherapy. Dendreon CEO Mitch Gold called it “the dawn of an entirely new era in medicine.” And while prostate cancer patients are excited for a new treatment option, the approval is perhaps most exciting for its potential to reignite interest in cancer immunotherapy research. There’s a lot of room for improving the approach—Provenge is, after all, expensive and highly individualized. Now that immunotherapy have been proven to work, there’s hope that the lessons learned in both its discovery and clinical development will aid scientists in inventing even better cancer vaccines.
2. Obesity Field Slims
The obesity drug race played out in dramatic fashion in 2010, with three biotech companies-Vivus, Arena, and Orexigen, each making their case for its weight-loss medication before FDA. As of this writing, Orexigen’s drug Contrave seems to be on the surest footing to approval, but longtime obesity-drug watchers know that caution seems to rule the day at FDA, so nothing is a sure bet.
Orexigen’s Contrave and Vivus’s Qnexa are both combinations of already-approved drugs, whereas Arena’s Lorqess is a completely new molecule. When C&EN covered the obesity race in 2009, it seemed that Lorqess (then going by the non-brand-name lorcaserin) had the cleanest safety profile, but Qnexa was best at helping patients lose weight.
But FDA’s panels didn’t always play out the way folks expected. There were safety surprises- notably the worries about tumors that cropped up in rats on high doses of Lorqess, and the extensive questioning about birth defect risks from one of the ingredients in Vivus’ Qnexa. The fact that FDA’s panel voted favorably for Orexigen’s Contrave, a drug that’s thought to have some cardiovascular risks, generated discussion because FDA pulled Abbott’s Meridia, a diet drug with cardiovascular risks, from the market in October.
The dust still hasn’t fully settled. Arena and Vivus received Complete Response Letters from FDA for Lorqess and Qnexa. Vivus has submitted additional documentation and a followup FDA meeting on Qnexa is happening in January. Also to come in January is the agency’s formal decision on Contrave. And if you’re interested in learning about the next wave of obesity drugs coming up in clinical trials, read this story in Nature News.
3. Sanofi & Genzyme: The Neverending Story
Speaking of drama, Sanofi’s pursuit of Genzyme has been in the headlines for months now, and promises to stretch well into 2011. The story goes something like this: Genzyme had a tumultuous year, as it struggled to correct the manufacturing issues that created product shortages and eventually led to a consent decree with FDA. In walked Sanofi, who offered—in a friendly way—to buy the company for $18.5 billion. Genzyme refused to consider what it viewed as a lowball offer. Weeks passed, they remained far apart on price with no signs of anyone budging, until Sanofi finally went hostile. Genzyme suggested it would be open to an option-based deal, which would provide more money later on if its multiple sclerosis drug candidate alemtuzumab reached certain milestones. Sanofi stuck to its $18.5 billion guns and is now trying to extend the time period to convince shareholders to consider its offer.
4. Final Stretch in HCV Race
This year, the industry finally got a peek at late-stage data for what are likely be the first drugs approved for Hepatitis C in more than two decades. Based on Phase III data, analysts think Vertex’s telaprevir will have an edge over Merck’s boceprevir once the drugs hit the market. Meanwhile, the next generation of HCV drugs had a bumpier year, with several setbacks in the clinic. Still, the flood of development in HCV has everyone hoping that eventually people with HCV can take a cocktail of pills, rather than the current harsh combination of interferon and ribavirin.
5. Pharma Covets Rare Diseases
Historically, research in rare diseases has been relegated to the labs of small biotechs and universities. But in 2010, big pharma firms suddenly noticed that if taken in aggregate, a pretty sizable chunk of the public—on the order of 6%–suffer from rare diseases. They also noticed that when there’s a clear genetic culprit, drug discovery is a bit more straightforward. Further, rare disease can sometimes be a gateway to approval in larger indications, making them all the more appealing. With that, Pfizer and GlaxoSmithKline both launched rare diseases units and made a series of acquisitions and licensing deals (Pfizer/FoldRx, GSK/Amicus, GSK/Isis, etc) to accelerate their move into the space. Meanwhile, Sanofi is trying to jump in with both feet through its proposed acquisition of Genzyme.
6. MS Pill Approved
Novartis gained approval in September for Gilenya, the first treatment for multiple sclerosis that is a pill rather than an injection. In even better news for people with MS, there more pills are rounding the corner towards FDA approval: Sanofi’s teriflunomide, Teva’s laquinimod, and Biogen’s BG-12. All of these drugs come with safety caveats, but the idea of new treatment options after years depending on interferons has gotten everyone in the MS field pretty excited.
7. Antibody-Drug Conjugates Prove Their Mettle
The concept of linking a powerful chemo drug to a targeted antibody, thereby creating something of a heat-seeking missile to blast tumor cells, isn’t new. But antibody-drug conjugate technology has finally matured to a point where it seems to be, well, working. Seattle Genetics presented very positive results from mid-stage studies of SGN-35 in two kinds of lymphoma. And ImmunoGen provided clear data showing its drug T-DM1 could significantly minimize side effects while taking down breast cancer.
8. Pharma Forges Further into Academia
With nearly every pharma firm paring back internal research, the focus on external partnerships has never been greater. Broad deals with universities are becoming more common, and Pfizer has arguably gone the furthest to evolve the model for working with academic partners. In May, Pfizer announced a pact with Washington University under which the academic scientists will look for new uses for Pfizer drug candidates. As part of the deal, they gain unprecedented access to detailed information on Pfizer’s compound library. And last month, Pfizer unveiled the Center of Therapeutic Innovation, a network of academic partnerships intended to bridge the “valley of death,” between early discovery work and clinical trials. The first partner is University of California, San Francisco, which scores $85 million in funding over five years, and the network will eventually be comprised of seven or eight partners, worldwide. Most notable is that Pfizer is planting a lab with a few dozen researchers adjacent to the UCSF campus to facilitate the scientific exchange.
9. Finally, New Blood Thinners
This year saw the FDA approval of a viable alternative to coumadin (aka warfarin), a 50-plus-year-old workhorse blood thinner that interacts with many foods and herbal supplements.
Boehringer’s Pradaxa (dabigatran) got a unanimous thumbs-up from an FDA panel for preventing stroke in patients with a common abnormal heart rhythm called atrial fibrillation. FDA approved the drug in October. The next new warfarin alternative to be approved could be Xarelto (rivaroxaban), which has had favorable results in recent Phase III clinical trials, as David Kroll over at Terra Sig explained. Both Xarelto and Pradaxa had already been approved for short term use outside the US.
Rivaroxaban and dabigatran work at different stages of the biochemical cascade that leads to clotting, as we illustrated here. Another drug candidate in the warfarin-alternative pipeline is BMS’s and Pfizer’s apixaban. Check out coverage of apixaban trials here and at Terra Sig. And in a separate blood-thinner class, FDA today rejected Brilinta, a possible competitor to mega-blockbuster Plavix.
10. Alzheimer’s Progress & Setbacks
Alzheimer’s disease has been a tough nut to crack, and news in 2010 has done little to dispel this reputation. This year Medivation’s Dimebon, which started life as a Russian antihistamine and showed some promise against Alzheimer’s, tanked in its first late-stage clinical trial. Later in the year, Eli Lilly halted development of semagacestat after the compound actually worsened cognition in Alzheimer’s patients. Semagacestat targeted the enzyme gamma-secretase, and the New York Times and other outlets reported the news as shaking confidence into a major hypothesis about what causes Alzheimer’s and how to treat it– the amyloid hypothesis.
But not everyone agreed with that assertion. Take Nobel Laureate Paul Greengard, who told C&EN this year (subscription link) that semagacestat’s troubles may have been due to the drug’s incomplete selectivity for gamma-secretase.
This year Greengard’s team discovered a potential way to sidestep the selectivity issue, by targeting a protein that switches on gamma-secretase and steers it away from activities that can lead to side effects. Greengard thinks the amyloid hypothesis is very much alive. But the final word on the amyloid hypothesis will come from trial results in next year and beyond, for drugs such as BMS-708163, Bristol Myers Squibb’s gamma-secretase inhibitor.
11. Avandia (Barely) Hangs On
Avandia was once the top selling diabetes medication in the world, but in 2010 long-running rumblings about the drug’s cardiovascular risks reached fever pitch. By the fall, Avandia was withdrawn from the European Union market and heavily restricted in the US.
Avandia (rosiglitazone) helps diabetics control their blood sugar levels by making cells more responsive to insulin. Widespread scrutiny of Avandia dates back to 2007, when a study led by Vioxx-whistleblower and Cleveland Clinic cardiologist Steve Nissen suggested Avandia increased the risk of heart attacks. In February 2010, a leaked government report that recommended Avandia be pulled from the market made headlines. In July, an FDA advisory panel voted on what to do about Avandia, and the results were a mixed bag, with most panel members voting either to pull the drug entirely or add severe restrictions. In the end, FDA sided with the “restrict” panelists- Avandia is still on the market, but it can only be prescribed to patients who can’t control their blood sugar with a first-line medication.
Clearly, researchers still have a lot to learn about how the drugs in Avandia’s class work. But we enjoyed reading Derek Lowe’s self-characterized rant about just how much effort has been put in so far. Among several other drugs in Avandia’s class, Rezulin (troglitazone) was pulled from the market many years ago because of adverse effects on the liver, but Actos (pioglitazone) remains on the market and appears to be safe.
12. Executive Musical Chairs
The year after a trio of mega-mergers and at a time when patent losses are piling up, drug companies shook up their management. The most notable changes came at Pfizer: First, the company abandoned its two-headed approach to R&D leadership and picked Michael Dolsten, former head of R&D at Wyeth, to lead research. Martin Mackay, Pfizer’s head of R&D, meanwhile jumped ship to lead R&D at AstraZeneca. Then, in a move that took everyone by surprise, Pfizer’s CEO Jeff Kindler suddenly stepped down and Ian Reade took over. At, Merck, president Kenneth Frazier will take over as CEO in January; Richard T. Clark will stay on as chairman of Merck’s board. And just this week, Sanofi-Aventis saidformer NIH director Elias Zerhouni would replace Marc Cluzel as head of R&D, while Merck KGaA appointed Stefan Oschmann as head of pharmaceuticals. Oschmann comes on from Merck & Co., where he was president of emerging markets.
In the biotech world, the most notable shift came in June, when George Scangos moved over from leading Exelixis totake the top job at Biogen Idec.
13. RNAi Rollercoaster
The year has been a tumultuous one for RNAi technology. Leaders in siRNA technology are experiencing growing pains as they try to turn promising science into commercialized products. Alnylam, arguably the best-known and biggest player in the RNAi arena, laid off 25% of its staff after Novartis decided not to extend its pact with Alnylam. Things only got worse when Roche announced it was exiting RNAi research, a move that hit its development partners Alnylam and Tekmira. Roche seemed to be primarily worried about delivery, an issue that is holding the field back from putting more RNAi-based therapeutics into the clinic.
But it’s not all bad news: the year brought a spate of big-ticket deals for companies developing other kinds of RNAi technology. GSK signed on to use Isis Pharmaceuticals’ antisense technology, which uses single-stranded rather than double-stranded oligonucleotides. And Sanofi entered into a pact with Regulus, the microRNA joint venture between Isis and Alnylam, worth $740 million. Further, Isis and Genzyme made some progress with mipomersen, the cholesterol drug developed using Isis’ antisense technology.
14. Revival of Interest in Cancer Metabolism
In cancer research, the old was new again in 2010, with a flurry of publications about depriving cancer cells of their energy source by taking advantage of quirks in their metabolism. That idea has been around since the 1920′s- when German biochemist Otto Warburg noticed differences in how cancer cells and normal cells deal with glucose. This year, Celgene handed over $130 million upfront for access to any cancer drugs that come out of Massachusetts biotech Agios Pharmaceuticals’ labs. One target in Agios’s crosshairs is an enzyme involved in glucose metabolism- pyruvate kinase M2. In addition to the Celgene/Agios deal, we noted that AstraZeneca and Cancer Research UK are in a three-year pact related to cancer metabolism, and the technology behind GlaxoSmithKline’s much-talked-about $720 million purchase of Sirtris has to do with depriving cells of energy.
15. More Job Cuts
Not to end this list on a sour note, but it wouldn’t be complete without acknowledging the ongoing narrative of layoffs and retooling at drug companies. This year brought brutal cuts at AstraZeneca, GSK, Bristol-Myers Squibb, and Abbott, along with the widespread and ongoing layoffs at Pfizer and Merck. Several features in C&EN looked at the impact the cuts are having on chemists:
From Blog: The Haystack
Apparently everybody in the hepatitis C race was busy over the holiday weekend, as Tuesday brought a flood of news from the sector. There was good news, bad news, and an acquisition.
Last things first: the acquisition. Bristol-Myers Squibb announced it will fork over $885 million for Zymogenetics, its partner in the development of pegylated interferon-lambda, in Phase II trials to treat hepatitis C (HCV). If you’ll recall, last year BMS paid $85 million upfront and a $20 million licensing fee for access to the drug. Under that arrangement, the Seattle-based biotech would have scored up to $430 million in milestones if the therapy actually made it to patients. Given Zymogenetics product pipeline and its one marketed product, Recothrom, the $885 million price tag doesn’t sound so outlandish.
Interferon-lambda uses the same cell-signaling pathway as interferon-alfa, one of the two cornerstones of current HCV therapy. But as we wrote earlier this year, because interferon-lambda has fewer functions in the body than interferon-alfa, it is expected to be as effective with milder side effects.
Onto the bad news: Idenix Pharmaceuticals said FDA put a clinical hold on two of its hepatitis C drugs, IDX184 and IDX320, due to liver toxicities in a small trial testing the safety of giving both drugs to healthy people. The company’s stock took a beating on the news, with shares falling by 47% to close at $3.18 yesterday. The question now is which of the molecules is causing the elevated liver enzymes. Leerink Swann analyst Howard Liang commented on the issue in a note to investors this morning: “The lack of association between the liver toxicity signals and IDX184 exposure and more extensive safety data on IDX184 would suggest us to that IDX320 is more likely the culprit than IDX184, which is the more important asset in our view.”
And the good news (part 1): Vertex Pharmaceuticals released more positive Phase III data for telaprevir, its much-anticipated protease inhibitor for HCV. The drug candidate was tested in some of the toughest patients—those who didn’t respond to or had only a partial response to the standard of care (pegylated interferon and ribavirin) or whose disease relapsed after standard of care. Vertex said 65% of those HCV patients were “cured” when adding telaprevir to the treatment regimen, compared to 17% in the control arm, which was given just the standard of care. Take a look at the company’s press release for more details on each segment of patients, but the relapsers had the most success with treatment, with a smaller portion (31%) of the folks that didn’t respond at all to interferon and ribavirin seeing complete suppression of the virus. In other words: there’s still room for at least some of the many compounds in development to treat the infection.
In other potentially good news for a biotech developing HCV drugs, Leerink Swann’s Liang also noted that Roche appears poised to start a Phase III trial for RG7128, a polymerase inhibitor discovered by Pharmasset, by the end of the year. The earlier-than-expected start to the late-stage trial would put the compound in a strong position to be the first polymerase inhibitor approved for HCV.
From Blog: The Haystack
UPDATED: Sep. 7- You can now find structures for the drug candidates disclosed at the symposium in this pdf document.
UPDATED: Aug. 24- Structure of Pfizer drug is incorrect. Will re-post shortly.
2:01:27 PM: Hello, this is Leigh Krietsch Boerner live tweeting from the First-time Disclosure of Clinical Candidate session at #acs_bsoton #acsmedi
2:02:31 PM: First up is David Millan from Pfizer #acs_boston #acsmedi
2:04:11 PM: The name of the drug is PF-03715455
2:04:32 PM: The name of the drug is PF-03715455 #acs_boston #acsmedi
2:05:51 PM: It’s used to treat chronic obstructive pulmonary disease (COPD), which affects 30 million people worldwide #acs_boston #acsmedi
2:07:41 PM: It’s a p38 inhibitor, which is expressed and activated in the lungs of COPD patients #acs_boston #acsmedi
2:33:35 PM: Structure of Pf-03715455 #acs_boston #acsmedi
2:34:39 PM: Next up is Michael Sofia from Pharmasset, Inc. #acs_boston #acsmedi
2:35:29 PM: The name of the drugs are PSI-352938 and PSI-353661 #acs_boston #acsmedi
2:36:14 PM: It’s to treat Hepatitis C, or HCV, which affects 180 million people worldwide. #acs_boston #acsmedi
2:48:51 PM: The target is NS5B-RdRP, which is part of the RNA genome of the HCV virus #acs_boston #acsmedi
3:07:11 PM: Both drugs are 2′-alpha-F, 2′-beta-C-methyl nucleoside class #acs_bsoton, #acsmedi
3:09:44 PM: PSI-352938 is in phase 1b clinical trials, PSI-353661 entering phase 1 #acs_boston #acsmedi
3:10:18 PM: Next up is Dr. Orn Almarsson #acs_boston, #acsmedi
3:11:54 PM: He is from Alkermes, which is a biotechnology company #acs_boston #acsmedi
3:13:07 PM: They are working towards treatments for reward/impulse control disorders ie substance abuse, binge eating, etc #acs_boston #acsmedi
3:14:35 PM: Target is opiod modulation #acs_boston #acsmedi
3:16:05 PM: Will discuss ALKS 33 #acs_boston #scsmedi
3:27:26 PM: Attenuates dopamine release in the NAc shell stimulated by ethanol, AMPH and cocaine #acs_boston #acsmedi
3:27:55 PM: Range from phase 1 studies to phase 2/3 #acs_boston #acsmedi
3:31:52 PM: Phase 2/3 is in alcohol dependance adaptive trial. #acs_boston #acsmedi
3:32:55 PM: Partial kappa-opiod agonist, partial delta-opiod agonist/antagonist, potent mu-opiod antagonist #acs_boston #acsmedi
3:33:53 PM: Next talk is Vincent Mascitti, discovery of nes class of SGLT2 inhibitors, from Pfizer #acs_boston #acsmedi
3:34:34 PM: Phase 2, bridged ketal series, dioxa-bicyclo[3.2.1]octane motif #acs_boston #acsmedi
3:35:19 PM: SGLT2 is sodium glucose co-transporter 2 to treat type 2 diabetes #acs_boston #acsmedi
3:37:09 PM: for review of natural product synthesis, see Washburn, W.N. J Med Chem 2009 52, 1785 #acs_boston #acsmedi
3:50:59 PM: Another paper on these molecules is V. Mascitti & C. Prville Org Lett, 2010, 12 (13), pp 2940–2943 http://bit.ly/bvdHNS #acs_boston #acsmedi
3:59:59 PM: Last talk of the session is Paul Watson from Inspire Pharmaceuticals, Inc. #acs_boston #acsmedi
4:01:01 PM: The drug is INS115644 (latrunculin B) #acs_boston #acsmedi
4:01:36 PM: It’s to treat glaucoma, which is an optic neuropathy that can cause vision loss. #acs_boston #acsmedi
4:07:54 PM: Target inhibitors of actomyosin contractilily and inhibitors of microfilament assembly #acs_boston #acsmedi
4:10:30 PM: Naturally found latrunculin B is an actin plolymerication inhibitor, found in the red sea sponge #acs_boston #acsmedi
4:11:48 PM: That is actin polymerization inhibitor…#acs_boston #acsmedi
4:23:49 PM: Drug has gone through phase 1 clinical trials for proof of concept. #acs_boston #acsmedi
4:28:32 PM: That concludes the session.