Hier ein Artikel zum Potential und den Entwicklungen des AK-Marktes insgesamt, sowie zur zunehmenden Wettbewerbssituation und Tendenzen:
Nature Biotechnology 25, 1194 - 1195 (2007)
doi:10.1038/nbt1107-1194
Antibodies' long revenue stream spurs pharma acquisitions
Peter Mitchell1
London
Introduction
MedImmune
MedImmune, bought by AstraZeneca for $15.6 billion, is just one of several firms with antibody capabilities that has caught pharma's eye.
New York–based Bristol-Myers Squibb's $415 million buyout of Waltham, Massachusetts–based Adnexus in September; the purchase in October of Aberdeen, UK–based Haptogen by Wyeth, of Madison, New Jersey; and Paris-based Sanofi Aventis' alleged interest in New York–based ImClone serve as reminders that big pharma is still looking to restock depleted pipelines through biotech acquisition. But the acquisition craze has also been fueled in part by the considerable attributes that set antibodies apart from small molecules, and even other protein drugs.
To start with, antibodies have shorter development times, which make them ideal for pharma's current plight, but they also are "the most versatile of the protein therapeutics, and they now have a good track record of coming through clinical studies," says Janice Reichert, senior research fellow at the Tuft University Center for the Study of Drug Development in Boston. The high cost of producing them can be recovered somewhat in their established high prices, and they "also have good acceptance on the markets."
Adding to this, a recent Tufts analysis showed that monoclonal antibodies (mAbs) tend to do better than small molecules in clinical trials. The study highlighted that in cancer, for example, about 14% of humanized mAbs between 1990 to present day successfully came through trials, compared to only 10% for small molecules. "Antibodies are usually studied for one particular biological action, while small molecules tend to be studied in a broader variety of indications," Reichert says. "So not only is there more risk of side effects with small molecules, but the cost of the studies tends to be higher, too."
The role of mAbs in oncology is another key attraction for pharma, says Christian Rohlff, CEO of antibody startup Oxford Genome Sciences in Oxford, UK. As major franchises such as lipid-lowering drugs come under attack from generic competition, big pharma is starting to focus strongly on oncology, he says. They hope to emulate the success of blockbusters like Herceptin (trastuzumab) and Avastin (bevacizumab). "In the last 18 months, everyone has concluded that this is the big market of the near-term future," Rohlff says, adding that if a company doesn't have a strong franchise in that space, "antibodies are the quickest and most direct way to move in."
Moreover, biotech consultant David Glover in Cambridge, UK, says mAbs are likely to be first to market against many types of targets, especially cell surface proteins. "Once that has happened, the competition tends to be very slow in coming along with non-antibody products," he notes. For example, there isn't a small-molecule anti-TNF [tumor necrosis factor] inhibitor yet.
But perhaps the main reason behind pharma's interest in antibodies (Table 1) is their current long market life. Once a mAb is approved it can generate cash for decades, unchallenged by me-too copies. "Of all the therapeutic proteins you could make a generic copy of, mAbs are right at the bottom of the list," says Glover. He notes it is relatively easy to create generic copies of simple peptide hormones, such as human growth hormone and insulin. But the complexity of mAbs is such that minor changes in glycosylation or amino acid sequence can greatly affect the molecule's potency and immunogenicity, even the epitope it recognizes—and thus change its safety profile. "That means most of the development—safety checks like the cross-reactivity profile—would need to be repeated for follow-on biologicals," says Glover, formerly medical director for Cambridge Antibody Technology, recently acquired by AstraZeneca, of London.
Table 1: Select pharma purchases of antibody firms in 2007
Full table
That need to retest—combined with the high unit production cost of antibodies—suggests that the price differential between first-to-market mAbs and follow-ons will not be as large as that between small-molecule drugs and generic copies. "Follow-on biologicals are likely to be only about 30% discounted below the price of the first to market," says Tim Race, biotech analyst at ING Wholesale Banking in London. "So, while revenues from small molecule drugs tend to drop off a cliff when the US patent expires, for biologicals it is more likely to show a steady decline."
There doesn't seem to be anything on the near horizon to change this either. "No one in the US at the moment is discussing anything like generic versions of antibodies," says Tufts' Reichert. "It just wouldn't fly, because the biotech and pharma firms will all argue that they are too complex to be made in a follow-on fashion." Moreover, a proposed new FDA regulatory regime for follow-on biologics was dropped from the recently reauthorized Prescription Drug User Fees Act legislation, pushing possible US follow-ons even further in to the future. (See page 1189.)
But the uniqueness of mAbs won't entirely protect first-in-class products from competition, cautions Glover. It might undermine their value even more than a pure generic copy would. "Rival pharma companies will try to make a better antibody aimed at the same target—a me-better product rather than a me-too one," he predicts. That trend is in fact already underway, he says: the first anti-TNF product to market was the chimeric antibody Remicade (infliximab), followed by the human antibody Humira (adalimumab). Similarly, the chimeric anti-epidermal growth factor antibody Erbitux (cetuximab) is coming under challenge from the human antibody panitumumab, developed by Amgen, of Thousand Oaks, California. "There are many companies making anti-TNF monoclonals at the moment, hoping to make them more potent than the early entrants," says Glover. "The original manufacturer will still be protected to some extent, but the newer antibodies are likely to be much more useful, and so they will take away market share."
Even so, there are ways for manufacturers of first-generation brands to fight back. "First-to-market antibody manufacturers will try to stay ahead by developing differentiated second-generation versions of their successful brands," says Jo Collet, of consultancy Propagate in Richmond, UK. She points to the emergence of technologies such as domain antibodies, which could generate variant products for inhaled, topical or oral delivery rather than injection.
Pharma companies watching this space might do well to study the European scene, says ING's Tim Race. He notes alternative versions of erythropoietin are just beginning to appear in Europe from Sandoz, of Holzkirchen, Germany; Shire, of Hampshire, UK; and others to challenge Johnson & Johnson's Procrit (epoetin alfa), whereas Novartis in 2006 won approval for its human growth hormone Omnitrope (somatropin). The fate of these first biosimilars could lay down a pattern for follow-on antibodies, if and when they finally arrive.
Table 1. Select pharma purchases of antibody firms in 2007
Figures and tables index
Biotech Pharma Date Amount Main platform
Source: BioWorld, BioCentury
Domantis (Cambridge, UK) GlaxoSmithKline (London) Acquisition closed Jan. 8, 2007 £230 ($454) million Domain Antibodies (dAbs), designed to have benefits of both small molecules and conventional antibodies
Therapeutic Human Polyclonals (Sunnyvale, California) Roche (Basel) Acquisition closed April 2, 2007 $56.5 million A transgenic mammalian platform designed to generate both mAb and polyclonal antibodies with enhanced efficacy
Abmaxis (Santa Clara, California) Merck (Whitehouse Station, New Jersey) Acquisition closed May 9, 2007 $80 million Antibody engineering technology called Abmaxis In-Silico Immunization (AISIM)
MedImmune (Gaithersburg, Maryland) AstraZeneca (London) Acquisition closed June 19, 2007 $15.6 billion Buyout includes MedImmune's approved mAb Synagis (palivizumab)
Haptogen (Aberdeen, UK) Wyeth (Madison, New Jersey) Acquisition disclosed Oct. 5, 2007 Not disclosed Haptomics technology, designed to overcome the challenge of raising antibodies to haptenic structures
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Danke bestoff für den Artikel. Der hat ihn bei WO ausgegraben.
Liest sich doch sehr aussichtsreich für den AK-Markt des nächsten Jahrzehnts. Und da ist Morphosys voll am mitmischen.
Insbesondere die Ausführungen zum Entwicklungs-Thema Biosimilars fand ich wie zugeschnitten auf Morphosys.
Statt me-too mABs werden me-better mABs entwickelt. Als Schlagwort ganz brauchbar, vor allem weil sich me-too mABs kaum kostengünstiger erstellen lassen wie das zugelassene Orignal und die ganzen Toxi-Studien komplett durchlaufen müssen.
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