Theralizumab: Difference between revisions

| verifiedrevid = 447552879

| tradename =

| pregnancy_category = N/A

| legal_status = never marketed

<!--Chemical data-->

| C= | H= | N= | O= | S=

| molecular_weight = ~148 [[kDa]]

'''TGN1412''' (also known as '''CD28-SuperMAB''') is the working name of an [[immunomodulator]]y drug which was withdrawn from development after inducing severe inflammatory reactions in the first human subjects to receive the drug.

| date = 2006-02-20

| accessdate = 2006-03-16

|archiveurl = http://web.archive.org/web/20060412052458/http://www.tegenero.com/research__development/drug_development/index.php <!-- Bot retrieved archive --> |archivedate = 12 April 2006}}</ref> it is a [[humanized antibody|humanised monoclonal antibody]] that not only binds to, but is a strong [[agonist]] for, the [[CD28]] receptor of the [[immune system]]'s [[T cell]]s.<ref name="Lin2004">{{Cite journal

| author = Chia-Huey Lin, Thomas Kerkau, Christine Guntermann, Martin Trischler, Niklas Beyersdorf, Yvonne Scheuring, Hans-Peter Tony, Christian Kneitz, Martin Wilhelm, Peter Mueller, Thomas Huenig, Thomas Hanke

| date = 2004-11-16

| title = Superagonistic Anti-CD28 Antibody TGN1412 as a Potential Immunotherapeutic for the Treatment of B Cell Chronic Lymphocytic Leukemia

| journal = [[Blood (journal)|Blood]] (ASH Annual Meeting Abstracts)

| volume = 104

| issue = 11

| pages = Abstract 2519

| id =

| url = http://meeting.bloodjournal.org/cgi/content/abstract/104/11/2519

}}</ref> CD28 is the co-receptor for the T cell receptor; It binds to receptors on the interacting partner in the reaction through one of its ligands (B7 family).

In its first human [[clinical trial]]s in March 2006, it caused catastrophic systemic organ failure in the subjects, despite being administered at a supposed sub-clinical dose of 0.1&nbsp;mg per kg; some 500 times lower than the dose found safe in animals.<ref name="NewScientist2006-08-17">{{Cite news

| url = http://www.newscientist.com/article.ns?id=dn9734

| title= Mystery over drug trial debacle deepens

| author=Andy Coghlan

| work = New Scientist

| date= 2006-08-14

| accessdate=2006-08-14

}}</ref> Six volunteers were hospitalized on 13 March 2006, at least four of these suffering from [[multiple organ dysfunction syndrome|multiple organ dysfunction]], and one trial volunteer is said to show signs of developing [[cancer]].<ref name="DaiyMail2008-08-07">{{Cite news

| url = http://www.dailymail.co.uk/news/article-399350/Elephant-man-drug-trial-victim-cancer.html

| title= 'Elephant man' drug trial victim has cancer

| author= Tahira Yaqoob

| work = Daily Mail

| date= 2006-08-07

| accessdate=2010-10-02

}}</ref>

The developing company, [[TeGenero|TeGenero Immuno Therapeutics]], entered into [[insolvency]] proceedings later in 2006. Tentative opinions from an as-yet uncompleted inquiry suggest that the problems resulted from "unforeseen biological action in humans", rather than breach of trial protocols, and the case therefore has had important ramifications for future trials of potentially powerful clinical agents.

Scientists in early 2007 put forth the theory that the drug acted in a different fashion in humans as compared with the laboratory animals in which the drug was first tried. The severe reactions in humans could have only occurred, they believe, in animals with [[Memory T cell|memory T lymphocytes]]. Animals raised in a sterile lab would presumably have no 'memory' of previous illnesses, thus would not exhibit the severe reactions that occurred in the human subjects.<ref>{{Cite news| url=http://www.telegraph.co.uk/news/uknews/1540591/Study-claims-to-solve-drug-trial-mystery.html | work=The Daily Telegraph | location=London | title=Study claims to solve drug trial mystery | first1=Nic | last1=Fleming | date=2008-04-12 | accessdate=2010-05-25}}</ref> However this is a misunderstanding of the research: the research says that non-human animals studied have fewer memory T cells than humans, and that stimulation through the CD28 receptor alone in memory T cells causes them to infiltrate organs and also activates them. <ref name=mirenda>{{cite journal|last=Mirenda|first=Vincenzo|coauthors=et al|url=http://bloodjournal.hematologylibrary.org/cgi/content/full/109/7/2968||title=Physiologic and aberrant regulation of memory T-cell trafficking by the costimulatory molecule CD28|journal=Blood|date=1|year=2007|month=April|volume=109|issue=7|pages=2968–2977|doi=10.1182/blood-2006-10-050724}}</ref> In conjunction with the probable differences between the animal CD28 and the human CD28 protein sequence, and the fact that the antibody had been 'humanized' so as to be ignored by the human immune system which may not be similarly applicable in the experimental animal systems, one would expect differences in response. The surprise to the authorities and the firm was perhaps, ironically, that the drug was too powerful, and by starting with a dose regime based on animal studies rather than employing a more 'homeopathic' regime, they brought the industry into disrepute.

The drug, which was designated as an [[orphan drug|orphan medical product]] by the [[European Medicines Agency]] in March 2005, was developed by [[TeGenero|TeGenero Immuno Therapeutics]], tested by [[Parexel]] and manufactured by [[Boehringer-Ingelheim]].<ref name="TeGenero2005-03-13">{{cite press release

| publisher = TeGenero

| date = 2005-03-13

| title = TeGenero AG receives EU-orphan drug designation for Humanized Agonistic Anti-CD28 Monoclonal Antibody TGN1412 for the treatment of B-cell Chronic Lymphocytic Leukaemia, B-CLL

| url = http://www.tegenero.com/documents/pr_tegenero_march_11_2005.pdf

|format=PDF}}</ref><ref name="TeGenero2003-11-17">

{{cite press release

| publisher = TeGenero

| date = 2003-11-17

| title = Boehringer Ingelheim and TeGenero sign agreement to develop and manufacture CD28-SuperMAB

| url = http://www.tegenero.com/documents/2003_11_tg005_pressrelease_e.pdf

|format=PDF}}</ref> TeGenero announced the first elucidation of the molecular structure of CD28 almost exactly one year prior to commencement of the TGN1412 phase I clinical trial.

==Description of the drug==

Mice of the inbred strain BALB/c were immunized with recombinant human CD28-Fc fusion proteins and boosted with a B lymphoma cell line transfected to express human CD28. Hybridomas were obtained by fusing B cells with the hybridoma partner X63Ag8.653 and screened for reactivity with human CD28 and TCR-independent mitogenic activity. Two monoclonals called 5.11A1 and 9D7 were identified. The more active of the two, 5.11A1, is a mouse IgG1 immunoglobulin. The [[complementarity determining region]]s of 5.11A1 were cloned into the framework of human IgG and combined with IgG1 (TGN1112) or IgG4 (TGN1412) constant regions. According to the company's Investigator Brochure, "TGN1412 is a humanised monoclonal antibody directed against the human CD28 antigen. The molecule was genetically engineered by transfer of the complementarity determining regions (CDRs) from heavy and light chain variable region sequences of a monoclonal mouse anti-humanC28 [sic] antibody (5.11A1, Luhder et al., 2003) into human heavy and light chain variable frameworks. Humanised variable regions were subsequently recombined with a human gene coding for the IgG4 gamma chain and with a human gene coding for a human kappa chain, respectively."<ref>[http://www.circare.org/foia5/tgn1412investigatorbrochure.pdf Investigator's Brochure], Circare.org, 19 December 2005</ref> The recombinant genes were transfected into [[Chinese hamster ovary cell]]s and the recombinant antibody harvested from culture supernatant.

==Mechanism of action==

[[Image:T cell activation.png|thumb|right|250px|T lymphocyte activation pathway is triggered when a T cell encounters its cognate antigen, coupled to an MHC molecule, on the surface of an infected cell or a phagocyte.]]

[[T cell#Activation|Activation of T cells]] normally requires both engagement of the [[T cell receptor|antigen receptor]] (signal 1) and [[co-stimulation]] (signal 2). Studies of monoclonal antibodies specific for mouse, rat, or human CD28 identified so-called "superagonistic" antibodies that could stimulate T cells without concurrent antigen-receptor stimulation (signal 1). Whether this activity represents a stronger activity or a different activity is uncertain. Two antibodies specific for human CD28 were identified. The more active of the two, TGN1112 (originally called 5.11A1), belonged to the IgG1 class of immunoglobulins. The other, TGN1412 (clone 9D7), belonged to the IgG4 class. The TCR-independent agonism of these antibodies involved binding to a specific part of the CD28 molecule called the C"D loop.<ref name="Luhder2003">{{Cite journal| author=Luhder F, Huang Y, Dennehy KM, Guntermann C, Muller I, Winkler E, Kerkau T, Ikemizu S, Davis SJ, Hanke T, Hunig T | title=Topological requirements and signaling properties of T cell-activating, anti-CD28 antibody superagonists | journal=J Exp Med | year=2003 | pages=955&ndash;66 | volume=197 | issue=8 | pmid=12707299 | doi=10.1084/jem.20021024 | pmc=2193880}}</ref> It was initially hypothesized that an antibody with this property could be therapeutically useful in stimulating the immune system in [[Immunosuppression|immunosuppressed]] patients. However, ''[[in vitro]]'' and ''[[in vivo]]'' data from animal studies later suggested that administration would lead to preferential activation of [[regulatory T cell]]s, leading to a net effect of T-cell downregulation. On its website, the company writes: "A pronounced T-cell activation and expansion mediated by CD28-SuperMAB in animal models is accompanied by the expression of anti-inflammatory [[cytokine]]s, like IL-10, rather than by the toxic [[cytokine storm]] of pro-inflammatory mediators induced by other agents that address the TCR complex.".<ref name="TeGenero2006-02-20"/> As it turned out, the results of the first trial in humans indicate that this may not always be the case.

A new explanation for the trial mishap was suggested by the findings of a recent paper in ''Clinical Immunology''. Pillai ''et al.'' found that all T cells that get activated using conventional TCR-mediated stimulation become regulatory for a brief time and express FOXP3. However, eventually most of these cells downregulate their regulatory capabilities and become [[effector cell]]s. Thus, attempts to induce FOXP3+ T cells might also induce effector cells capable of causing tissue damage.<ref>[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WCJ-4MM263D-1&_user=10&_coverDate=12%2F19%2F2006&_rdoc=4&_fmt=summary&_orig=browse&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=19d1b0be21ad54a180b27aed7de22cff "Transient regulatory T-cells: A state attained by all activated human T-cells"], ScienceDirect.com, 19 December 2006</ref>

Other cells activated by CD28 ligation in humans are [[eosinophil granulocyte]]s. They can release IFN-γ, IL-2, IL-4, and IL-13.<ref>[http://www.jem.org/cgi/content/full/190/4/487 "Expression of CD28 and CD86 by Human Eosinophils and Role in the Secretion of Type 1 Cytokines (Interleukin 2 and Interferon {gamma}): Inhibition by Immunoglobulin A Complexes"], JEM, Volume 190, Number 4, 16 August 1999</ref><ref>[http://www.jleukbio.org/cgi/content/abstract/72/4/769 "Human eosinophils express and release IL-13 following CD28-dependent activation"], Gaetane Woerly, Paige Lacy, Amena Ben Younes, Nadine Roger, Sylvie Loiseau, Redwan Moqbel and Monique Capron, Journal of Leukocyte Biology, 2002</ref> However, most ''in vitro'' experiments are limited to the use of purified peripheral blood mononuclear cells (PBMN's) that do not contain those cells.

To function as an agonist, it has been suggested that TGN1412 needs to be a whole [[antibody]], including the constant (Fc) region. According to a report by TeGenero, the F(ab)2 is not able to generate the required stimulation.<ref>[http://www.mhra.gov.uk/home/idcplg?IdcService=GET_FILE&dDocName=CON2023519&RevisionSelectionMethod=LatestReleased "Investigations into adverse incidents during clinical trials of TGN1412"], MHRA Interim report]</ref> Unlike the related clone TGN1112, an IgG1, TGN1412 is of the subclass IgG4. This choice was made as TGN1112 showed antibody-dependent cellular cytotoxicity on CD28+ Jurkat cells. Thus the function of antibody binding via an Fcγ receptor seems to be a requirement for the immune regulation. However, cell [[opsonisation]] by antibody leads normally to [[phagocytosis]] of the labeled cells, as seen in the case of [[HIV]].<ref>[http://www.blackwell-synergy.com/doi/abs/10.1046/j.1365-2249.1999.00848.x "CD4 depletion in HIV-infected haemophilia patients is associated with rapid clearance of immune complex-coated CD4+ lymphocytes"], DANIEL, MELK, SÜSAL, WEIMER, ZIMMERMANN, HUTH-KÜHNE, OPELZ, ''Clinical & Experimental Immunology'', Volume 115, Issue 3, Page 477 - March 1999</ref>

==Clinical trials==

Phase I [[clinical trial]]s were conducted by Parexel at an independent clinical trials unit in leased space on the premises of [[Northwick Park and St. Mark's Hospital]], [[London]], on 13 March 2006.<ref name="Parexel2005-03-15">{{cite press release

| date = 2006-03-13

}}</ref><ref name="njem">Suntharalingam G, Perry MR, Ward S, et al., [http://content.nejm.org/cgi/content/full/355/10/1018 Cytokine Storm in a Phase 1 Trial of the Anti-CD28 Monoclonal Antibody TGN1412], ''[[New England Journal of Medicine]]'' 7 September 2006, vol.355, p.1018&ndash;1028.</ref> Parexel is a company that carries out drug trials on behalf of pharmaceutical and biotechnology companies. Healthy volunteers were recruited to the study with a £2,000 fee, reportedly much higher than the 'few hundred quid' offered for other medical tests in the region.<ref name="DailyMail2006-03-20">{{Cite news

| url=http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=380395&in_page_id=1770

| title=Elephant Man couldn't resist drug test money

| author=Rebecca English

| work=Daily Mail

| date=2006-03-20

| accessdate=2006-03-21

}}</ref> The trial resulted in hospitalization of all six volunteers administered the drug, at least four of whom suffered [[Multiple organ dysfunction syndrome|multiple organ dysfunction]].<ref name="BBC2006-03-18">{{Cite news

| date=2006-03-18

| accessdate=2006-03-18

}}</ref>

The payment was seized upon by newspapers and reported in a sensationalist fashion.{{Citation needed|date=April 2010}} Good Clinical Practice (GCP) prohibits payments being made to Phase I trial volunteers on the basis of risk, and specifies that payments must be based upon the amount of time given up and the number of invasive procedures (e.g. blood sampling). For most trials, payments are in the range of around £1,000 per week - but the 'few hundred quid' trials mentioned above are those which the general public are most familiar with (since they only last a day or two, do not require working individuals to take time off work, and hence are more common).{{Citation needed|date=August 2011}}

The trial was a double-blind, randomized, [[placebo-controlled studies|placebo-controlled study]], with two of the eight subjects receiving a [[placebo]], and six receiving 1/500th of the highest dose used in previous experiments with [[Crab-eating Macaque|cynomolgus macaques]]. All six of the trial subjects who received the drug were male, aged 19 to 34 (median 29.5); none had a notable medical history, and all were well in the 2 weeks before the trial.<ref name="njem"/> The drug was given by intravenous infusion, starting at 8am, with an interval of around 10 minutes between patients, and each infusion lasting from 3 to 6 minutes.<ref name="njem"/> Roughly five minutes after the last participant had received his dose, the participant who had received the first dose complained of headache, and soon afterwards fever and pain. He took his shirt off, complaining that he felt like he was burning. Shortly after, the remaining participants who received the actual drug also became ill, vomiting and complaining of severe pain. The first patient was transferred to the Northwick Park hospital's intensive care unit 12 hours after infusion, with the others following within the next 4 hours.<ref name="njem"/> A severely affected volunteer, Mohammed Abdalla, a 28-year old who said he had hoped to set his brother up in business in Egypt, was described as having suffered a ballooned head. This led to his description as being similar to the "[[Joseph Merrick|Elephant Man]]".

All of the men were reported to have experienced [[cytokine release syndrome]] resulting in [[angioedema]], swelling of [[skin]] and [[mucous membrane]]s, akin to the effects of the complement cascade in severe allergic reaction. The patients were treated with [[corticosteroid]]s to reduce inflammation, and [[Plasmapheresis|plasma-exchange]] to attempt to remove TGN1412 from their circulation. The treating doctors confirmed in August 2006 that all six men had suffered from a [[cytokine storm]], and that, paradoxically, the men's white blood cells had vanished almost completely several hours after administration of TGN1412.<ref name="NewScientist2006-08-17"/>

According to a press release from 5 July 2006 on the North West London Hospitals NHS Trust website, where the men were treated, the patients continued to improve and "five of them went home within a month of the incident, while one patient remained in hospital until 26 June, when he also went home."<ref>[http://www.nwlh.nhs.uk/news/item.cfm?id=97 Press releases by North West London Hospitals NHS Trust], 5 July 2006</ref> However, Head of pharmacology at University College London Trevor Smart has suggested that the men may never fully recover, and may suffer long-term disruption to their immune systems.<ref name="DailyMail2006-03-20"/>

An article by ''[[The Sunday Times (UK)|The Sunday Times]]'' on 30 July 2006 reported lawyers' claims that the long-term damage to the patients may be worse than originally thought. Medical assessment by immunologist Professor Richard Powell were said to have revealed that the blood of the patients contained a low number of regulatory T-cells, below one percent compared to three to five percent for healthy male adults - although the clinical significance of any such finding are unknown. Powell also reportedly claimed that one of the patients has "definite early signs that a lymphoid malignancy is developing". Some of the men involved in the trial are said to have been told that they face "a lifetime of contracting cancers and all the various auto-immune diseases from [[Lupus erythematosus|lupus]] to [[Multiple sclerosis|MS]], from [[rheumatoid arthritis]] to [[Chronic fatigue syndrome|ME]]."<ref>[http://www.timesonline.co.uk/article/0,,2087-2291774,00.html Elephant Man drug victims told to expect early death], ''The Sunday Times'', 30 July 2006</ref>

TGN1412 had not previously been given to humans; however, the trial was preceded by animal testing, including in [[Primate|non-human primates]]. The company claims that these did not indicate any safety issues. The US patent application states "it could be shown in a pilot study that an [[in vitro]] administration of anti-human CD28-SuperMAB induces in a rhesus monkey [[in vivo]] a profound activation of T cells, without clinically visible side effects" and goes on to say "This antibody—in spite of its strong T cell-stimulatory properties—is very well tolerated in vivo, in contrast to all other known [[T cell]] activating substances."<ref name="USpatent">United States patent application US20060009382 filed by Thomas Hanke, Chia-Huey Lin</ref>

[[Image:CD28 structure.gif|thumb|right|250px|Structure of human CD28.]]

[[TeGenero]] has apologized to the families involved, insists that these effects were completely unexpected, and said that all protocols have been followed. An investigation by the UK drug regulator reported that the reaction was not due to contamination of the dose, or an incorrect dose being administered, but suggested that the problem was due to "on target" effects of the drug. Criticism has been raised that six participants were given the drug in such a short time, which is against the recommendations of standard literature. However, the [[Medicines and Healthcare products Regulatory Agency]] (MHRA) has confirmed that they had approved the trial, including the protocol of giving the dose to all men within a short time. It appears the MHRA approved a protocol involving the doses being administrated between 8.00h-10.00h (i.e., 2 hours). One of the placebo-receiving participants has explained the doses were given with 2-minute intervals. Even though the participants were dosed with short intervals, this is not a deviation from the approved protocol.

The MHRA has further stated that the initial dose of TGN1412 was intended to be the first of a course of injections, with the dosage being ramped up over time. It has been reported that the initial dose was one five-hundredth of that which the animal studies indicated was a maximum safe dose.<ref name="ft2006-03-16">{{Cite news

| title=Data for botched drugs trial show ‘nothing’ amiss

| author=Lisa Urquhart and Andrew Jack

| work=Financial Times

| date=2006-03-16

| accessdate=2006-03-17

| url=http://news.ft.com/cms/s/0a2ebf2a-b529-11da-aa90-0000779e2340.html

}}</ref> Dr. David Glover, an industry consultant, has suggested that because the antibody was raised against ''human'' CD28, the safe dosage may have been lower in humans than in animals.<ref name="Reuters2006-03-19">{{Cite news

| title=Protein differences may explain drug reaction

| author=Patricia Reaney

| work=Reuters

| date=2006-03-19

| accessdate=2006-03-19

| url=http://today.reuters.co.uk/news/newsArticle.aspx?type=topNews&storyID=2006-03-19T143944Z_01_L19788458_RTRUKOC_0_UK-BRITAIN-TRIAL-EXPERT.xml&archived=False}}</ref>

==Criticism and controversy==

Not much information has been released to the public about the ongoing investigations. At the moment, there appear to be two issues. There is the issue of the trial protocol of giving the drug to six participants within a short time. While this was approved by the MHRA, as mentioned earlier, it seems a two hour protocol was approved, but that the drug was administered to all participants within just twenty minutes, based on the statement of a study participant. It appears that neither the companies involved nor the authorities have commented on this point yet.

Another issue is whether the company should have known the drug would provoke this reaction in humans. The comments on the company webpage and in the patent application at least indicate the company knew this type of drug could cause a [[cytokine storm]]. An immunologist contacted by ''[[New Scientist]]'' and who wished to be anonymous has commented that “You don’t need to be a rocket scientist to work out what will happen if you non-specifically activate every T cell in the body.”<ref name="newscientist20060317">{{Cite news

| url=http://www.newscientist.com/article/dn8863-catastrophic-immune-response-may-have-caused-drug-trial-horror.html

| title=Catastrophic immune response may have caused drug trial horror

| author=Shaoni Bhattacharya and Andy Coghlan

| work=New Scientist

| date=2006-03-17

| accessdate=2006-03-19

}}</ref>

While the drug had appeared to be safe in animal models, researchers have noted that there are reasons why these may not be indicative of the response in humans, particularly with respect to this type of drug.<ref name="telegraph20060317">{{Cite news

| url=http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2006/03/17/ntrial117.xml&sSheet=/news/2006/03/17/ixhome.html

| title= Antibody 'puts immune system in overdrive'

| author= Celia Hall

| work=Telegraph

| date=2006-03-17

| accessdate=2006-03-19

| location=London

}}</ref> The BBC reported that “two of 20 monkeys used in earlier tests suffered an increase in the size of [[lymph node]]s,” but that “this information was given to the men and submitted to the test regulators.”<ref name="bbc20060320">{{Cite news

| url=http://news.bbc.co.uk/1/hi/england/london/4823992.stm

| title=Trial drug affected animal glands

| work=BBC News

| date=2006-03-20

| accessdate=2006-03-20

}}</ref> TeGenero say this was transient and was evidence of the extra T cells that the drug produces.<ref name="tegenero20060319">{{Cite web

| work=TeGenero

| date=2006-03-19

| accessdate=2006-03-20

|archiveurl = http://web.archive.org/web/20060521150601/http://www.tegenero.com/news/faqs_re_tgn1412/index.php <!-- Bot retrieved archive --> |archivedate = 21 May 2006}}</ref> Experiments with another drug affecting the CD28 receptor (but to a lesser extent than TGN1412) had also shown side effects in human trials.<ref name="nature20060317">{{Cite news

| url=http://www.nature.com/news/2006/060313/full/060313-17.html

| title=Tragic drug trial spotlights potent molecule

| author=Helen Pearson

| work=Nature

| date=2006-03-17

| accessdate=2006-03-19

}}</ref> There have been criticisms that the risks taken and the design of the protocol were insufficiently justified by proper [[statistics|statistical evidence]].<ref name="rss2007">{{Cite journal

| journal=Journal of the Royal Statistical Society

| volume=170A

| pages=517&ndash;579

| author=Working Party on Statistical Issues in First-in-Man Studies

| year=2007

| title=Statistical issues in first-in-man studies

}}</ref>

==The MHRA's views==

On 5 April 2006, the Medicines and Healthcare Products Regulatory Agency issued an interim report on the TGN1412 trial.<ref name="MHRA20060405">{{Cite news

| url=http://www.mhra.gov.uk/NewsCentre/Pressreleases/CON2023515

| title=Press release: Latest findings on clinical trial suspension

| author=MHRA

| work=Press Release

| date=2006-04-05

| accessdate=2010-06-04

}}</ref> They found no deficiencies in TeGenero’s pre-clinical work; there was no evidence of undisclosed studies. Parexel’s records and processes appeared in order (including dose measurement and administration) and the MHRA felt that their actions did not contribute to the serious adverse events, nor were there any deficiencies in the animal work; results accurately reflected the raw data.

German regulatory authorities inspected the production of the material by Boehringer Ingelheim, looking at the manufacture, testing, storage and distribution of the TGN1412. No deficiencies were identified which could have contributed to the serious adverse effects. Although tests are ongoing on the actual material used, the MHRA state that tests are consistent with the TGN1412 being up to specification at the moment.

The MHRA have concluded that the most likely cause of the reaction in trial subjects was an unpredicted biological action of the drug in humans. The interim report recognises that important scientific and medical questions about the risks of testing these agents in human subjects have been raised. To that end, the UK Secretary of State for Health has agreed to establish a group of leading international experts to consider those issues and to provide a report on the future authorisation of such trials (with an interim report at three months).

Until the expert group has reported, all further clinical trial applications involving first-in-humans trials of any monoclonal antibody or other novel molecules targeting the immune system will not be authorised in the UK, without having had additional expert opinion on whether the effects seen in the TGN1412 may be repeated. There will be a fuller report on the TGN1412 trial in future, but the expert group will run concurrently.

{{col-begin}}

{{col-break}}

* [[CD28]]

* [[First-in-man study]]

{{col-break}}

{{col-end}}

<!--This section uses the Cite.php citation mechanism. If you would like more information on how to add references to this article, please see http://meta.wikimedia.org/wiki/Cite/Cite.php -->

{{Reflist|2}}

* Patent applications for TGN1412

** [http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=US2006009382&F=0&QPN=US2006009382&RPN=US2006009382&DOC=dcb66f26dd9a5108c88241fac27a21f198 U.S. patent application US2006009382]

** [http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=US2006009382&F=0&QPN=EP1600164&RPN=EP1600164&DOC=cca34af198500dc47b33f0ab732cd3a34a European patent application EP1600164]

** [http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=DE10345008&F=8&QPN=DE10345008 German patent application DE10345008]

* [http://dx.doi.org/10.1038/440855a Report in <strong>Nature</strong> on TGN1412]

* [http://news.bbc.co.uk/1/hi/health/4914546.stm <strong>BBC News</strong>: Drug trial man 'may lose fingers']

* [http://news.bbc.co.uk/1/hi/health/5015224.stm <strong>BBC News</strong>: Regulators slam drug trial firm]

* [http://rosettapr.com/perspectives.php crisis communications case study of Tegenero clinical trial]

{{Monoclonals for immune system}}

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