Tositumomab

Source: Wikipedia, the free encyclopedia.
Tositumomab
Monoclonal antibody
TypeWhole antibody
SourceMouse
TargetCD20
Clinical data
Trade namesBexxar
AHFS/Drugs.comMonograph
MedlinePlusa609013
ATC code
Identifiers
CAS Number
DrugBank
ChemSpider
  • none
UNII
KEGG
ChEMBL
Chemical and physical data
FormulaC6416H9874N1688O1987S44
Molar mass143860.04 g·mol−1
 ☒NcheckY (what is this?)  (verify)

Tositumomab is a

IgG2a lambda antibody.[1][2]

The drug combination was developed by

Zevalin,[5] until the former's discontinuation in 2014.[6]

Clinical use

A personalized regimen using Bexxar was approved for the treatment of relapsed or

The radioactive dose was adjusted for each patient in order to maximize the radiation delivered to the tumor and minimize the exposure of other organs.

covalently bonded to 131I) tositumomab. A first dose of labelled antibody was given once, and whole-body radiation was measured with a gamma camera over seven days. Analysis of that imaging data allowed an optimal dose of labelled antibody to be calculated, which was then administered once a day, for up to seven days.[1][9]: 14–15  Each time the labelled antibody was administered, it was always preceded by unlabelled (non-radioactive) antibody. Early clinical trials had shown that total body residence times of radioactivity were longer in people who first received unlabelled antibody, so that a lower dose of labelled antibody was needed to deliver the required total dose of radiation; additionally labelled antibody targeted tumors better in people pre-treated with unlabelled antibody.[9]
: 21 

Availability

United States

Following a first

oncologists could not sell it directly to patients but had to refer patients to third party specialist centers, however a "muddled clinical trials strategy", supply chain issues, reimbursement problems, and emergence of non-radioactive competitors has also been blamed.[6][5][11]

Europe

The

orphan drug status, for the treatment of follicular lymphoma, to Amersham plc in 2003. This was withdrawn in October 2015 at the request of the new owner, GlaxoSmithKline.[12][13]

References

  1. ^ a b c d e "BEXXAR drug label" (PDF). FDA. GlaxoSmithKline. August 2012. Retrieved 18 January 2016.
  2. ^ "Guide to Antibody structure and isotypes". Abcam. Retrieved 25 July 2020.
  3. ^ Mozee, Carla (29 April 2005). "Glaxo to acquire Corixa for $300 million". MarketWatch.
  4. ^
    PMID 21436340
    .
  5. ^ .
  6. ^ a b Timmerman, Luke (26 August 2013). "Why Good Drugs Sometimes Fail: The Bexxar Story". Xconomy.
  7. ^ a b "Tositumomab - Product Approval Information - Licensing Action". FDA/Center for Drug Evaluation and Research. 2 July 2003.
  8. ^ a b c "Tositumomab product description". Food and Drug Administration. Archived from the original on 27 January 2018. Retrieved 25 July 2020.
  9. ^ "Briefing Information Iodine I-131 Tositumomab". Food and Drug Administration. 17 December 2002. Archived from the original on 25 January 2018. Retrieved 25 July 2020.
  10. ^ "GlaxoSmithKline LLC; Withdrawal of Approval of the Indication for Treatment of Patients With Relapsed or Refractory, Low Grade, Follicular, or Transformed CD20 Positive Non-Hodgkin's Lymphoma Who Have Not Received Prior Rituximab; BEXXAR". Federal Register. 23 October 2013. (78 FR 63226)
  11. ^ "EU/3/03/137". European Medicines Agency. 17 September 2018. Retrieved 25 July 2020.
  12. ^ "EU/3/03/136". European Medicines Agency. 17 September 2018. Retrieved 25 July 2020.