Skip to main content

New Drug Approvals 2013 - Pt. XII - Technetium Tc 99m Tilmanocept (LymphoSeekTM)



ATC code: V09IA09

On March 13th 2013, the FDA approved Technetium Tc 99m Tilmanocept (LymphoSeekTM), a radioactive diagnostic agent indicated for lymphatic mapping with a hand-held gamma counter to assist in the localisation of lymph nodes draining a primary tumour site in patients with breast cancer or melanoma

Melanoma is a malignant skin tumour, which, although rather uncommon, causes 75% of skin cancer related deaths.  Breast cancer accounts for almost 23% of all cancers in women and in 2008 caused 13.7% of cancer related deaths in women. Lymph nodes drain lymphatic fluid coming from tissues, if the tissues contain a tumour, the node will retain cancer cells coming from it. By removing and analysing the lymph node, precious informations can be obtained regarding the spread of the tumour.

Technetium Tc 99m Tilmanocept (ChEMBL: CHEMBL2108726) acts by accumulating in lymphatic tissue and selectively binding to mannose binding receptor (CD206, ChEMBL: CHEMBL2176854, Uniprot:P22897) found on macrophage and dendritic cells membrane. In vitro studies show that Technetium Tc 99m Tilmanocept binds to the human mannose binding receptor with an affinity of Kd = 2.76 x 10-11 M. Clinical studies show that it accumulates in lymph nodes within 10 min and up to 30 hours after the injection.

The PDBe entry (PDBe: 1egg) for a crystal structure of the macrophage mannose receptor is shown below.


Tilmanocept is a macromolecule composed of multiple units of diethylenetriaminepentaacetic acid (DTPA) and mannose, each covalently bonded to a 10 kDa backbone of dextran. The DTPA acts as a chelating agent for labelling with Technetium 99m (Tc 99m), while mannose, a naturally occurring sugar, acts as a target ligand. The active component is radioactive Tc 99m, a synthetic element widely used in nuclear medicine that decays with a half-life of 6 hours emitting Gamma-2 photons. The molecular formula of Technetium Tc 99m Tilmanocept is [C6H10O5]n.(C19H28N4O9S99mTc)b.(C13H24N2O5S2)c.(C5H11NS)a. It contains 3-8 conjugated DTPA molecules (b); 12-20 conjugated mannose molecules (c) with 0-17 amine side chains (a) remaining free. The calculated average molecular weight of Tilmanocept ranges from 15,281 to 23,454 g/mol.


The recommended dose of Technetium Tc 99m Tilmanocept is 18.5 MBq (0.5 mCi) as a radioactivity dose and 50 mcg as a mass dose, administered via injection at least 15 minutes prior the lymph node mapping. Technetium Tc 99m Tilmanocept has a half-life at the injection site of 1.75 to 3.05 hours.

LymphoSeek is produced by Navidea Biopharmaceuticals, Inc.
Full prescribing information can be found here.

Comments

Popular posts from this blog

SureChEMBL Available Now

Followers of the ChEMBL group's activities and this blog will be aware of our involvement in the migration of the previously commercially available SureChem chemistry patent system, to a new, free-for-all system, known as SureChEMBL. Today we are very pleased to announce that the migration process is complete and the SureChEMBL website is now online. SureChEMBL provides the research community with the ability to search the patent literature using Lucene-based keyword queries and, much more importantly, chemistry-based queries. If you are not familiar with SureChEMBL, we recommend you review the content of these earlier blogposts here and here . SureChEMBL is a live system, which is continuously extracting chemical entities from the patent literature. The time it takes for a new chemical in the patent literature to become searchable in the SureChEMBL system is 1-2 days (WO patents can sometimes take a bit longer due to an additional reprocessing step). At time of writi

New SureChEMBL announcement

(Generated with DALL-E 3 ∙ 30 October 2023 at 1:48 pm) We have some very exciting news to report: the new SureChEMBL is now available! Hooray! What is SureChEMBL, you may ask. Good question! In our portfolio of chemical biology services, alongside our established database of bioactivity data for drug-like molecules ChEMBL , our dictionary of annotated small molecule entities ChEBI , and our compound cross-referencing system UniChem , we also deliver a database of annotated patents! Almost 10 years ago , EMBL-EBI acquired the SureChem system of chemically annotated patents and made this freely accessible in the public domain as SureChEMBL. Since then, our team has continued to maintain and deliver SureChEMBL. However, this has become increasingly challenging due to the complexities of the underlying codebase. We were awarded a Wellcome Trust grant in 2021 to completely overhaul SureChEMBL, with a new UI, backend infrastructure, and new f

ChEMBL & SureChEMBL anniversary symposium

  In 2024 we celebrate the 15th anniversary of the first public release of the ChEMBL database as well as the 10th anniversary of SureChEMBL. To recognise this important landmark we are organising a two-day symposium to celebrate the work achieved by ChEMBL and SureChEMBL, and look forward to its future.   Save the date for the ChEMBL 15 Year Symposium October 1-2, 2024     Day one will consist of four workshops, a basic ChEMBL drug design workshop; an advanced ChEMBL workshop (EUbOPEN community workshop); a ChEMBL data deposition workshop; and a SureChEMBL workshop. Day two will consist of a series of talks from invited speakers, a few poster flash talks, a local nature walk, as well as celebratory cake. During the breaks, the poster session will be a great opportunity to catch up with other users and collaborators of the ChEMBL resources and chat to colleagues, co-workers and others to find out more about how the database is being used. Lunch and refreshments will be pro

ChEMBL 34 is out!

We are delighted to announce the release of ChEMBL 34, which includes a full update to drug and clinical candidate drug data. This version of the database, prepared on 28/03/2024 contains:         2,431,025 compounds (of which 2,409,270 have mol files)         3,106,257 compound records (non-unique compounds)         20,772,701 activities         1,644,390 assays         15,598 targets         89,892 documents Data can be downloaded from the ChEMBL FTP site:  https://ftp.ebi.ac.uk/pub/databases/chembl/ChEMBLdb/releases/chembl_34/ Please see ChEMBL_34 release notes for full details of all changes in this release:  https://ftp.ebi.ac.uk/pub/databases/chembl/ChEMBLdb/releases/chembl_34/chembl_34_release_notes.txt New Data Sources European Medicines Agency (src_id = 66): European Medicines Agency's data correspond to EMA drugs prior to 20 January 2023 (excluding vaccines). 71 out of the 882 newly added EMA drugs are only authorised by EMA, rather than from other regulatory bodies e.g.

RDKit, C++ and Jupyter Notebook

Fancy playing with RDKit C++ API without needing to set up a C++ project and compile it? But wait... isn't C++ a compiled programming language? How this can be even possible? Thanks to Cling (CERN's C++ interpreter) and xeus-cling jupyter kernel is possible to use C++ as an intepreted language inside a jupyter notebook! We prepared a simple notebook showing few examples of RDKit functionalities and a docker image in case you want to run it. With the single requirement of docker being installed in your computer you'll be able to easily run the examples following the three steps below: docker pull eloyfelix/rdkit_jupyter_cling docker run -d -p 9999:9999 eloyfelix/rdkit_jupyter_cling open  http://localhost:9999/notebooks/rdkit_cling.ipynb  in a browser