Skip to main content

New Drug Approvals - Pt. XIX - Pralatrexate (Folotyn)



Also approved on September 25th was Pralatrexate (tradename Folotyn). Pralatrexate is the first drug approved for the treatment of Peripheral T-Cell Lymphoma (PTCL), an aggressive form of non-Hodgkins lymphoma. Lymphoma is a cancer that begins in the lymphocytes of the immune system. PTCL is a rare disease, occurring in around 9,500 patients each year in the United States.
Pralatrexate, also known as PDX, is a folic analog that competitively inhibits dihydrofolate reductase (DHFR). Since Pralatrexate blocks the use/function of a metabolite, it is also an antimetabolite. Pralatraxate has high affinity for the folate transporter SLC19A1 (also known as RFC-1), and so is an example of a drug that is 'actively transported', and is also a substrate for polyglutamation by the enzyme folylpolyglutamate synthase (FPGS). Once polyglutamated Pralatrexate has a prolonged intracellular half-life, giving prolonged action in malignant cells. Pralatrexate is related to several other drugs, most notably Methotrexate, and 'old' launched drug, and also the clinical stage compounds - Ketotrexate, Edatrexate, and also the antiprotozoal agent Trimetrexate, all of which are DHFR inhibitors.
Pralatrexate is a polar, racemic small molecule (Molecular Weight of 477.5 g.mol-1), soluble in aqueous solutions. Pralatrexate is a mixture of diastereomers (stereoisomers that are not enantiomers, i.e. they are non-superimposable). Diastereomers can have different physical properties biological activities, and different reactivity. Pralatrexate has a volume of distribution (Vd) of 105L and 37L for the S- and R-diastereomers, respectively, a plasma protein binding (ppb) of 67%, a systemic clearance of 417 mL.min-1 (S-diastereomer) and 191 mL.min-1 (R-diastereomer), and an elimination half-life (T1/2)of 12-18 hours. Pralatrexate is not significantly metabolized by the phase I hepatic CYP450 isozymes or phase II hepatic glucuronidases, and has low potential to induce or inhibit the activity of CYP450 isozymes - elimination is primarily of unchanged drug in urine.
The recommended dosing of Pralatrexate is 30 mg.m-2 administrated as an intravenous injection once weekly for 6 weeks in 7-week cycles. The full prescribing information can be found here.

The structure (2S)-2-[[4-[(1RS)-1-[(2, 4-diaminopteridin-6-yl)methyl]but-3-ynyl]benzoyl]amino]pentanedioic acid is a folate analog in which the hydroxyl group of the pyrimidine ring has been replaced by an amine, and the central amino group of the molecule has been replaced by a stereocenter carbon with a methylacethylene attached to it (which may undergo nucleophilic atack). Pralatrexate diastereomers differ in configuration at this stereocenter only, and so they are also epimers.
<CHEMBL_DRUG>
<DRUG_NAME="Pralatrexate" TRADEMARK_NAME="Folotyn" APPROVAL_DATE="25-SEPT-2009" DRUG_MOLECULAR_WEIGHT=477.5>
<DRUG_STRUCTURE>
<DRUG_SMILES="O=C(O)[C@@H](NC(=O)c1ccc(cc1)C(CC#C)Cc2nc3c(nc2)nc(nc3N)N)CCC(=O)​O">
<InChI="InChI=1/C23H23N7O5/c1-2-3-14(10-15-11-26-20-18
(27-15)19(24)29-23( ​25)30-20)12-4-6-13(7-5-12)21(33)28-16
(22(34)35)8-9-17(31)32/h1,4-​ 7,11,14,16H,3,8-10H2,(H,28,33)(H,31,32)(H,34,35)(H4,24,25,26,29,3​ 0)/t14?,16-/m0/s1">
<InChIKey="OGSBUKJUDHAQEA-WMCAAGNKSA-N">
</DRUG_STRUCTURE>
<ChemDraw="Pralatrexate.cdx">
<DRUG_TARGET>
VGSLNCIVAVSQNMGIGKNGDLPWPPLRNEFRYFQRMTTTSSVEGKQNLVIMGKKTWFSI
PEKNRPLKGRINLVLSRELKEPPQGAHFLSRSLDDALKLTEQPELANKVDMVWIVGGSSV
YKEAMNHPGHLKLFVTRIMQDFESDTFFPEIDLEKYKLLPEYPGVLSDVQEEKGIKYKFE
VYEKND
</DRUG_TARGET>
</CHEMBL_DRUG>
The license holder is Allos Therapeutics, Inc. and the product website is www.folotyn.com.

Comments

Popular posts from this blog

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.

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

Accessing SureChEMBL data in bulk

It is the peak of the summer (at least in this hemisphere) and many of our readers/users will be on holiday, perhaps on an island enjoying the sea. Luckily, for the rest of us there is still the 'sea' of SureChEMBL data that awaits to be enjoyed and explored for hidden 'treasures' (let me know if I pushed this analogy too far). See here and  here for a reminder of SureChEMBL is and what it does.  This wealth of (big) data can be accessed via the SureChEMBL interface , where users can submit quite sophisticated and granular queries by combining: i) Lucene fields against full-text and bibliographic metadata and ii) advanced structure query features against the annotated compound corpus. Examples of such queries will be the topic of a future post. Once the search results are back, users can browse through and export the chemistry from the patent(s) of interest. In addition to this functionality, we've been receiving user requests for  local (behind the

A python client for accessing ChEMBL web services

Motivation The CheMBL Web Services provide simple reliable programmatic access to the data stored in ChEMBL database. RESTful API approaches are quite easy to master in most languages but still require writing a few lines of code. Additionally, it can be a challenging task to write a nontrivial application using REST without any examples. These factors were the motivation for us to write a small client library for accessing web services from Python. Why Python? We choose this language because Python has become extremely popular (and still growing in use) in scientific applications; there are several Open Source chemical toolkits available in this language, and so the wealth of ChEMBL resources and functionality of those toolkits can be easily combined. Moreover, Python is a very web-friendly language and we wanted to show how easy complex resource acquisition can be expressed in Python. Reinventing the wheel? There are already some libraries providing access to ChEMBL d

New Drug Approvals - Pt. XVII - Telavancin (Vibativ)

The latest new drug approval, on 11th September 2009 was Telavancin - which was approved for the treatment of adults with complicated skin and skin structure infections (cSSSI) caused by susceptible Gram-positive bacteria , including Staphylococcus aureus , both methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains. Telavancin is also active against Streptococcus pyogenes , Streptococcus agalactiae , Streptococcus anginosus group (includes S. anginosus, S. intermedius and S. constellatus ) and Enterococcus faecalis (vancomycin susceptible isolates only). Telavancin is a semisynthetic derivative of Vancomycin. Vancomycin itself is a natural product drug, isolated originally from soil samples in Borneo, and is produced by controlled fermentation of Amycolatopsis orientalis - a member of the Actinobacteria . Telavancin has a dual mechanism of action, firstly it inhibits bacterial cell wall synthesis by interfering with the polymerization and cross-linking of peptid