Drugs for Genomics Final

primaquine

- antimalarial prodrug

- can cause hemolysis in patients with G6PD deficiency because their red blood cells cannot handle the oxidative stress caused by the drug's metabolites

- exposure to peroxides (ex. vinca in fava beans) can result in reactive oxygen species (depletes NADPH stores resulting in resistance to malaria virus)

- occurs on X chromosome in people of African American ancestry

- A to G substitution in G6PD causes transition of asparagine to aspartic acid that decreases enzymatic activity

rifampicin

- prevents the initiation of RNA synthesis (prokaryotes) and is produced by the bacterium Streptomyces

- used to eliminate bacteria that can cause tuberculosis (TB)

- blocks the channel where RNA/DNA hybrid must pass through

- blocks bacterial RNA transcription

streptomycin

- inhibit initiation and cause the misreading of mRNA in bacteria

- aminoglycoside antibiotic that binds irreversibly to the 30S ribosomal subunit to inhibit bacterial protein synthesis

tetracycline

- binds to the 30S subunit and inhibits the binding of aminoacyl-tRNAs in bacteria

- broad-spectrum antibiotics that reversibly inhibit bacterial protein synthesis

chloramphenicol

- inhibits the peptidyl transferase activity of the 50S ribosomal subunit in bacteria

- protein synthesis inhibitor that acts on the 50S ribosomal subunit

erythromycin

- binds to the 50S subunit and inhibits translocation in bacteria

- discovered in a soil sample from the Philippines in 1949

- macrolide antibiotic that inhibits bacterial protein synthesis

cisplatin

- platinum-based chemotherapy agent that results in interstrand crosslinks

- given IV and used primarily in combination for treatment of testicular cancers

- causes mutagenesis by damaging DNA

warfarin

- vitamin K antagonist (anticoagulant)

- adverse effects and dosage depends on level of two proteins VKORC1 and CYP2C9

- VKORC1 polymorphisms account for 30% of variation

- low-dose haplotype A = more sensitive (Asian Americans)

- high-dose haplotype B = relatively resistant (African Americans)

BRACAnalysis CDx

- companion diagnostic genetic test used to detect germline mutations in the BRCA1 and BRCA2 genes

- analyzes DNA using blood sample

- helps identify patients eligible for PARP inhibitor therapy

nortriptyline

- second-generation tricyclic antidepressant used for the treatment of major depression

- metabolism depends on copy number variations in CYP2D6 (ultrarapid, extensive, intermediate, and poor metabolizers)

- faster metabolism occurs when there are one/multiple copies of functional allele and require higher dose

- slower metabolism occurs when alleles are nonfunctional and require a much lower dose

sulfasalazine

- activated by gut microbiome and is used in the treatment of IBD, UC, and Crohn's

- remains inactive until it reaches the distal gut where azo reductases encoded by the gut microbiome cleave the N-N double bond to release active 5-ASA

sorivudine

- antiviral drug that is highly active against herpes simplex and varicella zoster viruses

- metabolized by phosphorylases in the gut microbiome to bromvinuluracil (BVU)

- deadly consequences of combined treatment with 5-FU due to inhibition of DPD enzyme through irreversible binding by BVU causing toxic 5-FU build up

fluorouracil

- medication used in the treatment of cancer

- metabolized by DPD in the liver to inactive dihydrofluorouracil

- deadly consequences of combined treatment with BVU due to inhibition of DPD enzyme through irreversible binding causing toxic 5-FU build up

betibeglogene autotemcel (Zynteglo)

- ex vivo gene therapy for B-thalassemia

- hematopoietic stem cells (HSCs) isolated from patient and expanded in manufacturing facility

- HSCs infected with lentiviral vector expressing a functional B-globin gene with a Thr-87-Gln switch

- B-globin T87Q protein pairs with a a-globin to produce functional hemoglobin

- myeloablative conditioning prior to HSC infusion (destroy bone marrow to eliminate nonfunctional cells so that modified cells are able to integrate)

voretigene neparvovec (Luxturna)

- in vivo gene therapy for inherited vision loss due to RPE65 mutations

- first approved gene therapy

- one-time gene therapy for each eye via intraocular injection

- recombinant adeno-associated virus of serotype 2 (rAAV2) expressing a working copy of the RPE65 gene

onasemnogene abeparvovec (Zolgensma)

- in vivo gene therapy for spinal muscular atrophy (SMA)

- self-complementary adeno-associated viral serotype 9 (scAAV9) does not integrate

- AAV9 virus modified with SMN cDNA to deliver a working SMN1 gene

tisagenlecleucel (Kymriah) and axicabtagene ciloleucel (Yescarta)

- CAR-T cell therapies (cell-based cancer immunotherapy)

- autologous T cells are harvested from blood, genetically modified, stimulated, then reintroduced into the patient to attack the cancer

patisiran (Onpattro)

- RNA therapeutic and modified double stranded RNA used for the treatment of hATTR amyloidosis

- select C and U have 2'-O-(2-methyl) nucleosides

- binds to the TTR mRNA forming a complex that is recognized by RISC and TTR mRNA is cleaved by RISC which prevents translation into protein

- lipid nanoparticle bound by ApoE and endocytosed into a hepatocyte

- pH change after endocytosis releases siRNA

nusinersen (Spinraza)

- RNA therapeutic used for the treatment of spinal muscular atrophy (SMA)

- two major modifications include bases have 2'-O-(2-methoxyethyl) nucleosides and phosphates replaced with a thioate linkage

- after spinal injection drug binds to the SMN2 primary transcript which prevents exon 7 from being spliced out

- SMN2 mRNA containing exon 7 translated into protein which substitutes for missing SMN1 protein

eteplirsen (Exondys 51)

- RNA therapeutic used for the treatment of muscular dystrophy

- morpholino ASO

- binds to dystrophin primary transcript and exon 51 with stop codon mutation is spliced out (removes codon that would cause an unwanted truncation)

- resulting shorter dystrophin protein can be expressed

human insulin (Humulin)

- 2nd generation (bioengineered) hormone biopharmaceutical

- contain non-native amino acid changes to accelerate or prolong duration of action

- cDNA changed to code for different amino acids

insulin aspart (Novolog)

- hormone biopharmaceutical

- produced in S. cerevisiae

- Asp replaces Pro at position 28B

- decreased oligomerization

- rapid acting

insulin glargine (Lantus)

- hormone biopharmaceutical

- produced in E. coli

- Gly replaces Asn at position 21A

- two extra C-terminal Arg added to B chain

- decreased solubility

- slower acting

- micro-precipitates form on IM injection then slowly release

epoetin (Epogen)

- hormone biopharmaceutical

- first used to treat anemia associated with chronic renal failure

- has also been tried in the treatment of anemia that results from many conditions (FDA tightly restricted use in cancer-associated anemia)

- EPO cDNA was discovered and cloned into a mammalian expression vector

- the vector was transfected into mammalian host cells called Chinese hamster ovary (CHO) cells

- EPO cDNA become integrated into the genome of the host cells

- host cells transcribe EPO cDNA into mRNA and translate mRNA into protein

- EPO protein is glycosylated (N- and O- linked post-translational modifications)

- glycosylated EPO is secreted by the host cells

- EPO is harvested, purified, and formulated

filgrastim (Neupogen)

- cytokine biopharmaceutical

- water-soluble 175 amino acid protein with a molecular weight of approximately 19kD

- obtained from the bacterial fermentation of a strain of E. coli transformed with a genetically engineered plasmid containing the human G-CSF gene

- dosed 5 mcg/kg/day as a single daily injection

pegfilgrastim (Neulasta)

- cytokine biopharmaceutical

- covalent conjugate of filgrastim

- produced via the addition of 20kD monomethoxy polyethylene glycol (PEG) molecule covalently bound to the N-terminal methionyl residue of filgrastim

- average molecular weight is approximately 39kD

- dosed 6mg every chemotherapy cycle

alglucosidase alpha (Myozyme/Lumizyme)

- enzyme replacement therapy

- recombinant human a-1,4-glucosidase

- used to treat Pompe disease (1st gen)

- glycoprotein with N-linked mannoses that bind to mannose receptors on cell surface and cause internalization and accumulation of lysosomes

- produced in CHO cells however terminal sugars aren't mannose

- after harvesting from cells the glycoprotein is treated to remove other terminal sugars and expose mannose on the surface

- mannose density on the protein is low resulting in inefficient uptake and diminished efficacy over time for some patients

- specific activity of 3-5 U/mg

alglucosidase alpha-ngpt (Nexviazyme)

- enzyme replacement therapy

- recombinant human a-1,4-glucosidase enzyme conjugated with multiple synthetic bis-mannose-6-phosphate-tetra-mannose glycans

- used to treat Pompe disease (2nd gen)

- produced in CHO cells with synthetic mannose-phosphates added after protein is purified from CHO cells

- post-production glycoengineering

cipaglucosidase alfa-atga (Pombiliti)

- enzyme replacement therapy

- recombinant human a-1,4-glucosidase enzyme derived from a CHO cell line using perfusion methodology resulting in cellularly (CHO)-derived N-glycans

- used to treat Pompe disease (3rd gen)

- CHO cells engineered with golgi-mannosidases to produce high density mannose phosphate on the protein in host cells

- post-translational glycoengineering

miglustat (Opfolda)

- used in combination with Pombiliti

- N-alkylated iminosugar that is a synthetic analog of D-glucose

- binds to, stabilizes, and reduces inactivation of Pombiliti in the bloodstream after infusion

- bound miglustat dissociates from cipaglucosidase alfa-atga after the complex is internalized and transported into lysosomes

certolizumumab (Cimzia)

- Mab therapeutic that targets TNF-a

- humanized Fab with 2 PEG groups attached to the C-terminus

- approved for Crohn's disease

- the absence of the Fc region reduces antibody-dependent cellular cytotoxicity (ADCC)

ziv-aflibercept (Zaltrap)

- Mab therapeutic that is a recombinant soluble VEGF receptor fused to an antibody Fc region

- used for metastatic colorectal cancer with VEGF growth factor overexpression

- acts as a "trap" to prevent VEGF ligands from binding to VEGF receptors on cancer cells

- created using alternative splicing to produce different forms of a protein

- cDNA for the receptor was shortened to exclude the part of the DNA encoding the membrane bound portion of the VEGF receptor

- shortened cDNA was ligated to a cDNA for the Fc region

aflibercept (Elyea)

- Mab therapeutic that is a recombinant soluble VEGF receptor fused to an antibody Fc region

- used for neovascular macular degeneration (AMD)

- in AMD both the VEGF mRNA and protein are higher

- protein is identical to Zaltrap but formulated for ophthalmic dosing

trastuzumab (Herceptin)

- Mab therapeutic that binds to HER2

- used to treat metastatic breast cancer

- ONLY used in breast cancer cases where patients have tested positive for HER2 overexpression

pertuzumab (Perjeta)

- Mab therapeutic that targets a different epitope of HER2

- targets the extracellular dimerization domain (subdomain II) of HER2 and blocks ligand-dependent heterodimerization of HER2 with other HER family members including EGFR, HER3, and HER4

trastuzumab emtansine (Kadcyla)

- Mab therapeutic originally approved for use in women with HER2 positive cancers that either received prior therapy for metastatic disease or developed disease recurrence during or within six months of completing adjuvant therapy

- approved (since 2019) for patients with residual disease after neoadjuvant therapy (taxane + trastuzumab)

- a covalent MCC linker covalently connects a drug (DM1) to lysines in the Fc region of trastuzumab

- DM1 is a maytansine derivative/microtubule-depolymerizing agent

- has clinical activity against Herceptin-resistant tumors

- many tumors that develop resistance to trastuzumab still show elevated HER2 expression by IHC

- trastuzumab binds to extracellular HER2 and is internalized and the antibody is degraded intracellularly which releases DM1 so that free DM1 can then inhibit mitosis

nivolumab (Opdivo) and pembrolizumab (Keytruda)

- immunotherapy "checkpoint blockade" anticancer antibody

- cancer cells with defective mismatch repair have many thousands of point mutations that can cause resulting proteins to become mutation-associated neo-antigens (MANAs)

- checkpoint blockade facilitates immune recognition of the cancer cells as "non-self"

- bind to PD-1 receptor to block PD ligand binding which relieves the inhibition of T cells and facilitates immune attack of cancer

- PD-1 receptor binding normally inhibits T-cell activation to act as a natural "dampener" to prevent overactive immune responses but tumor cells express PD-L1 to avoid immune attack