Talazoparib, sold under the brand name Talzenna, is an orally available

poly ADP ribose polymerase Poly (ADP-ribose) polymerase (PARP) is a family of proteins involved in a number of cellular processes such as DNA repair, genomic stability, and programmed cell death. Members of PARP family The PARP family comprises 17 members (10 putative) ...

(PARP) inhibitor developed by

Pfizer Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfizer ...

for the treatment of advanced breast cancer with germline

BRCA mutation A ''BRCA'' mutation is a mutation in either of the ''BRCA1'' and ''BRCA2'' genes, which are tumour suppressor genes. Hundreds of different types of mutations in these genes have been identified, some of which have been determined to be harmful, ...

s. Talazoparib is similar to the first in class PARP inhibitor,

olaparib Olaparib, sold under the brand name Lynparza, is a medication for the maintenance treatment of BRCA-mutated advanced ovarian cancer in adults. It is a PARP inhibitor, inhibiting poly ADP ribose polymerase (PARP), an enzyme involved in DNA repair ...

. It was approved in October 2018, in the United States and June 2019, in the European Union for germline BRCA-mutated, HER2-negative locally advanced or metastatic breast cancer.

Side effects

The most serious side effects in studies were related to the blood forming system and included

anaemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...

(low red blood cell count),

neutropenia Neutropenia is an abnormally low concentration of neutrophils (a type of white blood cell) in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria ...

(low

neutrophil Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying in ...

blood cell count) and

thrombocytopenia Thrombocytopenia is a condition characterized by abnormally low levels of platelets, also known as thrombocytes, in the blood. It is the most common coagulation disorder among intensive care patients and is seen in a fifth of medical patients an ...

(low

platelet Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...

count). Serious forms of these conditions (grade 3 to 4) occurred in 39%, 21% and 15% of patients, respectively. Other adverse effects such as headache,

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

hair loss Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarri ...

and

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

were mostly mild.Talzenna

Interactions

Combination with drugs that inhibit

P-glycoprotein P-glycoprotein 1 (permeability glycoprotein, abbreviated as P-gp or Pgp) also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein ...

BCRP ATP-binding cassette super-family G member 2 is a protein that in humans is encoded by the ''ABCG2'' gene. ABCG2 has also been designated as CDw338 (cluster of differentiation w338). ABCG2 is a translocation protein used to actively pump drugs a ...

may increase talazoparib concentrations in the body.

Mechanism of action

Talazoparib acts as an inhibitor of

(PARP) which aids in single strand DNA repair. Cells that have BRCA1/2 mutations are susceptible to the cytotoxic effects of

PARP inhibitor PARP inhibitors are a group of pharmacological inhibitors of the enzyme poly ADP ribose polymerase (PARP). They are developed for multiple indications, including the treatment of heritable cancers. Several forms of cancer are more dependent on ...

s because of an accumulation of DNA damage. Talazoparib is theorized to have a higher potency than olaparib due to the additional mechanism of action called PARP trapping. PARP trapping is the mechanism of action where the PARP molecule is trapped on the DNA, which interferes with the cells ability to replicate. Talazoparib is found to be ~100 fold more efficient in PARP trapping than olaparib. However, this increased potency may not translate directly to clinical effectiveness as many other factors must be considered.

Commercialization

Talazoparib was originally developed by

BioMarin Pharmaceutical BioMarin Pharmaceutical Inc. is an American biotechnology company headquartered in San Rafael, California. It has offices and facilities in the United States, South America, Asia, and Europe. BioMarin's core business and research is in enzyme re ...

Inc. However,

Medivation Medivation was an American biopharmaceutical company focused on development of novel therapies to treat serious diseases for which there are limited treatment options. Medivation was headquartered in San Francisco, California, beginning operations ...

Inc. acquired all worldwide rights to talazoparib in August 2015, to expand their global oncology franchise. Medivation acquired talazoparib for $410 million with additional payments of up to $160 million in royalties and milestones. Under this agreement, Medivation assumed all financial responsibilities for the continued development, regulatory, and commercialization of talazoparib.

References

External links

* * {{Portal bar , Medicine Fluoroarenes PARP inhibitors Triazoles