Carfilzomib, sold under the brand name Kyprolis, is an

anti-cancer medication Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

acting as a selective

proteasome inhibitor Proteasome inhibitors are drugs that block the action of proteasomes, cellular complexes that break down proteins. They are being studied in the treatment of cancer; and three are approved for use in treating multiple myeloma. Mechanism Multipl ...

. Chemically, it is a

tetrapeptide A tetrapeptide is a peptide, classified as an oligopeptide, since it only consists of four amino acids joined by peptide bonds. Many tetrapeptides are pharmacologically active, often showing affinity and specificity for a variety of receptors in p ...

epoxyketone and an

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analog ...

of epoxomicin. It was developed by

Onyx Pharmaceuticals Onyx Pharmaceuticals Inc. has been a biopharmaceutical company headquartered in South San Francisco, California. The company developed and marketed medicines for the treatment of cancer. Onyx was founded in 1992 by Kevin J. Kinsella and Frank M ...

. The U.S.

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(FDA) approved it on 20 July 2012, for use in people with multiple myeloma who have received at least two prior therapies, including treatment with

bortezomib Bortezomib, sold under the brand name Velcade among others, is an anti-cancer medication used to treat multiple myeloma and mantle cell lymphoma. This includes multiple myeloma in those who have and have not previously received treatment. It is ...

and an immunomodulatory therapy (such as lenalidomide) and have demonstrated disease progression on or within 60 days of completion of the last therapy. Initial approval was based on response rate. Data demonstrating an Overall Survival (OS) benefit was later demonstrated in the ENDEAVOR trial and approved by the FDA.FDA Approves Carfilzomib Label Update in Myeloma , OncLive

The abbreviation CFZ is common for referring to carfilzomib, but abbreviating drug names is not

best practice A best practice is a method or technique that has been generally accepted as superior to other known alternatives because it often produces results that are superior to those achieved by other means or because it has become a standard way of doing ...

in medicine.

History

Carfilzomib is derived from epoxomicin, a natural product that was shown by the laboratory of Craig Crews at

Yale University Yale University is a Private university, private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the List of Colonial Colleges, third-oldest institution of higher education in the United Sta ...

to inhibit the proteasome. The Crews laboratory subsequently invented a more specific derivative of epoxomicin named YU101, which was licensed to Proteolix, Inc. Scientists at Proteolix invented a new, distinct compound that had potential use as a drug in humans, known as carfilzomib. Proteolix advanced carfilzomib to multiple Phase I and II clinical trials, including a pivotal

phase 2 clinical trial The phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases ...

designed to seek accelerated approval. Clinical trials for carfilzomib continue under

, which acquired Proteolix in 2009. In January 2011, the FDA granted carfilzomib fast-track status, allowing Onyx to initiate a rolling submission of its new drug application for carfilzomib. In December 2011, the FDA granted Onyx standard review designation, for its new drug application submission based on the 003-A1 study, an open-label, single-arm phase IIb trial. The trial evaluated 266 heavily-pretreated patients with relapsed and refractory multiple

myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, anemi ...

who had received at least two prior therapies, including bortezomib and either thalidomide or lenalidomide. It costs approximately $10,000 per 28-day cycle.

Mechanism

Carfilzomib covalently irreversibly binds to and inhibits the chymotrypsin-like activity of the 20S proteasome, an enzyme that degrades unwanted cellular proteins. Carfilzomib displays minimal interactions with non-proteasomal targets, thereby improving safety profiles over bortezomib. Inhibition of proteasome-mediated proteolysis results in a build-up of polyubiquitinated proteins, which may cause cell cycle arrest, apoptosis, and inhibition of tumor growth.

Clinical trials & side effects

Completed

A single-arm, Phase II trial (003-A1) of carfilzomib in patients with relapsed and refractory multiple myeloma showed that single-agent carfilzomib demonstrated a clinical benefit rate of 36% in the 266 patients evaluated and had an overall response rate of 22.9% and median duration of response of 7.8 months. The FDA approval of carfilzomib was based on results of the 003-A1 trial. In a Phase II trial (004), carfilzomib had a 53% overall response rate among patients with relapsed and/or refractory multiple myeloma who had not previously received bortezomib. This study also included a bortezomib-treated cohort. Results were reported separately. This study also found prolonged carfilzomib treatment was tolerable, with approximately 22% of patients continuing treatment beyond one year. The 004 trial was a smaller study originally designed to investigate the impact of carfilzomib treatment in relationship to bortezomib treatment in less heavily pretreated (1–3 prior regimens) patients. A Phase II trial (005), which assessed the safety, pharmacokinetics, pharmacodynamics and efficacy of carfilzomib, in patients with multiple myeloma and varying degrees of renal impairment, where nearly 50% of patients were refractory to both bortezomib and lenalidomide, demonstrated that pharmacokinetics and safety were not influenced by the degree of baseline renal impairment. Carfilzomib was tolerable and demonstrated efficacy. In another Phase II trial (006) of patients with relapsed and/or refractory multiple myeloma, carfilzomib in combination with lenalidomide and dexamethasone demonstrated an overall response rate of 69%. A Phase II trial (007) for multiple myeloma and solid tumors showed promising results."Phase II results of Study PX-171-007: A phase Ib/II study of carfilzomib (CFZ), a selective proteasome inhibitor, in patients with selected advanced metastatic solid tumors" - ASCO 2009; Abstract 3515. In Phase II trials of carfilzomib, the most common grade 3 or higher treatment-emergent adverse events were hematologic toxicity with

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 a ...

, anemia, lymphopenia, neutropenia, pneumonia, fatigue and hyponatremia. In a frontline Phase I/II study, the combination of carfilzomib, lenalidomide, and low-dose dexamethasone was highly active and well tolerated, permitting the use of full doses for an extended time in newly diagnosed multiple myeloma patients, with limited need for dose modification. Responses were rapid and improved over time, reaching 100% very good partial response. Furthermore, gastrointestinal disturbances, including diarrhea and nausea are non hematologic group of side effects commonly reported with proteasome inhibitors. Additionally, cardiovascular toxicity may be an outcome of carfilzomib treatment due to the effects on proteasomes in the myocardium. Thus, patient evaluation and risk assessment prior to initiation of therapy with carfilzomib is crucial.

ASPIRE trial

A phase III confirmatory clinical trial, known as the ASPIRE trial, compared carfilzomib, lenalidomide, and dexamethasone (KRd) versus lenalidomide and dexamethasone (Rd) in patients with relapsed multiple myeloma and found improved progression-free survival and overall survival. Treatment discontinuation because of adverse effects occurred less frequently in the KRd arm, and events included thrombocytopenia, hypertension, and heart failure.

References

External links

* {{Portal bar , Medicine Epoxides 4-Morpholinyl compunds Tetrapeptides Proteasome inhibitors