epoxy
Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also coll ...
ketone 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 analo ...
of
epoxomicin
Epoxomicin is a naturally occurring selective proteasome inhibitor with anti-inflammatory activity. It was originally discovered in 1992.Onyx Pharmaceuticals.
The U.S. Food and Drug Administration (FDA) approved it on 20 July 2012, for use in people with
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, an ...
who have received at least two prior therapies, including treatment with bortezomib and an immunomodulatory therapy (such as
lenalidomide
Lenalidomide, sold under the trade name Revlimid among others, is a medication used to treat multiple myeloma, smoldering myeloma, and myelodysplastic syndromes (MDS). For multiple myeloma, it is used after at least one other treatment and gene ...
) 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 in medicine.
History
Carfilzomib is derived from
epoxomicin
Epoxomicin is a naturally occurring selective proteasome inhibitor with anti-inflammatory activity. It was originally discovered in 1992.Craig Crews at Yale University 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
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...
accelerated approval The United States Food and Drug Administration (FDA) initiated the FDA Accelerated Approval Program in 1992 to allow faster approval of drugs for serious conditions that fill an unmet medical need. The faster approval relies on use of surrogate endp ...
. Clinical trials for carfilzomib continue under Onyx Pharmaceuticals, 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 who had received at least two prior therapies, including bortezomib and either thalidomide or
lenalidomide
Lenalidomide, sold under the trade name Revlimid among others, is a medication used to treat multiple myeloma, smoldering myeloma, and myelodysplastic syndromes (MDS). For multiple myeloma, it is used after at least one other treatment and gene ...
. It costs approximately $10,000 per 28-day cycle.
Mechanism
Carfilzomib covalently irreversibly binds to and inhibits the
chymotrypsin
Chymotrypsin (, chymotrypsins A and B, alpha-chymar ophth, avazyme, chymar, chymotest, enzeon, quimar, quimotrase, alpha-chymar, alpha-chymotrypsin A, alpha-chymotrypsin) is a digestive enzyme component of pancreatic juice acting in the duodenu ...
-like activity of the
20S proteasome
Proteasomes are protein complexes which degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that help such reactions are called proteases.
Proteasomes are part of a major mechanism by whi ...
, 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
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...
, 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, 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.