Dabrafenib [Tafinalar] and Trametinib [Mekinist] Approved for BRAF V600 Mutated Metastatic Melanoma

May 30, 2013

May 30, 2013 – From a Medscape News Release we learn today that two new drugs have been approved by the US Food and Drug Administration (FDA) for use in certain patients with metastatic or unresectable melanoma, along with a diagnostic test to identify patients who are suitable for treatment.

The new products, Dabrafenib [Tafinalar] and Trametinib [Mekinist], were both developed by GlaxoSmithKline. Both are orally available tablets, but they have slightly different mechanisms of action.

Dabrafenib [Tafinalar]  acts as a BRAF inhibitor and is approved for use in patients with melanoma whose tumors express the BRAF V600E gene mutation. It is seen as being a next-generation product but is in the same class as the first BRAF inhibitor to reach the market, Vemurafenib [Zelboraf] (Genentech).

Trametinib [Mekinist] has a related but slightly different mechanism and acts as a mitogen-activated, extracellular signal-regulated kinase inhibitor (MEK inhibitor). It is the first drug in this class to be approved and is indicated for use in patients with whose tumors express the BRAF V600E or V600K gene mutations.

Approximately half of melanomas arising in the skin have a BRAF gene mutation, the FDA notes in its approval notice. Alongside the new drugs, the agency also approved a genetic test, the THxID BRAF test, a companion diagnostic developed in collaboration with bioMérieux that will help determine wither a patient’s melanoma cells have the V600E or V600K mutation in the BRAF gene.

Melanoma is the leading cause of death from skin disease, the FDA adds. The National Cancer Institute estimates 76,690 Americans will be diagnosed with melanoma and 9480 will die from the disease in 2013.

Clinical Trial Data

Dabrafenib [Tafinalar]  was approved on the basis of data from the BREAK 3 study, conducted in 250 patients with previously untreated BRAF V600 mutation–positive metastatic melanoma. It showed that in such patients, Dabrafenib [Tafinalar]  significantly improved the median progression-free survival compared with chemotherapy with dacarbazine (5.1 vs 2.7 months; P < .0001). These results were published in July 2012 issue of the Lancet (2012;380:358-365).

The FDA notes that the most serious adverse effects reported in patients receiving Dabrafenib [Tafinalar] included an increased risk for cutaneous squamous cell carcinoma, fevers that may be complicated by hypotension, severe rigors, dehydration, kidney failure, and increased blood sugar levels requiring changes in diabetes medication or the need to start medicines to control diabetes.

The most common adverse effects reported in patients receiving Dabrafenib [Tafinalar]  included hyperkeratosis, headache, fever, joint pain, noncancerous skin tumors, hair loss, and hand–foot syndrome.

The pivotal study for Trametinib [Mekinist], the METRIC study, was a little different in that it was conducted in 322 patients who had already tried a prior regimen of chemotherapy. In this study, compared with chemotherapy, Trametinib [Mekinist] significantly improved progression-free survival as well as overall survival. The results were published in the New England Journal of Medicine.

The FDA notes that the most serious adverse effects reported in patients receiving Trametinib [Mekinist]  included heart failure, lung inflammation, skin infections, and loss of vision. Common adverse effects included rash, diarrhea, tissue swelling (peripheral edema), and skin breakouts that resemble acne.

The agency also noted that women of childbearing years should be advised that Dabrafenib [Tafinalar]  and Trametinib [Mekinist]  carry the potential to cause fetal harm. Men and women should also be advised that both drugs also carry the potential to cause infertility.

Being Investigated in Combination

Dabrafenib [Tafinalar]  and Trametinib [Mekinist]  have been approved for use as monotherapy, and not as a combination treatment, the FDA has emphasized. However, there is a lot of interest from clinicians in using both drugs together, and indeed the manufacturer is conducting a clinical trial with the combination.

Preliminary results from a clinical trial with the combination suggest that use of the 2 drugs together resulted in less toxicity, and specifically in fewer secondary skin cancers, than has been seen with  Vemurafenib [Zelboraf]  used alone.

GlaxoSmithKline is now conducting a phase 3 study (known as COMBI-AD) of the combination of Dabrafenib [Tafinalar]  and Trametinib [Mekinist]  in patients with BRAF V600 melanoma that has been completely removed by surgery. Such patients are at high risk for relapse, and the combination of drugs is being tested to see whether it can delay or prevent the recurrence of melanoma, the company noted.

Problem: Responses Are Short-lived

The new Dabrafenib [Tafinalar]  appears to be similar to the already-marketed Vemurafenib [Zelboraf], but there are important differences between the 2 BRAF inhibitors in their toxicity profiles, noted Kim Margolin, MD, from the Seattle Cancer Care Alliance in Washington..

Skin toxicities, particularly the emergence of low-grade squamous cancers and keratoacanthomas, which occurred in a substantial number of patients taking Vemurafenib [Zelboraf], appear to be quite unusual with Dabrafenib [Tafinalar], Dr. Margolin noted. However, a systemic “pyrexia reaction,” which is almost never seen with Vemurafenib [Zelboraf], has been seen in a substantial percentage of patients taking Dabrafenib [Tafinalar]. “We don’t know yet about the off-target mechanisms of these differences and how much may be due to the vehicle or the formulation for each of these oral agents,” she added.

However, the biggest problem with the BRAF inhibitors in the treatment of melanoma has been the lack of durable response: These drugs “tend to work for an average of 5 to 6 months,” Dr. Margolin noted. What to do when patients fail on these drugs remains a challenge, she added.

Ultimately, combination therapy with a BRAF inhibitor (such as Vemurafenib [Zelboraf]  or Dabrafenib [Tafinalar]) plus a MEK inhibitor (such as Trametinib [Mekinist]) is “likely to be most valuable for improved and lasting results,” according to Dr. Margolin. Firstclinical results along these lines have been published in the New England Journal of Medicine at the end of last year.


FDA Approves Companion Genetic Diagnostic Test for Erlotinib [Tarceva] in NSCLC

May 16, 2013

May 14, 2013 – The US Food and Drug Administration (FDA) today announced the approval of the cobas EGFR Mutation Test, a companion diagnostic for the cancer drug Erlotinib (Tarceva). This is the first FDA-approved companion diagnostic that can detect epidermal growth factor receptor (EGFR) gene mutations, which are present in approximately 10% of non-small cell lung cancers (NSCLCs).

The approval of this test comes at the same time as an expanded indication for Erlotinib (Tarceva). The FDA has also announced a labeling change for Erlotinib (Tarceva), and the drug is now indicated for first-line use in patients with metastasized NSCLC that tests positive for EGRF mutations. Until now, the official indication was second- or third-line use in advanced NSCLC.

“The approval of the cobas EGFR Mutation Test will allow physicians to identify non-small cell lung cancer patients who are candidates for receiving Erlotinib (Tarceva) as first-line therapy,” said Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health, in a statement. “Companion diagnostics play an important role in determining which therapies are the safest and most effective for a particular patient.”

The safety and effectiveness of the cobas EGFR Mutation Test was established with clinical data showing progression-free survival in NSCLC patients with specific types of EGFR mutations (exon 19 deletions or exon 21 L858R substitution mutations) for 10.4 months when they received Erlotinib (Tarceva) treatment, compared with 5.4 months for those who received standard therapy.

In the United States, Erlotinib (Tarceva) is currently the only drug available for use in EGFR-positive NSCLC, although elsewhere in the world, another similar drug is widely used: Gefitinib (Iressa). A third drug in this class of EGFR tyrosine kinase inhibitors (TKIs), Afatinib (Tomtovok, by Boehringer Ingelheim), is close to approval, with an FDA decision expected in July 2013. Afatinib will also have its own companion diagnostic test (Therascreen EGFR PCR Kit, from Qiagen).

Using an EGFR TKI in the first-line treatment of EGFR-mutated NSCLC is recommended by several clinical guidelines, including the American Society of Clinical Oncology.

Patient outcomes are significantly better when compared with chemotherapy, so much so that it “would be a tragedy not to use” an EGFR inhibitor in EGFR-positive patients, according to one expert in the field, Edward Kim, MD, PhD, assistant professor of medicine and director of clinical operations at the University of Texas MD Anderson Cancer Center, in Houston. To not know whether the tumor is mutation-positive is not acceptable anymore, he added.

However, testing for mutations is not yet routine, and there are difficulties with obtaining lung cancer samples of sufficient size and quality, as well as disagreement over which is the best method for obtaining such samples, as recently reported by Medscape Medical News. In addition, there are issues with the costs of such testing, as outlined in a comment from a surgeon is response to that article.

The cobas EGFR Mutation Test is manufactured by the Roche Molecular Systems. Erlotinib is comarketed by California-based Genentech, a member of the Roche Group and OSI Pharmaceuticals.


Incretin Mimetic Drugs for Type 2 Diabetes: Early Communication – Reports of Possible Increased Risk of Pancreatitis and Pre-cancerous Findings of the Pancreas

May 9, 2013

May 09, 2013 – We have just stumbled upon a recent press release to the public by the American Food and Drug Administration (FDA) on a looming drug safety problem of incretin mimetic drugs related to the pancreas. Find here the unedited press releaase in full:

[Posted 03/14/2013]

AUDIENCE: Gastroenterology, Endocrinology, Oncology, Patient

ISSUE: FDA is evaluating unpublished new findings by a group of academic researchers that suggest an increased risk of pancreatitis and pre-cancerous cellular changes called pancreatic duct metaplasia in patients with type 2 diabetes treated with a class of drugs called incretin mimetics. These findings were based on examination of a small number of pancreatic tissue specimens taken from patients after they died from unspecified causes. FDA has asked the researchers to provide the methodology used to collect and study these specimens and to provide the tissue samples so the Agency can further investigate potential pancreatic toxicity associated with the incretin mimetics.

BACKGROUND: Drugs in the incretin mimetic class include exenatide (Byetta, Bydureon), liraglutide (Victoza), sitagliptin (Januvia, Janumet, Janumet XR, Juvisync), saxagliptin (Onglyza, Kombiglyze XR), alogliptin (Nesina, Kazano, Oseni), and linagliptin (Tradjenta, Jentadueto). These drugs work by mimicking the incretin hormones that the body usually produces naturally to stimulate the release of insulin in response to a meal. They are used along with diet and exercise to lower blood sugar in adults with type 2 diabetes.

RECOMMENDATIONS: FDA has not reached any new conclusions about safety risks with incretin mimetic drugs. This early communication is intended only to inform the public and health care professionals that the Agency intends to obtain and evaluate this new information. FDA will participate in the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and National Cancer Institute’s (NCI) Workshop on Pancreatitis-Diabetes-Pancreatic Cancer in June 2013 to gather and share additional information. FDA will communicate its final conclusions and recommendations when its review is complete or when the Agency has additional information to report.

The Warnings and Precautions section of drug labels and patient Medication Guides for incretin mimetics contain warnings about the risk of acute pancreatitis. FDA has not previously communicated about the potential risk of pre-cancerous findings  of the pancreas with incretin mimetics. FDA has not concluded these drugs may cause or contribute to the development of pancreatic cancer.

At this time, patients should continue to take their medicine as directed until they talk to their health care professional, and health care professionals should continue to follow the prescribing recommendations in the drug labels.

Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program:

Complete and submit the report Online: http://www.fda.gov/MedWatch/report.htm
Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to 1-800-FDA-0178


EMA: Recommendation to suspend tetrazepam-containing medicines

May 8, 2013

May 09, 2013 – This is from the News and Press Release Archive of the European Medicines Agency (EMA) as of April 29, 2013.  Find here the unedited release in full:

29/04/2013

Recommendation to suspend tetrazepam-containing medicines endorsed by CMDh

Following the recent recommendation by the Pharmacovigilance Risk Assessment Committee (PRAC), the Co-ordination Group for Mutual Recognition and Decentralised Procedures – Human (CMDh) has endorsed by majority the PRAC recommendation to suspend the marketing authorisations of tetrazepam-containing medicines across the European Union (EU). The CMDh, a body representing EU Member States, is responsible for ensuring harmonised safety standards for medicines authorised via national marketing authorisation procedures across the EU.

Tetrazepam, a medicine of the benzodiazepine class, is used in several EU Member States to treat painful contractures (such as in low back pain and neck pain) and spasticity (excessive stiffness of muscles).

The CMDh position will now be sent to the European Commission, which will take a legally binding decision throughout the EU.

The review of tetrazepam was triggered by the French National Agency for the Safety of Medicine and Health ProductsExternal link icon (ANSM), following reports of serious skin reactions with this medicine in France. Having assessed all available data on the risk of skin reactions, including post-marketing data in the EU and the published literature, the PRAC concluded that tetrazepam is associated with a low but increased risk of serious skin reactions (including Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS syndrome) compared with other benzodiazepines. The Committee also noted that, in the light of the risks identified, the available data on the effectiveness of tetrazepam were not sufficiently robust to support its use in the authorised indications.

The CMDh agreed with the PRAC conclusion that the benefits of these medicines do not outweigh their risks, and adopted a final position that the marketing authorisations should be suspended throughout the EU.

The suspension of the marketing authorisations can be lifted if the companies that market these medicines provide data identifying a specific group of patients for whom the benefits of tetrazepam-containing medicines outweigh the risks.

Information to patients

  • Tetrazepam is a muscle relaxant used in painful conditions such as low back pain and neck pain as well as spasticity (excessive stiffness of muscles).
  • As a result of the risk of unpredictable, serious skin reactions identified, the CMDh position is that tetrazepam-containing medicines should no longer be used in the EU.
  • If you are taking a tetrazepam-containing medicine, you should not suddenly stop taking tetrazepam without your doctor’s advice. You should make an appointment with your treating doctor to discuss your treatment. Your doctor may also consider an appropriate alternative treatment for you.

Information to healthcare professionals

  • In light of the unfavourable benefit-risk balance, doctors should review their patients’ treatment at their next appointment, and may consider an appropriate alternative treatment.
  • Pharmacists should refer patients on a new or repeat prescription for tetrazepam to their treating physician.

The CMDh position is based on the PRAC review of all available data on the risk of skin reactions with tetrazepam, including post-marketing data in the EU and the published literature, and the available information on efficacy in licensed indications:

  • The review found that half of the reported reactions with tetrazepam are skin disorders, which are sometimes serious, life-threatening or fatal. Serious skin reactions include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), erythema multiforme and drug rash with eosinophilia and systemic symptoms (DRESS) syndrome. They are unpredictable and can occur at any stage during treatment, including after short-term treatment, and at recommended doses.
  • In the pharmacovigilance database of the originator product, Myolastan, a total of 513 cutaneous (or allergic) reactions were identified. 65 cases of SJS and TEN were reported. Although the majority of cases occurred in patients taking concomitant medications, the causal link with tetrazepam was strong in a high number of cases.
  • The risk of skin reaction is higher with tetrazepam than with other benzodiazepines. This is possibly explained by a structural difference between tetrazepam and other benzodiazepines (i.e. the substituted cyclohexenyl ring of tetrazepam).
  • Regarding its efficacy, four studies showed no difference between tetrazepam and other active medicines when used for spasticity. The efficacy of tetrazepam for painful contractures is supported mainly by two small double-blind placebo-controlled clinical trials showing limited efficacy.

In view of the serious, potentially fatal, skin reactions and the limited efficacy of tetrazepam, the benefit-risk balance of tetrazepam-containing medicines is considered no longer favourable.


More about the medicine

Tetrazepam belongs to a group of medicines called benzodiazepines. It is taken by mouth to treat painful contractures (sustained shortening of muscle tissue), and spasticity (excessive stiffness of muscles).

Tetrazepam-containing medicines have been approved since the 1960s via national procedures in several EU Member States (Austria, Belgium, Bulgaria, Czech Republic, France, Germany, Latvia, Lithuania, Luxembourg, Poland, Romania, Slovakia and Spain), and are available on prescription under various trade names, including Epsipam, Miozepam, Musapam, Musaril, Myolastan, Myopam, Panos, Relaxam, Spasmorelax, Tetra-saar, Tetramdura and Tetraratio. The full list is available in Annex I on the EMA website.

Benzodiazepines work by attaching to certain receptors in the brain, thereby increasing the activity of a substance called gamma-amino butyric acid (GABA). GABA decreases the excitability of many brain cells. By increasing GABA activity, benzodiazepines have a calming effect on various functions of the brain. In particular, tetrazepam is used for its muscle relaxant effects.

More about the procedure

The review of tetrazepam-containing medicines was initiated in January 2013 at the request of France, under Article 107i of Directive 2001/83/EC, also known as the urgent Union procedure.

The review was first conducted by the Pharmacovigilance Risk Assessment Committee (PRAC), the Committee responsible for the evaluation of safety issues for human medicines, which made a set of recommendations. As tetrazepam-containing medicines are all authorised nationally, the PRAC recommendations were sent to the Co-ordination Group for Mutual Recognition and Decentralised Procedures – Human (CMDh), which adopted a final position. The CMDh is composed of representatives of all EU Member States. Its main responsibility is to resolve disagreements between Member States involved in mutual recognition or decentralised procedures, to ensure that patients have the same level of protection, no matter where they are in the EU.

As the CMDh position was adopted by majority vote, the CMDh position will now be sent to the European Commission, which will take an EU-wide legally binding decision.


When you turn blue

May 7, 2013

When you turn blue: Ezogabine [Potiga] Linked To Retinal Abnormalities And Blue Skin Discoloration

May 07, 2013 – The American Food and Drug Administration (FDA) just released a warning to the public that the anti-seizure medication Potiga (Ezogabine) can cause blue skin discoloration and eye abnormalities characterized by pigment changes in the retina. FDA does not currently know if these changes are reversible. FDA is working with the manufacturer to gather and evaluate all available information to better understand these events. FDA will update the public when more information is available.

BACKGROUND: Potiga is approved as adjunctive (added on to other anti-seizure medications) treatment of partial-onset seizures in adult patients 18 years and older. Pigment changes in the retina have the potential to cause serious eye disease with loss of vision. It is not yet known whether the retinal pigment changes caused by Potiga lead to visual impairment, although several patients have been reported to have impaired visual acuity. In some cases, retinal abnormalities have been observed in the absence of skin discoloration. The skin discoloration in the reported cases appeared as blue pigmentation, predominantly on or around the lips or in the nail beds of the fingers or toes, but more widespread involvement of the face and legs has also been reported. Scleral and conjunctival discoloration, on the white of the eye and inside eyelids, has been observed as well. The skin discoloration generally occurred after four years of treatment with Potiga, but has appeared sooner in some patients.

RECOMMENDATION: In light of this new safety information all patients taking Potiga should have a baseline eye exam and periodic eye exams that should include visual acuity testing and dilated fundus photography, and may include fluorescein angiograms (FA), ocular coherence tomography (OCT), perimetry, and electroretinograms (ERG). Potiga should be discontinued if ophthalmic changes are observed unless no other treatment options are available. If a patient develops skin discoloration, serious consideration should be given to changing to an alternate medication. Patients who are taking Potiga and develop any changes in their vision or any discoloration of their skin, including of their lips and nail beds, should contact their health care professional right away.

Patients should not stop taking Potiga without talking to their health care professional. Stopping such treatment suddenly can cause serious and life-threatening medical problems such as recurrence of seizures.

REPORTING: Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program at http://www.fda.gov/MedWatch/report.htm. Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to 1-800-FDA-0178.


FDA limits duration and usage of Tolvaptan (Samsca) due to possible liver injury leading to organ transplant or death

May 2, 2013

April 30, 2013 –   The U.S. Food and Drug Administration (FDA) has determined that the drug Tolvaptan (Samsca) should not be used for longer than 30 days and should not be used in patients with underlying liver disease because it can cause liver injury, potentially requiring liver transplant or death.  Tolvaptan (Samsca) is used to treat low sodium levels in the Tolvapanblood. An increased risk of liver injury was observed in recent large clinical trials evaluating Tolvaptan (Samsca) for a new use in patients with autosomal dominant polycystic kidney disease (ADPKD. FDA has worked with the manufacturer to revise the Tolvaptan (Samsca) drug label to include these new limitations.

The Tolvaptan (Samsca) drug label has been updated to include the following information:

  • Limitation of the duration of Samsca treatment to 30 days. (Dosage and Administration and Warnings and Precautions sections)
  • Removal of the indication for use in patients with cirrhosis, a condition that involves scarring of the liver due to injury or long-term disease.  Use of Samsca in patients with underlying liver disease, including cirrhosis, should be avoided because the ability to recover from liver injury may be impaired. (Indications and Usage and Use in Specific Populations sections)
  • Description of liver injuries seen in clinical trials of patients with autosomal dominant polycystic kidney disease (ADPKD).
  • Recommendation to discontinue Samsca in patients with symptoms of liver injury.

The manufacturer of Tolvaptan (Samsca), Otsuka American Pharmaceutical, Inc., issued a Dear Health Care Provider letter on the potential risk of liver injury on January 22, 2013FDA is reviewing the information from clinical trials of patients with ADPKD and will update the public on the risk of liver injury with Tolvaptan (Samsca) if more information becomes available.


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