FDA approves drug for traveler's diarrhea
The most common travel-related illness, travelers' diarrhea is defined by the FDA as three or more unformed stools in 24 hours in a person who is traveling. The most common cause is bacteria found in food and water. Rifamycin (Aemcolo) is an antibacterial drug indicated to treat travelers' diarrhea caused by noninvasive strains of Escherichia coli in adults not experiencing fever or blood in the stool. It is administered orally over 3 or 4 days. In clinical trials, the most common adverse reactions were headache and constipation.
This drug is not recommended for use in patients with diarrhea complicated by fever and/or bloody stool or with diarrhea due to pathogens other than noninvasive strains of E. coli, because it is not effective in these cases. It should not be used by patients with a known hypersensitivity to rifamycin, any of the other rifamycin class of antimicrobial agents (such as rifaximin), or any component of Aemcolo.
Source: FDA approves new drug to treat travelers' diarrhea. US Food & Drug Administration. News release. November 16, 2018.
High cost discourages optimal insulin use
In the past 10 years, insulin prices have tripled and out-of-pocket costs per prescription doubled in the US. To determine how the high cost of insulin contributes to treatment nonadherence, researchers administered a survey to patients with type 1 or type 2 diabetes for whom insulin was prescribed within the past 6 months and who had an outpatient visit at the Yale Diabetes Center between June and August 2017. The primary outcome was cost-related underuse in the past 12 months, defined by a positive response to any one of six questions about patients' insulin use. The survey asked patients if the cost of insulin caused them to use less insulin than prescribed, try to “stretch out” the insulin dosage, take smaller doses than prescribed, stop using insulin, fail to fill an insulin prescription, or not start taking insulin as prescribed. The researchers also examined the association between sociodemographic, economic, and clinical factors and cost-related underuse, and the association between cost-related underuse and poor glycemic control (A1C of 9% or more obtained at time of visit or within 3 months). Adjustments were made for gender, body mass index, diabetes duration, and income.
Based on responses from 199 patients, the study showed that 25.5% (51 patients) reported cost-related insulin underuse. These patients were more likely to report lower incomes and to have poor glycemic control. About 61% of these patients discussed the cost of insulin with their clinician and 29% changed insulin type due to cost. The type of prescription drug coverage was not significantly associated with cost-related underuse.
The authors write, “These results highlight an urgent need to address affordability of insulin.”
Source: Herkert D, Vijayakumar P, Luo J, et al. Cost-related insulin underuse among patients with diabetes. JAMA Intern Med. [e-pub Dec. 3, 2018].
New approval for certain types of PTCL
The FDA has expanded the indications for brentuximab vedotin injection (Adcetris) to include certain types of peripheral T-cell lymphoma (PTCL). This is the first FDA approval for treatment of newly diagnosed PTCLs—rare, fast-growing non-Hodgkin lymphomas that develop from T-cells.
Brentuximab is a monoclonal antibody that binds to the CD30 protein found on some cancer cells. Under the new approval, it can be used to treat adults with previously untreated systemic anaplastic large cell lymphoma (ALCL) and other CD30-expressing PTCLs in combination with chemotherapy. It was previously approved to treat adults with previously untreated stage III or IV classical Hodgkin lymphoma (cHL), cHL after relapse, cHL after stem cell transplant when a patient is at a high risk of relapse or progression, systemic ALCL after failure of other treatment, and primary cutaneous ALCL or CD30-expressing mycosis fungoides after failure of other treatment.
The most common adverse reactions to brentuximab plus chemotherapy include peripheral neuropathy, nausea and vomiting, diarrhea, leukopenia, fatigue, oral ulcers, constipation, alopecia, fever, and anemia. Patients should be monitored for infusion reactions, anaphylaxis, neuropathy, fever, gastrointestinal complications, infections, tumor lysis syndrome, serious skin reactions, pulmonary toxicity, and hepatotoxicity. In addition, the prescribing information includes a Boxed Warning about the risk of progressive multifocal leukoencephalopathy, a potentially fatal infection of the brain.
Source: FDA approves first-line treatment for peripheral T-cell lymphoma under new review pilot. US Food & Drug Administration. News release. November 16, 2018.
Pediatric drug studies are often unfinished
Many drugs currently prescribed to children have not been studied or formally approved for pediatric use. The Pediatric Research Equity Act of 2003 authorizes the FDA to require postmarketing clinical studies on drug safety and effectiveness for pediatric patients, but recent research shows that many of these studies are never completed.
Researchers examined 114 new drugs or new uses for drugs that were approved by the FDA between 2007 and 2014. A total of 222 postmarketing studies in children were required for these approvals. As of December 2017, only 34% of those studies had been completed, and only 45% of completed studies had been reported in a journal. At the time of approval, only 16% of drugs approved with a mandate for postmarketing studies were labeled with any information on pediatric efficacy, safety, or dosing. This increased to only 41% after a median follow-up of 7 years.
“As a clinician, I was struck early on by how little evidence we often have to guide medication use in children,” commented study coauthor Florence Bourgeois, MD, MPH. “Although the FDA has an established process to ensure medicines are safe and effective in adults, this has historically been lacking for children.” The authors recommend more FDA oversight and use of enforcement tools to ensure completion of pediatric studies.
Sources: Hwang TJ, Orenstein L, Kesselheim AS, Bourgeois FT. Completion rate and reporting of mandatory pediatric postmarketing studies under the US Pediatric Research Equity Act. JAMA Pediatr. [e-pub Nov. 19, 2018]. Two thirds of required pediatric post-marketing drug studies are missing. Boston Children's Hospital. News release. November 19, 2018.