Several Medical Letter readers have asked about the meaning of non-inferiority trials. A non-inferiority trial is a comparison with an active control to determine whether the difference in response between the new drug and the active control is small enough (less than some pre-specified margin) to demonstrate that the new treatment is not less effective (or is only slightly less effective) than the control in achieving the primary outcome.1,2 Non-inferiority trials are appropriate when a proven effective treatment already exists and assigning some patients to a placebo group would be unethical...

The FDA has approved Rebyota (Ferring), a rectally-administered, live fecal microbiota suspension, for prevention of additional recurrences of Clostridioides difficile infection (CDI) following antibiotic treatment for a recurrent episode of CDI in adults. Rebyota is the first microbiome-based treatment to be approved for this indication. It is not approved for initial treatment of CDI. Fecal microbiota transplantation (FMT) has been used in patients with multiple CDI recurrences.

The FDA has approved three new once-daily fixed-dose antiretroviral drug combinations for treatment of HIV-1 infection. Symfi and Symfi Lo (Mylan) contain the non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz and the nucleoside reverse transcriptase inhibitors (NRTIs) lamivudine and tenofovir disoproxil fumarate (TDF) and were approved as complete antiretroviral regimens. Symfi Lo contains a lower dose of efavirenz than both Symfi and Atripla, a fixed-dose combination of efavirenz, TDF, and the NRTI emtricitabine that was approved in 2006. Cimduo (Mylan), which...

MoviPrep (Salix) is a new polyethylene glycol (PEG)-based bowel cleansing preparation approved for use in adults prior to colonoscopy. It contains ascorbic acid, which acts as an additional cathartic and flavoring agent, and requires a lower volume of fluid (3 L compared to the traditional 4 L) than most other PEG products. HalfLytely is an FDA-approved 2-L PEG product, but it must be taken with bisacodyl.

Posaconazole (Noxafil - Schering-Plough), an oral azole antifungal with a chemical structure similar to that of itraconazole (Sporanox), has been approved by the FDA to prevent Candida and Aspergillus infections in severely immunocompromised patients and for treatment of oropharyngeal candidiasis. It is likely also to be used off-label for treatment of other fungal infections, including those caused by Mucor and other Zygomycetes.

The dopamine agonist pramipexole (Mirapex - Boehringer Ingelheim) is the second drug approved by the FDA for treatment of moderate to severe restless legs syndrome (RLS). Ropinirole (Requip), another dopamine agonist, was approved for RLS in 2005. Both of these drugs were first approved for treatment of Parkinson's disease.

The FDA has approved Triumeq (Viiv Healthcare), a fixed-dose combination of the integrase strand transfer inhibitor (INSTI) dolutegravir and the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir and lamivudine, for once-daily treatment of HIV-1 infection. Dolutegravir (Tivicay) was approved as a single agent in 2013.

Standard approaches to therapy for gastroesophageal reflux disease (GERD) include lifestyle changes, over-the-counter and prescription drugs, and sometimes surgery. Emerging endoscopic anti-reflux procedures that are less invasive than surgery are potential additions to current treatment options. An endoscopicallyguided radiofrequency (RF) energy delivery system, Stretta (Curon Medical), was approved by the FDA for treatment of GERD in 2000.

Sitagliptin (Januvia) and metformin (Glucophage, and others) are now available in a single tablet (Janumet - Merck) for treatment of type 2 diabetes. The combination is approved by the FDA for use in patients not adequately controlled by sitagliptin or meformin alone or in those already taking both drugs. Metformin is also available in combination with the thiazolidinediones pioglitazone and rosiglitazone and with the sulfonylureas glipizide and glyburide.

The FDA has approved ranibizumab (Lucentis - Genentech) as an intravitreal injection for treatment of neovascular (wet) age-related macular degeneration (AMD). Ranibizumab is a derivative of bevacizumab (Avastin), which is FDA-approved for intravenous treatment of metastatic colorectal cancer and nonsmall cell lung cancer, but has also been used off label for intravitreal treatment of neovascular AMD.