Found this in my reading up on mdr-tb......google it and go to cdc
What is multidrug-resistant tuberculosis (MDR TB)?
Multidrug-resistant TB (MDR TB) is caused by an organism that is resistant to at least isoniazid and rifampin, the two most potent TB drugs. These drugs are used to treat all persons with TB disease.
What is extensively drug resistant tuberculosis (XDR TB)?
Extensively drug resistant TB (XDR TB) is a rare type of MDR TB that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin, or capreomycin).
Because XDR TB is resistant to the most potent TB drugs, patients are left with treatment options that are much less effective.
XDR TB is of special concern for persons with HIV infection or other conditions that can weaken the immune system. These persons are more likely to develop TB disease once they are infected, and also have a higher risk of death once they develop TB.
The problem is that nobody employed by Insmed would ever say anything in public which could be interpreted by the FDA as promoting off-label use.
Poster Board 1018: A Randomized, Double-Blind, Placebo-Controlled Study Of Liposomal Amikacin For Inhalation (Arikace®) In Patients With Recalcitrant Nontuberculous Mycobacterial Lung Disease, [Publication Number: A4126]
K.N. Olivier, MD, MPH
R. Gupta, M.D.
C.L. Daley, MD
K.L. Winthrop, MD, MPH
S. Ruoss, M.D.
D.J. Addrizzo-Harris, MD
P. Flume, MD
D. Dorgan, M.D.
M.A. Salathe, MD
B.A. Brown-Elliott, MS, MT (ASCP), SM
R.J. Wallace, MD
D.E. Griffith, MD
Arikace in NTM Study Group.
Session Info: Poster Discussion Session, [C27] DIAGNOSIS AND TREATMENT OF NONTUBERCULOUS MYCOBACTERIA INFECTIONS
Day/Date: Tuesday, May 20, 2014
Session Time: 8:15 AM - 10:45 AM
Poster Viewing: 8:15-9:15
Room: Sapphire Ballroom E-F (Level 4)
Location: Hilton San Diego Bayfront
That was an historic moment - the very first time the Company has publicly acknowledged the potential of Arikayce in the treatment of Tuberculosis.
There's an informative FDA presentation on the various GAIN fast-track pathways, which implies that a significant proportion of Breakthrough Therapy designations have subsequently been withdrawn because an expedited approval would have outpaced the manufacturing timeline.
I'm guessing Insmed's projections for the likely demand for the drug under various approval scenarios would have to have factored in off-label use in MDR-TB.