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May 24, 2012

TO: Marco Cavaleri
CC: Hans-Georg Eichler
European Medicines Agency
7 Westferry Circus- Canary Whar
London E14 4 HB
United Kingdom

RE: Conducting drug-drug interaction studies for bedaquiline (TMC207) and delamanid (OPC6783)

Dear Dr. Cavaleri,

We wish to draw to your attention our deep concern at development of two new products extremely important for tackling the growing epidemic of drug resistant tuberculosis (TB). Those arebedaquiline (TMC207) by Janssen and delamanid (OPC6783) by Otsuka.

These two new investigational TB drugs—the farthest along in development—are being studied in people withmulti-drug resistant TB, extensively drug resistant TB (XDR-TB) and pre-XDR-TB.  Both are entering phase III studies and have or are likely to be submitted to regulatory authorities this year. Yet bedaquiline and delamanid have not been studied together in the pharmacokinetic (PK) studies that will tell us how they interact and whether they are safe to use together.

However, when they are approved, it is inevitable that they will be used together in the field, because people with XDR-TB desperately need effective new oral drugs to shorten their time to culture conversion, and hopefully, cure.

Therefore, we call upon the FDA to require that the respective drug sponsors, Janssen and Otsuka, conduct the necessary PK studies to demonstrate whether the drugs are safe to use together. This requirement should be a condition for accelerated approval.

We are similarly making this request to the U.S. Food and Drug Administration. We are also in discussions with the drug sponsors to encourage the expeditious commencement of the necessary PK studies to ensure that sufficient data are available to inform guidance for the appropriate use of the two drugs in combination, once they are both approved.

We are readily available to dialogue further and look forward to your response. Please respond to Erica Lessem at at your earliest convenience.

Yours truly,


Polly Clayden, United Kingdom

Colleen Daniels, Australia

Nathan Geffen, South Africa

Denis Godlevskiy, Russian Federation

Mark Harrington, United States

Giselle Israel, Brazil

Bactrin Killingo, Kenya

Blessina Kumar, India

Erica Lessem, United States

Khairunisa Suleiman, South Africa

Ezio Tavora dos Santos Filho, Brazil

Wim Vandevelde, Belgium


for the Global Tubercuclosis Community Advisory Board (TB CAB)



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