Thyroid UK
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Naltrexone - and weight loss?

Naltrexone - and weight loss?

As we see a number of people interested in low dose naltrexone in the context of thyroid disorder/autoimmune disease, I thought this statement might be of some interest, albeit with serious question marks. Obviously the combination with bupropion (Welbutrin, Zyban) more often thought of as an anti-depressant raises more issues than it answers!

Orexigen Receives CHMP Day 180 List of Outstanding Issues

SAN DIEGO, July 30, 2014 /PRNewswire/ -- Orexigen Therapeutics, Inc. (Nasdaq: OREX) today announced it has received the Day 180 List of Outstanding Issues (LOI) from the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) for the NB32 Marketing Authorization Application (MAA). NB32 (naltrexone sustained release (SR) / bupropion SR) is an investigational drug candidate being evaluated for weight loss.

The key questions of the earlier Day 120 time point were adequately addressed by the Company based in part on the interim analysis of the Light Study cardiovascular outcomes trial. However, the Day 180 LOI raised new issues. Specifically, the CHMP requested further justification of the balance of benefits and risks of NB32 treatment as well as additional information regarding post-approval risk minimization measures and pharmacovigilance activities. Details were also requested of the Company's third-party suppliers of bupropion related to their starting materials.

The Company believes the CHMP's requests are addressable. However, in regards to the third-party suppliers, in order to have the time to coordinate responses from these suppliers, Orexigen has requested an extension of one month and plans to submit its response to the Day 180 LOI in September.

"We believe NB32 has a benefit risk profile that supports approval, and we are confident in our ability to justify its profile to the CHMP," said Michael Narachi, CEO of Orexigen.

About Orexigen Therapeutics

Orexigen Therapeutics, Inc. is a biopharmaceutical company focused on the treatment of obesity. The Company's lead product candidate is NB32. Based on successful results of the Light Study, an ongoing cardiovascular outcomes trial, Orexigen's strategy for NB32 is to pursue approvals worldwide and pharmaceutical partnerships for global commercialization. The Company has submitted applications for marketing authorization in the United States and Europe, with potential approvals in 2014. If approved, North American partner Takeda Pharmaceuticals will commercialize NB32 in the United States. The Company's other product candidate, Empatic™, has completed Phase 2 clinical trials. Further information about the Company can be found at


2 Replies

I tried low does Naltrexone and would have loved to continue, but it upset my stomach badly. As usual, you trade on set of symptoms for another.



I have been taking LDN for over a year and a half and so far (unfortunately) no weight loss 'side effect', but I've heard of quite a few people who have unintentionally lost weight taking Welbutrin. Interesting!