Contrave Launch Raises Hopes For Korean Obesity Market Growth
This article was originally published in PharmAsia News
Executive Summary
Following the successful debut of Arena's Belviq in 2015, Orexigen's Contrave, which will be released in South Korea in the second quarter through its partner Kwang Dong Pharm, is set to boost the domestic obesity treatment market which had been depressed since the country banned sales of sibutramine-based drugs in 2010.
SEOUL - Orexigen Therapeutics Inc.'s Contrave (naltrexone HCI and bupropion HCI extended release) is set to debut in South Korea in June as a monotherapy for weight management in overweight or obese adult patients, raising hopes the new treatment will boost the domestic obesity market.
Orexigen has already shipped an initial order of Contrave tablets to Kwang Dong Pharmaceutical Co. Ltd., its partner for South Korea. This shipment and a subsequent firm order from Kwang Dong for later in 2016 total about $5.9m, said Orexigen.
Contrave is poised to compete with Arena Pharmaceuticals Inc.'s Belviq (lorcaserin), which debuted in South Korea in early 2015 through its partner Ildong Pharmaceutical Co. Ltd. and is settled comfortably in the domestic obesity treatment market. Prescriptions of Belviq have reportedly reached KRW13.6bn ($11.6m) in 2015, becoming the top obesity drug in the country, albeit still with modest sales.
The second most prescribed obesity treatment last year was reportedly Alvogen Korea’s Furing, followed by Daewoong Pharmaceutical Co. Ltd.’s Dietamin (phentermine).
The total South Korean obesity treatment market had reached KRW100bn in 2009, but its value is estimated to have fallen to KRW80bn since, following a local sales ban on sibutramine-based drugs in 2010 due to adverse effects.
Competitive Benefits
Contrave, approved by the US FDA in September 2014, is therefore a latecomer but has seen stronger uptake in the US compared to Belviq and Vivus Inc.’s Qsymia (phentermine/topiramate). Belviq and Qsymia received US FDA approval in June 2012 and July 2012, respectively.
Contrave’s promising early uptake in the US is predominantly due to its improved risk-benefit profile compared to that of Belviq and Qsymia. While Belviq has a favorable safety profile, it only possesses modest efficacy. Qsymia’s efficacy is considered superior, but the drug is associated with several safety concerns, noted Datamonitor Healthcare
.
"Contrave is the only appetite suppressant that has received approval in the US and Europe at the same time," said an official at Kwang Dong.
Kwang Dong, which has a competitive beverage business, now appears to be searching for a new growth engine in the pharma business, helped by the latest partnership for Contrave.
Under the South Korea distributorship agreement with Kwang Dong reached last year, the South Korean pharma will be responsible for all commercialization activity and expenses for the drug. Orexigen will supply Contrave tablets to Kwang Dong in exchange for a $7m payment received in 2015, approximately 35-40% of net sales, potential sales-based milestone payments, and other fees (Also see "Contrave Bound For Korea As Orexigen Links With Local Firm" - Scrip, 12 Aug, 2015.).
Growing Market
Obesity and related comorbidities are a serious health problem in South Korea, where approximately 38% of men and 26% of women are obese according to recent statistics from the National Health Institute. In 2015, sales of anti-obesity medicines exceeded $71m in Korea, a 21% increase over the prior year.
"The market for anti-obesity medicines is growing rapidly in South Korea as obesity and related comorbidities are increasingly recognized as a serious health problem there," noted Michael Narachi, CEO of Orexigen.
The exact neurochemical effects of Contrave leading to weight loss are not fully understood. It has two components: naltrexone, an opioid antagonist, and bupropion, a relatively weak inhibitor of the neuronal reuptake of dopamine and norepinephrine.
Non-clinical studies suggest that naltrexone and bupropion have effects on two separate areas of the brain involved in the regulation of food intake: the hypothalamus (appetite regulatory center) and the mesolimbic dopamine circuit (reward system).
Other Candidates
According to BioMedTracker, several other anti-obesity drug candidates with South Korean connections are also undergoing Phase II clinical trials, including Hanmi Pharmaceutical Co. Ltd.'s GLP-1 receptor agonist HM11260C, which has been licensed out to Sanofi and is given a 26% likelihood of US approval.
Meanwhile, clinical trials of Chong Kun Dang Pharmaceutical Corp.’s Prader-Willi syndrome candidate beloranib, which has been licensed out to Zafgen Inc., have been suspended.
But Zafgen is hoping the strength of the Phase III efficacy data for beloranib, unveiled Jan. 20, along with further study results expected this quarter and a risk management plan it is developing, can lead to the FDA lifting a clinical hold on the safety-troubled drug (Also see "Zafgen Thinks Phase III Data Could Be Key To Lifting FDA Hold" - Pink Sheet, 20 Jan, 2016.).
The FDA placed beloranib on a complete clinical hold Dec. 2 following a second death due to thromboembolism in the treatment arm of the Phase III study, called bestPWS ZAF-311.