GC and GSK Korea will jointly sell the latter's new shingles vaccine, Shingrix.

According to industry sources, the two companies recently signed a co-promotion contract for Shingrix.

GC started training its sales representatives before the full-scale market release possibly as early as the end of 2022.

The co-promotion agreement follows GSK Korea's winning approval for Shingrix from the Ministry of Food and Drug Safety in September 2021.

Under the approval, hospitals can use Shingrix to prevent herpes zoster, also known as shingles, in adults over 50 or people aged between 18 and 49 who are at a high risk of shingles due to reduced immunity or immunosuppression.

Shingrix is ​​the first recombinant inactivated vaccine that combines glycoprotein E, a protein component of VZV, and AS01B. This immune enhancer boosts the immune response against antigens and induces a strong and sustained immune response.

A patient receives 0.5 mL of the vaccine intramuscularly twice at an interval of two months. As Shingrix is an inactivated vaccine, hospitals can also administer the vaccine to immune-compromised patients.

Shingrix has quickly expanded its market share in other countries.

After its launch in the U.S. in 2017, Shingrix took away the market share of Zostavax and controlled 98 percent of the U.S. market in just a year. The vaccine holds a 100 percent market share in some countries, including Canada, industry data showed. 

The new shingles vaccine's remarkable sales growth is attributed to its higher efficacy than its competitors.

GSK had confirmed a disease prevention effect of around 90 percent in all age groups through various clinical trials.

In a clinical trial involving adults over 50 years of age (ZOE-50), Shingrix proved a 97.2 percent disease-prevention effect during 3.2 years of follow-up. The vaccine also showed an 89.8 percent efficacy during 3.7 years of follow-up in a clinical trial for those over 70 years old (ZOE-70).

In comparison, MSD's Zostavax showed a 51 and 41 percent disease prevention effect in patients over 50 and 70 years of age, respectively.

SK Bioscience's Skyzoster does not have a separate disease prevention effect figure. However, as the vaccine received approval after passing a non-inferiority test with Zostavax, the disease prevention effect of the vaccine is likely similar to that of Zostavax.

GC has accumulated experience  in marketing a shingles vaccine as it co-marketed MSD's shingles vaccine Zostavax in the past.

After signing a co-promotion contract with MSD in 2013, GC jointly sold Zostavax for eight years until 2020.

Shingles occur when the varicella-zoster virus (VZV), which causes chickenpox, remains dormant in childhood and then reactivates. An age-related decline in immunity mainly causes herpes zoster. With age, the number and function of immune cells that inhibit VZV reactivation decrease, increasing the incidence and severity of herpes zoster.

Meanwhile, both companies declined to comment regarding the recent co-promotion agreement.