Generics of ‘Opsumit’ face tough competition in KOR

Samjin Pharm has launched Masiten after winning a patent challenge, and the priority of sale is set to expire on the first of next month

Daewoong’s ‘Macimit’ will enter the 15 billion won market, despite generics only having a 0.5% market share

The product photos of Opsumit (left) and Masiten (right).

In the market for the treatment of pulmonary arterial hypertension (PAH) with the active ingredient macitentan, the period of priority of sale given to the first generic drugs is set to expire on the first of next month.

 

While Janssen’s ‘Opsumit’ competes with Samjin Pharm’s ‘Masiten’ in the market, Daewoong Pharmaceutical’s newly launched ‘Macimit’ is expected to join the competition.

 

As the generic’s market share is insignificant at below 1%, Daewoong’s introduction into the market draws the pharmaceutical industry’s attention related to potential market expansion in the treatment of pulmonary arterial hypertension (PAH) with the active ingredient macitentan.

 

The sales of Opsumit 13%↓ in a year due to drug pricing decreases following the generic launch. The market size for the treatment of pulmonary arterial hypertension (PAH) with the active ingredient macitentan totaled 15.2 billion won last year, according to a pharmaceutical market research company IQVIA on the 29th.

 

This figure represents a 13% decrease from 17.4 billion won in 2022.

 

The market has gradually expanded, with 11.9 billion won in 2019, 16.3 billion won in 202, 16.0 billion won in 2021, and 17.4 billion won in 2022.

 

However, the sales decreased by over 10% last year.

 

The decrease in sales is likely due to the drug pricing decrease of the original medicine following the generic launch.

 

Samjin Pharm filed a claim for passive trials to confirm the scope of a right involving the active ingredient patent of Opsumit against Janssen in May 2022.

 

Samjin Pharm won the first trial in April of the following year.

 

Last May, Samjin Pharm launched Masiten Tab after receiving the trial results.

 

During the same period, the price of Opsumit, Janssen’s original medicine, decreased by 30%.

 

The Ministry of Health and Welfare (MOHW) issued a decrease in Opsumit price following the reimbursement listing of the drugs with the same active ingredient.

 

Janssen has appealed to the patent court in response to the first trial judgement.

 

However, the company did not file a suspension of execution related to the drug pricing reduction.

 

While accepting the government’s measure of drug pricing reduction, Janssen has decided to continue with the patent dispute with Samjin Pharm to protect the patent right.

 

The quarterly sales of the treatments Opsumit, the original drug for treating pulmonary arterial hypertension (PAH) with the active ingredient macitentan, and its generic, Masiten.

The quarterly sales of Opsumit steadily recorded 4.0 to 4.6 billion won until the second quarter of last year, then rapidly dropped to around 3 billion won after the third quarter.

 

The decrease is due to a reduction in drug pricing that took effect after the third quarter of last year, following the generic launch in May of last year.

 

Masiten had a market share of 0.5% in Q4 last year.

 

Will Daewoong’s introduction lead to an expansion of the generics market?

 

Samjin received a right for priority of sale after successfully challenging the Opsumit patent.

 

Daewoong also challenged the same patent for Opsumit, but Samjin was a step ahead in obtaining the approval for its generic version.

 

Therefore, Samjin obtained the priority of sale for the Opsumit generic alone.

 

The priority of sale was granted from April 21st of last year until March 1st of this year.

 

Although Samjin sold the generic without competition, Masiten’s impact on the market is insignificant.

 

Last year, Masiten generated cumulative sales of merely over 20 million won.

 

After the priority of sale ends, another generic is expected to enter the market on the 1st of next month.

 

Daewoong Pharmaceutical obtained approval for their Macimit, as a generic version of Opsumit, in May of last year.

 

It is anticipated that Daewoong Pharmaceutical will launch the product after next month.

 

Daewoong’s introduction draws the pharmaceutical industry’s attention regarding the potential market expansion of generics containing the active ingredient macitentan.

 

In the market of the treatment of pulmonary arterial hypertension (PAH) with the active ingredient macitentan, Masiten had a market share of 0.5% in the fourth quarter of last year.