Antidepressant Pristiq’s first generic seeks approval

Generic with modified saline base applies for approval to MFDS on Feb. 6

Successfully evades patent infringement, immediate market release possible

Pfizer

Apparently, generic makers are knocking on the door of depression medication Pristiq ER tablet.

 

This is the first time the original’s saline base-modified drug is applying for an approval.

 

On Feb.

 

10, Korea’s Ministry of Food and Drug Safety (MFDS) notified the Pristriq’s patent holder Pfizer that a drug with desvenlafaxine, the original’s active pharmaceutical ingredient (API), on modified saline base has applied for clearance on Feb.

 

6.

 

The original Pristiq ER tablet used succinate as a base, but the investigational drug has based the API on benzoic acid.

 

The generic’s approval application has been predicted long before, as Pristiq’s post-marketing surveillance (PMS) period of six years has expired on Feb.

 

5.

 

Although a company launching a new drug in Korea is imposed with a duty to conduct PMS for a set period of time, the original is protected from generic makers with the same API applying for approval during the period.

 

As a result, generic makers have waited for the original’s PMS period to expire on Feb.

 

5 and applied for approval straight away.

 

However, the antidepressant generics are unable to launch immediately despite MFDS’ green light, as the original has patented the saline base, expected to expire on Oct.

 

7, 2022.

 

For immediate release, the generic makers would have to challenge the patent, and the approval processing should undergo under the premise of launching the product regardless of the patent.

 

The conditions are stipulated by the Drug Approval-Patent Linkage System.

 

However, the group of applicants seeking for clearance on their generics seems likely to release the product right away.

 

In last July, five companies have requested for negative confirmation of patent scope and successfully evaded patent infringement.

 

Whan In Pharm, Myung In Pharm, Hanlim Pharm, Nexpharm Korea, and Samjin Pharm are the companies.

 

As Pfizer is not filing an appeal against the case, their patent infringement is close to a done deal.

 

If all the five companies have applied for desvenlafaxine generics on Feb.

 

6, they could win preferential sales rights on those items, because they have fulfilled three conditions—first to request trial, successfully challenged patent, and first to apply for approval.

 

Pfizer’s Pristiq ER tablet has been evaluated as a next generation depression medication as it has lower risk of drug interaction and less frequent adverse reaction reported like body weight change or sexual dysfunction.

 

According to UBIST last year, the original drug has generated 3.1 billion won from outpatient prescription.

 

Although the drug has sold lesser than other 10-billion-won-club Lundbeck’s Lexapro and Lilly’s Cymbalta, the drug has promising prospective as the antidepressant market in Korea has skyrocketed recently and surpassed 150 billion won.

 

Assessing the changes in the market, central nervous system (CNS) drug-specializing pharmaceutical companies have been eyeing on Pristiq’s follow-on drugs.

 

Pristiq ER tablet is administered once-daily to adult with depression.

 

The generics with modified saline base have applied for indication with same effect and administration method.