By Brendan Pierson

Sept 23 (Reuters) - Amneal Pharmaceuticals has sued Colorado in an effort to block a state law requiring it to provide free generic EpiPens to pharmacies.

In a complaint filed on Friday in federal court in Denver, Colorado, New Jersey-based Amneal said that the law, which was passed last year and took effect in January, was an illegal taking of its property under the 5th Amendment of the U.S. Constitution.

The law aims to bring down the often high costs of auto-injectors like Viatris' EpiPen, handheld devices that treat life-threatening severe allergic reactions by automatically injecting a dose of the drug epinephrine.

It requires all health insurance plans that cover auto-injectors to provide them at a cost of no more than $60 for a two-pack, a requirement that Amneal is not challenging.

The law also requires pharmacies to provide the injectors with the same $60 price cap to people whose insurance does not cover them, and manufacturers in turn to provide the pharmacies with a free replacement or reimbursement for each injector sold under that requirement.

The company's generic version of the device Adrenaclick, which was approved in 2018, generally costs more than $100 without insurance, while a pack of brand-name EpiPens can cost as much as $700.

Amneal said it has had to replace 304 injectors since the program began.

"Colorado's reimburse-or-resupply requirement plainly effects an unconstitutional, 'per se physical taking' of Amneal's personal property in violation of the Fifth Amendment," it said, asking the court to issue an order blocking enforcement of the law.

The office of Colorado Attorney General Philip Weiser declined to comment.

Viatris drew harsh criticism from U.S. lawmakers in 2016 for increasing the price of EpiPens sixfold in less than a decade.

It reached a $465 million settlement with the U.S. Department of Justice in 2017 over claims that it used anticompetitive tactics to drive up the price, and in 2022 agreed to pay $264 million to settle related private litigation.

Pfizer, which manufactured the product for Viatris, has also reached settlements with private plaintiffs totaling almost $400 million.

The case is Amneal Pharmaceuticals v. Weiser, U.S. District Court for the District of Colorado, No. 1:24-cv-02609.

For Amneal: Jay Lefkowitz of Kirkland & Ellis

For Colorado: not yet available

Read more:

Mylan, U.S. finalize $465 million EpiPen settlement

EpiPen antitrust litigation settled; Viatris to pay $264 million

Pfizer to pay $50 mln to settle drug wholesalers' EpiPen antitrust claims

(Reporting By Brendan Pierson in New York)