Drugs giant Pfizer is paying nearly $24 million to the US Department of Justice (DOJ) to settle allegations that its contributions to an assistance fund were kickbacks. The company said the settlement reflects its desire to put the case behind it and focus on the needs of patients.

Pfizer insisted, however, that donations to independent charitable organizations “can provide significant assistance to patients with their co-payments for prescriptions, and that it “continues to believe these programs help patients lead healthier lives."

The investigation into the New York drugmaker’s practices is part of US authorities’ look at a co-pay charity scheme said to have involved up to now several of biopharma's biggest names, including Johnson & Johnson, Celgene, Biogen, Gilead Sciences, Regeneron, United Therapeutics, Horizon and Valeant.

The government said drugmakers have been joining forces with NGOs to promote their medicines and in some cases lift prices, thereby circumventing the rules of federally funded healthcare programs. It said Pfizer probably used a patient foundation as a "conduit" to cover Medicare patients' co-payments for its kidney cancer drugs Sutent and Inlyta, as well as its arrhythmia drug Tikosyn.

Pfizer was accused of hiking prices on Tikosyn by 40% at the end of 2015. Authorities said it worked with the foundation to create a fund that would help patients afford co-pays at the new price. It then referred patients to the fund.

The US Federal Bureau of Investigation (FBI) said the alleged setup "violates the basic trust patients extend to the healthcare system and threatens the financial integrity of the Medicare program.” Medicare patients may not participate in co-pay coupon programs that sponsored by drugmakers directly.

As part of the settlement, the DOJ said Pfizer has entered a five-year corporate integrity agreement that requires it to implement measures to ensure that its dealings with patient assistance groups are compliant.