Horizon Pharma CEO Timothy Walbert says the company will re-evaluate its relationship with Express Scripts after the pharmacy benefits manager filed suit against the drugmaker and terminated one of its drug dispensers, Linden Care.

Express Scripts announced it would remove Linden Care from its network after alleging the company did not fulfill key components of the pharmacy network agreements in dispensing Horizon’s drugs. It also said it is evaluating several other pharmacies that appear to be predominantly dispensing Horizon prescription drugs.

The PBM said it is reviewing and evaluating “all similar captive pharmacy arrangements that we know of and will work to identify others. By captive pharmacies, we mean those pharmacies that derive the vast majority of their prescription volume from one manufacturer and/or one product.”

Walbert denies that Linden Care is a “captive pharmacy,” beholden to Horizon. He adds that less than 5 percent of net sales are prescriptions filled by Linden Care and processed by Express Scripts.

Walbert says that Express Scripts has “significant control over prescriptions that flow to specialties pharmacies” and that it also operates its own mail-order pharmacy, thus creating a “clear conflict of interest.”

“Our philosophy of ensuring that patients get the medicine their doctors prescribe is threatening Express Scripts' profiteering and exposing what we believe is a lack of care for patients and respect for physicians,” Walbert says in a statement.

The war of words between the two companies came the same week Valeant Pharmaceuticals executives tried to allay nervous investors following weeks of scandal about its pricing practices and relationship with a specialty pharmacy.

Express Scripts also filed a complaint in a Delaware court against Horizon seeking to recover roughly $140 million, contending it refused to honor contractual obligations under a manufacturer rebate agreement.

Horizon says it terminated the rebate agreement about a year ago, contending Express Scripts didn’t live up to its contractual obligations and failed to fix the breaches when notified by Horizon. The present lawsuit relates to that terminated agreement, Walbert says, noting that the PBM is pursuing damages related to prescriptions occurring after the contract was terminated.

“At best Express Scripts is being reckless in its allegations, and at worse it is intentionally attempting to mislead investors,” Walbert says.