Express Scripts Holding Co built a multi-billion enterprise pressuring drug companies to lower their prices for U.S. patients. Now it is quietly building a side business: getting paid to help drug companies dispense a new generation of high-priced drugs.

Chief Medical Officer Steve Miller told Reuters in an interview that Express Scripts is in talks with biotechnology companies Biomarin Pharmaceutical Inc, Spark Therapeutics Inc and Bluebird Bio Inc to have its specialty pharmaceutical business exclusively distribute their new hemophilia therapies when they are expected to become available in 2019 and 2020,.

Biomarin, Spark and Bluebird confirmed to Reuters that they were speaking to a payers – a group generally defined as pharmacy benefit managers, health plans and government agencies. Analysts project those drugs could top $1 million to $1.5 million in price.

Rather than rail against the drugs’ expected high prices, Miller echoes the familiar drug company argument that the potentially curative therapies will likely be worth the high cost if they supplant the hundreds of thousands of dollars in annual medical costs to treat ailments such as hemophilia, which affects about 20,000 people in the United States alone.

“Even if they charge $1 million, that’s a great deal,” Miller said. “So there are going to be some gene therapies where it is very clear that everyone who has that disease should get it.”

By working closely with biotech companies, Miller says it can help their expensive therapies succeed commercially. To manage any potential conflicts of interest, he said Express Scripts separates its benefits management and specialty pharmacy businesses.

The move into hemophilia builds on exclusive rights Express Scripts already has to distribute Spark’s Luxturna – an $850,000 treatment for a rare genetic disorder that, left untreated, causes children to go blind. It has a similar deal with Biogen Inc (BIIB.O) on Spinraza, he told Reuters. The drug costs $750,000 the first year and treats the rare condition spinal muscular atrophy that often kills babies within months of their birth. Spark and Biogen confirmed the agreements.

The company also helps manage one of the most expensive gene-based cancer treatments on the market: the $475,000 Novartis AG gene-based cancer therapy Kymriah – a personalized treatment that requires a long hospital stay. Novartis confirmed the arrangement to Reuters.

Those deals put Express Scripts in a vastly different role than its traditional business managing prescription drug claims for the employees of its corporate and government clients, a business Cigna Corp (CI.N) found so valuable that it agreed in March to acquire Express Scripts for $52 billion.

Express Scripts has been expanding its low-profile specialty pharmacy business – which dispenses drugs that usually aren’t sold through drugstores because they require special handling. By using its own pharmacy instead of outsiders, Express Scripts is able to hold onto more of the profits along the drug distribution chain.

Specialty pharmacy is one of Express Script’s fastest growing businesses and accounts for about a third of its sales and profits, ISI Evercore analyst Ross Muken said. The company earned $4.1 billion last year on total revenue of more than $100 billion – it does not break out financial information for specialty pharmacy.

Many of the newest, most advanced medicines – including gene-based therapies and personalized cancer treatments – will be dispensed through specialty pharmacies, and Express Scripts is pitching biotech companies for exclusive arrangements.