Myriad Genetics (MYGN -1.24%) telegraphed its plan to acquire Crescendo Bioscience three years ago, and now it has followed through on the deal.

The Salt Lake City, UT-based diagnostics company said today it has agreed to acquire South San Francisco-based Crescendo Bioscience for $270 million in cash, minus a $25 million loan Myriad made to the start-up in 2011.

By acquiring Crescendo, Myriad is getting its hands on Vectra DA, a molecular diagnostic test that measures the level of disease activity in patients with rheumatoid arthritis. The company's test is supposed to help doctors and patients determine whether the inflammatory disease can be controlled over time with cheap medications like methotrexate, or whether the patient responds better to more expensive products like Amgen's etanercept (Enbrel) or AbbVie's adalimumab (Humira). Those top-selling drugs are expensive, sometimes costing $20,000 a year, and they don't work for everyone. The company introduced Vectra DA in 2010, won Medicare reimbursement last year, and hit one of the necessary sales milestones in November that triggered the ultimate buyout by Myriad.

Crescendo, founded in 2002, currently has about 130 employees, the company said in a statement. The 2011 financing agreement with Myriad outlined the basic structure of today's takeover, which was based on Crescendo reaching certain revenue milestones as a private company.

Aeris Capital AG, Skyline Ventures, Safeguard Scientific, Mohr Davidow Ventures and Kleiner Perkins Caufield & Byers were among Crescendo's previousinvestors. Crescendo most recently raised $28 million in a Series D financing in January 2013, and a $31 million Series C financing in September 2011.

Separately, Myriad reported that its annual revenue climbed 37 percent. It increased its financial forecast to $740 million to $750 million for the fiscal year ending June 30, up from its previous forecast of $700 million to $715 million.

This article originally appeared on Xconomy, along with: