Roche ($RHHBY) is pairing a companion diagnostic test already linked to its Herceptin breast cancer drug with two new blockbuster treatments also produced by the company, bringing more of its personalized medicine development strategy to fruition.

The Swiss drug and diagnostics company said its HER2/neu (4B5) test will also help spot patients who would be ideal for Perjeta and Kadcyla. Roche's Ventana Medical Systems developed the rabbit monoclonal primary antibody assay.

Kadcyla recently won European approval as a targeted cancer drug for patients with previously treated HER2-positive advanced breast cancer, following FDA approval in February. The FDA signed off on Perjeta similarly last year, but in September granted an historic approval to use it as a breast cancer treatment before surgery.

Mara Aspinall, president of Ventana Medical Systems, said in a statement that the expanded use of its HER2 assay will allow the test to "continue to provide important diagnostics information for breast cancer treatment decisions." The test will be available in markets where Perjeta and Kadcyla are approved for therapy around the world, Roche said.

The news is just another outgrowth of one of the smarter and more forward-thinking corporate acquisitions in recent years. Roche grabbed Ventana, a tissue diagnostics company, for $3.4 billion in 2008, just when the push for companion diagnostics to help pair targeted treatments with ideal patients was starting to build more momentum.

Ventana doesn't just develop tests for Roche drugs, which gives Roche a rich revenue stream as companion diagnostic tests become more commonplace. Ventana said it is now involved with more than 150 collaborative projects outside of Roche to develop and market companion diagnostic tests around the world. It has worked with more than 45 biopharmaceutical partners in the last decade, Ventana said, including recent agreements with Incyte ($INCY), Bayer, Pfizer ($PFE) and Takeda's Millennium unit.