The exact amount of Kadcyla produced in a year is not mentioned in the provided sources. However, we can gather some information about the drug from these sources. Kadcyla is a medication used to treat HER2-positive breast cancer, and it contains the active ingredient ado-trastuzumab emtansine [3]. It is manufactured by Genentech, a subsidiary of Roche [2].

Kadcyla was first approved by the US Food and Drug Administration (FDA) in 2013 [1]. It is an expensive drug, with an annual cost of around $150,000 per patient [3]. The drug is administered intravenously, and it works by targeting and destroying cancer cells while minimizing damage to healthy cells [2].

Despite its high cost, Kadcyla has been shown to be effective in treating HER2-positive breast cancer. Clinical trials have demonstrated that the drug can significantly improve progression-free survival and overall survival rates in patients with this type of cancer [3].

In conclusion, while the exact amount of Kadcyla produced in a year is not available in the provided sources, we know that it is an expensive medication used to treat HER2-positive breast cancer. It is manufactured by Genentech, a subsidiary of Roche, and has been shown to be effective in clinical trials.

Sources:
[1] https://www.drugpatentwatch.com/p/biologics/tradename/KADCYLA
[2] https://www.kadcyla.com/
[3] https://www.news-medical.net/drugs/Kadcyla.aspx