Hi,
XGEVA™ is the new drug passed in Mar-2011 and there is no established CMS LCD/NCD, so it is payer to payer choice to ask for their different measurement methodology and documentation requirement.
Billing requirements for unclassified or miscellaneous codes may vary by payer; however, payers typically require providers to list drug name, dosage, and NDC number in Box 19 (or corresponding field for electronic claims) when billing with unclassified code Note: XGEVA™ is supplied as a 120 mg dose; its NDC is 55513-0730-01
Once the CMS LCD/NCD (probably from Mar 2012) will establish, the things will get resolved.
You can find following reference regarding the same.
http://wpsmedicare.com/j5macpartb/departments/claims/j3490billingtips.shtml
http://www.flasco.org/Resources/Documents/2011%20DRUG%20UPDATES.pdf
https://www.amgenassistonline.com/StreamResource.ashx?...
http://www.medicarepaymentandreimbursement.com/2010/07/how-to-bill-j-codes-correctly-by-units.html