- Serum based assays of free serum IGF-I/II, total serum IGF-I and shed IGF-1R receptor will be run using the samples obtained prior to the first dose of R1507 and at specified times during treatment as described in Table 3.3. All serum samples will be shipped to the Roche CSO and forwarded for analysis to the designated laboratories. Serum based assays will be performed by Roche Central Lab (MicroCoat) and Roche Diagnostics (Penzberg).