RT Journal Article SR Electronic T1 First-in-Human Imaging with 89Zr-Df-IAB2M Anti-PSMA Minibody in Patients with Metastatic Prostate Cancer: Pharmacokinetics, Biodistribution, Dosimetry, and Lesion Uptake JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.116.176206 DO 10.2967/jnumed.116.176206 A1 Neeta Pandit-Taskar A1 Joseph A. O'Donoghue A1 Shutian Ruan A1 Serge Lyashchenko A1 Jorge A. Carrasquillo A1 Glen Heller A1 Danny F. Martinez A1 Sarah M. Cheal A1 Jason S. Lewis A1 Martin Fleisher A1 Jennifer S. Keppler A1 Robert E. Reiter A1 Anna M. Wu A1 Wolfgang A. Weber A1 Howard I. Scher A1 Steven M. Larson A1 Michael J. Morris YR 2016 UL http://jnm.snmjournals.org/content/early/2016/08/10/jnumed.116.176206.abstract AB Anti-prostate-specific membrane antigen (PSMA) imaging with minibodies has the advantage of faster clearance due to smaller size. We conducted a Phase I dose escalation study with 89Zr-desferrioxamine-IAB2M (89Zr-IAB2M), an anti-PSMA minibody, in patients with metastatic prostate cancer (mPC). Methods: Patients received 185 MBq (5 mCi) of 89Zr-IAB2M and Df-IAB2M at total mass doses of 10 mg (n = 6), 20 mg (n = 6), and 50 mg (n = 6). Whole-body (WB) and serum clearance, normal organ and lesion uptake, and radiation-absorbed dose were estimated and the effect of mass escalation was analyzed. Results: Eighteen patients were injected and scanned without side effects. WB clearance was monoexponential with median biological half (T1/2b) of 215 h, while serum clearance showed biexponential kinetics with a median T1/2b of 3.7 h (12.3 %/L) and 33.8 h (17.9 %/L). The RAD estimates were 1.67, 1.36, and 0.32 mGy/MBq to liver, kidney, and marrow, respectively, with an effective dose of 0.41 mSv/MBq (1.5 rem/mCi). Both skeletal and nodal lesions were detected with 89Zr-IAB2M, most visualized by 48 h imaging. Conclusion: 89Zr-IAB2M is safe and demonstrates favorable biodistribution and kinetics for targeting mPC. Imaging with 10 mg minibody mass provides optimal biodistribution, and imaging at 48 h post-injection provides good lesion visualization. Assessment of lesion targeting is being studied in detail in an expansion cohort.