ImaginAb’s PSMA Imaging Agent Detects More Lesions Compared to Standard Imaging Methods for Detection of Prostate Cancer in Phase I/IIa Study 


LOS ANGELES, Jan. 6, 2016—ImaginAb Inc. today announced clinical results from a Phase I/IIa trial of IAB2M, ImaginAb’s proprietary precision imaging agent for the detection of metastatic prostate cancer. In the study, IAB2M was able to detect bone lesions and soft-tissue lesions with far greater specificity and sensitivity than standard imaging methods. The study was conducted by researchers at Memorial Sloan Kettering Cancer Center (MSK), with results being presented on Jan. 7 at the 2016 Genitourinary (GU) Cancers Symposium in San Francisco.

“There’s a pressing need for improved imaging biomarkers to identify disease distribution and treatment response in both localized and advanced prostate cancer patients,” said Michael J. Morris, M.D., of Memorial Sloan Kettering Cancer Center and investigator in the study. “IAB2M’s high concordance with pathology results provides evidence that positive imaging results represent prostate cancer.”

IAB2M is a radiolabeled monoclonal antibody fragment targeting prostate-specific membrane antigen (PSMA), a transmembrane protein that is highly expressed in prostate cancer. The technology is being developed as a diagnostic imaging agent for use with positron emission tomography (PET) to accurately stage men diagnosed with prostate cancer.

The Phase I/IIa study included 38 patients with progressive metastatic prostate cancer. All patients underwent standard imaging using CT, bone scintigraphy (BS) and FDG PET, followed by imaging with IAB2M. Whole body PET/CT scans were performed. Researchers evaluated the lesion targeting and uptake of IAB2M and correlation with pathology of biopsied lesions.

In bone, IAB2M detected 344 lesions (83.9%), CT 209 (51%), BS 211 (51.5%), and FDG 109
(26.6%). For soft tissue, IAB2M detected 119 (81.5%), CT 83 (56.8%), and FDG 79 (54.1%). Of 27 evaluable biopsies, 20/27 (74.1%) were positive for prostate cancer; 20/24 (83.3%) IAB2M positive lesions were pathology positive; and 3/3 (100%) IAB2M negative lesions were negative on pathology. All imaging and pathology correlated (true pos + true neg) in 23/27 (85.2%) biopsies.

“These data provide important clinical proof of concept demonstrating how our technology can detect more lesions than standard imaging,” said Benjamin Chen, Chief Executive Officer of ImaginAb. “IAB2M provides a way for physicians to physically see the location and extent of diseased tissue, and holds promise as an important tool to make treatment decisions.”

The study, “A phase I/IIa trial of Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) imaging with 89Zr-Df-IAB2M in metastatic prostate cancer (PCa),” is available on the 2016 GU Cancers Symposium website at

After skin cancer, prostate cancer is the most common cancer among men. About 1 man in 7 will be diagnosed with prostate cancer during his lifetime. ImaginAb’s IAB2M imaging agent can improve diagnostic intelligence and may impact the clinical development of therapeutics, particularly in the anti-androgen space, as existing measures of radiographic progression are insensitive and biased toward late-stage disease.

About ImaginAb
ImaginAb Inc. is an immune imaging company focused on providing actionable insight into patient selection and treatment progress for cancer immunotherapy, enabling truly personalized medicine. ImaginAb engineers antibody fragments called minibodies that maintain the exquisite specificity of full-length antibodies while remaining inert in the body. Used with widely available PET scan technology, these novel minibodies illuminate high-value molecular targets, providing physicians with a whole-body picture of immune activity. ImaginAb is also advancing a best-in-class imaging agent to improve prostate cancer management and patient outcomes. ImaginAb’s products have the potential to improve patient care and lower healthcare costs. For more information about ImaginAb’s pipeline and technology, visit

Media Contact:
Jason Spark
Canale Communications for ImaginAb Inc.