The Vivos team felt that our meeting with the US FDA on 5/20/22 was a significant positive turning point in the FDA review process. We proposed an additional
short-term animal test to prove beyond any doubt that RadioGel™ can deliver a precise dose of therapeutic radiation and does not migrate from the tumor site. We now have a
clear path forward with the review team toward obtaining the IDE needed for the first in human clinical trials.
Eight of the eleven FDA staff that reviewed our original IDE submission were new and not familiar with RadioGel™. They resurfaced legacy questions
on dosimetry and the potential for migration which we have repeatedly addressed, but we’ve realized that another animal test is the most efficient means to answer those questions once and for
all. We agreed to provide the detailed test plan in another submission and the agency agreed to expedite the schedule for their review. This costs time, but helps ensure that they
will accept the results.
Since we anticipated this outcome, we have been in detailed discussions with Johns Hopkins University to perform the animal testing. During the meeting we presented
a detailed outline of the proposed testing to obtain interim feedback. The FDA agreed with our outline and provided initial feedback on what they expect to see in the detailed test plan.
The test is straight forward. We will induce VX-2 tumors in rabbits and then measure the activity over time using PET/CT to show, once again, that the Y-90 stays at
the injection site. We will then euthanize the rabbits and quantitatively measure the remaining activity in the tumor using very sensitive counters and compare it to the starting activity
corrected for decay.
I closed the meeting with a summary as follows:
RadioGel™ will be a leader in Precision Radionuclide Therapy (PRnT). We have the highest Therapeutic Index of any device that the FDA has
reviewed. This allows us to administer very high therapeutic doses with insignificant collateral damage to healthy tissue. We can treat lymph nodes with small amounts of Y-90 and achieve
doses of 300 Gy or more.
RadioGel™ is intrinsically safe. Even if a significant amount of it activity migrated, which we know does not happen, the risk to the patient
would be very low. We pointed out that the FDA has approved other brachytherapy products with much higher activity that is not fully contained. One of the side effects listed on the product label
is occasional death.
Finally, we believe that RadioGel™ should have a broad indication for use as a device that allows administering precision radionuclides to any
tumor. It is our intent to demonstrate the safety and effectiveness of RadioGel ™in thyroid cancer therapy and then follow up with additional data to expand the indications for
use to other tumor types and anatomic locations.
Michael K. Korenko, Sc.D. – President & CEO
Michael K. Korenko, Sc.D.
President & CEO