New higher-capacity cyclotron to stabilize isotope supply

Zevacor Molecular (Fishers, IN) announced that it had gained funding approval for a new 70-MeV commercial cyclotron to produce key isotopes. The company says the unit will be the first and only 70-MeV unit dedicated to medical use in the United States. (“MeV” is million electron volts, a measure of cyclotron power.) The 70 MeV unit will tasked primarily to produce Strontium 82 (Sr-82), which in turn produces Rubidium (Rb-82) that is injected into patients for cardiac imaging. Start-up is planned by the fall of 2016.

Medical isotopes, critical to diagnostic imaging and therapies in oncology, neurology and cardiology, have been subject to supply shortages, “making it difficult to offer these diagnostics and therapeutics,” says John Zehner, COO of Zevacor. “This investment will allow us to provide year round production of medically necessary isotopes for patients.”

Specifically addressing shortages of Sr-82, Zehner told Pharmaceutical Commerce that US national labs including Brookhaven and Los Alamos produce roughly half the needed supply of Sr-82, and labs in Canada, South Africa, Russia and elsewhere meet additional demand “when they have time. It’s difficult to keep those sources coordinated, and as we see an increase in demand for this product, it becomes even more difficult to keep the supply even so the product is available day in and day out.”

Downstream, supplies were most recently exacerbated by a voluntary FDA recall by Bracco Diagnostics’ CardioGen-82 (Rb-82), a leading Sr-82-based injectable. The company resumed production in February after months of interrupted supply.

Shelf life is another issue that can lead to shortages. Sr-82 has a shelf life of only six weeks; other radioisotopes can be as short as one hour.

Competitively, the 70 MeV cyclotron rating will allow Zevacor to produce isotopes at higher, more commercially viable quantities than the prevalent commercial systems, most if not all are rated at 45-or-below MeV. As for competing against radiopharma leader Cardinal Health, Zehner says there’s presently no direct Sr-82 competition with the company. Beyond Sr-82, future production may include additional research isotopes not widely available in the United States including Copper-67, a therapeutic for treating cancer.

Zevacor manufactures and distributes radiopharmaceuticals for use with SPECT (single-photon emission computed tomography) and PET (positron emission tomography) scans. The company has not disclosed from whom it will purchase the 70 MeV cyclotron, but sources are limited; two leading providers are IBA Group and Best Medical International and Best Cyclotron Systems.