Zirconium (89Zr) girentuximabum senvedoxamum

The FDA is seeking more data to compare the imaging agent used in Telix\'s phase 3 trial and its scaled-up manufacturing process planned for commercialization. \n The FDA has asked the radiopharmaceutical developer Telix for more information about the production of its novel PET imaging agent in kidney cancer before it can move forward with its review. The agency also flagged deficiencies at two of Telix’s contracted manufacturing and supply chain providers, delivering Form 483s that will need to be corrected before it can resubmit its application, the company said.The setback marks the second this year for Telix’s radiodiagnostic portfolio, after the Australian developer received a complete response letter in April for a separate PET agent aimed at brain cancer, with the FDA requesting more clinical data.  In clear-cell renal cell carcinoma, Telix has been developing Zircaix as a companion diagnostic under its TLX250 therapy program. The agent links a zirconium-89 isotope with the antibody girentuximab, which targets the carbonic anhydrase IX enzyme that’s overexpressed on certain kidney tumor cells.Telix has paired that antibody with the beta-emitter lutetium-177 to help attack the cancer, as a radio-antibody-drug conjugate currently in phase 2 development. The company is also exploring the harder-hitting actinium-225, which releases alpha particles, as a therapy codenamed TLX252 with a first-in-human trial planned in Australia. The latest CRL was related to the company’s chemistry, manufacturing and controls submission, Telix said. The FDA is now seeking more data to compare the imaging agent used in its ZIRCON phase 3 trial and the scaled-up manufacturing process planned for commercialization.The company said in a statement that it “believes these concerns are readily addressable,” and that it plans to request a meeting with the agency to determine a timeline for resubmission. Telix’s stock price dropped about 25% on the news, before rebounding to a loss of 13%, landing at about $10.65The agency previously asked for more CMC data on Zircaix and sterility assurance last year, before fully accepting the company’s rolling biologic submission in February after it was first launched in December 2023.  “TLX250-CDx breaks new ground as a highly novel biologic-based PET imaging agent using a first-in-class isotope,” said Telix Group CEO Christian Behrenbruch. “Like many radiopharmaceuticals, it has a complex supply chain, and as the field advances, this creates new challenges around the regulatory framework applied to these products.”TLX250-CDx previously received a breakthrough therapy designation and priority review, and Telix has opened an FDA expanded access program for the agent in the U.S.“We believe the outstanding matters are resolvable and that we can address the remaining FDA requests within a reasonable time frame,” Behrenbruch said. If it\'s approved, Telix said Zircaix will become the first available imaging agent for the non-invasive diagnosis of clear-cell renal cell carcinoma, the most common subtype of kidney cancer and one of the disease’s most aggressive.In the pivotal ZIRCON trial, which included 284 participants, Zircaix demonstrated 86% sensitivity and 87% specificity, as well as a 93% positive predictive value across three independent radiology readers.