Skip to main content
An official website of the United States government

Vemurafenib plus Copanlisib in Radioiodine-Refractory (RAIR) Thyroid Cancers

Trial Status: complete

This purpose of this phase Ib trial is to develop a new drug treatment to reverse resistance to radioiodine therapy in treating patients with BRAF gene mutated thyroid cancer that does not respond to radioiodine therapy alone (radioiodine-refractory), so that radioiodine can be given to shrink these tumors. BRAF gene mutation in thyroid cancer makes it unlikely to respond to radioiodine therapy. This trial investigates the highest doses of copanlisib and vemurafenib that, when given in combination, do not cause serious side effects, and whether the study treatment will make radioiodine therapy work better in patients with BRAF-mutant thyroid cancers. Iodine-124 (I-124) is used only to detect thyroid cancers on imaging studies called positron emission tomography/computed tomography (PET/CT) scans. Iodine-131 (I-131) is used to detect thyroid cancers on scans and to shrink thyroid tumors. Some tumors do not absorb enough (I-131) to cause them to shrink. In some tumors, mutation of the BRAF gene is the primary reason I-131 cannot be absorbed and why it does not shrink those tumors. Vemurafenib inhibits BRAF, and in some patients this drug can increase the amount of radioiodine taken up by tumors with BRAF mutations. Copanlisib blocks PI3K, which is a protein that causes radioiodine resistance by forcing thyroid cancer cells to eliminate radioiodine before it can deliver radiation to kill the tumor. Giving copanlisib and vemurafenib may cause radioiodine to be better absorbed and held longer in thyroid cancer cells, making radioiodine treatment more effective in treating patients with BRAF-mutant thyroid cancers.