Celgene and Agios Pharmaceuticals have won FDA approval for an acute myeloid leukemia (AML) treatment intended for patients with specific mutations of the isocitrate dehydrogenase 2 (IDH2) gene.
Idhifa® (enasidenib) is an IDH2 inhibitor approved yesterday as a treatment for adults with relapsed or refractory AML who show IDH2 mutations in blood or bone marrow samples following use of a companion diagnostic, Abbott Laboratories’ RealTime IDH2 Assay.
While Celgene received the formal FDA approval, the biotech giant has worked with Agios over seven years to develop Idhifa, previously known as AG-221 and CC-90007.
Idhifa is the first development candidate developed through the first of several collaborations between the companies, launched in April 2010. Celgene offered $130 million upfront, including an equity investment, for rights to co-develop an unspecified number of drugs discovered through Agios’ cancer metabolism research platform, based on the concept of “starving” cancer by targeting key metabolic enzymes unique to rapidly proliferating cancer cells.
Celgene also agreed to pay Agios $120 million in milestone payments per drug developed by the companies.
Idhifa will be the first Agios treatment to reach the market, marking its transition from a clinical-stage company.
“A full approval by the FDA based on Phase1/2 data is a strong demonstration of Idhifa’s positive clinical value, which we believe could lead to strong market adoption,” Canaccord Genuity healthcare analyst John Newman, Ph.D., said in a note to investors.
The FDA based its approval of Idhifa on results from a single-arm trial of 199 patients with relapsed or refractory AML who had IDH2 mutations as detected by the RealTime IDH2 Assay. The trial measured the percentage of patients with complete remission (CR), as well as patients with complete remission with partial hematologic recovery (CRh).
Remissions and Reduced Transfusions
Following a minimum of six months of treatment, according to the FDA, 19% of patients experienced CR for a median 8.2 months, while 4% of patients experienced CRh for a median 9.6 months. Of the 157 patients who required transfusions of blood or platelets due to AML at the start of the study, 34% no longer required transfusions after treatment with Idhifa.
“The use of Idhifa was associated with a complete remission in some patients and a reduction in the need for both red cell and platelet transfusions,” stated Richard Pazdur, M.D., director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.
The FDA gave Idhifa its orphan drug designation, as well as its Priority Review designation, under which the agency commits to taking action on an application within six months where the FDA determines that the drug, if approved, would significantly improve the safety or effectiveness of treating, diagnosing, or preventing a serious condition.
The orphan drug designation “will grant (Celgene) greater Idhifa pricing power,” Dr. Newman added.
Common side effects associated with Idhifa include nausea, vomiting, diarrhea, increased levels of bilirubin, and decreased appetite. Women who are pregnant or breastfeeding should not take Idhifa because it may cause harm to a developing fetus or a newborn baby, the FDA said.
Idhifa was approved with boxed warning stating that differentiation syndrome can occur and can be fatal if not treated. Signs and symptoms may include fever, dyspnea, acute respiratory distress, radiographic pulmonary infiltrates, pleural or pericardial effusions, rapid weight gain, peripheral edema, or hepatic, renal, or multiorgan dysfunction.
Upon the first suspicion of symptoms, doctors are advised to treat patients with corticosteroids and monitor patients closely until symptoms go away.
According to the NIH’s National Cancer Institute, this year approximately 21,380 people will be diagnosed with AML, while approximately 10,590 patients with AML will die of the disease.