Exelixis, Inc. a biopharmaceutical company, has initiated submission of its rolling New Drug Application (NDA) to the US Food & Drug Administration (FDA) for cabozantinib for the treatment of advanced renal cell carcinoma (RCC) patients who have received one prior therapy.

Cabozantinib was granted Breakthrough Therapy designation by the FDA in August 2015. Exelixis agreed with FDA that the submission would be a rolling NDA and the company has filed the first component of the application for potential approval of cabozantinib in the United States. The rolling NDA allows completed portions of an NDA to be submitted and reviewed by the FDA on an ongoing basis. Exelixis plans to complete the NDA submission before the end of 2015.

The rolling NDA submission is based on results of METEOR, a phase 3 pivotal trial comparing cabozantinib to everolimus in patients with advanced RCC who experienced disease progression following treatment with a VEGF receptor tyrosine kinase inhibitor. In July 2015, Exelixis announced top-line results from METEOR demonstrating that the trial had met its primary endpoint of improving progression-free survival (PFS); compared with everolimus, cabozantinib was associated with a 42 per cent reduction in the risk of disease progression or death. These data were later presented at the European Cancer Congress in September 2015 and concurrently published in The New England Journal of Medicine.

“New treatment options are urgently needed for patients with advanced renal cell carcinoma,” said Michael M. Morrissey, Ph.D., president and CEO of Exelixis. “The initiation of the NDA submission process for cabozantinib marks an important step forward in our efforts to make a meaningful difference in the lives of people with advanced kidney cancer, and we look forward to working closely with the FDA towards the goal of making cabozantinib available to these patients and their physicians as soon as possible.”

Cabozantinib is currently marketed in capsule form under the brand name Cometriq in the United States for the treatment of progressive, metastatic medullary thyroid cancer (MTC), and in the European Union for the treatment of adult patients with progressive, unresectable locally advanced or metastatic MTC. Cometriq is not indicated for patients with RCC. In the METEOR trial, and all other cancer trials currently underway, Exelixis is investigating a tablet formulation of cabozantinib distinct from the Cometriq capsule form. The tablet formulation of cabozantinib is the subject of the NDA for advanced RCC.

The American Cancer Society’s 2015 statistics cite kidney cancer as among the top ten most commonly diagnosed forms of cancer among both men and women in the US. Clear cell RCC is the most common type of kidney cancer in adults. If detected in its early stages, the five-year survival rate for RCC is high; however, the five-year survival rate for patients with advanced or late-stage metastatic RCC is under 10 per cent, with no identified cure for the disease.

Until the introduction of targeted therapies into the RCC setting a decade ago, treatments for metastatic RCC had historically been limited to cytokine therapy (e.g., interleukin-2 and interferon). In the second and later-line settings, which encompass approximately 17,000 drug-eligible patients in the US and 37,000 globally, two therapies have been approved for the treatment of patients who have received prior VEGF receptor TKIs. However, despite the availability of several therapeutic options, currently approved agents have shown little differentiation in terms of efficacy and have demonstrated only modest progression-free survival benefit in patients refractory to sunitinib, a commonly-used first-line therapy.

The majority of clear cell RCC tumours exhibit down-regulation of von Hippel-Lindau (VHL) protein function, either due to gene inactivation or epigenetic silencing, resulting in a stabilization of the hypoxia-inducible transcription factors (HIFs) and consequent up-regulation of VEGF, MET and AXL. The up-regulation of VEGF may contribute to the angiogenic nature of clear cell RCC, and expression of MET or AXL may be associated with tumor cell viability, a more invasive tumor phenotype and reduced overall survival. Up-regulation of MET and AXL in clear cell RCC has also been shown to occur in response to treatment with VEGF receptor TKIs in preclinical models, indicating a potential role for MET and AXL in the development of resistance to these therapies.

Cabozantinib inhibits the activity of tyrosine kinases including MET, VEGF receptors, AXL and RET. These receptor tyrosine kinases are involved in both normal cellular function and in pathologic processes such as oncogenesis, metastasis, tumour angiogenesis and maintenance of the tumor microenvironment.

Cabozantinib, marketed under the brand name Cometriq, is currently approved by the US Food and Drug Administration for the treatment of progressive, metastatic medullary thyroid cancer (MTC).

The European Commission granted Cometriq conditional approval for the treatment of adult patients with progressive, unresectable locally advanced or metastatic MTC. Similar to another drug approved in this setting, the approved indication states that for patients in whom Rearranged during Transfection (RET) mutation status is not known or is negative, a possible lower benefit should be taken into account before individual treatment decisions.

The most commonly reported adverse drug reactions (=25 per cent) are diarrhea, stomatitis, palmar-plantar erythrodysesthesia syndrome (PPES), decreased weight, decreased appetite, nausea, fatigue, oral pain, hair color changes, dysgeusia, hypertension, abdominal pain, and constipation. The most common laboratory abnormalities (=25 per cent) are increased AST, increased ALT, lymphopenia, increased alkaline phosphatase, hypocalcemia, neutropenia, thrombocytopenia, hypophosphatemia, and hyperbilirubinemia.