FibroGen shares skid lower as a surprise adcomm raises risks on roxa OK
FibroGen will likely have to delay its US rollout for roxadustat once again.
In an unexpected move, the FDA is convening its Cardiovascular and Renal Drugs Advisory Committee to review the NDA in an advisory committee meeting. The date is yet to be confirmed.
Just a few weeks ago, SVB Leerink analyst Geoffrey Porges predicted that the roxa approval could come ahead of the PDUFA date on March 20 — effusive despite already being let down once by the FDA’s extension of its review back in December. AstraZeneca, which is partnered with FibroGen on the chronic kidney disease-related anemia drug, disclosed regulators had requested further clarifying analyses of clinical data.
But the involvement of a “historically tough committee,” Yaron Werber of Cowen wrote, could weigh all of that down. And it did, with the stock $FGEN crashing 23.51% to $38.65.
“Management confirmed that roxadustat’s NDA submission is officially being reviewed by the benign hematology department and thus we assume this division has now sought out the CV/renal committee presumably to address some outstanding risk/reward questions about roxadustat,” he noted. “Historically, the CV/renal committee has proven difficult for anemia drugs, dictating a notably high bar for safety during similar reviews for ESAs.”
FibroGen has long touted that by mimicking the effect of high altitude, roxadustat could stimulate the production of red blood cells and increase hemoglobin level without triggering the cardiovascular side effects plaguing patients taking erythropoiesis-stimulating agents, the current standard of care.
But subsequent data releases stirred concerns about differences in non-dialysis-dependent patients, compared to dialysis-dependent groups.
The key debate, according to a recent Porges note, has always been around the potential of a black box warning — and how far it would go.
FibroGen CEO Enrique Conterno “suggested that the extent of the black box warning would influence adoption in the NDD setting, which he reiterated is several times the size of the DD market. In DD, he suggested that the black box language shouldn’t have much impact on adoption, given the labeling for ESAs and their near-universal use in that population.”
In a statement, Conterno stood by the efficacy and safety profile of the drug, which is already approved in China, Japan and Chile.