Exelixis enters the back half of 2026 with two questions hanging over the same stock. The first is a regulatory event with a named calendar date. The FDA target action date for the first New Drug Application of zanzalintinib, an oral kinase inhibitor in previously treated metastatic colorectal cancer, is December 3, 2026. The second is a legal one that just moved: late in August the Federal Circuit affirmed the district court judgment that three cabozantinib patents are not invalid, holding the earliest possible effective date for the MSN generic application in early 2030. The market has already responded to the second. The shares sit near $59, up from a fall low in recent memory, at a market capitalization close to $14.6 billion.
The franchise that funds everything is cabozantinib, sold in the United States as CABOMETYX and COMETRIQ and marketed by partners outside the country. Second-quarter total revenues reached $628.7 million, up 11% year over year. GAAP diluted earnings per share stood at $0.82. Full-year guidance sits at $2.55 billion in total revenues, trimmed by roughly $75 million from the prior August guidance on slower patient kinetics in the neuroendocrine tumor indication.
Three variables carry the thesis from here. The first is the December PDUFA outcome for zanzalintinib and the commercial ramp that follows in colorectal cancer. The second is the STELLAR-304 top-line readout for zanzalintinib plus nivolumab in non-clear cell renal cell carcinoma, expected in the second half of 2026. The third is the durability of cabozantinib volume in a second line that is increasingly crowded, with the first generic approval no earlier than January 15, 2030 but three separate applications already in the pipeline. The falsifiable test is the December 3, 2026 action date itself.
The counterargument deserves a sentence of its own before the sections below. The stock has roughly doubled off its low and now embeds a fair amount of zanzalintinib value, while the guidance cut signals that even the legacy franchise is growing slower than a year ago. The debate is no longer whether cabozantinib is a durable drug. It is how much the market is already paying for the second generation of the pipeline before it has earned the label.