The heart of it
Exelixis built a profitable business on a single cancer drug, cabozantinib, and spent years betting that a successor compound called zanzalintinib would widen the foundation. The filed numbers show the existing franchise growing steadily and margins expanding sharply. But the clinical story around zanzalintinib just got messier: a key trial subgroup missed its target in June 2026, and the FDA’s decision on the first zanzalintinib application is still three months away. The math is healthy. The next chapter is unresolved.
How a single pill became a $2 billion business
Exelixis spent most of its early life as a drug-discovery shop burning cash on compounds that mostly didn’t work. Cabozantinib, a molecule that blocks signals telling tumors to grow and spread, changed that. It won FDA approvals across kidney cancer, liver cancer, and thyroid cancer over the better part of a decade, and the company slowly rebuilt itself around royalties and product sales from that one franchise. By the time the 10-K for fiscal year 2025 was filed, annual revenue had crossed two billion dollars and the net margin, meaning what’s left of each dollar of sales after every bill is paid, had expanded to nearly a third of revenue. That’s a business that has learned to run lean.
The question Exelixis has been trying to answer for several years is whether it can do this twice. Zanzalintinib, internally called XL092, is the company’s attempt at a next-generation version of the same basic idea, designed to hit more targets with fewer side effects. Everything in the current pipeline strategy flows from whether that bet pays off.
What the August 31 filing actually changed
On August 31, 2026, Exelixis filed an 8-K disclosing that a court had affirmed the validity of several CABOMETYX patents, pushing the earliest date a generic competitor could enter the U.S. market to at least January 2030. That matters because generic competition, when it arrives, typically collapses a brand-name drug’s revenue within months. A confirmed runway to the end of the decade means the existing cash engine has room to keep running while the pipeline matures.
Also in August, the FDA approved CABOMETYX for a new group of patients: adults and children aged 12 and older with previously treated neuroendocrine tumors, a category that includes certain pancreatic cancers. New approved uses mean new patients, and new patients mean incremental revenue from the same drug with no additional development cost. The catch, noted when Exelixis lowered its full-year 2026 revenue guidance in early August, is that uptake in this indication is coming in slower than the company had anticipated.
The trial that split in two
The more consequential event of the summer happened in June 2026, before the 8-K. Exelixis announced final results from STELLAR-303, a Phase 3 trial testing zanzalintinib combined with atezolizumab in metastatic colorectal cancer, meaning cancer that has spread beyond the colon. The combination did produce an overall survival benefit across the full trial population. That’s the good news, and it’s the basis for an FDA application accepted earlier in the year with a decision deadline of December 3, 2026.
The complication: a pre-specified subgroup of patients whose cancer had not spread to the liver missed its survival endpoint, meaning the benefit in that group was not statistically significant. As one Seeking Alpha contributor characterized it, writing on September 1, the subgroup miss alongside the guidance cut supported a cautious outlook on the stock, though this reflects a single contributor’s view rather than a named sell-side rating. The subgroup result doesn’t automatically derail the FDA review, but it hands regulators a harder question about which patients actually benefit, and it gives the agency room to narrow any label it might approve.
The number that compounds quietly
While the pipeline debate plays out, the core business filed a straightforward quarter. Q2 2026 net product revenues rose roughly ten percent from the same quarter a year earlier, with CABOMETYX accounting for nearly all of it. Total revenues grew at a similar pace. That’s growth roughly in line with a healthy mid-size economy, not a company in distress.
Our data show the profit picture improving faster than the revenue line. Net margins have roughly doubled since 2021, meaning Exelixis is keeping a much larger share of each dollar it brings in. A business that expands its margin while growing revenue is compounding its earnings faster than its sales figures suggest.
What the valuation arithmetic shows
Our data put the current price-to-earnings multiple, the price tag per dollar of annual profit, well below the company’s own decade-long median, placing today’s valuation in the 12th percentile of its own history. On that earnings measure, the stock is priced cheaply relative to its own past. The price-to-sales ratio, the price tag per dollar of revenue, tells the opposite story: it sits near the top of its own historical range. The tension between those two readings reflects exactly the moment the company is in. Earnings have grown faster than revenue because margins expanded. Whether that margin expansion is durable, or whether it required conditions that won’t repeat, is a question the filed numbers alone cannot answer.
Two binary events are pending within the quarter covered by this analysis: STELLAR-304 Phase 3 results in non-clear cell kidney cancer, expected before year-end, and the FDA’s December 3 decision on zanzalintinib in colorectal cancer. Neither outcome is in the filings yet. Both will be when they arrive.
Reading the numbers
- $573 million, Q2 2026 net product revenue (from the Q2 2026 10-Q). This is what Exelixis collected from selling CABOMETYX and COMETRIQ in a single quarter, after deducting rebates and discounts. It’s up 10% from a year earlier. Think of a store that rang up $520 last July and $573 this July: same shelves, more sales. It matters because this one franchise is funding every clinical trial in the pipeline.
- 34% net margin, fiscal 2025 (from the FY2025 10-K). For every dollar of revenue, Exelixis kept about 34 cents as profit. In 2021, it kept 16 cents. The improvement means the company is spending proportionally less to run the business even as it spends more on trials. A household analogy: a family earning $100,000 that used to save $16,000 a year now saves $34,000, without earning more.
- January 15, 2030, earliest generic entry date (from the August 31, 2026 8-K). A court confirmed that CABOMETYX patents hold until at least this date. Generic drugs typically enter at a fraction of the brand price and take most of the market quickly. This ruling means the revenue runway is legally protected for roughly three and a half more years, giving zanzalintinib time to establish itself before the core franchise faces that pressure.
- P/E at 12th percentile of own history (BullScope Valuation Model, methodology at bullscope.ai/methodology; price and earnings inputs from Exelixis SEC filings cited above). The price-to-earnings ratio sits at 17.2 times versus a decade-median of 22.9 times, placing it in the 12th percentile of its own history. IF the multiple were to revert toward its decade median and IF net margins held near current levels, the arithmetic would imply a materially higher price, but the subgroup miss and pending FDA decision represent discrete risks that could justify a sustained discount. The data describe the gap; they do not resolve it.
Sources
- Exelixis 8-K filed August 31, 2026 (SEC EDGAR)
- Exelixis 10-Q for quarter ended July 3, 2026 (SEC EDGAR)
- Exelixis 10-K for fiscal year ended January 2, 2026 (SEC EDGAR)
- Seeking Alpha: Exelixis Hold, zanzalintinib subpopulation miss and STELLAR-304 data
- TradingView: Exelixis Q2 2026 revenue and guidance update
- Investing.com: Exelixis Q2 2026 earnings and guidance cut
