What happened

Shares of Exelixis (EXEL 2.16%) rose 10% in September, according to data from S&P Global Market Intelligence, after the company announced a series of positive developments throughout the month related to various cancer therapies.

So what

Exelixis is already on track to generate $1 billion in annual sales in 2021 through its primary drug Cabometyx, which is approved to treat first- and second-line renal cell carcinoma as well as advanced hepatocellular carcinoma.

Scientists looking at test tubes

Image source: Getty Images.

It announced mid-month that Cabometyx, along with Bristol-Myers Squibb immunotherapy Opdivo, saw a statistically significant reduction in kidney cancer death risk of 40% compared to Pfizer's Sutent.

Exelixis also announced partnerships with NBE-Therapeutics to develop multiple antibody-drug conjugates (ADCs) to treat cancer and Catalent's Redwood Bioscience to develop multiple ADCs using the latter's proprietary SMARTag site-specific bioconjugation technology.

Now what

Despite the good news, Exelixis stock stumbled soon afterward. After rising to a month-high of around $27 a share, it dropped to below $24 a stub where it continues to trade today.

Exelixis has dozens of clinical trials in process where Cabometyx is used as a monotherapy or combination therapy, which should give the biotech stock plenty of runway for future growth as a leader in renal cell carcinoma.