What happened

Shares of NovoCure (NVCR -0.81%), which makes devices for treating cancerous solid tumors with electric fields, rocketed 152% higher last year, according to data from S&P Global Market Intelligence.

That sizzling performance makes it one of last year's hottest healthcare stocks. For context, the S&P 500 returned 31.5% in 2019.

Man sitting at desk wearing NovoCure's Optune, which appears like netting on his head and includes an over-the-shoulder attachment to the head device.

NovoCure's Optune. Image source: NovoCure.

So what

We can attribute NovoCure's stock's powerful 2019 performance in part to the company's May approval from the U.S. Food and Drug Administration (FDA) to use its tumor-treating fields (TTF) technology to treat malignant pleural mesothelioma, an aggressive and rare form of lung cancer. Prior to this green light, the company's Optune device was only approved to treat one indication in the United States and in some international markets: glioblastoma (GBM), the most common primary brain cancer in adults.

In July, NovoCure announced that Medicare would begin providing coverage of Optune for newly diagnosed GBM patients effective Sept. 1, 2019. Then in August, it announced that Optune received a Chinese innovative medical device designation, similar to breakthrough status available in the U.S. That basically speeds up the regulatory process.

In addition, NovoCure's financial performance was better than expected. In the third quarter, revenue jumped 42% year over year and the company achieved profitability. It posted earnings of $0.02 per share, whereas Wall Street had been anticipating a loss of $0.05 per share.

Now what

Major big news could be on the near-term horizon. NovoCure and its exclusive Chinese partner, Zai Lab, hope to receive approval any time now to launch Optune for GBM in mainland China.

Moreover, Bill Doyle, NovoCure's executive chairman, said in last quarter's earnings release, "If approved, the indications in our late-stage pipeline will create a more than 20-fold increase in our U.S. addressable market." Those indications include brain metastases, lung cancer, pancreatic cancer, ovarian cancer, and liver cancer.