What happened

Like most biotechs, Inovio Pharmaceuticals (NASDAQ:INO), a pre-revenue vaccine developer, had a rather poor showing in December. Specifically, it lost exactly a quarter of its value last month, according to data from S&P Global Market Intelligence.

The upside is that Inovio's year-end sell-off wasn't triggered by a clinical or regulatory setback. Rather, its shares simply fell in tandem with the broader market. So, not surprisingly, they've also come charging back with the market's sharp reversal over the first two weeks of the new year -- gaining a healthy 21% year to date. 

Man in a suit facing a wall of white arrows pointing to the left and a bigger yellow arrow pointing to the right.

Image Source: Getty Images.

So what

The particularly noteworthy aspect of last month's downturn is the fact that Inovio -- and, really, all biotechs -- plummeted regardless of events on the ground. As proof, Inovio kicked off December with a solid clinical update: the start of the company's phase 2 cancer trial with big pharma partner AstraZeneca (NYSE:AZN).

Turning to the details, the two companies announced on Dec. 4 that the first patient had been dosed in a mid-stage trial designed to assess Astra's MEDI0457 (formerly INO-3112 prior to the licensing deal) in combination with the checkpoint inhibitor durvalumab across a diverse array of cancers associated with the human papilloma virus. This upbeat clinical update failed to save Inovio's stock from the ravages of the moody market, however. 

Now what

Inovio's stock appears set to continue its recent rally in the days and weeks ahead. After all, this clinical-stage biotech sports a promising late-stage cervical dysplasia vaccine known as VGX-3100, which has the potential to generate hundreds of millions in sales over the next decade, according to EvaluatePharma.

That said, Inovio's stock will probably remain at the mercy of the broader market until the company finally transforms into a commercial-stage operation and begins to generate profits on a consistent basis. Shareholders should, therefore, expect a good deal of volatility going forward, despite the monstrous commercial opportunity offered by the company's portfolio of high-value vaccine candidates.

Check out the latest Inovio earnings call transcript.