As of now, 2017 is turning out to be a bust for shareholders of both Inovio Pharmaceuticals (NASDAQ:INO) and Novavax (NASDAQ:NVAX). However, both clinical-stage biotech stocks were looking pretty good earlier in the year. Inovio's slump came following a stock offering, while Novavax stock sank on investors' disappointment with a clinical update from the company.

With Inovio and Novavax shares down significantly so far this year, which stock is now the better buy? Here's how the two biotechs compare. 

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The case for Inovio

Inovio has several irons in the fire that could eventually pay off. The company's lead candidate is DNA-based immunotherapy VGX-3100. Inovio initiated a late-stage study evaluating VGX-3100 in treating cervical dysplasia caused by human papillomavirus (HPV) after the FDA placed a clinical hold on the study in October 2016. Results from the study should be available in 2019. 

The company also licensed another immunotherapy, MEDI0457 (formerly INO-3112), to MedImmune, a subsidiary of AstraZeneca (NYSE:AZN). MedImmune is moving forward with a phase 1/2 study of MEDI0457 in combination with Imfinzi for treating HPV-related head and neck cancer.

Inovio's infectious disease program includes a few promising candidates. The biotech recently reported that its HIV vaccine PennVax-GP produced some of the highest overall levels of immune response rates ever observed in a human study by an HIV vaccine. In June, Inovio completed enrollment in an early-stage study of its experimental Zika virus vaccine. The biotech was the first to advance a Zika vaccine to clinical studies. 

Inovio is also attracting interest from large biopharmaceutical companies. In addition to AstraZeneca, Inovio has forged collaboration deals with Regeneron (NASDAQ:REGN) and Roche (NASDAQOTH:RHHBY). Regeneron and Inovio plan to evaluate Regeneron's PD-1 inhibitor REGN2810 and Inovio's T cell activator INO-5401 and immune activator INO-9012 for the potential treatment of brain cancer. Roche and Inovio plan to study a combination of INO-5401 and Roche's Tecentriq in treating patients with advanced bladder cancer.

Although Inovio's stock offering caused its share price to plunge, the company now has a solid cash position as a result. Inovio should be able to fund its clinical studies for quite a while without requiring additional cash.

The case for Novavax

Like Inovio, Novavax claims several promising vaccine candidates. The most advanced of these candidates is the biotech's experimental RSV F vaccine, which is in a late-stage clinical study for maternal immunization of infants. Novavax expects to report on an "informational analysis" from this study later in 2017.

The RSV F vaccine disappointed in a late-stage study for immunizing older adults last year. However, Novavax reported encouraging results from a phase 2 study evaluating safety and immunogenicity of the RSV F vaccine in older adults and plans another phase 2 study evaluating efficacy in 2018. The company also has an early-stage study of the vaccine in pediatric immunization underway. 

Novavax also recently announced exciting news about a pre-clinical candidate, its nanoparticle-based influenza vaccine called NanoFlu. Pre-clinical results showed NanoFlu generated significantly more antibody responses than the leading approved flu vaccines. Novavax is quickly moving forward with a phase 1/2 clinical study of NanoFlu based on these results. If all goes well, the company could potentially file for regulatory approval of NanoFlu by early 2020. 

At the end of the second quarter, Novavax reported cash, cash equivalents, and marketable securities totaling $187.3 million. That should fund the company's operations into 2018, but Novavax will likely need to generate more cash at some point. 

Better buy

Both of these biotechs face considerable risks. There could be clinical failures and regulatory rejections. Those are risks for every clinical-stage biotech. 

However, I think that Inovio's risk profile could be better than Novavax's. One key reason is that Inovio has more pipeline candidates to spread the risk. Also, Novavax has already experienced a major disappointment with its lead candidate, which fuels worries about the RSV F vaccine's chances in other studies.

In addition, Inovio appears to be able to go longer without the need for another stock offering than Novavax can go. Inovio's partnerships with big companies like AstraZeneca, Regeneron, and Roche provide it with more sources of revenue than Novavax has.

Novavax could be a big winner over time. For now, though, I think the better buy is Inovio.  

Keith Speights has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.