Fears over the SARS-CoV-2 virus, and a potential COVID-19 pandemic, are hurting the stock market. On Feb. 27, the S&P 500 fell by about 138 points, representing a 4.4% decline.

The health-related risks posed by COVID-19 are a more significant concern. Fortunately, several pharmaceutical and biotech companies are racing to develop vaccines and treatments for the disease. One of the companies that has emerged as a leader of this endeavor is none other than Gilead Sciences (NASDAQ:GILD). It is worth wondering whether the company's shares are worth buying right now. 

Gilead Sciences' remdesivir shows promise in treating COVID-19

Gilead Sciences is currently looking to develop a treatment for COVID-19, namely a drug called remdesivir, which was previously investigated as a treatment for Ebola but with little success. Gilead Sciences hopes that remdesivir will be successful as a treatment for COVID-19, and this isn't merely wishful thinking. According to World Health Organization (WHO) officials, remdesivir may not only be able to treat COVID-19 successfully, but it shows the most promise out of all the potential treatments.

Gilead Sciences has been moving rapidly to get remdesivir on the market. In late February, the company announced that it had initiated two phase 3 studies to investigate the efficacy of remdesivir as a treatment for COVID-19. 

Person wearing face mask holding test tube with blood labeled for coronavirus testing.

Image source: Getty Images.

Gilead Sciences faces competition 

If COVID-19 keeps spreading worldwide, Gilead Sciences will do the world a great service if it releases a treatment for the disease. And of course, the company would benefit financially as well. With that said, however, other companies are looking to develop treatments or vaccines for COVID-19. For instance, Johnson & Jonhson (NYSE:JNJ) partnered up with the U.S. Department of Health and Human Services (HHS) to develop a vaccine for the disease. In a press release, Johnson & Jonhson said it was looking to "screen its library of existing antiviral compounds with the goal of identifying those with antiviral activity against COVID-19." 

Another company trying to develop a vaccine for COVID-19 is Moderna (NASDAQ:MRNA). This biotech company created a potential vaccine for the disease in record time and recently shipped a batch of this vaccine to the National Institute of Allergy and Infectious Diseases (NIAID) to begin a phase 1 study. Moderna's shares are up by 59% year to date, a terrific performance considering the S&P 500 is down by 4.4% since the beginning of the year. Clearly, investors have lofty expectations for Moderna's potential vaccine for COVID-19.

There are still other companies looking to develop vaccines for COVID-19, but Gilead Sciences is further along than most of its competitors. 

Other reasons to consider Gilead Sciences

There are several reasons to consider buying shares of Gilead Sciences, that is, outside of its recent attempt to prevent a global pandemic. First, there's the company's HIV lineup. Gilead Sciences boasts several HIV drugs whose sales could grow at a nice clip in the coming quarters. In particular, there's HIV treatment drug Biktarvy, with sales for the fiscal year 2019 of $4.7 billion, compared to $1.2 billion in 2018. 

There's also HIV treatment drug Descovy. Although this product has not been performing particularly well -- with its sales remaining practically flat in 2019 compared to 2018 -- the U.S. Food and Drug Administration (FDA) approved Descovy for the prevention of HIV in October 2019. Thanks to this approval, sales of Descovy could pick up once again. 

Second, Gilead Sciences has several interesting pipeline candidates, including filgotinib, a potential treatment for rheumatoid arthritis (RA) that the company submitted to the FDA for review in December 2019. Of course, there are other treatments for RA, including AbbVie's (NYSE:ABBV) Humira. However, Gilead Sciences has high hopes for filgotinib.

The company's Chief Commercial Officer Johanna Mercier said:

Despite currently available treatment options many patients are still living with symptoms of inadequately controlled RA around the world. In fact, only one out of five patients living with RA achieve complete remission at year one, which means four to five do not. Filgotinib has a compelling and differentiated clinical profile that we believe may uniquely address the significant unmet need for patients with RA. 

Gilead Sciences also believes filgotinib has the potential to add five indications over the next four years. The drug is currently being evaluated for the treatment of Crohn's disease, ulcerative colitis, and psoriatic arthritis.

Furthermore, Gilead Sciences could benefit from its partnership with Galapagos (NASDAQ:GLPG). Last year, Galapagos received an equity investment of $1.1 billion as well as an upfront payment of $3.95 billion from Gilead Sciences. For its part, Gilead Sciences acquired "an exclusive product license and option rights to develop and commercialize all current and future programs in all countries outside Europe." Gilead Sciences could find more exciting products to market thanks to this agreement. 

Should you buy?

It is difficult to assess what effect (if any) Gilead Sciences' potential treatment for COVID-19 will have on its financial results. At this point, no one knows whether the company's remdesivir will prove effective at treating COVID-19. Even if it is, other companies could develop vaccines or treatments for the disease -- thus stealing Gilead Sciences' thunder -- or the epidemic could slow down (or both) by the time remdesivir hits the market. 

We don't know which of these scenarios will come true, and for that reason, I would recommend assessing Gilead Sciences' prospects outside of its potential treatment for COVID-19. And based on these prospects, Gilead Sciences looks like a stock worth serious consideration. 

Finally, despite its recent rally (Gilead Sciences' shares are up by 15.4% year to date), the company is trading at just 11 times future earnings, and its price-to-earnings growth (PEG) ratio is 0.52. These attractive valuation metrics constitute yet another reason to seriously consider buying shares of this biotech stock