There are quite a few companies that have found ways to grow their business during the ongoing COVID-19 pandemic. This is especially true for a number of biotechs now working on developing a potential treatment for, or vaccine against, the virus; shares of such companies have largely surged over the past couple of months.

Although many of these treatments and vaccines are still have quite a way to go before they're widely available, it's still worth taking some time to look through what's going on in the COVID-19 space right now.

Here are five biotech stocks that are leading the way when it comes to addressing COVID-19.

Multiple test tubes, with one labeled COVID-19

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1. Regeneron Pharmaceuticals

Regeneron Pharmaceuticals (NASDAQ:REGN) wasn't among the initial wave of companies to announce a potential COVID-19 drug. However, investor excitement quickly sent shares surging when the company announced that its rheumatoid arthritis drug, Kevzara, could help treat COVID-19 patients.

More specifically, Kevzara is designed to reduce the amount of inflammation that arthritis patients typically have by inhibiting certain proteins called interleukins. These proteins are directly involved in regulating the body's response to inflammation. The idea is that Kevzara, which affects the interleukin-6 (IL-6) pathway, could also reduce the inflammatory response seen in COVID-19 patients, helping reduce the severity of their symptoms.

Earlier this month, Regeneron and its partner Sanofi launched a second phase 2/3 trial testing Kevzara as a COVID-19 treatment. About 300 people with severe symptoms will be enlisted from countries in Europe and North America.

At this point, Regeneron's biggest competition comes from other potential IL-6 inhibitors. Roche Holding's Actemra, another IL-6-inhibiting drug, has shown impressive anecdotal results in China as well. The U.S. Food and Drug Administration (FDA) also recently approved a phase 3 trial to see if Actemra could help patients with severe COVID-19-related symptoms.

2. Gilead Sciences

Gilead Sciences (NASDAQ:GILD) was one of the first companies to announce work on potential treatments. Remdesivir, an antiviral drug candidate originally designed to treat Ebola, showed promising early results in mitigating symptoms in patients with COVID-19.

Since then, Remdesivir has embarked on two late-stage trials in China, two more late-stage trials in Asia, and one trial involving U.S. health authorities. However, a recent scientific paper examining 12 COVID-19 patients treated with the drug showed mixed results regarding Remdesivir's efficacy. Gilead's CEO has since stated that further clinical updates would be forthcoming this month, so investors should keep their eyes peeled for additional information coming soon.

Although Remdesivir is one of the leading COVID-19 antiviral treatments on the market, it faces potential competition from some other drugs. Most notably, anti-malaria drug chloroquine has been touted by President Trump as a possible treatment.

The federal government is currently investigating chloroquine and hydroxychloroquine as potential treatments. Although the FDA has given doctors authorization to prescribe these drugs in certain situations when they think that would help patients in need, both drugs need more clinical data before they can see widespread use.

Vaccine bottle and a syringe, against a blue background

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3. Inovio Pharmaceuticals

Inovio Pharmaceuticals (NASDAQ:INO) is just one of many small-cap vaccine developers that have become hot stocks amid this pandemic. The company announced it had begun work on a COVID-19 vaccine, INO-4800, back in January, and claimed that it managed to create an initial candidate just hours after the virus's genetic code was decoded. Earlier this month, INO-4800 officially entered phase 1 clinical testing.

The main case for Inovio is that the company has had previous success in addressing other types of coronaviruses. INO-4700, currently undergoing phase 2 trials, is a vaccine candidate designed to prevent MERS (Middle Eastern Respiratory Syndrome), a disease caused by another coronavirus that has symptoms similar to COVID-19. This past experience and success in creating a MERS vaccine candidate have many investors excited about Inovio's chances with INO-4800.

Inovio has also said it will be producing one million vaccine doses by the end of the year. While that would be an impressive achievement for a company of its size, it's still questionable whether it could truly produce and distribute such quantities around the world.

4. Moderna

Most other COVID-19 vaccines being developed right now are DNA-based, but Moderna (NASDAQ:MRNA) is leading the way with a new type of vaccine. The company's experimental mRNA-vaccine technology has the potential to be more efficient and easier to develop than DNA-based counterpart vaccines.

There's a distinct possibility that this new technology could lead to Moderna developing the best-performing COVID-19 vaccine on the market. However, the catch is that mRNA-based vaccines are still highly experimental, and it remains anyone's guess as to how human patients will react to this new type of vaccine.

Moderna's COVID-19 vaccine, mRNA-1273, was shipped to U.S. health authorities back in February, and human trials began in March. Considering that the virus's genetic sequence was decoded in January, that means Moderna managed to develop a new vaccine and begin clinical testing in a little over two months, a remarkable turnaround time.

With no other mRNA-based COVID-19 vaccine candidates currently in clinical trials, Moderna's biggest competition will come from makers of DNA-based vaccines. This includes Inovio, which began developing its own vaccine at almost the same time that Moderna did.

Medical professional with a face mask holding a vaccine bottle

Image source: Getty Images.

5. Novavax

Like many other vaccine makers, Novavax (NASDAQ:NVAX) has a number of promising products on the horizon, including a potentially game-changing flu vaccine, NanoFlu. However, shares of the company have almost quadrupled since the start of the year, when the company announced it was working on a COVID-19 vaccine.

More specifically, Novavax has been testing a number of potential vaccine candidates in animals over the past couple of months. The company decided that candidate NVX-CoV2373 demonstrated the most potential in preclinical tests, with the drug showing immunogenicity -- helping amplify the immune system's response to viruses. The company announced recently that it would begin early-stage human trials sometime in May.

The only problem for Novavax is that it's a little behind the curve when it comes to COVID-19 vaccine development. Both Inovio and Moderna began clinical trials in March or April, giving them a slight head start that will be hard for Novavax to make up. Considering the urgency to get a COVID-19 vaccine developed, the first companies to finish clinical testing could easily scoop up the lion's share of initial demand.

However, the sheer number of people who will want to protect themselves from COVID-19 is large enough that Novavax could still make some money from its vaccine, although less than it could have made if it was first to the market.