If you're looking for a stock with potential to rise 1,000%, you might find it in the coronavirus vaccine and treatment space. It's the world's most-watched area right now. Why? Because companies that can help end the pandemic with a vaccine or drug are heading for big rewards. For example, Moderna and Pfizer -- makers of the first commercialized vaccines -- expect to make billions of dollars on them this year.

Moderna and Pfizer have plenty of share-price growth potential. But if you're looking for a possible 10-bagger, you might be better off checking out companies that aren't yet on everyone's radar screens. Let's take a look at two exciting players working on coronavirus treatments -- and see if they have what it takes to become tomorrow's stock-market winners.

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1. Humanigen

Humanigen (HGEN) shares soared more than 54% in one trading session after the company reported positive results from its investigational monoclonal antibody treatment for hospitalized COVID-19 patients. Lenzilumab. paired with other treatments, improved patients' "relative likelihood of survival without need for invasive mechanical ventilation" by 54%. Treatments used in the study included steroids and Gilead Sciences' Veklury (remdesivir).

Lenzilumab acts on "cytokine storms," which are overreactions of the body's immune system. In a cytokine storm, the body doesn't just fight off a virus -- it also attacks its own cells. Halting or preventing a cytokine storm is key to keeping many patients off ventilators.

Humanigen says it's now preparing to request Emergency Use Authorization (EUA). If authorized, lenzilumab would be the first antibody treatment authorized for hospitalized patients. The U.S. Food and Drug Administration (FDA) has authorized three antibody treatments so far -- but they are all for use in non-hospitalized patients. And the FDA hasn't yet authorized a treatment for coronavirus-related cytokine storm, so that would be another first.

Humanigen's specialty is addressing cytokine storms. And, beyond COVID-19, its lead candidate lenzilumab is involved in four other clinical trials -- each in phase 2. The company also has launched a phase 1 trial for another candidate in solid tumors.

2. Redhill Biopharma

Redhill Biopharma (RDHL -8.25%) shares haven't yet benefited from the company's clinical trial success; the stock is down about 16% year to date. But there's no reason to be pessimistic about Redhill. In December, the company announced positive safety and efficacy data from its phase 2 trial of opaganib in hospitalized COVID-19 patients. More than 52% of opaganib patients no longer required oxygen support by the 14th day of treatment; that's compared to only about 22% of the control group.

Here's how opaganib stands out: The oral drug candidate targets a part of human cells that plays a role in viral replication -- instead of targeting the virus itself. And that means variants of concern may not affect its efficacy. Another plus: Opaganib has shown antiviral and anti-inflammatory activity.

In February, Redhill said it planned to expand its global phase 2/3 trial of opaganib for severe COVID-19 to the U.S. That study is now more than 75% enrolled, the company said this past week. It expects to report results in the second quarter.

Redhill has another candidate in a phase 2/3 trial for COVID-19. And beyond the coronavirus program, the company has six candidates in the pipeline for gastrointestinal indications and oncology. Redhill has three gastrointestinal products on the market; it launched two of them last year.

The next 10-baggers?

Wall Street is optimistic about both companies. If analysts are right, Humanigen and Redhill could climb 100% and 200%, respectively, within 12 months. The two companies have coronavirus candidates that look compelling so far. More positive data and/or EUAs clearly would be reason for a big share-price increase for either company. And such a gain could easily exceed analysts' price forecasts.

So far, the FDA only has authorized 10 treatments for COVID-19. There's more than enough room for others. If a drug can cover a broad enough patient group, it could bring in billions. For instance, Veklury generated $1.9 billion in the fourth quarter of 2020.

But here's what could hold back Humanigen and Redhill from massive share gains: So far, investors have preferred the vaccine race to the treatment one. For example, over the past year, vaccine stocks Novavax and Moderna have outperformed treatment makers Gilead Sciences and Regeneron Pharmaceuticals:

GILD Chart

GILD data by YCharts.

That trend may reverse -- especially as more and more people are vaccinated and vaccines show efficacy in the real world. With the vaccine problem "solved," investors might want to bet more heavily on the treatment space. If this happens and if Humanigen and Redhill bring treatments to market, they may become 10-baggers. But even if their stock prices increase less than 1,000%, these companies still could be solid wins for healthcare portfolios.