If you're looking for stocks that can make big moves in a short amount of time, the biotech industry has you covered. There are some drugmaker stocks out there that could shoot higher or tumble lower this spring.

Developing useful new drugs can be an extremely lucrative endeavor but only if they get a green light from government regulators. Both of these companies are waiting for important approval decisions from the U.S. Food and Drug Administration (FDA).

Sarepta Therapeutics

Sarepta Therapeutics (SRPT -2.17%) develops and markets treatments for Duchenne muscular dystrophy (DMD). This is a progressive inherited disorder caused by a lack of dystrophin, a structural protein that grows between muscle fibers and keeps them from rubbing against each other.

Dozens of known mutations to the dystrophin gene lead to DMD, but Sarepta's approved treatments are limited to patients with some of the more common ones. The company also has an experimental gene therapy in late-stage development, called SRP-9001, that delivers a modified microversion of the dystrophin gene to muscle tissue. In theory, this approach could work for anyone who inherits a faulty dystrophin gene.

Last year, Sarepta's approved treatments generated $844 million in revenue. Approval for SRP-9001 could drive this figure much higher by allowing the company to reach a larger patient population. An eventual approval decision, though, is far from guaranteed.

Way back in January 2021, the first assessment of a placebo-controlled trial with SRP-9001 failed to show a significant functional improvement compared to the placebo group. There are a lot of details to mull over, but it looks like the study failed because patients with less severe disease were randomized to receive a placebo.

The FDA is reviewing an application for the accelerated approval of SRP-9001 based on the likelihood that observed microdystrophin production leads to a clinical benefit. An approval decision is expected on or before May 29, and it's hard to guess what the outcome will be.

A couple of weeks ago, the FDA announced it would convene a panel of independent experts to discuss Sarepta's application sometime before the proposed May 29 date. Keep your eyes open for the briefing document the FDA makes public ahead of the meeting. It's the first chance we'll have to know what the agency thinks about Sarepta's attempt to earn accelerated approval based on microdystrophin production instead of waiting for evidence of functional improvements.

Regeneron

Regeneron (REGN -1.66%) entered the public consciousness back in 2020 when then-President Trump praised its then-experimental antibody for curing a serious case of COVID-19. Seasoned biopharma industry investors are even more familiar with its lead drug, a blindness-preventing injection called Eylea.

First approved in 2011, U.S. sales of Eylea reached $6.3 billion in 2022. That worked out to 51% of total revenue last year. Next May, Eylea is expected to lose exclusivity in the U.S., and sales could quickly collapse under the weight of biosimilar competition.

Regeneron's developing a high-dose version of Eylea that will require fewer injections. Since each intraocular Eylea injection requires a doctor's visit, longer periods between doses is a significant improvement.

Most Eylea patients are well over 65 years old, and the drug is a huge expense for Medicare. The Inflation Reduction Act gives Medicare authority to negotiate prices on older drugs, which could include Eylea. Regeneron contends the high-dose version that could earn approval on or before June 27 is new and therefore not subject to the new rule.

Smart buys now?

Investors should understand the risks before they take a chance on either of these stocks. Sales of Sarepta's approved treatments are rising, but the company still lost more than $700 million last year. More cautious investors might want to wait until the company can make ends meet before betting hard-earned money on the stock.

Eylea's responsible for most of Regeneron's revenue but not for long. Dupixent is a treatment for eczema, asthma, and other inflammatory disorders that launched in 2017, and its sales could exceed Eylea's this year. Regeneron's collaboration partner Sanofi reported Dupixent sales that climbed 40% last year to $8.6 billion.

Regeneron stock is trading at around 21.8 times trailing 12-month earnings. With soaring Dupixent sales, Regeneron can deliver a positive return even if the company's attempts to maintain Eylea's exclusivity don't work out. Buying the stock now and holding it over the long run looks like a smart move.