In the days before electronic filing, new drug applications required so much paper they could fill entire offices from floor to ceiling. Just getting the U.S. Food and Drug Administration (FDA) to officially begin reviewing one is an accomplishment.

All three of these biotech stocks could move in the weeks ahead, because the FDA is expected to hand down decisions regarding some applications currently under review. Here's what you need to know.

Company (Symbol) Market Cap Candidate Under Review Indication PDUFA Date
TherapeuticsMD Inc. (NASDAQ:TXMD) $1.2 billion TX-001HR Hot flashes due to menopause Oct. 28
AcelRx Pharmaceuticals Inc. (NASDAQ:ACRX) $265 million Dsuvia Acute pain Nov. 3
Loxo Oncology Inc. (NASDAQ:LOXO)  $4.9 billion  Larotrectinib NRTK gene fusion–positive cancers Nov. 26  

Data sources: Company filings and Yahoo! Finance.

TherapeuticsMD Inc.: Flashy combo

This spring, the FDA accepted TherapeuticsMD's new drug application for TX-001HR, and with a PDUFA date set for Oct. 28, an approval decision is right around the corner. The experimental hormone therapy significantly reduced the frequency and severity of hot flashes due to menopause during clinical trials underpinning the application.

TherapeuticsMD's experimental therapy is a bit more opportunistic than innovative. TX-001HR is simply a combination of progesterone and estradiol, two hormones pharmacists have been combining on their own for decades to treat the condition. Given their well-understood profiles, a thumbs-up from the FDA seems likely.

TherapeuticsMD thinks there could be up to 2.5 million Americans using unapproved compounded therapies. While patients aren't particularly bothered, keeping up with regulatory guidelines can make using compounded therapies a bit expensive. If the company eventually convinces insurers to pay extra for its version of the popular concoction, the company's recent $1.2 billion market cap could climb.

Three healthcare providers in a pharmacy.

Image source: Getty Images.

AcelRX Pharmaceuticals Inc.: Biotech bouncer

This stock received a brutal beating last year when the FDA refused to approve Dsuvia for the treatment of temporary pain in medically supervised settings. The application for AcelRX's fast-acting opioid was held up while the company submitted additional safety information. 

AcelRx Pharmaceuticals' candidate is a tablet that contains sufentanil, an extremely potent opioid currently available for intravenous use or through an epidural. Taking an oral route isn't just easier for patients and providers, it tends to smooth out the effects of the pain drug over a longer duration. 

The FDA recently convened a panel of independent experts that voted 10–3 in favor of recommending the approval of Dsuvia. The agency generally follows panel recommendations even though it isn't required to, but that doesn't assure success for Dsuvia.

The painkiller is effective at a dose of just 0.03 mg, which means a thimbleful could take down an entire football team. If the company hasn't fully addressed all the FDA's safety concerns, there could be more pain ahead.

Smiling doctor.

Image source: Getty Images.

Loxo Oncology Inc.: Anywhere is fine

The more oncologists know about your tumors, the more they can do to fight them. Loxo Oncology's lead candidate, larotrectinib, is about to become a new treatment for patients with tumors that harbor an NTRK gene fusion.

Larotrectinib is especially exciting because it appears to work on solid tumors anywhere in the body, as long as they exhibit the right mutation. The experimental therapy shrank tumors for three-quarters of patients with advanced-stage cancer across a handful of different studies that evaluated a total of 55 patients.

Since Loxo rushed larotrectinib's application to the FDA without a large pivotal study, there's always a chance the FDA will ask for one first. Given the treatment's excellent safety profile so far, though, an accelerated approval seems like the likely outcome. None of the patients experienced life-threatening side effects from a drug that appears to improve their odds of long-term survival. 

Question mark on a bed of hundred-dollar bills.

Image source: Getty Images.

It's all about expectations

Loxo Oncology sports a $5.0 billion market cap at recent prices even though larotrectinib is aimed at a relatively small patient population. That means investors buying shares at recent prices are already expecting success, and anything less will result in swift losses.

AcelRx Pharmaceuticals is on the opposite end of the spectrum, with a $265 million market valuation that could rise several times if Dsuvia becomes a standard acute-pain treatment dispensed by healthcare providers. An FDA approval that comes with a favorable prescribing label would be a step in the right direction.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.