It’s Tuesday morning and the US session is about to get underway for a fresh day of trading in the biotechnology sector. Things have finally recovered (from a volume perspective) after the lull brought about by the Thanksgiving break and it looks as though we are going to get some pretty volatile action today.

As we move into a fresh session, here’s a look at two of the biggest movers in the biotechnology space during the early part of this week, with a discussion of where we expect each to go next.

The companies in our crosshairs are Regeneron Pharmaceuticals, Inc. (NASDAQ:REGN) and Catalyst Pharmaceuticals, Inc. (NASDAQ:CPRX).

First up, then, Regeneron.

This one is a data-driven move. The company announced during the late session on Monday that it had analyzed the data from a pair of phase 2 trials of one of its lead development programs – a combination of two drugs called nesvacumab and EYLEA (aflibercept) – which Regeneron was investigating as a potential therapy for the treatment of for the treatment of diabetic macular edema (DME) and wet age-related macular degeneration (wet AMD).

These are two incredibly large markets and they are markets with equally large unmet needs right now. The current standard of care treatments in both spaces are insufficiently effective, especially over a long period of time, and essentially just delay degeneration as opposed to halting it.

Regeneron was trying to change this with its combination asset but, as per the latest release, it doesn’t look like it’s going to succeed – at least this time around.

On the back of the news, the company details the fact that both phase 2 trials have failed to demonstrate enough of a degree of impact on severity in both DME and wet AMD, with the trial failing to hit its primary endpoints as a result.

When a trial fails against its primaries, as is the case here, it’s very difficult to justify advancing into the next stages of a development pathway. This is exactly what we are seeing with Regeneron right now and the company is trading around 3% down on its preannouncement market capitalization as a result.

Keep in mind that this is a $40 billion biotechnology company so the fact that it is trading at a 3% discount is substantial, even if the numbers don’t look that substantial at a glance.

There is a good chance that we will see this one continue to depreciate heading into the middle of this week as markets absorb the news and readjust valuation to reflect the fact that this combination program is now terminated.

Next up is Catalyst.

This one is also a data-driven move but, fortunately for the company shareholders, it’s gone the other way. On Tuesday, Catalyst announced positive top-line results from a second Phase 3 clinical trial (LMS-003) (one already completed and did so successfully) of its lead development asset – a drug called Firdapse for the treatment of Lambert-Eaton myasthenic syndrome (LEMS). LEMS is an autoimmune disease and one in which the immune system attacks the body’s own tissues. The attack occurs at the connection between nerve and muscle (the neuromuscular junction) and interferes with the ability of nerve cells to send signals to muscle cells.

As per the just reported data, Catalyst was able to show that its drug can be both safe and effective in this target population (again, this is a population that’s crying out for fresh treatment options) and, on that basis, the trial met its defined co-primary endpoints.

In contrast to our expectations for Regeneron, there is a good chance we will see this one pickup a considerable amount of strength near term as the company heads into its registration application submission for this asset.

Management expects to file an NDA at some point during the first quarter of next year. Keep in mind that this is an asset (and an application) that has already been turned down once, with the agency in the US issuing a “Refusal to File” letter regarding an initial NDA in February 2016.

As such, even though the data was positive, there is no guarantee of approval and this has to be considered when picking up and exposure to this binary event.

From a share price perspective, the company initially picked up some strength on the news but then slipped a little on the back of a parallel announcement that it will be issuing some shares to raise cash.