The first company to take a real hit on Tuesday was Axovant Sciences (NASDAQ:AXON). Axovant has been developing a drug called intepirdine as a potential therapy for patients with mild to moderate Alzheimer’s disease. On Tuesday, however, the company reported data from a phase 3 investigation studying patients in this population and comparing the asset to standard of care therapy in the space. Unfortunately for shareholders and patients, the data from the trial was not good.

The trial had two primary endpoints that served as co-primaries, meaning each was just as important as the other. These were a) improvement in cognition and b) improvement in measures of activities of daily living as measured by the Alzheimer’s Disease Assessment Scale-Cognitive Subscale and by the Alzheimer’s Disease Cooperative Study-Activities of Daily Living scale.

Both these scales are industry gold standard measuring points, meaning that if the company was able to register an improvement in these patients against one or the other, there would be a good chance that the drug would pick up a positive response from the FDA when Axovant submitted a registration application based on the data.

However, as per the latest news, patients registered neither an improvement in cognition nor improvement in measures of activities of daily living, meaning the trial failed against both its co-primary endpoints.

On the back of the news, Axovant has taken a considerable hit to its market capitalization, falling around 75% during the session on Tuesday. Premarket activity on Wednesday has called about 5%, but there is a good chance we will see this will continue to depreciate during the early session today as activity resumes and markets absorb the news.

The second major mover in the biotechnology space on Tuesday was again a decline and, this time, the company in question is PTC Therapeutics, Inc. (NASDAQ:PTCT).

This is a bit of a strange situation.

The company is trying to develop a drug called Ataluren in a target indication of Duchenne muscular dystrophy (DMD). This is a notoriously difficult population of patients to treat for a variety of reasons (the fact that it is a gene related disease and that it affects children are among the prime rate of these reasons) and there exists a graveyard of failed attempts over the past two decades. Most of these attempts looked promising in the early stages but failed to live up to potential as their respective development programs matured and, in parallel, the patient sample that was being tested expanded in size.

This was the case for PTC, or at least partly. The company submitted a registration application to the FDA back in early 2016 and subsequently received a Received a Refusal to File letter from the agency. After an appeal throughout the summer of last year, which culminated in October 2016, the agency once again rejected the application.

However, subsequent to the secondary rejection, PTC used what’s called a file under protest submission and effectively forced the FDA to accept the submission. The agency did just that and, much to the surprise of markets, set a PDUFA for the drug of October 24, 2017.

There’s also an advisory committee meeting in place, however, and it’s news surrounding this meeting that has got the company dipping this week. Specifically, we got some briefing documents and this statement was pulled from the documents in question:

The application contains a large number of exploratory analyses that lack interpretability and are often entirely based on unblinded data. The presentation of the data in the application is often unclear as to which analyses were used by the applicant. Ultimately, no positive results from any prospectively planned analyses that are persuasive have been provided with this application. In the one instance where an exploratory analysis (the unblinded post hoc analysis of Study 007) was prospectively tested (in Study 020), the results were clearly negative.

To put it lightly, this isn’t a great tone being set by the documents for the drug heading into the meeting, which will take place this Thursday. Markets have picked up on this tone and what it implies for the asset’s chances of picking up approval come PDUFA and – in turn – are selling off on PTC.

We’ll likely see the real response come at the outcome of the meeting, so shareholders should brace for impact come the end of the week.