Biogen Inc's (BIIB  ) stock jumped during trading last Thursday with the company's announcement that recent trials of its anti-Alzheimer's drug aducanumab were successful. The success of aducanumab's recent trials is already being met with speculation from industry experts.

Biogen's announcement brought immediate benefits during trading to the tune of a 3.4% jump by the end of trading on Thursday. The jump in price is a breath of fresh air for the company after it faced a harrowing 29% drop in price in March after a previous aducanumab trial was terminated after the drug appeared to have no effect on patients. Speculation surrounds the possibility of whether the company will now seek approval to begin selling the drug from the Food and Drug Administration.

From a business standpoint, approval by the FDA could greatly help Biogen financially. There are currently no treatments for Alzheimer's disease, which has created a sizable unmet need that Biogen, and Biogen alone, could benefit from if it were to gain approval. Biogen could also stand to gain in terms of its public image; one could imagine that being the company to provide the first treatment for Alzheimer's would do wonders for one's reputation.

Biogen could not help but be met with immediate skepticism, however. The earlier failed clinical trial of Biogen's drug has left many industry experts worried despite the success of the more recent trial. Dr. David Knopman of the Mayo Clinic stated, "I don't see how you can conclude anything other than that another trial needs to be done" about the study. Speaking in a recently written piece on the Science Translational Medicine website, Dr. Derek. Lowe expressed the need for additional trials of the drug. "No, the burden of proof is still on Biogen, and the way to provide that proof is to immediately start enrolling patients in a confirmatory trial. That's what others have done under these circumstances..." said Lowe, "and by golly the confirmatory trials confirmed that these drugs didn't work."

Biogen faces an uphill battle with approval for the aducanumab. The trial, while successful, is marred by the negative results of the March trial, which has created uncomfortable ambiguity concerning the overall effectiveness of aducanumab. The ambiguity might pass FDA scrutiny if the drug did not have side-effects, such as brain swelling. Perhaps more concerning were the results of the heralded trial itself; patients stopped taking aducanumab due to abnormalities only to start again, and additionally, 40% of the patients had not completed their trial before Biogen ended it.

The ambiguity and mixed results of Biogen's trials, along with the scrutiny of many industry experts who do not believe that the ostensibly successful trial warrants approval, may negatively affect the approval process for Biogen. Considerable concern regarding the potential harm may cause the FDA to opt against approval, which will leave Biogen with no other choice but to continue trials or abandon aducanumab entirely.