With so many FDA decisions coming out in a few months, it is an exciting time for biotech investors. For all three of these stocks -- Spectrum Pharmaceuticals (NASDAQ:SPPI), Orexigen Therapeutics (NASDAQ:OREX), and Avanir Pharmaceuticals (UNKNOWN:AVNR.DL) -- obtaining FDA approval will be critical to their growth strategies and will impact their long term revenue. Betting on FDA approval decisions is not for the faint of heart—the decisions come with substantial risk. Should the FDA choose not to approve a drug, it could set back the development timeline for years and cause for the company to have to conduct additional trials. In addition, once a drug is approved the company faces a whole new set of challenges related to sales. The drugs mentioned in this article have the potential to make a substantial revenue impact on their respective companies.

Spectrum Pharmaceuticals has a PDUFA date of August 9th, for its peripheral T-Cell Lymphoma drug Beleodaq. Beleodaq recently received priority review from the FDA, which is designated for drugs that have the potential to be a substantial improvement over currently existing treatments.

With analysts from Edison Investment Research anticipating peak annual sales of around $130 million, Beleodaq would be a welcome addition to Spectrum's top line. Spectrum could use the additional revenue provided by Beleodaq as in its most recent quarter Spectrum lost $27.6 million. Investors should note that Spectrum may not have as much difficulty with commercialization given that the company already has several drugs on the market and has likely built up relationships with a variety of oncologists in the course of commercializing those drugs.

Orexigen Pharmaceuticals recently received some seemingly unfortunate news when the FDA delayed making a decision on its obesity drug Contrave. The decision for Contrave is now expected on September 11, 2014. This setback is not necessarily bad for Orexigen shareholders,as the FDA mentioned that the holdup was related to the post-approval cardiovascular studies that Orexigen will have to conduct. This bodes well because there would be no point in discussing post-approval studies if the FDA was not going to approve the drug. If approved, Contrave would be Orexigen's only product on the market.

I previously wrote about why I believe that Contrave will be more successful than its competitors have been in the obesity-fighting marketplace. If Contrave is commercially successful -- assuming approval -- it'll hopefully make a big difference in reducing cash burn at Orexigen (the company burned about $70 million in operating cash flow in the trailing-12 months, leaving it with $155 million in the bank). Obtaining FDA approval will provide substantial revenue for Orexigen, as it will be entitled to milestone payments from its marketing partner Takeda Pharmaceuticals. An added benefit is that, with the costs of marketing in North America handled by Takeda, Orexigen can focus its remaining cash on clinical opportunities instead of an expensive commercialization push.

Avanir Pharmaceuticals is expecting an FDA decision on November 26th for its anti-migraine drug AVP-825. AVP-825 is a version of sumatriptan (which is a commonly used anti-migraine drug), that is delivered through inhalation. AVP-825 has the potential to provide many benefits over currently approved products.

Due to the nature of its delivery (intranasally via dry powder), AVP-825 may provide an ease of use for patients with difficulty swallowing pills, and may provide benefits over currently approved versions of the drug. A key advantage is that in a head-to-head study versus oral sumatriptan, AVP-825 provided relief faster than its oral counterpart. From a financial standpoint, AVP-825 could have peak sales of $125 to $200 million, according to Jeffries. Avanir needs the revenue, as the firm lost more than $12 million last quarter. Should AVP-825 reach the market, it has the potential to push Avanir into profitability. Given that Avanir has had trouble executing on analyst projections -- Nuedexta sales, while increasing for 12 consecutive quarters, still only made it to $24.4 million last quarter, well under analyst peak sales projections -- it's fair to be uncertain how successful this therapy will be. But there is another potential issue -- as of last quarter, Avanir had $54 million in cash and equivalents, but burned through $69 million in operating cash over the trailing-12 months. Shareholder dilution could occur in the future.

Final thoughts
Each of the drugs mentioned in this article has the potential to significantly impact their respective companies. Should the FDA approve each of the drugs, it will help to steer the companies toward profitability and will help to guide long term growth. It is important to note for any investor, however, that the FDA is not the end all be all of success. If these companies obtain FDA approval for their drugs, they will then have to go through the challenge of successfully marketing each of the drugs.