Every sector relies on innovation to grow to some extent, but it's possibly the most vital component to success in the biotech sector.

Biopharmaceutical companies don't have the luxury of simply sitting on their laurels and living off of the residual income of branded drugs due to the relatively short lifetime of most issued drug patents and an ever-growing competitive field of prospective companies. This means that biopharma companies literally live and die by innovation.

Source: AstraZeneca.

What investors should understand is that innovation in the biotech sector comes in a number of forms. Sometimes it involves collaborations between small and large drug developers while other forms of collaboration come internally in the form of new treatment platforms. Examples of these new treatments include the recent focus on cancer immunotherapies that work by retraining the body's immune system to recognize and attack cancer cells, as well as antibody-drug conjugates which latch a chemotherapy toxin on an antibody through a linker, which then releases that toxin when it comes into contact with a specific protein signature from the targeted cancer cells.

Long story short, innovation is paramount to biopharmaceutical success.

But, beyond just looking at different treatment pathways, biopharmaceutical companies are also looking at unique ways they can utilize new compounds to treat a bevy of diseases. Below are nine different therapies that biopharma companies have derived from some of the unlikeliest of sources. Keep in mind that this out-of-the-box thinking is what can occasionally make the difference between a biopharmaceutical that will survive and one that won't.

In no particular order, the nine drugs derived from the unlikeliest sources are:

Source: GW Pharmaceuticals.

1. Sativex
Developed by U.K.-based GW Pharmaceuticals (NASDAQ:GWPH) and currently marketed in 11 countries (not the U.S.), Sativex is one of the world's first prescription medicines derived from cannabis. GW Pharmaceuticals has identified some five dozen cannabinoids which work with the natural cannabinoid receptor system found within the human body, allowing it the possibility to regulate biologic functions through receptor control. Sativex itself is a combination of two cannabinoids (CBD and THC) and was approved to minimize the effects of spasticity in multiple sclerosis patients in select ex-U.S. countries. Within the United States it remains to be seen if Sativex will be approved, but it currently has three ongoing phase 3 trials as a treatment for cancer pain and an additional phase 3 trial beginning this year for MS spasticity.

Source: Eden, Janine, and Jim, Flickr.

2. Byetta
Approved by the Food and Drug Administration in 2005 and currently owned by AstraZeneca (NASDAQ:AZN). Byetta is a twice-daily injection designed as an adjunct to proper diet and exercise to control blood sugar in type 2 diabetes patients. What's truly unique about Byetta is that it was derived from the saliva of the Gila monster which is a lizard found only in the Southwestern U.S. and Mexico. Although Byetta is an injection and most diabetic patients would prefer the convenience of pills, it still managed a combined $606 million in worldwide sales in 2013, up from just $223 million in the previous year.

3. Premarin
Originally developed by Wyeth, which was subsequently purchased by Pfizer (NYSE:PFE), Premarin is a conjugated estrogen formulation given to women to treat symptoms of menopause, as well as treat osteoporosis following menopause. There are two particularly interesting facts about Premarin. The first is that it's derived from the urine of pregnant mares (i.e., adult female horses). The second is that despite being well beyond its patent expiration by a few decades, there is still no generic version of the therapy available. This resulted in nearly $1.1 billion in revenue for Pfizer from Premarin in 2013.

4. Heparin
Heparin has been in use as an anticoagulant since the mid-1930s and can still be used in operating rooms and in intravenously infused dialysis patients to this day. To be clear, in recent years scientists have discovered a way to synthetically engineer Heparin , however, Sagent Pharmaceuticals is still manufacturing Heparin vials  derived from porcine intestinal mucosa -- or in English, from pig intestines -- to this day.  

5. Proferrin
Manufactured by privately held Colorado Biolabs, Proferrin is an iron-supplement that Colorado Biolabs asserts is the only iron supplement in the U.S. that uses solely heme iron polypeptides. Because it's not an ionic iron it doesn't compete with other nutrients for absorption which improves total absorption rates for iron-deficient individuals. Proferrin is not affected by food intake, either. But, what's most unique about Proferrin is that it's derived from bovine (cow) hemoglobin.

6. Prialt
Currently manufactured by Jazz Pharmaceuticals (NASDAQ:JAZZ), Prialt is a severe pain medication for sufferers of chronic conditions such as cancer that is injected directly into the fluid surrounding the spinal cord. Perhaps the most interesting aspect of Prialt is that it's an identical synthetic formulation to the venom of the Conus magus snail, a sea-dwelling snail. Normally naturally occurring compounds are modified to make a drug more effective, but this was a rare instance where the sea snail venom itself was perfect just the way it was. Unfortunately for Jazz, Prialt sales were largely flat year-over-year, bumping higher to $27.1 million in fiscal 2013 from $26.7 million in 2012.  

Bothrops jararaca, Source: Felipe Sussekind, Wikimedia Commons.

7. Capoten
Known in its multiple generic forms as captopril, this drug is used to treat hypertension (high blood pressure) in patients. Captopril gained FDA approval in 1981 and became the first oral angiotensin-converting-enzyme, or ACE, inhibitor. Most uniquely, though, it was developed after researching the blood pressure-dropping effects of a Brazilian pit viper (Bothrops jararaca) and developing synthetic versions of this vipers' venom which had a mimicking effect of lowering blood pressure in patients.

8. Integrilin
Originally developed by Millennium Pharmaceuticals and co-promoted by Schering-Plough which are both now part of Merck (NYSE:MRK) and Takeda Pharmaceuticals, Integrilin is an injection given to patients with acute coronary syndrome to decrease the chance of a new heart attack or death, including patients undergoing percutaneous coronary intervention. Similar to Capoten above, Integrilin was derived from mimicking the glycoprotein IIb/IIIa blocker barbourin found in the venom of the Southeastern pygmy rattlesnake. However, sales of the myocardial infarction prevention therapy have fallen in each of the past two years from $230 million in 2011 to just $186 million in 2013 according to Merck's annual reports. 

9. Aggrastat
Lastly, we have Aggrastat, a drug now marketed by Medicure Pharma in the U.S. and Correvio International ex-U.S., but originally developed by Merck, that's designed to reduce the rate of thrombotic cardiovascular events such as a heart attack. Similar to Integrilin above, researchers isolated and synthesized a protein found in the venom of the African saw-scaled viper (Echis carinatus) to develop this anticoagulant used to reduce the chance of a blood-clot-based CV event.  

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.