In the world of business, disruption is the agent of change. Companies that get too comfortable with their market dominance often grow too large and complacent, allowing younger and hungrier competitors to introduce innovative new products that render their business models obsolete.

In recent years, Apple disrupted the entire PC and cell phone markets with its iOS devices. In the health-care industry, that same disruptive effect can be spotted in three companies that possess potentially game-changing technologies -- Organovo (ONVO -8.89%), Antares Pharma (ATRS), and MannKind (MNKD -0.48%).

Let's take a closer look at these three companies, and the companies that could be affected by their medical innovations.

Will 3-D-printed organs render waiting lists obsolete?
Organovo uses 3-D printers to print human tissues. Although the idea of using its 3-D printers to eventually print out human organs has captured the media's attention, let's not get ahead of ourselves yet.

Organovo's 3D printer. Source: 3dprinter.net.

Organovo's first marketed product will be a 3-D-printed liver assay for toxicology, which is superior to the traditional 2-D cell cultures used by the pharmaceutical industry during clinical studies. Organovo claims that its 3-D-printed liver assays can retain key liver functions for up to 40 days and can be tested on with multiple doses of the same drug -- two key advantages that 2-D cell cultures lack.

By testing drugs more thoroughly on 3-D liver assays during preclinical trials, pharmaceutical companies are less likely to fail during phase 3 trials because of unforeseen liver toxicity in test patients. According to CEO Keith Murphy, 25% of the failed or withdrawn drugs between 1990 and 2010 were due to liver toxicity that wasn't initially predicted during earlier clinical studies.

Organovo expects to launch its 3-D-printed liver assays by late 2014. However, it hasn't provided a long-term timetable for actual 3-D organ printing, although a full-sized printed liver would be the next obvious step.

At this point, Organovo is still a very speculative bet on a technology that could eventually render organ transplants obsolete. Last quarter, the company generated less than $0.1 million in revenue -- a 95% plunge from the $0.5 million it reported a year earlier. Its revenue consists entirely of collaboration revenues.

Nevertheless, investors are still giving Organovo the benefit of the doubt, and shares have rallied more than 300% over the past 12 months.

Hate needles?
For patients who hate needles, Antares' reusable needle-free injectors could be worth a look. Antares' Vision injectors use a mechanical spring to push a drug out of a syringe at high speed, moving it through the thin folds of the skin and into the fatty tissue underneath.

One of Antares' needle-free injectors. Source: Medgadget.com.

Antares showcased this technology with needle-free insulin injectors until 2009, when it stopped selling the product to new U.S. customers. Since then, Antares has generated the majority of its revenue from sales of pre-filled injectors to Teva Pharmaceutical (TEVA -0.90%), Actavis, and Ferring.

Teva and Ferring are the biggest buyers of Antares' needle-free injectors. Teva currently uses them for the 5 mg dose of the human growth hormone Tev-Tropin, and Ferring uses them for the 4 mg and 10 mg doses of the human growth hormones Zomajet 2 Vision and Vision X.

Although Antares' technology is impressive and could disrupt sales of traditional needles from larger companies such as Sanofi and Baxter International, the company still hasn't attracted much attention as a viable investment. Last quarter, Antares' revenue dipped 3% year over year to $5.5 million, and it remains unprofitable.

Antares' big hope for the future is Otrexup, its auto-injectable version of a generic arthritis and psoriasis drug, methotrexate, which was approved in October. Antares believes that patients who get methotrexate injections at a clinic will prefer an auto-injected version they can use at home. The company estimates that Otrexup could generate peak annual sales of $100 million to $200 million -- not a bad boost for a company that generated only $22.6 million in revenue last year.

Will MannKind's inhalable insulin disrupt the insulin industry?
On the topic of needle-free solutions, we should also look at MannKind, the last company standing in the market for inhalable insulin.

There was a time when Big Pharma was obsessed with producing inhalable insulin, since most diabetes patients should prefer an inhaler over a needle. Unfortunately, when Pfizer (PFE -0.60%) released the first inhalable insulin product, Exubera, in 2006, that dream quickly fell apart. Exubera required a massive inhaler, used a confusing, non-linear dosage pattern, and cost more than regular injected insulin.

In the end, Pfizer discontinued Exubera less than a year later and took a $2.8 billion writedown on the disaster. Seeing Pfizer's failure, other hopeful partnerships such as Aradigm/Novo Nordisk and Alkermes/Eli Lilly soon dissolved as well.

MannKind's Afrezza. Source: Company website.

MannKind, however, stood its ground. Even after two FDA rejections, the company is still convinced that its inhalable insulin, Afrezza -- which uses a smaller inhaler, has a linear dosage pattern, and uses a faster-acting insulin analog than Exubera's human insulin -- still has a chance to become a blockbuster treatment. Afrezza also appears to cause fewer respiratory problems than Exubera.

If MannKind succeeds, Afrezza could eventually generate annual peak sales of $2 billion and take a bite out of the injected insulin market dominated by Novo, Sanofi, and Lilly. MannKind resubmitted a new drug application for Afrezza in October, which means a possible approval could come some time next year.

The Foolish takeaway
Organovo, Antares, and MannKind all represent disruptive medical innovations that you can invest in today.

However, investing in a product before it is launched -- such as Organovo's 3-D-printed liver assays and MannKind's Afrezza -- can be risky, so do your due diligence on these companies first. Meanwhile, Antares looks stale as a growth investment, but its products could definitely mean less tears for kids getting their shots at the doctor's office.

In closing, dear readers -- what other disruptive medical innovations do you think will alter the course of the health-care industry over the next decade? Please share your ideas in the comments section below!