The healthcare sector is in the midst of an unprecedented technological boom at the moment. Despite major advancements across several medical fields, though, this innovation bonanza is, quite literally, showing no signs of slowing down. 

Armed with this insight, we asked three of our Motley Fool investors which companies they think are on the cusp of changing healthcare as we know it. They suggested Bellicum Pharmaceuticals (BLCM), Apple (AAPL -1.22%), and Novocure (NVCR 0.33%). Read on to find out why. 

A hand holding a vial of DNA.

Image source: Getty Images.

A hidden gem in immuno-oncology

George Budwell (Bellicum Pharmaceuticals): Genetically modified cell-based cancer therapies are now a reality following the back-to-back approval of both Gilead Sciences' Yescarta and Novartis' Kymriah earlier this year. But while Gilead and Novartis' respective CAR-T therapies did show unprecedented abilities to treat hard-to-treat forms of blood cancers in clinical trials, they also both produced some serious -- even potentially deadly -- side effects that may keep them from becoming frontline anti-cancer therapies. 

The small-cap clinical-stage biotech Bellicum Pharmceuticals, however, may have a way to circumvent these problematic side effects. Bellicum has developed a molecular switch mechanism that can induce either apoptosis (programmed cell death), or proliferation (to enhance potency) of their genetically modified cell therapies following infusion. Gilead and Novartis, by contrast, are limited to treating patients experiencing life-threatening side effects -- such as cytokine release syndrome -- with standard immunosuppressants, and this ad hoc approach hasn't always worked unfortunately. 

The one glaring problem with Bellicum's value proposition, though, is that the company is a few years away from grabbing a major regulatory approval capable of making it a cash flow positive operation. And that fact almost certainly means that Bellicum will eventually tap the public markets for funds at least a few more times in the years ahead.  

That being said, Bellicum is developing a well-differentiated anti-cancer technology that could become the gold standard in cell-based therapies down the road. So while the biotech does need to shore up its long-term financial outlook, Bellicum's novel cell therapy platform also gives it a real shot at reshaping the entire field in the not-so-distant future.  

This tech giant is making waves in the healthcare sector 

Sean Williams (Apple): There are a number of companies doing wonders in the healthcare field. For instance, cancer immunotherapy drug developers are giving advanced cancer patients a new lease on life, while medical device makers are improving the quality of life for diabetes patients. But one company with deep pockets that could change the game is a bit untraditional: Apple.

Apple, which is best known for its iPhone, iPad, and Macbook, announced its entrance in to the health space in 2014 when it introduced the Health app with its launch of iOS. The Health app allows users to keep track of their wellness in four key areas: activity, sleep, mindfulness, and nutrition. While the Health app is continually a work in progress, it's a step toward increasing wellness awareness with the public, and shuffling consumers toward that next step: cloud-based sharing.

The advent of the Apple Watch and other wearable technology may one day allow your doctor to collect real-time data that could improve your personalized wellness plan. CNBC pointed out in April of this year that Apple's been working on a blood-glucose measurement device for diabetics that'll work without the need for a needle. Considering how often patients have to test their blood sugar, this would be a major quality of life advancement. A proprietary model appears to have been tested out by Apple CEO Tim Cook.  

In June, Apple forged a partnership with blood glucose monitoring device maker Dexcom (DXCM -2.67%) that'll link Dexcom's device with the Apple Watch. Apple's Bluetooth technology that allows devices to link to its Watch isn't unique to Dexcom (it'll potentially work with other devices), but it's just another example of how Apple can use wearables, technology, and/or the cloud to personalize the treatment process.

While it could be a nascent revenue generator for years, look for healthcare to slowly grow into a notable portion of Apple's revenue stream in the decades to come.

A new weapon in the cancer fight

Brian Feroldi (Novocure): While we've made tremendous progress in the war against cancer, more than half a million Americans still die each year as a result of their diagnosis. Clearly, there's still plenty of work left to do.

Novocure is one company that's blazing new trails in the fight. The company figured out a few years ago that cancerous tumors can't replicate themselves as easily when an electric field is nearby. That unique insight lead the company to create a product called Optune, which is a FDA-approved medical device that treats brain cancer.

Optune looks like a swimmers cap that has a cord coming out of the back. To use it, a patient simply puts the device on their head and hooks it up to a portable electronics kit. Once turned on, Optune creates a series of electric fields that go to work on the brain cancer while leaving the rest of the body unscathed. 

It might sound like Optune is too good to be true, but the company has the data to prove that the device is the real deal. The company published data from a long-term study that showed that adding Optune to standard-of-care therapy chemotherapy more than doubled survival rates at five years. That's an impressive result for an incredibly hard to treat cancer.

While Optune's appeal has allowed Novocure to grow like crazy, there's reason to believe that the party is just getting started. Novocure is currently running trials to prove that Optune works in lung, pancreatic, and ovarian cancers, too. If they succeed then the sky is the truly the limit for this company's growth potential.