It could be the perfect time to add Tandem Diabetes Care (NASDAQ:TNDM), IQVIA Holdings (NYSE:IQV), and Gilead Sciences (NASDAQ:GILD) to portfolios. Why? Because these Motley Fool investors think the launch of a new game-changing device for diabetes will send Tandem's sales soaring; increased spending on drug development will be a boon to IQVIA; and pipeline data could cure Gilead Sciences' ailing share price. Read on to see if these stocks are right for your portfolio.

A big advance in diabetes treatment

Todd Campbell (Tandem Diabetes Care): One of the most intriguing healthcare stocks I'm interested in adding to my portfolio this month is Tandem Diabetes, an insulin pump maker that plans to launch its automated insulin delivery system in August.

A stethoscope listening to a piggy bank.

Image source: Getty Images.

Tandem currently markets the t:slim X2, an insulin pump that patients can use instead of multiple daily insulin injections. Usually, patients pair up these pumps with DexCom's (NASDAQ:DXCM) continuous glucose monitor (CGM), but until now, the two couldn't automatically monitor and dose insulin as necessary.

That will change in August when Tandem Diabetes launches Basal-IQ, a feature that automatically pauses insulin delivery when CGM readings predict blood sugar levels could become too low. The ability to prevent hypoglycemia, a life-threatening condition, clears the way for patients to use these devices to automatically treat diabetes and, perhaps, delay its progression.

Tandem's insulin system will be the second such automated system to become available. The first system, Medtronic's (NYSE: MDT) MiniMed 670G, has been a big success with 70,000 people who were using it as of March, up from 20,000 people in December. Because over 1 million people have type 1 diabetes and could benefit from these systems, there's reason to think that Tandem's sales could head materially higher following its debut -- especially because the t:slim X2 is smaller than the MiniMed 670G and, when paired up with DexCom's newest CGMs, it offers patients the ability to change sensors and check their blood sugar with finger sticks less often than with the MiniMed 670G.

Tandem's a lot smaller company than Medtronic, but it's a pure play on this next-generation solution. And because the addressable market is so big, I can't help but think it makes sense to stash some Tandem shares away in growth portfolios.

A hidden healthcare winner 

Brian Feroldi (IQVIA Holdings): Developing a new drug from scratch is an extremely difficult and expensive process that is fraught with risk. That's why many biotech companies choose to partner up with a contract research organization (CRO) when they think they have found a potential winner. Doing so gives the compound the best chance of success.

IQVIA Holdings is the go-to CRO partner for many biotech companies. The reason is that IQVIA employs a worldwide army of researchers who specialize in running clinical trials and compiling data. That deep experience is highly prized by biotech executives, who want to make sure that the clinical development process goes as smoothly as possible.

For investors, what's great about IQVIA's business is that the company gets paid no matter how the drug in development fares during the trial. Better yet, since the drug development process takes years to complete, IQVIA's revenue becomes highly predictable as new compounds are added to its pipeline. For example, last quarter the company reported that it had more than $15 billion worth of projects in its research and development backlog. 

Another fact to applaud is that IQVIA also helps its customers to commercialize drugs that do find their way to market. The company does this by selling access to its one-of-a-kind database of patient records and prescriptions that help biotech and pharma companies with targeting. 

All told, IQVIA boasts a highly attractive business model that should enable double-digit revenue growth for the foreseeable future. With shares currently trading for less than 17 times next year's earnings estimates, I think this is a great company for healthcare investors to get to know.

Good news should be on the way

Keith Speights (Gilead Sciences): Once upon a time, Gilead Sciences was a high-flying biotech stock with the wind at its back. That hasn't been the case for a while, though. Plunging sales for its hepatitis C virus (HCV) franchise has dragged down Gilead's revenue, earnings, and share price. But good news should be on the way for Gilead.

The biotech expects the HCV sales deterioration to stabilize this year. The HCV market has boiled down to a one-on-one matchup between Gilead and AbbVie (NYSE:ABBV). Price cuts were a common theme over the past couple of years, but that shouldn't be a major factor anymore. It will just be Gilead versus AbbVie competing for a smaller number of hepatitis C patients. That's actually a much-improved scenario than Gilead has faced in recent years.

If HCV doesn't weigh on total revenue and earnings nearly as much, that means investors will focus more on Gilead's HIV drugs. They should like what they see with Biktarvy, Gilead's latest HIV drug, launched in the first quarter. Biktarvy's sales should ramp up quickly and eventually reach $6 billion or more annually. 

Then there's the pipeline. Gilead should soon announce late-stage results for filgotinib in treating rheumatoid arthritis. Filgotinib could become the company's first immunology blockbuster drug. Gilead also has selonsertib, a strong candidate for treating nonalcoholic steatohepatitis (NASH), and is pursuing additional indications for cancer therapy Yescarta.

Like I said, good news should be on the way. That makes Gilead a great stock to buy in July, in my view.