Conflicting statements from the Trump administration have made owning biotech stocks feel like a roller-coaster ride in recent weeks, but there are a few stocks I'd happily buy and hold despite the sway of political uncertainty. Shares of Ligand Pharmaceuticals (NASDAQ:LGND), Celldex Therapeutics (NASDAQ:CLDX), and Portola Pharmaceuticals (NASDAQ:PTLA) are looking awfully inexpensive, and incoming catalysts will make owning any one of these companies downright exciting this year.

Let's take a closer look to see if any are right for you.

Giving cash to a doctor.

Image source: Getty Images.

1. Ligand Pharmaceuticals: Not as expensive as it looks

This biotech stock has a lot to like, although a recent price of about 300 times trailing earnings might turn value-minded investors off before they take a closer look at its bulging pipeline. When the company last reported, it boasted a whopping 150 clinical-stage programs that could eventually add to revenue generated by 14 commercial-stage drugs using its technology.

Ligand's unique partnership-based business model shifts heaps of development and commercialization expenses to deep-pocketed partners that add its flagship product, Captisol, to their branded drugs. The behind-the-scenes additive adds value to active pharmaceutical ingredients in branded drugs such as Kyprolis and Promacta by boosting their solubility and other factors.

Captisol also provides the company a relatively steady source of high profit-margin revenue. As an important component of Promacta and Kyprolis, Captisol royalties are a low-margin source of fairly steady revenue that could rise by leaps and bounds. Since 2008, the number of partner-owned drugs Ligand receives royalties from rose from just one in 2008 to 14 in 2016. It's impossible to predict how many of the drugs in development will add to its royalty stream, but the sheer volume of research conducted by its partners on Ligand technology-containing drugs suggests more than enough to drive this biotech's bottom line and its stock price much higher in the years to come.

2. Celldex Therapeutics: Underappreciated pipeline

This biotech stock imploded last year, after its lead candidate, Rintega, failed to outperform standard chemotherapy among patients with a difficult-to-treat form of brain cancer. Since the meltdown, the company has had a hard time getting investors to notice a robust clinical-stage pipeline full of unique oncology candidates unrelated to Rintega.

At the front of the line is glembatumumab vedotin, or "glemba" if you appreciate brevity. This is a super-lethal dose of chemo attached to a protein that won't let go until it's taken in by a tumor cell expressing glemba's target protein on its surface. Glemba beat the pants off standard chemo in a small group of difficult-to-treat breast cancer patients, and a larger study intended to support an application to treat this group is expected to produce data near the end of the year.

The company is also expected to announce data this year from a combination study with glemba and varlilumab, another Celldex candidate, in advanced melanoma patients. Even earlier this year, we could see results from an investigator-sponsored trial with glemba as a treatment for a rare form of eye cancer.

With a measly valuation of just over $400 million, success for any of this company's pipeline candidates would spell huge gains for investors.

3. Portola Pharmaceuticals: Bumps on the road to profit town

Owners of this small-cap biotech stock hit a couple unexpected roadblocks last year, and its price is still about 32% lower than it was a year ago. The company doesn't have a product to sell yet, but that could change in the first half of this year. Portola shares enjoyed some lift recently, when the FDA accepted an application for its oral blood-thinner candidate (betrixaban) for long-term protection against blood clots in patients that recently suffered a heart attack or stroke, and an approval decision is expected by the end of June.

Lab technician pipetting blood into vials.

Image source: Getty Images.

The market pummeled Portola shares twice last year: once in response to mixed data from betrixaban's pivotal trial, and again in response to a complete response letter from the FDA concerning its anticoagulant reversal agent, Andexxa. Acceptance of the betrixaban application suggests the results related to the pursued indication were sufficient. With respect to Andexxa, the agency cited manufacturing site issues and requested more data concerning its ability to reverse activity of a less popular blood thinner.

At recent prices, Portola's enterprise value of around $1.4 billion seems awfully cheap for a company that could soon launch a drug in the same class as blockbuster drugs Eliquis and Xarelto. Further ahead, the company could also enjoy an immediately successful launch of Andexxa, if its resubmission earns approval. It's the only antidote for increasingly popular oral blood thinners in late-stage clinical development. An unsecured $50 million loan from Eliquis partners Bristol-Myers Squibb and Pfizer recently illustrated how eager they are to see an antidote for their drug become available.

In case you're wondering why my disclosure info below doesn't reveal personal holdings in these three stocks, I'm afraid they simply don't fit my risk profile. I'm getting a bit too old to invest in companies that aren't yet profitable, but as a younger man I'd have picked these up in a heartbeat. You'll be hard-pressed to find better picks in the biotechnology industry right now.