If there is one thing that distinguishes Opko Health's (OPK -1.60%) chairman and CEO Dr. Phillip Frost, it's that he likes to buy things. From his company's stock to rolling up companies under the medical device maker's big tent, Frost is willing to put his money where his mouth is.

The latest acquisition is Cytochroma, a small drug maker with two drug candidates in late-stage trials. The first drug, Replidea, treats secondary hyperparathyroidis -- or the secretion of too much hormones in the neck -- in patients with end-stage renal disease and insufficient vitamin D, while the second drug, Alpharen, treats hyperphosphatemia in dialysis patients.

Although surgery is the typical standard of care for secondary hyperparathyroidism, doctors may also treat it with Amgen's (AMGN -0.50%) Sensipar (also called Mimpara in Europe) that generated $243 million in global revenues for the biotech in the third quarter, a 27% increase over the year-ago period. Sensipar raked in $694 million over the first nine months of 2012, a 17% year-over-yeargain.

Hyperphosphatemia is an excess of phosphates in the blood, and it can be caused by the opposite of secondary hyperparathyroidism: The phosphate levels rise because production of the parathyroid hormones is too low. One of the treatments for the condition is sevelamer, which Sanofi (SNY -1.56%) markets under the name Renagel and which generated $312 million in the first six months of 2012, more than double the year before.

So it would seem that if Opko can continue shepherding Replidea and Alpharen through the FDA's regulatory labyrinth, it ought to have two drugs on its hands that could provide it with some meaningful revenues once they're commercially launched.

We're not done yet
Of course, that's just the latest bit of buying Opko's done. A week or so before Cytochroma, it purchased a Brazilian biopharmaceutical and diagnostics company, giving it immediate entry into the largest South American market. And that came on the heels of the purchase of a CLIA lab, Prost-Data, which runs 18 phlebotomy sites throughout the U.S. CLIA labs perform tests on humans and are regulated by the Centers for Medicare and Medicaid Services. Opko anticipates the lab will support its near-term commercial launch of its novel biomarkers and associated algorithm for the detection of prostate cancer.

Opko does have new products coming to market, such as a new Alzheimer's diagnostic test that it's partnered with Bristol-Myers Squibb (BMY 0.96%). The two just recently expanded their collaboration beyond just Alzheimer's, but LabCorp (NYSE: LH) has licensed that particular test to develop in North America and the United Arab Emirates.

About face!
As for his company's stock, Frost buys a little bit every day or so, tens of thousands of shares at a clip. Over the course of time, he's amassed a holding that represents about 40% of the 298 million outstanding shares, or a 120-million-share portfolio. The notable thing, however, is that he hasn't bought any in more than two weeks as the stock soared at one point to over $7 a stub (with many of his purchases in recent months at $5 or below, he's doing quite well).

Many believe Frost is grooming Opko for its own acquisition, as he did with Key Pharmaceuticals in the mid-1980's when Schering-Plough (now a part of Merck) bought it out, and then with Ivax, which Teva Pharmaceuticals ended up acquiring almost two decades later.

I've been leery of Frost's growth-by-acquisition strategy because it's all fine and dandy until it's not. Acquisitions often run into trouble because there's difficulty blending corporate cultures or any of a number of potential problems. Until those arise, the growth achieved looks wonderful, and then suddenly it doesn't anymore.

Yet I've also warned against shorting the stock, too, as many seem want to do. It still has more than 17% of its float sold short, which could easily cause a squeeze and may indeed have played a role in the stock's 34% gain this past month.

Let me know below if you think Opko's got its eye on the ball here or will get bought out before its buying binge causes it indigestion.