A finale has at last arrived for the biotech drama of summer 2013. Amgen (NASDAQ:AMGN) announced yesterday that it will buy Onyx Pharmaceuticals (UNKNOWN:ONXX.DL) for $10.4 billion, or $125 per share. Eight weeks ago, the bigger biotech offered around $10 billion, or $120 per share, for Onyx. That's roughly half a billion dollars worth of drama, but it was a lot of fun to watch.

A riveting plot line
It didn't take long after the news first broke at the end of June about Amgen's initial overture for Onyx to say "no" to the deal. Onyx wanted to sell, but Amgen's price "significantly undervalued" the company. At least, that's what Onyx officials said then.

Speculation began almost immediately as to how high Onyx's price tag would ultimately go -- and which big company would close the deal. As for the price, Geoffrey Porges with investment firm Sanford C. Bernstein guessed that Onyx would go for $150 per share but said that $180 per share was in the realm of possibility. Deutsche Bank analyst  Robyn Karnauskas thought that the sale price would be around $148 per share.

Quite a few companies were seen as potential acquirers. Reports floated that Pfizer (NYSE:PFE) was interested. That made sense, considering that there was already a connection between the two companies. Pfizer received Breakthrough Therapy Designation from the Food and Drug Administration in April on a breast cancer drug that it licensed from Onyx.

Novartis (NYSE:NVS) also was seen as a serious contender. The thought was that Onyx would be a good fit with the Swiss drugmaker's cancer drug lineup. Of course, that would be true of several other big pharmaceutical companies as well.

Even the Securities and Exchange Commission became involved in the drama along the way. During the week following Amgen's initial offer, the SEC froze the assets of what it called "suspicious foreign traders" who appeared to be engaged in insider trading of call options on Onyx stock.

More recently, as Amgen expressed renewed interest in the deal, Onyx again threw a twist into the plot by hesitating to reveal data from an ongoing clinical study of blood-cancer drug Kyprolis. The issue obviously was resolved, but it could have cost Onyx. Amgen had been reportedly offering $130 per share prior to the snag.

Two thumbs up?
Now that the drama has been seen and the credits are rolling, what rating does the Amgen/Onyx deal deserve? I'd give it two thumbs up.

Amgen gets a boost to its product lineup that will soon face some challenges. Teva Pharmaceuticals (NYSE:TEVA) is scheduled to begin marketing a biosimilar version of Neulasta in the U.S. this November. The Israel-based company already sells a biosimilar that competes against Neupogen in Europe.

Onyx makes for a good fit for Amgen's oncology business, also. Its previous products focused more on related issues from cancer rather than treating cancer directly. With its pipeline and now Onyx, however, Amgen is clearly moving in the direction of tackling cancer head-on.

As for Onyx, its shareholders receive huge gains. I'm sure many were hoping that the price tag would have been higher, but $125 per share isn't bad. Remember the old saying: A bird in the hand is worth two in the bush. There's no guarantee that any of the other companies that were rumored to be interested would have paid any more than Amgen did.

As I said earlier, this has been a fun drama to watch. Now that it's over, I'm ready for the sequel.

Fool contributor Keith Speights has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.