Roche shareholders must feel as though they got some bad stuff when they handed over $46.8 billion to buy Genentech in March. In a major study, Avastin, Genentech’s colon cancer drug, failed to prevent the recurrence of colon cancer in patients who had undergone surgery. Roche shares promptly tumbled.

Roche investors were thinking Avastin sales would double from $4.4 billion, and Roche still sounds confident that the drug will do about that well treating colon cancer in its earlier stages, as it was designed to do. Roche said a positive result on the study was not a foregone conclusion, calling its success a “coin toss.” But this is unlikely to placate its stockholders because it implies Roche didn’t adequately account for the risk.

In fact, it looks increasingly like Roche was high on Avastin’s prospects when it raised its offer for Genentech, apparently trying to get in before a would-be positive result from the study drove Genentech’s stock any higher.

Deals of the day:

* News Corp’s stake in German pay-TV broadcaster Premiere will grow to 30.5 percent as the media conglomerate agreed to take up almost a third of new shares issued in Premiere’s second capital hike.

* British telecoms and retail group Carphone Warehouse beat fourth-quarter customer growth forecasts and raised cash flow guidance for 2009-10, boosting its shares as it confirmed plans to split in two.

* British property investor Carpathian received a 20 euro cents per share indicative offer from New Europe Property Investments, the companies said, sending Carpathian shares up as much as 32 percent.

* Dutch insurer Aegon became the latest foreign insurer to exit Taiwan as it sold its Taiwanese life insurance unit, resulting in a 400 million euro negative hit to second-quarter earnings.

* Africa Israel Properties, a subsidiary of real estate developer Africa Israel Investments, said it has agreed to sell a Tel Aviv property for 166.5 million shekels ($39.5 million).

(PHOTO: A woman holds the antidepressant drug Prozac, also known as fluoxetine, in Leicester, central England February 26, 2008 in this posed photograph. REUTERS/Darren Staples (BRITAIN)