A few heavy special charges and generic competition to its antithrombotic blockbuster Plavix has lead to Bristol-Myers Squibb posting a $134 million net loss for the fourth quarter, compared with a profit of $499 million a year ago.

The biggest charge was $353 million for an increase in reserves to be used towards a $499 million settlement agreed with the US government, following investigations into the company's pricing and marketing practices. It also took a $220 million charge to retire debt and another one of $96 million related to downsizing and streamlining of worldwide operations.

Sales fell 16.1% to $4.21 billion, and Plavix (clopidogrel) revenues tumbled 53% to $496 million, once again suffering from B-MS’ failure to stop Apotex from flooding the US market with its generic version of the drug last summer before an injunction was put in place.

Remaining supplies of Apotex’ copycat version are clearly still cutting into Plavix sales and although there are signs that the impact is wearing off, all eyes are now on the outcome of the patent infringement case between B-MS (with partner Sanofi-Aventis) and Apotex that began on Monday. Generic competition also did for sales of cholesterol-lowerer Pravachol (pravastatin), which lost US patent protection in April last year and collapsed 75% to $146 million, while anticancer agent Taxol (paclitaxel) sank 28% to $130 million, due to increased competition in Europe.

Nevertheless there were some bright spots for B-MS, notably the performance of the antipsychotic Abilify (aripiprazole), up 62% to $362 million and The firm's HIV franchise also made a solid contribution, with revenues from Sustiva (efavirenz) rising 31% to $222 million and Reyataz (atazanavir) up 36% to $255 million, while sales of cancer drug Erbitux (cetuximab) leapt 38% to $167 million.

Less impressive was the performance of new Sprycel (dasatanib) for leukaemia, launched in June, as sales only rose to $14 million from $11 million in the third quarter, while Orencia (abatacept) revenues, approved a year ago in the USA for rheumatoid arthritis and touted as a potential blockbuster, brought in just $32 million.

Chief executive Jim Cornelius was still upbeat and expressed his faith in the firm’s “robust late-stage pipeline,” notably the three cancer drugs ixabepilone, vinflunine and ipilimumab. He added that “demand for our major products continues to increase at a double-digit rate, and Plavix market share is increasing as remaining generic inventory depletes."