Exhibit 12.1

Omeros Corporation

Computation of Deficiency in the Coverage of Fixed Charges by Earnings Before Fixed Charges



|                                                                       |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   |  |   |        |  
|---------------------------------------------------------------------- |  | ---------------------------------------- | ------- | - | ----------------------- | - | ------- | ---- |  | - | ------- | - |  | ---- | ------- | - |  | - | ------- | - |  | - | ------ | -
|                                                                       |  | For thenine
monthsendedSeptember 30,2010 |         |   | Year Ended December 31, |  
|                                                                       |  | 2009                                     |         |   | 2008                    |   |         | 2007 |  |   | 2006    |   |  | 2005 |        
|                                                                       |  | (in thousands, except share data)        |        
|Earnings before fixed charges:                                         |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   | 
|Loss from continuing operations before income taxes                    |  | $                                        | (22,020 | ) |                         | $ | (21,089 | )    |  | $ | (23,827 | ) |  | $    | (23,091 | ) |  | $ | (22,777 | ) |  | $ | (7,366 | )
|Add fixed charges                                                      |  |                                          | 1,441   |   |                         |   | 2,596   |      |  |   | 834     |   |  |      | 697     |   |  |   | 692     |   |  |   | 587    |  
|Add amortization of capitalized interest                               |  |                                          |        |   |                         |   |        |      |  |   |        |   |  |      |        |   |  |   |        |   |  |   |       |  
|Add distributed income of equity investees                             |  |                                          |        |   |                         |   |        |      |  |   |        |   |  |      |        |   |  |   |        |   |  |   |       |  
|Subtract capitalized interest                                          |  |                                          |        |   |                         |   |        |      |  |   |        |   |  |      |        |   |  |   |        |   |  |   |       |  
|                                                                       |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   |  |   |        |  
|Loss before fixed charges                                              |  | $                                        | (20,579 | ) |                         | $ | (18,493 | )    |  | $ | (22,993 | ) |  | $    | (22,394 | ) |  | $ | (22,085 | ) |  | $ | (6,779 | )
|                                                                       |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   |  |   |        |  
|Fixed Charges:                                                         |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   |  |   |        |  
|Interest expense                                                       |  | $                                        | 1,057   |   |                         | $ | 1,948   |      |  | $ | 280     |   |  | $    | 151     |   |  | $ | 91      |   |  | $ |       |  
|Amortization of debt expense                                           |  |                                          | 166     |   |                         |   | 254     |      |  |   | 55      |   |  |      |        |   |  |   |        |   |  |   |       |  
|Estimate of interest expense within rental expense                     |  |                                          | 218     |   |                         |   | 394     |      |  |   | 499     |   |  |      | 546     |   |  |   | 601     |   |  |   | 587    |  
|Preference security dividend requirements of consolidated subsidiaries |  |                                          |        |   |                         |   |        |      |  |   |        |   |  |      |        |   |  |   |        |   |  |   |       |  
|                                                                       |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   |  |   |        |  
|Total fixed charges                                                    |  | $                                        | 1,441   |   |                         | $ | 2,596   |      |  | $ | 834     |   |  | $    | 697     |   |  | $ | 692     |   |  | $ | 587    |  
|                                                                       |  |                                          |         |   |                         |   |         |      |  |   |         |   |  |      |         |   |  |   |         |   |  |   |        |  
|Deficiency of earnings available to cover fixed charges                |  |                                          | (22,020 | ) |                         |   | (21,089 | )    |  |   | (23,827 | ) |  |      | (23,091 | ) |  |   | (22,777 | ) |  |   | (7,366 | )