<PAGE>   1
                                                                    EXHIBIT 11.1



                  ARONEX PHARMACEUTICALS, INC. AND SUBSIDIARIES


              STATEMENT REGARDING COMPUTATION OF PER SHARE EARNINGS

The following reflects the information used in calculating the number of shares
in the computation of net loss per share for each of the periods set forth in
the Statements of Operations.

<TABLE>
<CAPTION>
                                                                                                                           INCOME
                                                                                               AVERAGE                     (LOSS)
                                                            DAYS                                SHARES         INCOME        PER
                                           SHARES       OUTSTANDING      SHARES X  DAYS      OUTSTANDING       (LOSS)       SHARE
<S>                                       <C>              <C>             <C>              <C>              <C>           <C>
NINE MONTHS ENDED SEPTEMBER 30, 1999:      16,379,309        3               49,137,927
                                           16,415,664        50             820,783,200
                                           22,415,664        14             313,819,296
                                           22,463,211        21             471,727,431
                                           22,474,987        1               22,474,987
                                           22,494,671        1               22,494,671
                                           22,495,050        64           1,439,683,200
                                           22,496,505        26             584,909,130
                                           22,555,435        1               22,555,435
                                           22,555,977        8              180,447,816
                                           22,560,179        27             609,124,833
                                           22,697,866        20             453,957,320
                                           22,719,999         6             136,319,994
                                           22,723,765        3               68,171,295
                                           22,723,927        13             294,411,051
                                           22,773,927        5              113,869,635
                                           22,775,753        9              204,981,777
                                           22,788,071        1               22,788,071
                                                            273           5,832,657,069 /273  21,365,044     (7,305,000)    (0.34)

NINE MONTHS ENDED SEPTEMBER 30, 2000:
                                           22,853,782        21             479,929,422
                                           22,873,782        3               68,621,346
                                           22,876,765        4               91,507,060
                                           22,877,930        12             274,535,160
                                           22,879,230        23             526,222,290
                                           22,888,646        6              137,331,876
                                           22,905,144        14             320,672,016
                                           22,922,078        54           1,237,792,212
                                           25,854,652        44           1,137,604,688
                                           25,890,127        1               25,890,127
                                           25,890,127        74           1,915,869,398
                                           25,890,567        1               25,890,567
                                           25,900,901        5              129,504,505
                                           25,913,022        2               51,826,044
                                           25,918,209        7              181,427,463
                                           25,918,417        2               51,836,834
                                           25,932,005        1               25,932,005
                                                            274           6,682,393,013 /274  24,477,630     (12,049,000)   (0.49)

QUARTER ENDED SEPTEMBER 30, 1999:          22,555,977        8              180,447,816
                                           22,560,179        27             609,124,833
                                           22,697,866        20             453,957,320
                                           22,719,999        6              136,319,994
                                           22,723,765        3               68,171,295
                                           22,723,927        13             295,411,051
                                           22,723,927        5              113,869,635
                                           22,775,753        9              204,981,777
                                           22,788,071        1               22,788,071
                                                             92           2,085,071,792  /92  22,663,824     (5,399,000)    (0.24)

QUARTER ENDED SEPTEMBER 30, 2000:
                                           25,890,127        74           1,915,869,398
                                           25,890,567        1               25,890,567
                                           25,900,901        5              129,504,505
                                           25,913,022        2               51,826,044
                                           25,918,209        7              181,427,463
                                           25,918,417        2               51,836,834
                                           25,932,005        1               25,932,005
                                                             92                          /92  25,894,422     (4,131,000)    (0.16)

</TABLE>

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