Patienter der ikke viste respons (manglende fuldstændig hæmatologisk respons (CHR) efter 6 måneder, øget leukocyttal, intet større cytogenetisk respons (MCyR) efter 24 måneder), tab af respons (tab af CHR eller MCyR) eller svær intolerance over for behandling, fik lov at krydse over til den anden behandlingsarm.
Patients showing lack of response (lack of complete haematological response (CHR) at 6 months, increasing WBC, no major cytogenetic response (MCyR) at 24 months), loss of response (loss of CHR or MCyR) or severe intolerance to treatment were allowed to cross over to the alternative treatment arm.