The sponsor had become aware of a possible future change of the MTX-analysis method at some local laboratories participating in the study. In order to secure the quality of the data for endpoint analysis the sponsor introduced duplicate samplings for MTX analysis in the protocol. The back-up samples were frozen and kept for central analysis in case an up-dated analytical method could be suspected to have had a negative impact on the quality of the analysis results at any site during the conduct of the study. If there was no need for central analysis, the back-up samples would be destroyed after study completion. In addition to the above substantial changes some changes of administrative character and corrections of typographical errors were also made.

Due to slow recruitment of study patients two sites in the Czech Republic were added and the study period was prolonged until Q1 2015. Adequate methods of contraception were described in detail. This was a non-substantial amendment.

- Clarified and completed the definitions of population analysis sets - Specified that not all clinic sites would collect blood samples for the folate pharmacokinetic (PK) analysis due to administrative reasons - Clarified definitions and descriptions of certain specified study procedures - Included a number of non-substantial changes of minor importance for the study performance

- Allowed the age group 6 to 11 years to take part in the study in Cohort 2, in case the DSMB assessment of the clinical data collected during Cohort 1 could support a recommendation for enrollment of these younger patients without risking their safety. The opinion of the DSMB was that children in the age group six (6) to 11 years (both included) would not present PK or PD profiles different from that seen in children aged 12 years old. Thus the safety monitoring currently implemented in the study was considered satisfactory to guarantee the safety of enrolled patients even at a lower age limit (i.e. 6 years instead of 12). Upon completion of Cohort 1, the DSMB will convene and assess the clinical data collected until that time-point to give a recommendation for enrolment age that ensures that the safety of younger children will not be put at risk during the execution of Cohort 2. This change was made to allow the collection of safety data in these younger patients and to facilitate patient enrollment in the present study. - Included changes in the responsibilities of the DSMB - Amended the timelines for serious adverse event reporting to avoid unnecessary reporting prior to dosing of the study specific treatment - Updated administrative information - Included a number of non-substantial changes of minor importance for the study performance

- Allowed the number of patients treated with Modufolin (MOD) to be increased with 3 additional evaluable patients exposed to MOD in the dose recommended by the DSMB for future development. This change was added to generate additional safety data for the recommended dose before continuing with the pivotal study. - Included an update of the COG management recommendations during MOD rescue allowing a dosing frequency of q3h in case of Grade B toxicities. This that was supported by findings from this study and safety data collected from 45 patients with colorectal carcinoma exposed to MOD in clinical trials. - Adapted the blood sampling time points to clinical practice although this change lead to rescue treatments initiated before the analytical results were available. - Removed MTX back-up samples aimed for central analysis as such results would not contribute or influence the clinical treatment decisions based on locally analyzed MTX values available in real time. - Included a number of non-substantial changes of minor importance for the study performance.