7 . 2 Criteria for Study Discontinuation 
Patients should understand that once they have 
completed (at least one cycle of therapy) , they will be 
asked to be followed long-term. They can stop study 
treatment at any time (see section 7.1), however they 
will still be considered on study until the study has 
been terminated. 
The study can be discontinued only with the 
understanding of the investigators, sponsor, RAC and 
the FDA. 
8.0 ADVERSE EXPERIENCES 
Depending on the extent of the adverse experience, adverse 
events should be reported by each site investigator to their 
local Institutional Review Board (IRB) , Institutional 
BioSafety Committee (IBC) and to Genetic Therapy, Inc. as 
specified in Appendix III. 
Adverse reactions or deaths requiring immediate 
reporting should be made by telephone to (301) 402-0764 
(available 24 hours a day, recorder after working hours) . 
The principal investigator will take the responsibility 
of informing and preparing reports for the Recombinant 
Advisory Committee (RAC) through the NIH Office of 
Recombinant DNA Activities (ORDA) and to the FDA. 
HHS Guidelines for Research Involving Recombinant DNA 
Molecules ; It is the responsibility of the institution and 
those associated with it to adhere to the intent of the 
Guidelines as well as to their specifics. 
9.0 EVALUATION OF RESPONSE /ENDPOINTS 
9 . 1 Study Endpoints : 
(i) The study is designed primarily to determine whether the 
FACC gene can be transferred to hematopoietic progenitors 
and whether those cells can be readministered to patients 
without toxicity. 
(ii) Endpoints for clinical effect will be primarily 
evaluated by quantitation of progenitor growth in the 
presence of MMC; this should serve as a functional assay of 
efficacy. Other efficacy endpoints will be improvement in 
peripheral blood counts and marrow cellularity. 
9 . 2 Response Criteria ; 
No response - Less than 0.1% of circulating mononuclear cells 
contain the retroviral vector. No RNA signal from the 
retroviral vector at any time during the study. 
Incomplete response 
A. Less than 0.1% of circulating mononuclear cells contain 
the retroviral vector. An RNA signal is detected from 
the vector at any time during the study. 
B. More than 0.1% of circulating mononuclear cells contain 
the retroviral vector. No RNA signal is detected from 
the vector at any time during the study. 
Partial response - More than 0.1% but less than 2% of 
circulating mononuclear cells contain the retroviral vector. 
An RNA signal is detected from the vector at any time during 
the study. 
Complete response - More than 2% of circulating mononuclear 
cells contain the retroviral vector. An RNA signal is 
detected from the vector at any time during the study. 
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