2 yearsa

Neither induction nor postremission intensification improved CR or DFS

"Median survival-

"Median survival-

with standard-risk B-lineage ALL received high-dose MTX, while T-ALL patients received postremission cyclophosphamide and cytarabine, and high-risk B-lineage patients received both high-dose MTX and high-dose cytarabine.48 The median remission duration was 57 months for standard-risk patients, with a 5-year survival of 55%. However, this approach did not appear to improve the outcome of high-risk patients except for those with pro-B ALL who achieved a continuous CR rate of 41%, in contrast to only 19% for other high-risk patients. The outcome for high-risk patients, with SCT in CR1, has been explored by other groups and is discussed below.


Recently, monoclonal antibodies targeted to epitopes present on lymphoblasts have also been evaluated. Rituximab, a chimeric humanized mouse antibody directed against CD20, which is expressed in approximately 20% of ALL cases, is being explored as an adjunct to standard chemotherapy in frontline and salvage therapy. Initial reports suggest that its addition may improve response rates, but with short-term follow-up55; longer follow-up will be needed to determine its potential to improve DFS. Campath-IH is a monoclonal humanized form of a rat antibody active against CD52, an antigen on nearly all normal B and T lymphocytes that may be present on the surface of most cases of ALL.5657 Although the experience with this antibody in relapsed, refractory ALL has been limited, Campath-IH has been shown to clear blasts from the peripheral blood after failure of traditional chemotherapy.5758 The CALGB has recently begun testing the feasibility of incorporating Campath-1H into the initial treatment of adult ALL in an attempt to eradicate MRD in early CR1 (CALGB 10102).

Other novel agents are being considered for addition to frontline therapy for this disease subset. For example, clofarabine, a purine analog, was recently approved for refractory or relapsed pediatric ALL.59 Nelarabine (GW506U78), a prodrug of guanosine ara-binoside, has been shown to have activity in relapsed precursor T ALL.60-62

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