Clinical evaluation of an advanced category antihaemophilic factor prepared using a plasma/albumin-free method: pharmacokinetics, efficacy, and safety in previously treated patients with haemophilia A.

The efficacy and safety of an advanced category recombinant antihaemophilic factor produced by a plasma- and albumin-free method (rAHF-PFM) was studied in 111 previously treated subjects with haemophilia A. The study comprised a randomized, double-blinded, crossover pharmacokinetic comparison of rAHF-PFM and RECOMBINATE rAHF (R-FVIII); prophylaxis (three to four times per week with 25-40 IU kg(-1) rAHF-PFM) for at least 75 exposure days; and treatment of episodic haemorrhagic events. Median age was 18 years, 96% of subjects had baseline factor VIII <1%, and 108 received study drug. Bioequivalence, based on area under the plasma concentration vs. time curve and adjusted in vivo recovery, was demonstrated for rAHF-PFM and R-FVIII. Mean (+/-SD) half-life for rAHF-PFM was 12.0 +/- 4.3 h. Among 510 bleeding events, 473 (93%) were managed with one or two infusions of rAHF-PFM and 439 (86%) had efficacy ratings of excellent or good. Subjects who were less adherent to the prophylactic regimen had a higher bleeding rate (9.9 episodes subject(-1) year(-1)) than subjects who were more adherent (4.4 episodes subject(-1) year(-1); P < 0.03). One subject developed a low titre, non-persistent inhibitor (2.0 BU) after 26 exposure days. These data demonstrate that rAHF-PFM is bioequivalent to R-FVIII, and suggest that rAHF-PFM is efficacious and safe, without increased immunogenicity, for the treatment of haemophilia A.

Bone marrow leukemic progenitor cell content in pediatric T-lineage acute lymphoblastic leukemia patients with an isolated extramedullary first relapse.

Isolated extramedullary relapse in childhood acute lymphoblastic leukemia (ALL) is associated frequently with the T-lineage immunophenotype and may be accompanied by occult bone marrow disease. We employed highly sensitive multiparameter flow cytometry and blast colony assays to quantify the leukemic progenitor cell (LPC) burden in the pretreatment bone marrows of 15 pediatric T-lineage ALL patients with an isolated extramedullary first relapse. Sites of extramedullary relapse were CNS (11 patients), testes (3 patients), and both CNS and testes (1 patient). Bone marrow LPC were detectable in 8 patients (53%) and undetectable in 7 patients (47%) at day 0 of post-relapse induction therapy, with LPC counts ranging from 0/10(6) mononuclear cells (MNC) to 518/10(6) MNC (mean +/- SEM, 50+/-34/10(6) MNC). Five of 9 patients with an early relapse (< 18 months after achieving a first complete remission [CR1]) and 3 of 6 patients with a late relapse (> or = 18 months from CR1) had detectable bone marrow LPC at day 0. Five of 8 patients with NCI-defined poor risk ALL and 3 of 7 patients with NCI-defined standard risk ALL had detectable LPC at day 0. Following post-relapse induction chemotherapy. LPC counts were detectable in bone marrows of 4 of 6 evaluated patients. Thus, approximately half of the extramedullary relapse T-lineage ALL patients studied had substantial occult involvement of the bone marrow. These findings may partly explain the previously observed poor prognosis of T-lineage patients following a CNS relapse.

Duration of hospitalization as a measure of cost on Children's Cancer Group acute lymphoblastic leukemia studies.

PURPOSE: We used duration of hospitalization as a surrogate for cost and event-free survival as a measure of effectiveness to estimate the cost-effectiveness ratios of various treatment regimens on Children's Cancer Group trials for acute lymphoblastic leukemia. PATIENTS AND METHODS: The analyses included 4,986 children (2 to 21 years of age) with newly diagnosed acute lymphoblastic leukemia enrolled onto risk-adjusted protocols between 1988 and 1995. Analyses were based on a model of 100 patients. The marginal cost-effectiveness ratio (hospital days per additional patient surviving event-free) was the difference in total duration of hospitalization divided by the difference in number of event-free survivors at 5 years for two regimens. Relapse-adjusted marginal cost of frontline therapy was the difference in total duration of hospitalization for frontline therapy plus relapse therapy divided by the difference in number of event-free survivors at 5 years on the frontline therapy for two regimens. RESULTS: One or two delayed intensification (DI) phases, augmented therapy, and dexamethasone all improved outcome. Marginal cost-effectiveness of these regimens compared with the control regimens was 133 days per patient for DI, 117 days per patient for double DI, and 41 days per patient for augmented therapy. Dexamethasone resulted in 17 fewer days per patient. Relapse-adjusted marginal costs were 68 days per patient for DI and 52 days for double DI. Augmented therapy and dexamethasone-based therapy resulted in 16 and 82 fewer hospital days, respectively. The estimated cost-effectiveness for treating any first relapse was 250 days per patient. CONCLUSION: DI, double DI, augmented therapy, and dexamethasone-based therapy are cost-effective strategies compared with current treatment of first relapse.

Abnormalities of chromosome bands 13q12 to 13q14 in childhood acute lymphoblastic leukemia.

PURPOSE: Little is known about nonrandom deletions of chromosome bands 13q12 to 13q14 (13q12-14) in acute lymphoblastic leukemia (ALL). We determined the prognostic significance of cytogenetically identified breakpoints in 13q12-14 in children with newly diagnosed ALL treated on Children's Cancer Group protocols from 1988 to 1995. PATIENTS AND METHODS: Breakpoints in 13q12-14 were identified in 36 (2%) of the 1,946 cases with accepted cytogenetic data. Outcome analysis used standard life-table methods. RESULTS: Seventeen patients (47%) with an abnormal 13q12-14 were classified, according to the National Cancer Institute (NCI), as poor risk, and 15 patients (42%) were standard risk; four (11%) were infants less than 12 months of age. Eight cases had balanced rearrangements of 13q12-14, 27 patients had a partial loss of 13q, and one had both a partial gain and a partial loss. The most frequent additional abnormalities among these patients were an abnormal 12p, a del(6q), a del(9p), a 14q11 breakpoint, and an 11q23 breakpoint. Nineteen patients were pseudodiploid, 10 were hyperdiploid, and seven were hypodiploid. Patients with an abnormal 13q12-14 had significantly worse event-free survival than patients lacking such an abnormality, with estimates at 6 years of 61% (SD = 14%) and 74% (SD = 1%), respectively (P =.04; relative risk = 1.74). Overall survival, however, was similar for the two groups (P =.25). The prognostic effect of an abnormal 13q was attenuated in a multivariate analysis adjusted for NCI risk status and ploidy (P =.72). CONCLUSION: Aberrations of 13q12-14 may contribute to leukemogenesis of childhood ALL and confer increased risk of treatment failure but are associated with other poor-risk features.

Randomized comparison of cisplatin/vincristine/fluorouracil and cisplatin/continuous infusion doxorubicin for treatment of pediatric hepatoblastoma: A report from the Children's Cancer Group and the Pediatric Oncology Group.

PURPOSE: Previous studies demonstrated that chemotherapy with either cisplatin, vincristine, and fluorouracil (regimen A) or cisplatin and continuous infusion doxorubicin (regimen B) improved survival in children with hepatoblastoma. The current trial is a randomized comparison of these two regimens. PATIENTS AND METHODS: Patients (N = 182) were enrolled onto study between August 1989 and December 1992. After initial surgery, patients with stage I-unfavorable histology (UH; n = 43), stage II (n = 7), stage III (n = 83), and stage IV (n = 40) hepatoblastoma were randomized to receive regimen A (n = 92) or regimen B (n = 81). Patients with stage I-favorable histology (FH; n = 9) were treated with four cycles of doxorubicin alone. RESULTS: There were no events among patients with stage I-FH disease. Five-year event-free survival (EFS) estimates were 57% (SD = 5%) and 69% (SD = 5%) for patients on regimens A and B, respectively (P =.09) with a relative risk of 1.54 (95% confidence interval, 0.93 to 2.5) for regimen A versus B. Toxicities were more frequent on regimen B. Patients with stage I-UH, stage II, stage III, or stage IV disease had 5-year EFS estimates of 91% (SD = 4%), 100%, 64% (SD = 5%), and 25% (SD = 7%), respectively. Outcome was similar for either regimen within disease stages. At postinduction surgery I, patients with stage III or IV disease who were found to be tumor-free had no events; those who had complete resections achieved a 5-year EFS of 83% (SD = 6%); other patients with stage III or IV disease had worse outcome. CONCLUSION: Treatment outcome was not significantly different between regimen A and regimen B. Excellent outcome was achieved for patients with stage I-UH and stage II hepatoblastoma and for subsets of patients with stage III disease. New treatment strategies are needed for the majority of patients with advanced-stage hepatoblastoma.

Clinical significance of deletions of chromosome arm 6q in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group.

We have compared outcome for 167 (9.0%) children with a del(6q) and 1713 (91%) children without a del(6q) treated on Children's Cancer Group (CCG) risk-adjusted treatment protocols for acute lymphoblastic leukemia (ALL). Thirty-three patients had a del(6q) as the sole aberration; 22 patients had a del(6q) only as a secondary abnormality. Thirty-six cases had a del(6q) and high hyperdiploidy (>50 chromosomes). Six patients with a del(6q) also had +16 and 8 patients had loss of a sex chromosome. Frequent recurring breakpoints were q13, q15, q21, q23, and q25. Patients with a del(6q) were more likely to have T-lineage ALL (p < 0.001), a mediastinal mass (p = 0.01), and higher WBC counts (p = 0.04), although only half of these patients were classified as poor risk. Event-free survival at 6 years was similar for patients with or without a del(6q), with estimates of 77% (SD = 5%) and 74% (SD = 2%), respectively (p = 0.44). This finding was also observed within NCI poor and standard risk groups. Thus, cytogenetically detectable del(6q) is not associated with adverse risk in pediatric ALL.

Prognostic impact of trisomies of chromosomes 10, 17, and 5 among children with acute lymphoblastic leukemia and high hyperdiploidy (> 50 chromosomes).

PURPOSE: Children with acute lymphoblastic leukemia (ALL) and high hyperdiploidy (> 50 chromosomes) have improved outcome compared with other ALL patients. We sought to identify cytogenetic features that would predict differences in outcome within this low-risk subset of ALL patients. MATERIALS AND METHODS: High-hyperdiploid ALL patients (N = 480) were enrolled between 1988 and 1995 on Children's Cancer Group (CCG) trials. Karyotypes were determined by conventional banding. Treatment outcome was analyzed by life-table methods. RESULTS: Patients with 54 to 58 chromosomes had better outcome than patients with 51 to 53 or 59 to 68 chromosomes (P = .0002). Patients with a trisomy of chromosome 10 (P<.0001), chromosome 17 (P = .0002), or chromosome 18 (P = .004) had significantly improved outcome compared with their counterparts who lacked the given trisomy. Patients with a trisomy of chromosome 5 had worse outcome than patients lacking this trisomy (P = .02). Patients with trisomies of both chromosomes 10 and 17 had better outcome than those with a trisomy of chromosome 10 (P = .09), a trisomy of chromosome 17 (P =.01), or neither trisomy (P<.0001). Multivariate analysis indicated that trisomy of chromosome 10 (P = .001) was the most significant prognostic factor for high-hyperdiploid patients, yet trisomy of chromosome 17 (P =.02) or chromosome 5 (P = .01) and modal chromosome number (P = .02) also had significant multivariate effects. CONCLUSION: Trisomy of chromosomes 10 and 17 as well as modal chromosome number 54 to 58 identify subgroups of patients with high-hyperdiploid ALL who have a better outcome than high-hyperdiploid patients who lack these cytogenetic features. Trisomy of chromosome 5 confers poorer outcome among high-hyperdiploid patients.

Prognostic significance of cytogenetic abnormalities of chromosome arm 12p in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group.

BACKGROUND: The authors have determined the prognostic significance of cytogenetically detectable 12p abnormalities, which are frequent in children with acute lymphoblastic leukemia (ALL), in a large cohort of patients treated on risk-adjusted protocols of the Children's Cancer Group (CCG). METHODS: The presence of an abnormal 12p was identified among 1880 children with newly diagnosed ALL; outcome was assessed by standard life table methods. RESULTS: A total of 174 cases (9%) had cytogenetically detectable 12p abnormalities; the majority of cases had a balanced translocation, a del(12p), or an add(12p). In the overall cohort, event free survival (EFS) at 6 years was similar for patients with or without a 12p abnormality (76%, SD = 6%, vs. 75%, SD = 2%, respectively; P = 0.60). Among patients with pseudodiploidy, an abnormal 12p conferred improved outcome (P = 0.008; relative risk = 0.51; 95% confidence interval [CI], 0.31-0.85). There was a trend for improved EFS for those with abnormalities in both chromosome 12 homologues (P = 0.16; relative risk = 0.39; 95% CI, 0.10-1.55) and those with low hyperdiploidy (P = 0.07; relative risk = 0.44; 95% CI, 0.18-1.09). Among T-lineage ALL patients, there was a trend for worse outcome for abnormal versus normal 12p (P = 0.14; relative risk = 1.97; 95% CI, 0.78-4.93). There was no difference in EFS for the 12 patients with a dic(9;12) compared with patients lacking an abnormal 12p. CONCLUSIONS: These data suggest that although a cytogenetically detectable 12p aberration is a favorable risk factor for children with ALL and pseudodiploidy, it is not prognostic for the overall group of pediatric ALL patients treated with contemporary therapies of the CCG.

Children's Cancer Group trials in childhood acute lymphoblastic leukemia: 1983-1995.

Since 1968, the Children's Cancer Group (CCG) has treated more than 16,000 children with acute lymphoblastic leukemia (ALL). Herein, we report improvements obtained in CCG trials during two successive series of studies (1983-1988 and 1989-1995). Overall, 10-year EFS was 62% +/- 10% for the 1983-1988 series and 72% +/- 1% for the 1988-1995 series (P< 0.0001). Five-year cumulative rates of isolated CNS relapses were 5.9% and 4.4%. Therapy based on the Berlin-Frankfurt-Münster 76/79 study improved outcomes for intermediate and higher risk patients in the first series. For intermediate risk patients, delayed intensification (DI) was most crucial for improved outcome and cranial irradiation was safely replaced with maintenance intrathecal methotrexate, providing patients received intensified systemic therapy. In the second series, randomized trials showed better outcome with one vs no DI phase for lower risk patients, with two vs one DI phase for intermediate risk patients, and with the CCG 'augmented regimen' for higher risk patients with a slow day 7 marrow response. Cranial irradiation was safely replaced with additional intrathecal methotrexate for higher risk patients with a rapid day 7 marrow response. In a subsequent study, substitution of dexamethasone in place of prednisone in induction and maintenance improved outcome for standard risk patients. All patients received dexamethasone in DI. These successful treatment strategies form the basis for our current ALL trials.

Hypodiploidy with less than 45 chromosomes confers adverse risk in childhood acute lymphoblastic leukemia: a report from the children's cancer group.

We have determined the prognostic significance of hypodiploidy (<46 chromosomes) in a large cohort of children with acute lymphoblastic leukemia (ALL) treated by the Children's Cancer Group. Among 1,880 patients, 110 (5.8%) had hypodiploid karyotypes: 87 had 45 chromosomes, 15 had 33 to 44 chromosomes, none had 29 to 32 chromosomes, and 8 had 24 to 28 chromosomes (near-haploidy). Six-year event-free survival (EFS) estimates for patients with 45 chromosomes, 33 to 44 chromosomes, or 24 to 28 chromosomes were 65% (standard deviation [SD], 8%), 40% (SD, 18%), and 25% (SD, 22%), respectively (log rank, P =.002; test for trend, P =.0009). The combined hypodiploid group had worse outcome than nonhypodiploid patients, with 6-year EFS of 58% (SD, 7%) and 76% (SD, 2%), respectively (P <.0001). EFS for the subgroup with 45 chromosomes was similar to that of patients with pseudodiploidy (P =.43) or 47 to 50 chromosomes (P =.76). None of the patients with 24 to 28 chromosomes had a t(4;11), a t(9;22), or a t(1;19), and most received highly intensive therapy. The adverse risk associated with 33 to 44 and 24 to 28 chromosomes remained significant in multivariate analyses adjusted for important risk factors including age, white blood cell count, and Philadelphia chromosome status. Thus, hypodiploidy with less than 45 chromosomes, particularly 24 to 28 chromosomes, is a significant adverse risk factor despite treatment with contemporary intensive therapies.

Paucity of leukemic progenitor cells in the bone marrow of pediatric B-lineage acute lymphoblastic leukemia patients with an isolated extramedullary first relapse.

Isolated extramedullary relapse in childhood acute lymphoblastic leukemia (ALL) may be accompanied by occult bone marrow disease. We used a highly sensitive assay to quantify leukemic progenitor cells (LPCs) in the bone marrow of such patients. Multiparameter flow cytometry and blast colony assays were used to detect LPCs in the bone marrow of 31 pediatric B-lineage ALL patients with an isolated extramedullary first relapse. Sites of relapse were central nervous system (22 patients), testes (7 patients), and eye (2 patients). Bone marrow (BM) LPC counts ranged from 0/10(6) mononuclear cells (MNCs) to 356/10(6) MNCs (mean +/- SE, 27.8+/-13.1/10(6) MNCs). LPCs were undetectable in 19 patients (61%). The BM LPC burden at the time of extramedullary relapse was similar, regardless of site (Wilcoxon P = 0.77) or time of relapse (Wilcoxon P = 0.80). Compared with higher risk, standard risk at initial diagnosis showed a trend for increased BM LPC burden (mean +/- SE, 44.6+/-17.1 versus 7.5+/-3.3; Wilcoxon P = 0.22). After successful postrelapse induction chemotherapy, LPC counts in 21 evaluated patients ranged from 0/10(6) to 175/10(6) MNCs (mean +/- SE, 15.9+/-9.6/10(6) MNCs). By comparison, LPC burden was higher after successful induction chemotherapy among children with an early BM relapse (range, 0 to 3262/ 106 MNC; mean +/- SE, 166+/-107; Wilcoxon P = 0.11). Thus, not all patients with an extramedullary relapse have occult systemic failure with substantial involvement of the bone marrow, and after reinduction therapy, LPC counts were lower in these patients than in patients treated for an overt BM first relapse.

Association of chromosome arm 9p abnormalities with adverse risk in childhood acute lymphoblastic leukemia: A report from the Children's Cancer Group.

Cytogenetic abnormalities of chromosome arm 9p occur frequently in children with acute lymphoblastic leukemia (ALL). We analyzed 201 such cases (11%) in 1,839 children with newly diagnosed ALL treated between 1989 and 1995 on risk-adjusted protocols of the Children's Cancer Group (CCG). The majority of patients (131; 65%) with a 9p abnormality were classified as higher risk. Nearly all patients had complex karyotypes; most cases had deletions of 9p, add/der(9p), a dicentric involving chromosome arm 9p, and/or balanced translocations and inversions involving 9p. Event-free survival (EFS) estimates at 6 years for patients with and without a 9p aberration were 61% (standard deviation [SD] = 5%) and 76% (SD = 2%; P <.0001). In addition, patients with a 9p abnormality had an increased cumulative incidence of both marrow (P =.04) and central nervous system (P =.0001) relapses. Overall survival also was significantly worse for patients with an abnormal 9p (P <.0001). These effects were most pronounced in standard-risk patients (age 1 to 9 years with white blood cell count <50,000/microL): 6-year EFS of 61% (SD = 9%) versus 80% (SD = 2%; P <.0001). Also, a 9p aberration was an adverse risk factor for B-lineage, but not T-lineage patients. The effect of 9p status on EFS was attenuated, but maintained in a multivariate analysis of EFS after adjustment for Philadelphia chromosome status, age, white blood cell (WBC) count, sex, race, and ploidy group (P =.01). Thus, abnormalities of chromosome arm 9p identify a subgroup of standard-risk patients with increased risk of treatment failure.

Poor treatment outcome of Philadelphia chromosome-positive pediatric acute lymphoblastic leukemia despite intensive chemotherapy.

Children with Philadelphia (Ph) chromosome positive (+) acute lymphoblastic leukemia (ALL) represent a subgroup at very high risk for treatment failure. This study included 1322 children enrolled between 1988 and 1994 on CCG risk-adjusted studies for ALL who had centrally reviewed cytogenetic data. Thirty patients had a t(9;22) and are referred to as Ph+; 1292 were Ph-. 23 of these 30 patients were treated on the CCG-1882 high risk ALL protocol. The event-free survival (EFS) outcome in CCG-1882 was significantly worse for Ph+ compared with Ph- patients, with 4-year estimates of 11.3% (SD = 9.8%) and 73.4% (SD = 2.3%), respectively (p < 0.0001).

Treatment outcome and prognostic factors for infants with acute lymphoblastic leukemia treated on two consecutive trials of the Children's Cancer Group.

PURPOSE: Infants represent a very poor risk group for acute lymphoblastic leukemia (ALL). We report treatment outcome for such patients treated with intensive therapy on consecutive Children's Cancer Group (CCG) protocols. PATIENTS AND METHODS: Between 1984 and 1993, infants with newly diagnosed ALL were enrolled onto CCG-107 (n = 99) and CCG-1883 (n = 135) protocols. Postconsolidation therapy was more intensive on CCG-1883. On both studies, prophylactic treatment of the CNS included both high-dose systemic chemotherapy and intrathecal therapy, in contrast to whole-brain radiotherapy, which was used in earlier studies. RESULTS: Most patients (>95%) achieved remission with induction therapy. The most frequent event was a marrow relapse (46 patients on CCG-107 and 66 patients on CCG- 1883). Four-year event-free survival was 33% (SE = 4.7%) on CCG-107 and 39% (SE = 4.2%) on CCG- 1883. Both studies represent an improvement compared with a 22% (SE = 5.1%) event-free survival for historical controls. Four-year cumulative probabilities of any marrow relapse or an isolated CNS relapse were, respectively, 49% (SE = 5%) and 9% (SE = 3%) on CCG-107 and 50% (SE = 5%) and 3% (SE = 2%) on CCG-1883, compared with 63% (SE = 6%) and 5% (SE = 3%) for the historical controls. Independent adverse prognostic factors were age less than 3 months, WBC count of more than 50,000/microL, CD10 negativity, slow response to induction therapy, and presence of the translocation t(4;11). CONCLUSION: Outcome for infants on CCG-107 and CCG- 1883 improved, compared with historical controls. Marrow relapse remains the primary mode of failure. Isolated CNS relapse rates are low, indicating that intrathecal chemotherapy combined with very-high-dose systemic therapy provides adequate protection of the CNS. The overall unsatisfactory outcome observed for the infant ALL population warrants the future use of novel alternative therapies.

Prognostic significance of T-lineage leukemic cell growth in SCID mice: a Children's Cancer Group study.

Contemporary intensive therapies are effective for the majority of pediatric T-lineage acute lymphoblastic leukemia (ALL) patients, thus current challenge is to identify patients who may benefit from alternative treatment modalities. Previously, we demonstrated that human leukemic cell growth in the severe combined immunodeficiency (SCID) mouse was a significant prognostic factor for very high risk B-lineage ALL patients. In the current report we show that primary leukemic cells from 24 of 88 (27%) T-lineage ALL patients (SCID+) caused histopathologically detectable leukemia in SCID mice. These SCID+ patients were similar to SCID- (n = 64) patients with respect to virtually all presenting features, including age, sex, race, and leukocyte count. Growth of primary leukemic cells in SCID mice was not a significant predictor of outcome for the aggregate population of T-lineage ALL patients. Two-year event-free survival (EFS) outcomes for SCID+ patient and SCID- patients were 76.2% (SD = 5.6%) and a 64.0% (SD = 10.4%; p = 0.20). Overall survival also was similar between the two groups (p = 0.36). Among the subset of patients with M1 or M2 marrow status by day 7 of induction chemotherapy (rapid early responders), those who were SCID+ had poorer outcomes than those who were SCID-, with a 2-year EFS of 68.4% (SD = 11.9%) vs. 85.7% (SD = 6.0%) and relative hazard rate of 3.06 (p = 0.06). These data suggest that leukemic cell growth in SCID mice may identify a subset of T-lineage ALL patients who are at higher risk for relapse despite achieving a rapid early response to induction chemotherapy.

Clinical significance of Philadelphia chromosome positive pediatric acute lymphoblastic leukemia in the context of contemporary intensive therapies: a report from the Children's Cancer Group.

BACKGROUND: Children with Philadelphia (Ph) chromosome positive (+) acute lymphoblastic leukemia (ALL) represent a subgroup at very high risk for treatment failure. In this report, the authors assessed the outcome of Ph+ ALL in a large cohort of children treated on contemporary intensive chemotherapy protocols of the Children's Cancer Group (CCG). METHODS: This study included 1322 children enrolled between 1988-1995 on CCG risk-adjusted studies for ALL who had centrally reviewed cytogenetic data. Thirty patients had a t(9;22)(q34;q11) translocation and were referred to as Ph+; 1292 were Ph negative(-). Outcome analyses used standard life table methods. RESULTS: Compared with Ph- ALL patients, Ph+ ALL patients were more likely to be black (P=0.008), age >10 years (P=0.02), and have a leukocyte count > or =50,000/L (P <0.0001). Nearly all Ph+ (96.7%) and Ph (98.3%) patients achieved remission after induction therapy, yet event free survival outcome was significantly worse for Ph+ patients compared with Ph- patients, with 4-year estimates of 20.1% (standard deviation [SD] = 9.1%) and 75.8% (SD =1.2%), respectively (P <0.0001). This difference was maintained among patients regardless of presenting leukocyte count, age, or early response to therapy. Ten Ph+ patients underwent bone marrow transplantation (BMT) at the time of first remission; six of these patients remained event free at the time of analysis, and represent the majority (six of eight) of patients surviving event free. CONCLUSIONS: The findings of the current study confirm that Ph chromosome positivity represents a significant independent adverse risk factor for childhood ALL that has not been abrogated by current intensive chemotherapy programs. BMT at the time of first remission, as well as other alternative strategies employing biotherapeutic agents, should be considered in future front-line trials for pediatric patients with Ph+ ALL.

Primary blasts from infants with acute lymphoblastic leukemia cause overt leukemia in SCID mice.

The establishment of an in vivo animal model system for infant acute lymphoblastic leukemia (ALL) would allow the testing of new agents against primary leukemic cells from infant ALL patients. We have demonstrated previously that growth of B-lineage leukemic cells in mice with severe combined immunodeficiency (SCID) was a significant prognostic factor for children with high risk ALL. We now have examined the significance of this prognostic variable for 13 infants with newly diagnosed ALL treated at participating institutions of the Children's Cancer Group (CCG). Chromosomal translocations were detected in 10/12 evaluated cases, including five with t(4;11), one each with t(7;9) and t(7;11), t(1;19), and t(9;22), and two with t(11;19). Twelve of the thirteen infants with ALL achieved remissions following induction chemotherapy. Primary leukemic cells from 8 of the 13 infants caused overt leukemia in SCID mice. Among these 8 SCID+ infants, 7 were CD10- and seven had cytogenetic or molecular evidence of an 11q23 rearrangement. Six of the 8 SCID+ infants have relapsed; only 2 remain in remission following chemotherapy or bone marrow transplant. However, among the 5 SCID- infants there were also two relapses. These data are suggestive of a poorer outcome for SCID+ infants, but larger numbers of patients must be analyzed to assess their statistical significance. In summary, we have established a SCID mouse model for human infant ALL that will be useful for 1) predicting short-term and long-term outcome of patients, 2) testing pharmacokinetics, efficacy, and toxicity of new agents, and 3) elucidating the in vivo mechanisms of chemotherapeutic drug resistance in infant ALL.

Prognostic significance of B-lineage leukemic cell growth in SCID mice: a Children's Cancer Group Study.

Primary leukemic cells isolated from children (N = 681 ) with newly diagnosed B-lineage ALL enrolled on risk-adjusted treatment protocols of the Children's Cancer Group (CCG) were injected via the tail vein into 7-10 week old SCID mice. Leukemic cells from 104 of 681 patients (15.3%) were able to engraft and proliferate in one or more SCID mouse organs. These SCID+ patients were somewhat more likely than SCID patients to be older than 10 years of age (p = 0.03) and have WBC counts >20,000/microL (p = 0.04), but the groups were similar with respect to all other presenting features. Event-free survival (EFS) outcome at 3 years of follow-up was similar for SCID+ patients compared with SCID- patients (79.2%, SD = 5. 1% vs. 84.8%, SD = 2.8%; p = 0.20). Overall survival also was similar between the two groups (p = 0.93). This result was maintained within the subgroups of lower risk (N = 448) and higher risk (N = 233) patients. However, there were trends for poorer outcome among patients whose cells caused overt leukemia in SCID mice and infiltrated either 6 or more organs (p = 0.03), skeletal muscle (p = 0.0003), kidney (p = 0.05), or spleen (p = 0.06). Thus, engraftment of primary leukemic cells in SCID mice was not a significant predictor of outcome for the aggregate population of B-lineage ALL patients, the majority of whom were low risk, treated according to contemporary intensive chemotherapy programs of the CCG. However, development of disseminated overt leukemia and infiltration of SCID mouse skeletal muscle by primary leukemic cells from adjacent bone marrow may reflect a biologically more aggressive disease and identify patients at higher risk for treatment failure.

Clinical significance of MLL-AF4 fusion transcript expression in the absence of a cytogenetically detectable t(4;11)(q21;q23) chromosomal translocation.

Leukemic cells from bone marrow (BM) of 17 infants and 127 children with newly diagnosed ALL, as well as fetal liver and BM and normal infant BM samples, were analyzed for presence of a t(4;11) translocation using standard cytogenetic techniques and expression of an MLL-AF4 fusion transcript using standard reverse transcriptase-polymerase chain reaction (RT-PCR) assays as well as nested RT-PCR that is 100-fold more sensitive than standard RT-PCR. Overall, 9 of 17 infants and 17 of 127 noninfant pediatric ALL patients were positive for expression of MLL-AF4 fusion transcripts, as determined by standard and/or nested RT-PCR assays. None of the MLL-AF4(+) cases were positive for E2A-PBX1 or BCR-ABL fusion transcript expression. Although 8 of 9 MLL-AF4(+) infants had cytogenetically detectable t(4;11)(q21;q23), 15 of the 17 MLL-AF4(+) noninfants were t(4;11)-. Infants with MLL-AF4(+) ALL had poor outcomes, whereas non-infant MLL-AF4(+)/t(4;11)- patients had favorable outcomes similar to MLL-AF4(-) patients. Notably, MLL-AF4 transcripts also were detected by nested RT-PCR in 4 of 16 fetal BMs, 5 of 13 fetal livers, and 1 of 6 normal infant BMs, but not in any of the 44 remission BM specimens from pediatric ALL patients. Our results provide unprecedented evidence that MLL-AF4 fusion transcripts can be present in normal hematopoietic cells, indicating that their expression is insufficient for leukemic transformation of normal lymphocyte precursors.

Augmented post-induction therapy for children with high-risk acute lymphoblastic leukemia and a slow response to initial therapy.

BACKGROUND: Children with high-risk acute lymphoblastic leukemia (ALL) who have a slow response to initial chemotherapy (more than 25 percent blasts in the bone marrow on day 7) have a poor outcome despite intensive therapy. We conducted a randomized trial in which such patients were treated with either an augmented intensive regimen of post-induction chemotherapy or a standard regimen of intensive post-induction chemotherapy. METHODS: Between January 1991 and June 1995, 311 children with newly diagnosed ALL who were either 1 to 9 years of age with white-cell counts of at least 50,000 per cubic millimeter or 10 years of age or older, had a slow response to initial therapy, and entered remission at the end of induction chemotherapy were randomly assigned to receive standard therapy (156 children) or augmented therapy (155). Those with lymphomatous features were excluded. Event-free survival and overall survival were assessed from the end of induction treatment. RESULTS: The outcome at five years was significantly better in the augmented-therapy group than in the standard-therapy group (Kaplan-Meier estimate of event-free survival [+/-SD]: 75.0+/-3.8 vs. 55.0+/-4.5 percent, P<0.001; overall survival: 78.4+/-3.7 vs. 66.7+/-4.2 percent, P=0.02). The difference between treatments was most pronounced among patients one to nine years of age, all of whom had white-cell counts of at least 50,000 per cubic millimeter (P<0.001). Risk factors for an adverse event in the entire cohort included a white-cell count of 200,000 per cubic millimeter or higher (P=0.004), race other than black or white (P<0.001), and the presence of a t(9;22) translocation (P=0.007). The toxic effects of augmented therapy were considerable but manageable. CONCLUSIONS: Augmented post-induction chemotherapy results in an excellent outcome for most patients with high-risk ALL and a slow response to initial therapy.