Predictors of Clinical Outcome to Pentostatin, Cyclophosphamide and Rituximab (PCR) Followed by Campath for Relapsed/Refractory CLL – A Study of the Eastern Cooperative Oncology Group, E2903.
Abstract Background: This is an initial report of a correlative laboratory study of an ECOG clinical trial, E2903, to investigate an array of prognostic factors that are potentially associated with the clinical outcome in previously treated, high risk Chronic Lymphocytic Leukemia (CLL) patients. The ultimate goal of this study is to develop a prognostic model for this group of patients. Method: We have previously reported (ASH, 2007) on initial clinical and toxicity results using a combination of PCR followed by Campath. To date we have clinical response data on 37 patients and have conducted correlative prognostic factor analysis on these patients at entry to the study. The prognostic parameters assessed were fluorescence interphase hybridization (FISH) panel, CD38, ZAP-70 and IGVH (mutated vs. unmutated) status and plasma levels of pro- and anti-angiogenic cytokines. In addition, features such as clinical stage, age, sex and laboratory parameters including total white blood count, absolute lymphocyte count (ALC) and beta 2 microglobulin (b2m) were studied as predictors of response to PCR. Results: As of July 2008, the response data for the first 41 (the accrual goal is 110) patients who started the induction treatment are available. Of these 41, 3 patients are ineligible and one patient had no response data. The median age was 63 (range 51–76) with 29 males and 8 females, median b2m was 4 (range 2–28), 11 (31%) were Rai stage 0–2, and 26 (69%) were Rai 3–4. The median number of prior treatments was 2 (range 1–5); 15 of 23 (65%) patients tested for IGVH were unmutated, while on FISH analysis 4 had del 6q, 8 had del 11q, 4 had del 17p and 30 patients had complex FISH defects (>1 defect). Despite the prevalence of high risk features in this cohort of patients, 17 out of 37 responded (best response=partial response), 18 were stable and 2 had progressive disease with an overall response rate of 46%. Prognostic parameters most strongly associated with a clinical response included CD38 negative (p=0.008), ZAP-70 negative status (p=0.01) and mutated status (p=0.03). Responses were independent of age, sex, b2m, ALC, number of prior therapy or FISH defects. Responders showed a prolonged progression-free survival (PFS) compared to the PFS of non-responders (i.e., 2-yr PFS 29% vs. 0%, respectively, p<0.0001). Prognostic parameters most strongly associated with PFS included being both ZAP-70 negative (p=0.0009) and CD38 negative (p=0.004). Also, ZAP-70 negative and CD38 negative status was a strong predictor of favorable PFS (p=0.002). Mutated status was borderline significant (p=0.07) in univariate analysis and there was no obvious correlation of baseline angiogenic cytokine plasma levels with PFS. These results also hold in a multivariable Cox model. In the Cox model, mutated status was significantly associated with PFS (HR=0.2, p=0.01). Conclusion: We believe that the PCR regimen is highly effective at inducing responses in previously treated relapsed or refractory CLL patients who carry high risk prognostic markers. Thus, while no CRs were seen all but 2 patients had a PR or were stable after 6 cycles of PCR. The prognostic parameters most strongly associated with predictors of clinical outcome appear to be ZAP-70, CD38 and mutation status. The ability to attain a response also appears to be important for achieving a prolonged PFS. In summary, we believe that the strong clinical activity of PCR in a high risk group of CLL patients provides more evidence for pursuing the regimen as a platform for other combinations. In addition, we have generated a first level prognostic model that will continue to be refined as we proceed to complete this trial.
Whole Arm Duplication of 1q in Myeloid Neoplasm, with Emphasis On Derivative (1;7)(q10;p10).
Abstract Abstract 4238 Background Duplication of the long arm of chromosome 1 (1q) is a recurrent finding in hematologic neoplasms. It is most commonly observed as an unbalanced whole arm translocation with chromosome 7, resulting in concurrent deletion of 7q (ISCN as der(1;7)(q10q10)). It is less frequently observed as an unbalanced translocation with a chromosome other than chromosome 7 or as a duplication of only a segment of 1q. The der(1;7) has been described in myelodysplastic syndrome (MDS), and acute myeloid leukemia (AML), and is reportedly less commonly associated with myeloproliferative neoplasms (MPN). The effect of this rearrangement on prognosis is unclear, although it is classified by the International Scoring System (IPSS) as a karyotypic variant of del(7q)/-7 and is thus assigned poor risk. We have initiated a thorough review of all cases of duplication of the long arm of chromosome 1 seen at our institution. Methods After approval from the Institutional Review Board, all cases seen at Mayo Clinic over a 20 year period (1989-2009) were searched for a duplication of the long arm of chromosome 1. The sole exclusion criterion was a complex karyotype (3 or more independent chromosome abnormalities in the clone). Cytogenetic and hematopathology review was done and relevant clinical data were abstracted from the Mayo Clinic record. Survival of MDS patients and MPN patients was determined from time of cytogenetic diagnosis of der(1;7) until death or last contact with the patient, using the Kaplan-Meier method. Results Among 23,375 unique patients at Mayo Clinic with a cytogenetic study for hematologic neoplasm, 229 (0.98%) patients carried a duplication of 1q. Within this group, 99 (0.42%) had duplication of part of 1q, 123 (0.53%) carried a whole arm duplication of 1q, and 7 patients carried an isochromosome 1q (resulting in 4 copies of 1q). The most common karyotype among those with a whole arm duplication of 1q was der(1;7) (n=84), followed by similar whole arm translocations involving chromosomes 9 and 19 (n=7 each) or chromosomes 12, 13, 14, 15, 16, 17, 18, 20, 21, or 22 (n=1 to 6 each). We focused on 65 der(1;7) patients who had adequate hematopathological material that could be reviewed and sub-classified according to WHO criteria. MDS was identified in 30 patients and MPN in 20. MDS (therapy related, RARS, RAEB-1 or 2) was seen in 9 patients (14%), MDS/ refractory cytopenia with multilineage dysplasia (RCMD) in 19 (29%). MDS/Myeloproliferative neoplasm (MPN) in 2 (3%), MPN not otherwise classified in 5 (8%), and MPN / primary myelofibrosis (including 1 post-polycythemic and one post-thromobocythemic) (PMF) in 15 (23%). The bone marrow was apparently normal in 5 patients (8%), CLL was noted in 3 (5%), and 1 each exhibited features of systemic mast cell disease or myeloma. Acute myeloid leukemia (AML) was identified 5 patients (8%). The M:F ratio of the der(1;7) patients was 2.8:1. The median age at occurrence of the der(1;7) was 63 years (range: 13-87 years). All 5 AML patients have died (median survival 9 months). Of the MDS and MPN patients, the median survival was 2.2 and 2.8 years, respectively, from the time of cytogenetic diagnosis. Overall survival was not significantly different between the MDS and MPN group, and they exhibited 30% survival after 5 years (see Figure). Conclusions Duplication of 1q was observed in nearly 1% of the Mayo Clinic patients who had a bone marrow cytogenetic study for a hematologic neoplasm. Among those with a der(1;7), AML was uncommon but MDS and MPN were similar in frequency. Median survival of 2.2 to 2.8 years for the MDS and MPN group justifies assignment to a more favorable group than the current IPSS assignment. Disclosures: No relevant conflicts of interest to declare.