Long-Term Outcomes of Patients with Acute Myeloid Leukemia Treated with Salvage High-Dose Etoposide and Cyclophosphamide
Bibliographic record
Abstract
Abstract Background Salvage chemotherapy using high-dose etoposide and cyclophosphamide (VP-Cy) was developed for acute leukemia and myeloid malignancies resistant to cytarabine-based induction regimens. The Leukemia/Bone Marrow Transplant (L/BMT) program of British Columbia has a 25-year experience using VP-Cy for patients with relapsed and refractory (R/R) acute myeloid leukemia (AML). We report on a retrospective analysis to evaluate the efficacy and early toxicity of this regimen. Methods The L/BMT database was searched to identify R/R AML patients treated with VP-Cy. Patients were treated with etoposide 2.4 g/m2 given as continuous infusion over 34 hours on days 1-2 followed by cyclophosphamide 2 g/m2/day on days 3-5. The primary aims of this analysis were to determine response rate, long-term survival outcomes, and early toxicity. Secondary aims were to determine the impact of initial induction chemotherapy, using either standard-dose cytarabine and daunorubicin (7+3) or high-dose cytarabine and daunorubicin (HiDAC-D), on response rate to salvage as well as to assess the impact of cytogenetics and FLT3-ITD mutations on outcome. Survival curves were calculated using the Kaplan-Meier method, and comparisons between curves were made using the log-rank test. Chi-squared test was used to compare differences in categorical variables. Results 169 patients diagnosed with R/R AML treated with VP-Cy from 1991-2015 were identified. Baseline characteristics are shown in Table 1. CR rate was 45% and 5-year OS was 20% (95% CI 14-26%) for the entire cohort. Rate of CR (p=0.98) and median OS (p=0.8) were not different between cohorts receiving standard-dose cytarabine vs. high-dose cytarabine during initial induction. 74% (56/76) of responding patients received allogeneic hematopoietic stem cell transplant. 42% (32/76) of patients relapsed after initially responding to VP-Cy and the median CR duration was 221 days (range: 36 to 2561 days). In responding patients (n=76), 5-year relapse-free survival (RFS) and OS were 33% (95% CI 24-46%) and 35% (95% CI 25-47%) respectively. Initial disease status did not significantly influence response rate [52% (refractory day 14) vs. 42% (refractory day 28) vs. 47% (relapsed), p=0.46] although median OS was longer in patients with refractory disease [422 days (refractory day 14) vs. 281 days (refractory day 28) vs. 122 days (relapsed), p=0.03)]. Patients with FLT3-ITD mutation (30/78) had lower CR rate (23% vs. 53%; p=0.01) and worse OS (median OS 135 days vs. 357 days; p<0.0001) compared to those without. Patients with adverse risk cytogenetics (34/169) had a trend towards lower CR rate (38% vs. 50%; p=0.2) and a significantly worse OS (median OS 155 days vs. 304 days; p<0.0001) compared to patients with favourable/intermediate cytogenetics. Rate of early death (<60 days) was 12% (20/171) and causes included: bacterial infection (n=4), fungal infection (n=3), intracranial hemorrhage (n=1), and progressive AML (n=9). Conclusion VP-Cy is an effective salvage regimen with response rates, long-term survival and rates of early death comparable to reported outcomes using cytarabine-based salvage regimens. Initial dose of cytarabine given during induction did not influence response rate or survival. The probability of long-term survival for the entire cohort was low (20%) and outcomes were significantly worse in patients with FLT3-ITD mutation and adverse risk cytogenetics, emphasizing the need for investigation of novel treatments in these groups. Figure (a) Overall Survival. (b) Relapse-Free Survival in Patients Achieving CR Status After VP-Cy. Figure. (a) Overall Survival. (b) Relapse-Free Survival in Patients Achieving CR Status After VP-Cy. Figure Baseline Characteristics of Cohort. Figure. Baseline Characteristics of Cohort. Table 1 Table 1. Disclosures Song: Celgene: Honoraria, Research Funding; Janssen: Honoraria; Otsuka: Honoraria. Toze:Roche Canada: Research Funding. Gerrie:Roche Canada: Research Funding.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".