TrialCurvePROLONG (final analysis): reconstructed Kaplan–Meier curves
Ofatumumab maintenance prolongs progression-free survival in relapsed chronic lymphocytic leukemia: final analysis of the PROLONG study. Curves rebuilt as patient-level data (Guyot 2012) and checked against the statistics printed on the figure.
| Publication | Blood Cancer J. 2019 Dec 4;9(12):98. doi: 10.1038/s41408-019-0260-2 |
|---|---|
| DOI | 10.1038/s41408-019-0260-2 |
| Registry | — |
| Phase | — |
| Conditions | — |
| Interventions | — |
| Sponsor | — |
| Enrolment | — |
| Source licence | Figure published under CC BY 4.0 |
Progression-free survival (investigator-assessed) — ITT
From figure panel A · validated against the values printed on the figure · curve source: pixel measurement confirmed by vision model
Reconstructed from the published curve. Median: Ofatumumab 34.4 months; Observation 16.9 months. Survival at 18 months: Ofatumumab 73%; Observation 48%. Hazard ratio Ofatumumab vs Observation 0.54 (95% CI 0.43–0.68).
| Arm | N | Events | Median (Months) |
|---|---|---|---|
| Ofatumumab | 240 | 119 | 34.4 |
| Observation | 240 | 162 | 16.9 |
- Ofatumumab vs Observation: reconstructed HR 0.54 (95% CI 0.43–0.68)
Landmark survival (reconstructed)
| Time | Ofatumumab | Observation |
|---|---|---|
| 6 mo | 89.2% | 75.2% |
| 12 mo | 81.1% | 57.9% |
| 18 mo | 72.7% | 48.1% |
| 24 mo | 65.5% | 37.8% |
| 36 mo | 47.2% | 27.7% |
| 48 mo | 35.7% | 20.2% |
| 60 mo | 31.0% | 17.7% |
Checks against the published figure
- Ofatumumab median: printed 34.2, reconstructed 34.4 pass
- Observation median: printed 16.9, reconstructed 16.9 pass
Overall survival — ITT
From figure panel B · curves cross-checked by two independent readings · curve source: pixel measurement confirmed by vision model
Reconstructed from the published curve. Median: Observation not reached; Ofatumumab not reached. Survival at 18 months: Observation 92%; Ofatumumab 90%. Hazard ratio Ofatumumab vs Observation 1.04 (95% CI 0.75–1.43).
| Arm | N | Events | Median (Months) |
|---|---|---|---|
| Observation | 240 | 70 | not reached |
| Ofatumumab | 240 | 76 | not reached |
- Ofatumumab vs Observation: reconstructed HR 1.04 (95% CI 0.75–1.43)
Landmark survival (reconstructed)
| Time | Observation | Ofatumumab |
|---|---|---|
| 6 mo | 99.1% | 98.7% |
| 12 mo | 95.7% | 94.4% |
| 18 mo | 92.0% | 90.5% |
| 24 mo | 88.3% | 86.9% |
| 36 mo | 75.4% | 78.3% |
| 48 mo | 67.3% | 66.6% |
| 60 mo | 60.8% | 58.7% |
Time to next-line treatment (TTNT)
From figure panel A · validated against the values printed on the figure · curve source: pixel measurement confirmed by vision model
Reconstructed from the published curve. Median: Ofatumumab 37.4 months; Observation 27.6 months. Survival at 18 months: Ofatumumab 76%; Observation 66%. Hazard ratio Ofatumumab vs Observation 0.68 (95% CI 0.54–0.86).
| Arm | N | Events | Median (Months) |
|---|---|---|---|
| Ofatumumab | 240 | 133 | 37.4 |
| Observation | 240 | 156 | 27.6 |
- Ofatumumab vs Observation: reconstructed HR 0.68 (95% CI 0.54–0.86)
Landmark survival (reconstructed)
| Time | Ofatumumab | Observation |
|---|---|---|
| 6 mo | 94.0% | 89.3% |
| 12 mo | 87.1% | 74.6% |
| 18 mo | 75.7% | 65.7% |
| 24 mo | 68.0% | 56.5% |
| 36 mo | 50.8% | 39.4% |
| 48 mo | 36.9% | 28.3% |
| 60 mo | 31.6% | 13.5% |
Checks against the published figure
- Ofatumumab median: printed 37.4, reconstructed 37.4 pass
- Observation median: printed 27.6, reconstructed 27.6 pass
PFS after next-line treatment (randomization to second progression or death) — Patients receiving next-line treatment for relapse
From figure panel B · curves cross-checked by two independent readings · curve source: pixel measurement confirmed by vision model
Reconstructed from the published curve. Median: Ofatumumab not reached; Observation not reached. Survival at 18 months: Ofatumumab 89%; Observation 91%. Hazard ratio Ofatumumab vs Observation 0.88 (95% CI 0.48–1.61).
| Arm | N | Events | Median (Months) |
|---|---|---|---|
| Ofatumumab | 153 | 19 | not reached |
| Observation | 168 | 24 | not reached |
- Ofatumumab vs Observation: reconstructed HR 0.88 (95% CI 0.48–1.61)
Landmark survival (reconstructed)
| Time | Ofatumumab | Observation |
|---|---|---|
| 6 mo | 97.2% | 98.1% |
| 12 mo | 94.2% | 93.3% |
| 18 mo | 89.2% | 90.9% |
| 24 mo | 89.2% | 88.4% |
| 36 mo | 86.0% | 83.1% |
| 48 mo | 84.7% | 82.1% |
| 60 mo | 82.4% | 80.4% |
About these data
Pseudo-IPD reproduces the published curves and numbers at risk; the rows are not real patients. Cite the publication (DOI above) and TrialCurve. The source figure is © the authors (CC BY 4.0); the charts here are redrawn from the reconstruction.
Load these data in R or Python
# R
library(survival)
d <- read.csv("https://trialcurve.com/data/trials/prolong-final-analysis-1.csv")
survfit(Surv(time, event) ~ arm, data = d)
coxph(Surv(time, event) ~ arm, data = d)
# Python
import pandas as pd
from lifelines import KaplanMeierFitter
d = pd.read_csv("https://trialcurve.com/data/trials/prolong-final-analysis-1.csv")
for arm, g in d.groupby("arm"):
KaplanMeierFitter().fit(g.time, g.event, label=arm).plot_survival_function()
Suggested citation: Blood Cancer J. 2019 Dec 4;9(12):98. doi: 10.1038/s41408-019-0260-2 doi:10.1038/s41408-019-0260-2. Reconstructed data: TrialCurve (2026), https://trialcurve.com/trials/prolong-final-analysis
Report a problem with these data
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