Q#5 Best Overall Response (BOR) , Objective Response Rate (ORR) ,95% Confidence Interval (CI) &P-value Oncology

Definition of Best Overall Response (BOR)

Best Overall Response (BOR) is the best treatment response a patient achieves during a clinical trial.

It is determined based on tumor size changes and classified into four categories:

1.Complete Response (CR) – The tumor disappears completely.

2.Partial Response (PR) – The tumor shrinks significantly but is still present.

3.Stable Disease (SD) – The tumor neither shrinks nor grows significantly.

4.Progressive Disease (PD) – The tumor grows or worsens.

Imagine 5 patients are taking a new cancer drug.

Each patient’s response is tracked over time.

•If a patient improves over time, the best response is counted (e.g., PR → CR → CR is recorded as CR).

•If a patient worsens after improvement, the worst response is counted if the patient does not recover

•(e.g., PR → PD is recorded as PD).

Imagine 5 patients are taking a new cancer drug.

Each patient’s response is tracked over time.

•If a patient improves over time, the best response is counted (e.g., PR → CR → CR is recorded as CR).

•If a patient worsens after improvement, the worst response is counted if the patient does not recover

•(e.g., PR → PD is recorded as PD).

Patient	Response Type	Best Overall Response (BOR)
Patient 1	CR (Tumor disappeared)	CR
Patient 2	PR (Tumor shrank)	PR
Patient 3	SD (No significant change)	SD
Patient 4	PR first, then PD later	PD (worst response counts)
Patient 5	PR first, then CR later	CR (best response counts)

PR → CR → CR → CR

👉 BOR = CR (Best was 100%)SD → PR → PR → SD

👉 BOR = PR (Best was 80%)PR → SD → PD → PD

👉 BOR = PD (Got worse at the end)SD → SD → SD → SD

👉 BOR = SD (No change)PR → CR → PD

👉 BOR = PD (Got worse at the end)Definition of Objective Response Rate (ORR)

Objective Response Rate (ORR) is a measure used in oncology clinical trials to assess how well a treatment works.

It is the percentage of patients whose cancer shrinks (Partial Response – PR) or disappears (Complete Response – CR) after treatment.

ORR does not include Stable Disease (SD) or Progressive Disease (PD).

A 95% Confidence Interval (CI) is a range of values that tells us where the true result is likely to be.

What is a 95% Confidence Interval (CI)?

95% Confidence Interval (CI) for Objective Response Rate

•Drug A: (0.1941 – 0.993) → This means we are 95% sure that the true response rate for Drug A is between 19.41% and 99.3%.

•Drug B: (0.0250 – 1.000) → The response rate for Drug B is between 2.5% and 100% (very wide range due to low patient count).95% Confidence Interval (CI) for Objective Response Rate

•Drug A: (0.1941 – 0.993) → This means we are 95% sure that the true response rate for Drug A is between 19.41% and 99.3%.

•

•Drug B: (0.0250 – 1.000) → The response rate for Drug B is between 2.5% and 100% (very wide range due to low patient count).Difference in Objective Response Rate

•0.75 (75%) → Drug A had a 75% higher response rate than Drug B.95% CI for the Difference in ORR

•0.3257 → This means the actual difference could vary, but there’s a 32.57% chance that Drug A is better than Drug B.P-value

•0.2207 → The p-value tells us if the difference between Drug A and Drug B is statistically significant.

•Since 0.2207 > 0.05, this means the difference is not statistically significant, meaning we cannot be sure that Drug A is truly better than Drug B (the result could be due to chance).