Celsion Corporation (CLSN)

[No-dough-go]

Look at it like this. Local recurrence might have a PFS of 6 months and IDR's might have a PFS of 18 months. The overall PFS actually increases when you add the IDR's to the equation. Additional PFS events does not mean that PFS decreases as they are added since it clearly depends on the time that those different events occur and in most abstracts that I've read, local recurrence happens sooner than the other events, therefore the other events actually will increase the overall median PFS.

Oxford Journal RFA Study

From page 661 of the above:

In 26 of 40 patients (65%), intrahepatic recurrence (LTP,
n = 5; IDR, n = 15; LTP + IDR, n = 6) was found during the follow-up period of 24.1 +15.7 months (range 1–50. These were found 2–39 months (3–18 for LTP, 2–39 for IDR after RFA with the median of 11 months (6 for LTP,18 for IDR), 95% con?dence interval (CI), 10.5–18 months (3.4–11.4 for LTP, 7.8–24.5 for IDR)

In a short example, let's assume of PFS distribution for local recurrence (in months)1,5,6,10,15 which provides a median PFS of 6, then let's toss in other IDR PFS events of 8,9,12,17,22 which yields a median PFS of 12. The overall distribution becomes 1,5,6,8,9,10,12,15,17,22 which yields an overall median PFS of 10. This is how overall median PFS can actually increase with the inclusion of other events.