Replies to post #6795 on 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.

[sdtrond]

No you're confused. :-)

I said, "My point is that TTP will be lower than PFS. Do you disagree on this?"

And you reply, "And, yes, I absolutely disagree by light years that TTP would be longer than PFS. How can it not?"

So which is it? I believe you simply wrote it wrong from context, since the rest of your post deals with your objection.

Here's my example. Let's say TTlP (time to local progression) is around 9 months. TTdP (distant) is 11 months. TTexP (ex-hep) is 14. And death is about 30 months.

So TTP might be 12 months but PFS (including all components) would be extended out becuase of the (admittedly few) events triggered by death without tumor progression.

As you say, GOOD GRIEF. :-)

Your reasoning is flawed when you say,
"(1) There's lots of ways a PFS can happen.
(2) There's only one way a TTP can happen.
Therefore PFS is far more likely to happen -- and SOONER -- obviously!"

The sooner is incorrect.
Yes PFS EVENTS will occur more frequently than TTP events. But the actual VALUE of PFS can be pushed out by the non-TTP events.