mRNA cancer vaccine shows protection at 5-year follow-up, Moderna and Merck say

[zaptrem]

"Previous data from the trial reported that 107 participants received the mRNA vaccine and Keytruda treatment, while the remaining 50 only received Keytruda. At the two-year follow-up, 24 of the 107 (22 percent) who got the experimental vaccine and Keytruda had recurrence or death, while 20 of 50 (40 percent) treated with just Keytruda had recurrence or death, indicating a 44 percent risk reduction"

Statistically, if those in the control group had gotten the treatment, then in expectation 9 of those people wouldn't have had their cancer return or died. It must be exciting to run these sorts of trials with super promising drugs, but also a little bittersweet/dark.

[Neywiny]

You make a very good point. But the other side of it is that sometimes it goes poorly. The vaccine could have some previously unknown bad reaction with the Keytruda and the numbers get 44% worse instead. In this case it would be better to be in the vaccine group, but that's not guaranteed.

[readthenotes1]

40% recurrence seems insanely high after just 2 years.

It makes me wonder what the selection criteria for candidates were

[46493168]

There are affordances for "this works so well and has so few side effects that we are ethically bound to give the control group the drug too." This happened with AZT for HIV.

[yak90]

## 12. Fisher exact test ## (2026-1-25, 10:56pm)

Frequency data = 24 107 | 131 20 50 | 70 -------------------------------------- 44 157 201

[### Fisher's exact test ###]

   Ho (Null hypothesis) : There is no
      association between two classification
      of the rows and columns.
   Ha (Alternative hypo) : There is an
      association between two classification
      of the rows and columns.

        p = 0.108418 NS (2 tails)
             --> Ho was not rejected.

(Reference: Chi square test) X2 = 2.8036907 (p = 0.094048) X2Y = 2.2362266 (p = 0.134809) (Adjusted by Yates Correction)