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The-Fox-Says t1_ixuydyk wrote

Reply to comment by H2AK119ub in Brain cancer vaccine succeeds at prolonging survival in Phase 3 trial by Sorin61

I work in the clinical trial space and this is exactly why we developed synthetic control arms. Patients can get the drugs/care they need and we can still get FDA approved trials that are double blind to have a similar outcome from a placebo arm trial.

It also really helps with rare forms of cancer where the cohorts are tiny.

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itwasquiteawhileago t1_ixvdc9l wrote

Some of the oncology trials I've been on compare IP to SOC. In many cases SOC is what they call "watchful waiting" (i.e., doing nothing). I'm no oncology expert, but I do work in the clinical trial space and have worked on dozens of various oncology studies over the years and see this regularly. Often times they can cross over from SOC to study drug if their condition worsens within a certain timeframe, but how they make those decisions when developing the protocol is not something to which I am involved.

I know sometimes the best results only really mean maybe a few more months before the inevitable. Those trials are rough because people just want to live the rest of their lives as comfortable as possible, so being in a clinical trial that, best case, may extend their life a few months, is not always appealing. But without these trials, we'll never get anywhere in the long run.

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H2AK119ub t1_ixvvblk wrote

Your latter point is probably why this trial took such a long time to accrue patients. Also, the difference between the treatment and external control in primary disease is 3 months for OS. IME - watch and wait is used for low grade disease.

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impy695 t1_ixw797b wrote

Would you be willing to explain what a synthetic control arm is and why are they better? I've never heard the term before.

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Dzugavili t1_ixwakfp wrote

Basically, you make a fake control group using data from previous patients: eg. 90 days into a clinical trial, you'd expect X% of patients in the control group to have died, and if you know that for certain, you don't need to have a control group actually sit there and die for you to confirm it.

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impy695 t1_ixwbat1 wrote

Interesting, how would it work with thr placebo effect? Or is it something you use in separate trials for the same drug that way only some trials have a placebo group?

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Dzugavili t1_ixwby4y wrote

I suspect in most cases, you'd be able to recycle control data from a previous study, and hope their placebo effect should be similar enough; or that your treatment effect is substantially stronger than optimism.

But given the kind of conditions we'd be likely to use this methodology for, I don't know if the placebo effect has a strong effect on outcomes.

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puffferfish t1_ixy59sb wrote

A “placebo effect” isn’t really applicable in this case. It would be optimal to have a control for patients, something like giving them a pill with every ingredient aside from the drug, but this is likely not going to influence something like brain cancer. Brain cancer will not be influenced psychologically, and there is enough data to know on average how long patients with this cancer will survive. In a phase 3 trial it is important to get enough patients to participate for good statistics, and to do it as ethically as possible. To do this, you can just leave out an active “placebo” arm of the trial.

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beesgrilledchz t1_ixwxhx9 wrote

Thank you. Thank you for your work. I hope we can one day help everyone with these tumors.

PNET gives me nightmares.

I have had far too many conversations with families saying “we possibly can’t save your child but if you are willing to try, we might save another child in the future. Leukemia was once a death sentence. It’s treatable now, because there were families like you, willing to try”

I’m going to go cry for every one of those kids and their brave families, who were willing to try.

I see their faces in my dreams.

Edit: that was too nihilistic. I have seen kids signed up for highly experimental trials who were doing really well

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DubC_Bassist t1_iy060bk wrote

“Synthetic Control Arms”?!! I’m not negotiating with a Cyborg.

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ForProfitSurgeon t1_ixvdoeg wrote

We need to make sure we do enough human testing before it is ready for the rich.

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