October 19, 2020

The Niche

Knoepfler lab stem cell blog

Red flags in Sally Davies letter on 3-person IVF mitochondrial transfer

sally davies, 3-person IVF
Sally Davies, who seems upbeat on 3-person IVF.

There’s been some back and forth between me and some members of the UK Parliament and others in the UK on the issue of mitochondrial transfer or 3-person IVF technology.

Some of this has involved the UK equivalent of the Surgeon General, Professor Dame Sally Davies, who at one point apparently called my views “bunk”. I wrote back to her via Lord Alton articulating my concerns and respectfully responding to the bunk allegation.

I am not opposed in principle to mitochondrial transfer technology, but rather from an impartial scientific and factual perspective it is clear to me that far more data from additional animal studies is needed. At some point with any experimental biotechnology intended for human use scientists and doctors have to take the plunge and try it in humans, but my view is that the animal data supporting mitochondrial transfer is incomplete at best.

Now I just recently indirectly received a letter from Davies, which seemed intended to rebut my concerns. I found some things about the letter to be surprising and in some cases to be red flags.

With all due respect, Davies seems to have a dismissive attitude toward those who disagree with her on the urgency for human mitochondrial transfer to proceed as soon as possible. This is evident in a newspaper article she wrote and also in this letter. You can see it without having to read between the lines in her word choices to describe the press and opponents of the immediate approval of the technology: ‘overly simplistic’, ‘sensationalist’, ‘unsophisticated’.

The most surprising element of her letter in reply to my concerns was her argument against a need for additional animal research and data.

It seems she and other proponents of this technology moving forward immediately have a tendency to pick and choose whether to value animal data depending on whether it supports their case or not. In this passage, they are fans of animal data, which they view as fairly definitive:

“The view of the Expert Panel was that experiments involving Pro-nuclear Transfer (PNT) and Maternal Spindle Transfer (MST) in animals (mice, macaques, and some other animals) have not given any cause for concern.”

So on the one hand she and others advocating immediate approval of this technology have asserted that mitochondrial transfer would be safe for humans based essentially entirely on animal studies including the non-human primate work of Mitalipov.

On the other hand, she goes on to argue that additional work of that kind would be bad:

“The use of non-human primate experiments was deemed by the Expert Panel, in its 2013 and 2014 reports, to no longer be necessary given the differences between non-human primate and human eggs / early embryos. Performing such unnecessary animal experiments would indeed be unethical given that non-human primates were not considered a good model for the human in this context.”

It sure seems like a self-contradictory argument, right?

I find the use of the word ‘unethical’ to be strikingly strong.

It is notable that in the past, if memory serves, the Expert Panel did feel that more data was needed (and that data is still not available), but it’s not clear what changed their minds.

Remarkably, then in a nutshell what she seems to be saying is that the only ethical thing to do since animal models are imperfect–except of course the specific past ones that we feel supported safety–is to experiment on humans and do it now.

That is more ethical?

This all sounds a lot more like politics than biomedical science. I say, let’s focus on the data and not the politics, but I’m not holding my breath.

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