Is the hypothesis ofPGS/PGT-A supportable?Norbert G le icher, MDM e d i c a l D i r e c t o r a n d C h i e f S c i e n t i s t , C e n t e r F o r H u m a n R e p ro d u c t i o n , N e w Yo r k , N YP r e s i d e n t , F o u n d a t i o n F o r R e p ro d u c t i v e M e d i c i n e , N e w Yo r k , N YG u e s t I n v e s t i g at o r, R o c ke fe l l e r U n i v e rs i t y, N e w Yo r k , N YP r o fe s s o r ( A d j ) , D e p a r t m e n t O f O b s t e t r i c s & G y n e c o l o g y, V i e n n a U n i v e rs i t y S c h o o l O f M e d i c i n e , V i e n n a , A u s t r i a

Dansk Fertilitetsselskabs Årsmøde | March 10-11, 2018| Middelfart, Denmark

Conflict StatementDr. Gleicher is listed as co-inventor on a number of pending patent applications claiming diagnostic and therapeutic benefits from determination of CGG repeat numbers and ovarian FMR1 genotypes and sub-genotypes.

Dr. Gleicher is co-inventor of awarded U.S. patents, claiming therapeutic benefits for supplementation of DHEA in women with diminished ovarian reserve, a topic discussed in this talk. Other patent applications in regards to DHEA and other fertility-related claims, with no relationship to this talk, are pending. Dr. Gleicher receives royalties from, and owns shares in Fertility Neutraceuticals, LLC, a distributor of a DHEA product.

Dr. Gleicher is co-inventor of three pending patent applications claiming potential therapeutic benefit for anti-Müllerian hormone (AMH) in infertile women. Dr. Gleicher owns shares in OvaNova Laboratories, LLC.

The PGS Hypothesis▪ Aneuploidy is a major cause of IVF failure and miscarriages after IVF

▪ Elimination of aneuploid embryo before embryo transfer, therefore, will improve IVF outcomes and reduce miscarriages

History▪ Polar body biopsy (Verlinsky et al 1990s)

▪ PGS 1.0 (~2000-2008)

▪ PGS 2.0 (2008-2017)

▪ PGS 3.0/PGT-A (as of July 2016)

History cont.▪ PBB, PGS 1.0 and PGS 2.0, all, reported results as

euploid/aneuploidy

▪ Only PGS 3.0/PGT-A reports results as euploid/mosaic/aneuploid

▪ “Implementation of the most recent PGS technologies has been shown to improve pregnancy rates per transfer in randomized controlled trials, meta-analysis and case-controlled prospective studies.”

Besser and Mounts 2017

The errors in IVF outcome assessments with reference embryo transfer

n=10

PGS

Blastocysts

Selection by OR

General population (n=100)

▪ Assuming 8 live births, the live birth rate will be 80% with reference ET, but only 8% with reference cycle start (“intent to treat”)

Is there evidence that the PGS hypothesis does not work?▪ 2 models▪ Orvieto R, Reprod Biol Endocrinol 2016

▪ Scriven PN, Reprod Biol Endocrinol 2017

Barad DH et al, Am J Obstet Gynecol 2017

The Value of PGS

Can one biopsy reflect the complete TE?

P-values for observing no mosaicism, given different hypotheses r and a threshold of 0.05 (dotted line)

P-values for observed mosaicism, given different hypotheses r, and varying numbers of abnormal-aneuploidy cells in biopsy

Reprod Biol Endocrinol; In press

Does the TE reflect the ICM?

▪ Yes, marginally

▪ ~10-15% discrepancy

Is there self-correction downstream?

Effects of Pre-Implantation Chromosome Mosaicism on Embryo Development and Survival

Richard J. Paulson• Preimplantation genetic screening: What is the clinical efficiency?• Fertil Steril 2017;108:228-230

• “We must be cognizant of the reality that this type of screening is inherently inefficient and that many normal embryos are discarded”

• “The proportion of normal embryos that are discarded...may be as high as 40%”

Greco and et al, N Engl J Med 2015;373:2089-90.

Bernabeu et al ESHRE 2016

Mosaic Euploid

Age (years) 31.0 30.6

Embryos (n) 54 382

Clinical pregnancies (%) 26.9% 40.2%

Clinical miscarriages (%) 7.1% 18.1%

Ongoing pregnancies (%)* 25.0% 32.9%

* All births normal

OBJECTIVE: To determine the pregnancy outcome potential of mosaic embryos, detected by means of preimplantation genetic screening (PGS) with the use of next-generation sequencing (NGS).DESIGN: Retrospective study.SETTING: Genetics laboratories.PATIENT(S): PGS cycles during which either mosaic or euploid embryos were replaced.INTERVENTION(S): Blastocysts were biopsied and processed with the use of NGS, followed by frozen embryo transfer. Trophectoderm (TE) biopsies were classified as mosaic if they had 20%-80% abnormal cells.MAIN OUTCOME MEASURE(S): Implantation, miscarriage rates, and ongoing implantation rates (OIRs) were compared between euploid and types of mosaic blastocysts.RESULT(S): Complex mosaic embryos had a significantly lower OIR (10%) than aneuploidy mosaic (50%), double aneuploidy mosaic (45%), and segmental mosaic (41%). There was a tendency for mosaics with 40%-80% abnormal cells to have a lower OIR than those with <40% (22% vs. 56%). However, few embryos (n = 34) with a mosaic error in 40%-80% of the TE sample were replaced. There was no difference between monosomic and trisomic mosaics or between entire chromosome mosaicism or segmental mosaicism. Implantation rates were significantly higher (70% vs. 53%), miscarriage rates lower (10% vs. 25%), and OIRs higher (63% vs. 40%) after euploid embryo transfer than after mosaic embryo transfer.CONCLUSION(S): Forty-one percent of mosaic embryos produced an ongoing implantation. Complex mosaic blastocysts had a lower OIR than other mosaics. Mosaic monosomies performed as well as mosaic trisomies and mosaic segmental aneuploidies. The results suggest that embryos with >40% abnormal cells and those with multiple mosaic abnormalities (chaotic mosaics) are likely to have lower OIRs and should be given low transfer priority.

2016 PGDIS Guidelines

Hypothesis▪ Like cancer cells, blastomeres of early stage embryos show▪ Increased expression of gene products favoring cell progression

▪ While lacking cell cycle checkpoint genes

▪ Such a constellation favors genetic instability and mitotic errors in cancer and embryos

▪ Embryo aneuploidy was believed to be mostly meiotic; now known to be mostly mitotic

Kort et al, Hum Reprod 2016

Ghevaria et al, RBMOnline 2016

Hypothesis

Hypothesis cont.▪ Counterintuitively to the PGS hypothesis, aneuploidy in

trophectoderm may play a role in invasiveness of the embryo during implantation

▪ Supported by excellent live birth rates and low miscarriage rates

▪ Supported by tolerance-inducing aneuploidy recently reported in cancer

ConclusionsPGS biopsy results:

▪ Are biologically nonsensical

▪ Are technically unfeasible

▪ Are unvalidated

▪ Produce large numbers of false-positive diagnoses and, therefore, have resulted in disposal of large numbers of normal embryos

▪ Fail to improve IVF outcomes

▪ Negatively affect IVF outcomes in at least selected patient populations

CHR Staff (* Visiting Scientists)

David F Albertini, PhDDavid H Barad, MS, MDAli Brivanlou, PhD, MD*Sarah Darmon, PhD, MSDieter Egli, PhD*Norbert Gleicher, MDVitaly A Kushnir, MDEmanuela Lazzaroni-Tealdi, MSAya Shohat-Tal, PhD*Andrea Vidali, MD*Andrea Weghofer, PhD, MS, MBA, MD*Yan-Guang Wu, PhD*Yao Yu, PhD*

Affiliates

Rockefeller University:Ali Brivanlou, PhD, MDGist Croft, PhD

Salk Institute for Biological Studies:Pradeep Reddy, PhD