Simbryo discloses $5.25M round for organoid-based fertility diagnostics
Yael Katz's biotech sold the offering to 24 investors as it began marketing an assay designed to predict embryo implantation outcomes.
By Ryan Merket · Published
Why it matters
Simbryo is financing a commercial push for a functional uterine assay while its evidence remains at the preprint stage. Adoption will depend on whether clinics see predictive value beyond existing biopsy add-ons.
Yael Katz, founder and CEO of Simbryo Technologies, has raised $5.25 million for a fertility diagnostic that grows models of a patient's uterine lining and tests how they interact with stem-cell-derived embryo models.
A Form D accepted by the Securities and Exchange Commission on July 27th shows the Houston-based biotechnology company sold $5,250,972 of a planned $5,252,615 offering to 24 investors. The financing comprised equity and options, warrants or similar rights under the SEC's Rule 506(b) exemption. Simbryo reported no commissions or finder's fees.
The filing documents a financing that began well before its disclosure. Simbryo recorded its first sale on September 26th, 2025, roughly 10 months before the Form D appeared. The company announced the availability of its flagship Simbryo FX assay one month later, on October 27th, placing the financing alongside its move from laboratory development into clinic sales.
The filing does not identify the 24 investors or provide a valuation. Simbryo's investor page says its backers span biotechnology, deep tech, consumer products, women's health and healthcare delivery, without naming firms or individuals.
Katz returns to clinical diagnostics
Katz founded Simbryo in 2023 after building BrainCheck, a cognitive-health software provider that helped physicians detect and manage impairment. A Northwestern- and Princeton-trained neuroscientist, Katz worked in biotechnology and pharmaceutical consulting and was an early employee at video software provider JW Player before co-founding BrainCheck, according to her Rice University profile.
BrainCheck had raised about $21 million by its $10 million Series B in 2021. With Simbryo, Katz has returned to diagnostics around a narrower clinical question: whether an IVF patient's endometrium, the tissue lining the uterus, is capable of supporting implantation.
Katz has described repeated embryo transfers as an inadequate way to detect endometrial problems. "The way that patients find out that they have a problem, versus being unlucky, is through repeated embryo transfer failure," she said when Simbryo FX was introduced in October 2025.
The financing also backs a team with experience in the stem-cell models underpinning the test. Simbryo lists Aryeh Warmflash as chief science officer. His academic research has included human embryonic stem-cell patterning and micropatterned culture systems that let researchers study early developmental processes under controlled conditions.
Simulating implantation in the lab
Simbryo FX starts with tissue collected through an endometrial biopsy. Simbryo grows patient-derived organoids, miniature living models that preserve aspects of the uterine lining's structure and hormone response. The organoid cells are placed on micropatterned surfaces and combined with blastoids, standardized models of a five- or six-day-old embryo produced from pluripotent stem cells.
The assay measures two implantation-like behaviors: the amount of human chorionic gonadotropin, or hCG, produced in the culture and the extent to which blastoid cells invade the organoid-derived tissue. Simbryo argues that using standardized blastoids reduces embryo quality as a variable, allowing the laboratory to focus on differences in the patient's endometrium.
A January 2026 medRxiv preprint from Katz, Warmflash and nine co-authors described biopsies collected from 139 patients across four fertility clinics. The researchers reported that hCG production and blastoid invasion correlated with patients' clinical histories and the outcomes of subsequent embryo transfers. Transcriptomic measurements of the biopsy samples and organoids did not show a clear relationship with those outcomes.
The evidence remains at the preprint stage. The study establishes a correlation between the laboratory readouts and transfer outcomes; it does not establish through a randomized trial that changing treatment based on a Simbryo FX score improves pregnancy or live-birth rates. Simbryo said its combined measures predicted the likelihood of failure in the next transfer with high specificity.
That distinction will matter as Simbryo sells into a fertility market already crowded with biopsy-based add-ons. ReceptivaDx, for example, measures BCL6, a marker associated with endometrial inflammation and endometriosis. Other tests analyze gene expression, immune activity, infection or the microbiome. Simbryo's pitch centers on observing implantation-like activity directly in a patient-derived tissue model.
Simbryo is also positioning FX as the core of a broader testing menu. Its provider offering includes optional pathology, inflammation, microbiome, endometriosis-marker and implantation-window tests from a single biopsy, along with tissue banking. The company says biopsies for FX can be collected at any point in a patient's cycle and that reports integrate with eIVF and other electronic medical record systems.
A commercial push beyond Houston
Simbryo's SEC filing continues to list Houston as its principal place of business. Katz also began extending its laboratory network toward Cincinnati's life-sciences corridor in 2025. In September, Simbryo announced plans to move into LifeSciKY's 15,000-square-foot shared wet laboratory in Covington, Kentucky, where Katz said the company was working with Cincinnati Children's Hospital.
The new capital gives Katz room to turn an intricate laboratory workflow into a repeatable clinical service. Simbryo must process biopsies, grow patient-specific tissue, produce standardized blastoids and return interpretable results on timelines that fit IVF treatment decisions. The filing confirms substantial investor support for that undertaking. Clinic adoption and prospective evidence will determine whether Simbryo FX becomes a routine part of fertility care or remains another optional test layered onto an already expensive treatment process.