IMDX Submits GraftAssureDx for FDA Review and Reports Q4 2025 Results Submitted GraftAssureDx TM for kidney transplant rejection testing for FDA review on Wednesday, March 25 Welcomed second favorable head-to-head data s

Submits GraftAssureDx for FDA Review and Reports Q4 2025 Results

TN., March 26, 2026 - Insight Molecular Diagnostics Inc., iMDx, (Nasdaq: IMDX), today published the following letter to shareholders

in conjunction with its fourth quarter results:

are pleased to share that GraftAssureDx has become, to our knowledge, the first ever kitted dd-cfDNA assay to be submitted to the FDA

for regulatory review. Our FDA submission this week represents the culmination of 12 years of clinical development and three years of

highly focused technical product development.

see many positive signals that the transplant community is ready for GraftAssureDx.

the past three months, we have doubled the number of transplant centers interested in what we are building. We are now engaged with 37

centers in the U.S. and 11 internationally, through our research-use-only assay as well as through our registry study.

The 37 centers that we are engaged with in the U.S. include 28 transplant centers that want to join our registry trial, which

we discuss in more detail under "2026 goals."

are thrilled to be able to share such a significant improvement in market access since our last update. The 37 centers in the U.S. with

which we are engaged represent more than 25% of all transplants performed annually in the United States. We look forward to engaging

with more centers over the coming quarters as word continues to spread about the advantages of our technology.

expect that our test kits will deliver new value in the roughly $2 billion addressable market for regulated transplant rejection testing.

We believe we are delivering the right product to the right market, at the right time, and that we are in the first stages of a dramatic

shift in patient management, positioning ourselves to lead.

clear to us that market demand for regulated and decentralized molecular testing is growing. At the same time, more head-to-head data

has emerged showing the reliability of our GraftAssure technology in field, and new peer-reviewed publications are highlighting the benefits

the remainder of this letter, we will cover:

timelines on FDA submission and authorization:

forward, the FDA guides to a 150-day review process for de novo submissions like ours, and therefore we continue to plan for an

FDA-authorized product this year. To note, when the FDA has a question, it can stop the clock relative to its 150-day guidance. Consequently,

our teams are working to anticipate and prepare for FDA reviewer questions so that we may respond quickly and remain on track in the

have made a review-ready submission with sufficient analytical data and clinical evidence to support that our assay is safe and effective

for using the fractional measurement of dd-cfDNA to assess the likelihood of transplanted organ rejection.

we've previously discussed, we will continue to collect clinical samples to add incremental claims associated with our assay including

absolute measurements of dd-cfDNA (copies per milliliter) and our combination score (CM-score). Supplementary data collection is a standard

practice in IVD submissions and does not affect the expected approval timeline of our initial submission.

are grateful to our clinical trial partners for helping to advance the science of transplant patient management. We are also grateful

for the support of Bio-Rad Laboratories, which not only invested in our equity for a fourth time in February, but also provided in-kind

support and a team of scientists who worked tirelessly alongside us to support a timely FDA submission.

iMDx leadership is proud of its broader team's ability to manage complexity and coordinate with multiple stakeholders, including

our kit manufacturer, software vendor, the clinical trial sites, and our strategic partner, Bio-Rad.

believe that 2026 represents our transition from a product development-stage company into a commercialization-stage company, and accordingly,

we are making controlled investments in sales and marketing to support our kidney transplant assay. Our goals for 2026 include the following:

February, at the Cutting Edge of Transplantation (CEoT) conference in Scottsdale, Ariz., a leading American transplant hospital presented

its head-to-head study findings comparing our flagship organ transplant assay technology with a leading industry competitor providing

centralized testing. In medical diagnostics, a head-to-head study is the highest level of comparison one can conduct, involving the same

sample tested by two separate tests. The hospital's independent conclusion was favorable for our assay, and the researcher presenting

the data shared that his hospital seeks to implement in-house testing because of their assessment.

above study represents the second head-to-head comparison between GraftAssure and other technologies on the market. In June 2025,

we announced separate favorable head-to-head data that was presented at the European Society of Organ Transplantation (ESOT) Congress

in London as well as at the European Renal Association (ERA) meeting. Notably, the study showed high diagnostic concordance between the

two assays for rejection.

expect more head-to-head data to emerge as more researchers and institutions engage and begin to utilize our technology. The emergence

of this data is a positive development ahead of commercial launch of the FDA-authorized product, as it builds confidence with clinicians

before choosing to switch to in-house testing.

emerging clinical utility

believe that over the next three years, the organ transplant rejection testing market is likely to shift from one that is primarily dominated

by tests used to avoid biopsies in for-cause patients to tests that actively manage patients post-transplant. Importantly,

we believe this will enable a new era of surveillance, prophylaxis and therapy monitoring: Clinicians will be trying to catch organ rejection

as early as possible so that kidneys express less damage and stay in patients longer.

the health of a transplanted organ is important, because everyone - from patient to clinician to donors at the time that they selflessly

opt into organ donation - wants the donated organ to support another person's second shot at life. For this reason, transplanted

organ rejection is a major and heartbreaking tragedy.

assay is designed to help clinicians monitor the health of the patient's transplanted organ. It does this by measuring donor-derived

cell-free DNA (dd-cfDNA), which is fragments of DNA from the transplanted organ that circulate in the patient's bloodstream. When

the organ is healthy, these fragments are present at low, stable levels. And when the organ is under stress or being rejected, more organ

cells are injured and release higher amounts of this DNA into circulation. By measuring this signal through a simple blood draw, dd-cfDNA

testing provides a non-invasive readout of organ health. This type of testing is already available on the market via a test-send-out

model from centralized labs. We are seeking to enable transplant centers to perform this type of testing in-house.

we are finding is that our assay may offer unique benefits beyond simply enabling in-house testing with shorter turnaround times. We

believe that the unique design of our assay is also poised to expand the clinical usefulness of dd-cfDNA testing, for reasons we discuss

assay can measure both the absolute quantities of the donated organ's DNA fragments as well as their relative quantities. One historical

limitation of dd-cfDNA testing has been that it works well in finding antibody-mediated rejection (AMR), but not so well with finding

t-cell mediated rejection (TCMR). Recent work done with our research partners, built on the recent publication by Vaulet et al., referenced

below, shows how well our assay's CM-score performed (p=0.0158) at finding TCMR-related activity. One explanation may be,

per the paper, "that infiltrating recipient immune cells undergo cell death within the graft during TCMR, contributing

substantially to circulating total cfDNA levels and thereby diluting the relative dd-cfDNA fraction when expressed as a percentage.

[O]ur findings for the first time provide a plausible mechanistic explanation for why low-grade TCMR is difficult to detect when dd-cfDNA

is expressed as a percentage alone."

layman's terms, it looks like TCMR may be self-masking. By putting more recipient DNA into the blood, TCMR throws off the fractional

measurement of dd-cfDNA, making the signal harder to see. Because our assay was designed to also quantify the absolute amount

of dd-cfDNA, which is unaffected by the increase in recipient DNA, these data suggest that our assay may allow for a more accurate measure

of the likelihood of transplanted organ rejection.

this year, we expect to see more publications coming out that show how combining the relative and absolute measure (CM-score) improves

the positive predictive value of dd-cfDNA testing. Meaning, using our assay has the potential benefit of fewer false positives, and therefore

helping clinicians to potentially avoid unnecessary biopsies. We expect this will become more important as the market for dd-cfDNA shifts

from for-cause testing to ongoing monitoring, or screening.

believe that screening organs will only increase in importance as new and more effective ways to treat organ rejection emerge. In recent

quarters, better pharmaceutical solutions to organ rejection are starting to gain a foothold - including in the form of anti-CD38

drugs, which are immunotherapies that were developed to treat cancer. We are starting to see signs that 2026 could be the year that anti-CD38

drugs such as felzartamab and daratumumab start to enter routine clinical practice in treating transplanted organ rejection.

studies are on-going and results that show effective management of AMR are likely to build on the excitement that was generated with

the publication of the phase 2 study of felzartamab in the New England Journal of Medicine (NEJM). As a reminder, our assay was used

in monitoring the transplanted organ health in the ground-breaking NEJM study published in 2024, which led to the

FDA's Breakthrough Therapy Designation of felzartamab in October 2024.

and even more favorably, GraftAssure's ability to pick up on low levels of signal - known as sensitivity - may also

play a role in expanding the clinical utility of dd-cfDNA testing. We have demonstrated analytical sensitivity for dd-cfDNA quantification

at low levels and the lowest relative change value (RCV), defined as the difference between the two values to signify meaningful change,

both critical for recurrence monitoring. GraftAssure can quantify lower levels of dd-cfDNA and pick up meaningful longitudinal trends

well before the moment of pathogenesis and graft deterioration.

sum, we believe that our assay's positive predictive value and analytical performance both position GraftAssure well to be the

technology of choice in this emerging clinical environment.

since our November shareholder letter: