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Women's Health Firm Nixxi Preparing Preterm Birth Test for Launch


NEW YORK — Having launched a digital screening test for preterm birth in November, diagnostics firm Nixxi is preparing this quarter to release a mass spectrometry-based test for predicting preterm birth and infant morbidity.

The company is currently working out a partnership with a CLIA lab and completing a validation study that to support the launch of the test, said Avi Patil, founder and CEO of the Phoeniz, Arizona-based firm.

Called DocNatal, the test uses mass spec to measure the levels of the metabolites 11-deoxycorticosterone (DOC) and 16-alpha-hydroxyprogesterone (16α-OHP) in maternal serum to identify women at increased risk of delivery prior to 32 weeks.

Last November Nixxi launched an assessment tool called PopNatal, which uses patient surveys based on preterm birth risk factors identified by the National Institute of Child Health and Development, combined with an algorithm the company has developed, to generate a risk score.

"A woman gets a text message, she clicks on the link, a browser opens up on her mobile device into a secure, HIPAA-compliant interface," Patil said, describing how the test works. He said the survey takes 10 to 15 minutes to complete and collects information on around 300 datapoints.

The test is meant to increase access to screening for preterm birth risk, Patil said, noting that a significant proportion of this risk is concentrated in underprivileged populations that may have less access to medical care.

"Many women who deliver preterm don't have typical risk factors," he said. "So, if you're really going to effectively reduce rates of preterm delivery, you need to screen everyone. You can't settle for just screening women with good insurance, because that's actually probably your lowest risk population."

Women identified by PopNatal as being at high risk for preterm birth are "the ideal population" for the DocNatal test, Patil said.

He said that since launching PopNatal, Nixxi has been working with several large OB-GYN to implement it and understand how it might best be used.

"One of the things we are trying to do as we have conversations with different groups is understand the best use-case scenarios," he said. The company is also collecting prospective data on test performance as it rolls it out commercially. According to Nixxi, PopNatal identifies patients at risk of delivering before 37 weeks gestation with a sensitivity of 75 percent and specificity of 60 percent. Patil said those performance figures are based on a cohort "in the thousands" of women, though the company has not presented that data in a peer-reviewed publication.

Nixxi this month did publish data in PLOS One on the DocNatal test and its ability to identify women at risk of delivering prior to 32 weeks gestation and identifying which neonates would have significant morbidity following delivery.

The study looked at 58 women from the Building Blocks of Pregnancy Biobank at the Indiana University School of Medicine. A model combining the two metabolites with corticosteroid exposure and sex of the fetus identified neonates with a high morbidity with an area under the receiver operating curve (AUROC) of .975. It predicted preterm delivery with an AUROC of .94.

In a study published last year looking at patients in the same cohort, the Nixxi team found that the two metabolites could identify women delivering before 32 weeks with a sensitivity of 89 percent and specificity of 59 percent and an area under the (AUROC) curve of 81 percent.

Patil highlighted as a key finding in the PLOS One study the test's ability to separately assess risk of preterm birth and neonate morbidity. He said that while there is significant overlap between the two, doctors and payors are interested in being able to look at them separately.

"It has been very challenging to understand how to identify babies that will be in the [neonatal intensive care unit] for a long time," he said, noting that because of this, preterm birth risk has been used as a proxy measurement.

"But there are babies that have poor neonatal outcomes that may not deliver as prematurely," he said.

As it brings its test to market, Nixxi will face competition most directly from Sera Prognostics, which officially released its PreTRM proteomic test for preterm birth risk several years ago but has held back on ramping up commercialization as it lines up payor coverage and fleshes out the evidence supporting use of the test. Last week, Sera announced it is collaborating with insurer Anthem and its subsidiary HealthCore on a 5,600-subject study looking at whether use of the test improves outcomes and lowers spending.

In Sera's initial validation study, the Proteomic Assessment of Preterm Risk (PAPR) study, the test was able to identify women who gave birth at or before 35 weeks gestation with an area under the curve (AUC) of .93 and women who gave birth at or before 37 weeks with an AUC of .75. In a more recent study, researchers found the test could identify women who gave birth prior to 32 weeks with an AUC of .71, which went up to .76 when body mass index was included as part of the score.

The DocNatal test has shown a higher level of performance at the 32-week cutoff used by Nixxi, but that figure is based on a small number of patients from a single cohort, as opposed to the large multicenter prospective trials run by Sera to support the PreTRM test.

Patil said Nixxi is currently evaluating the test in a larger validation cohort and that the company expects data from that study to be available in the next three months. He said the company was in discussions with payors about the test and was planning to begin with a narrow, targeted rollout.

He said the company was considering raising funds to support the commercialization effort, but he declined to say how much it might target in a financing round.