Rallybio has reported positive data from a Phase I/II clinical trial, during which antibody candidate RLYB211 demonstrated proof of concept in fetal and neonatal alloimmune thrombocytopenia (FNAIT).

RLYB211 is a polyclonal anti-human platelet antigen (HPA)-1a antibody being developed to prevent FNAIT, a rare disease characterised by uncontrolled bleeding in fetuses and newborns.

Results from the first cohort of the ongoing Phase I/II trial showed that RLYB211 quickly and entirely cleared HPA-1a positive platelets from the circulation of HPA-1a negative subjects.

This indicates that treatment with an anti-HPA-1a antibody could help prevent FNAIT, the company said.

Rallybio co-founder and CEO Martin Mackay said: “These data reinforce our conviction in our approach as we prepare to move RLYB212 into the clinic.

“We will continue to work expeditiously with our partners, including the Fraunhofer Institute for Translational Medicine and Pharmacology and German Red Cross, to advance a potential preventive treatment to benefit the mothers and babies at high risk of this devastating disease.”

How well do you really know your competitors?

Access the most comprehensive Company Profiles on the market, powered by GlobalData. Save hours of research. Gain competitive edge.

Company Profile – free sample

Thank you!

Your download email will arrive shortly

Not ready to buy yet? Download a free sample

We are confident about the unique quality of our Company Profiles. However, we want you to make the most beneficial decision for your business, so we offer a free sample that you can download by submitting the below form

By GlobalData
Visit our Privacy Policy for more information about our services, how we may use, process and share your personal data, including information of your rights in respect of your personal data and how you can unsubscribe from future marketing communications. Our services are intended for corporate subscribers and you warrant that the email address submitted is your corporate email address.

HPA-1a negative healthy male subjects in the first cohort of the Phase I/II trial received 1000 IU RLYB211 or placebo one hour following administration of HPA-1a positive platelets.

According to the data, RLYB211 noticeably fast-tracked the HPA-1a positive platelets clearance when compared to placebo. The mean half-life was 0.32 hours versus 65.29 hours, respectively.

RLYB211 was also observed to be safe and well-tolerated, without any serious adverse events.

The Phase I/II trial is designed to determine the RLYB211 dose required to rapidly eliminate HPA-1a positive platelets. It is being conducted in Germany.

Apart from RLYB211, the company is developing RLYB212 for FNAIT prevention.

Designed for subcutaneous use, RLYB212 is a human monoclonal anti-HPA-1a antibody that is anticipated to enter the clinic in the first half of next year.

When given to expectant at-risk mothers, both RLYB211 and RLYB212 are intended to rapidly remove fetal HPA-1a positive platelets from circulation and avert maternal alloimmunisation, subsequently avoiding the FNAIT risk in the fetus.