Retrogenix data in regulatory applications


Retrogenix’s cell microarray technology is a powerful tool for off-target or specificity screening for a variety of different molecules, from antibodies and proteins to whole cells and small molecules. Data from Retrogenix’s IND-enabling specificity studies have been included in numerous regulatory applications. To help our team and our clients better understand how Retrogenix data can support IND and BLA submissions, we initiated a feedback process to follow up on specificity screening studies carried in the past 2 years and find out how those molecules are progressing.

Overall submissions

We have received responses from over 60 of the clients that we surveyed. Around one third (35%) have submitted applications to the regulators that include Retrogenix data, and 15% are in the process of submission. This covers 70 submission made to four major regulatory agencies – the FDA, EMA, PMDA and NMPA (Fig.1). The remainder mainly used the Retrogenix data for lead selection purposes, although, some molecules were not progressed due to unexpected cross-reactivity or for other internal project reasons.

Total number of molecules submitted to each regulatory agency that included Retrogenix data.

Fig.1: Retrogenix’s IND-enabling specificity data have been extensively used in regulatory submissions worldwide. The 70 submissions represent 50 different biotherapeutics (some applications were successfully submitted in multiple regions)

Success Rate

Across the board, for all submissions that used Retrogenix data, the acceptance rate was 90% with 7% of the applications still in the process of submission (Fig. 2).

   Fig. 2: Acceptance rates of IND applications which include Retrogenix data 

Cross-Reactivity Screening Methods

Until recently, standard toxicology target-binding assessment relied heavily on tissue cross reactivity (TCR) or immunohistochemistry. However, FDA guidance does state that other methods can be used. Encouragingly, from sponsor feedback, we saw that 38% of the molecules put forward for regulatory approval relied on Retrogenix data only for target specificity screening (Fig. 3).

Percentage of submissions containing Retrogenix data only.


Fig.3: A high percentage of submissions contained only Retrogenix data for cross-reactivity assessment

Type of Molecule Submitted

Due to the wide variety of specificity screening projects we undertake, we have seen many different molecule types being submitted to the regulators. However, antibodies and CAR-T cells or ScFvs are the predominant candidates, with a total of 25 antibody and 22 cell therapy applications being put forward for IND approval by our respondents (Fig.4) based upon data from specificity screenings carried in the past 2 years.

Categories of different biotherapeutics submitted for regulatory approval

Fig. 4: Number of each type of biotherapeutic submitted across all regions

If would like a more detailed analysis of how Retrogenix data have been used in NDA or IND submissions, or would like to discuss a potential study, please get in touch with us using our contact form below.

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