J-STAR Research Inc.

PORTON

Payload-Linker Capabilities

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  • Payload-Linker Process Development & Manufacturing for Payload-Linker(10-100 L, OEB 4&5). 
  • Bioconjugation (10 L, OEB 5, non-GMP)
  • Pre-clinical to Phase I to III deliveries.
  • Late-stage development studies to support clients with NDA filings.

Research & Development

Selected case histories

Payload-Linker

Developed a robust six step procedure. Procedure was made 3 x times more efficient than prior to our involvement. The major issue was in the last step only 7-10% isolated yield. By employing IPC assays, mass balance determinations, following the reaction by LCMS, followed by a set of DoEs we developed a robust last step in ~ 90% assay yield.

Purification ~ 65% isolated assay yield with remainder in heads and tails. Successful tech transferred to GMP. Significant improvements made on preparation of peptide linker (T3P mediated coupling 80% yield over 2 steps).

Payload-linker Antibody-Drug Conjugate (ADC)

Developed analytical methods to follow the conjugation reaction, reaction purity, and ADC purity after purification using a NAP-10 column. After several rounds of conjugations, it was determined that ADC can be formed with very high reproducibility in DAR value for a given reaction condition, and DAR was found to be very linear with the linker-antibody ratio. The purity of payload was the key determinant of DAR with lower purity in payload resulting in lower DAR.

Identified parameters that impacted the purity of the payload and consequently allowed us to set purity specifications to ensure the successful preparation of ADCs. Additional work was performed to evaluate the modification of the NAP-10 purification protocol by collecting smaller fractions, and this was found to improve the purity of the ADC, although the recovery is lower.

GMP Capabilities

Newly built 3,000 sq ft GMP facility with 3 individual suits.

HP API Scale up capabilities from bench scale to 100L Scale.

Proven track record at cGMP manufacturing at kilogram scale with effective containment control.

GMP Equipment includes STELLAR® Laboratory Freeze Dryer apparatus and Buchi BOGO 850C Flash and Prep-HPLC instruments.