Seikagaku Corporation said the US Food and Drug Administration issued a Complete Response Letter (CRL) on September 9 (US time) on its application to sell SI-6603, a treatment for lumbar disc herniation known generically as condoliase, in the United States. The Tokyo-listed drugmaker, which filed the biologics application in March 2026, disclosed the letter the following day on Japan's TDnet system.
A CRL does not reject a drug outright; it tells an applicant that the current filing cannot be approved as submitted. In this case, Seikagaku said the FDA's objections were entirely about manufacturing, not medicine. The agency pointed to two problems: deficiencies flagged in an earlier inspection of the facility that produces SI-6603's active pharmaceutical ingredient, which the company had not fully resolved, and separate cGMP deficiencies newly identified at a contract manufacturer that handles the drug's formulation.
Crucially, Seikagaku said the FDA raised no concerns about the drug's efficacy or safety, including its clinical trial results, and did not ask for additional clinical trials. That distinction matters for a company whose US entry now hinges on fixing supply-chain quality controls rather than re-proving the drug works.
Seikagaku said it will work closely with the FDA and its US license partner, Ferring Pharmaceuticals, toward an early resubmission, though it gave no date for when that might happen or how long remediation at the two facilities could take. The company also said it is still assessing what the delay means for its consolidated earnings forecast for the fiscal year ending March 2027, and will make further disclosures if the review produces something reportable.
For now, the file sits with Seikagaku's manufacturing partners rather than its clinical dossier, but a US launch has no new date.