[180025549]
What is the current minimum dna input for f1cdx assay by foundation medicine, inc. (fmi)? I work at fmi and know the in-process spec for dna extraction was set at 55 ng. However, from some time during year 2019, the limit is lowered to include samples with dna yields in the range of 27 - 55 ng. When the dna yield is lowered, some quality metrics of sequence will have lower quality, for example, median exon coverage and estimated on target library size would decrease with a decreased extracted dna input. I tried to find out if there are validation info for this lowered extracted dna yield requirement and the communication with fda from within fmi internal groups and failed to find any definitive answers. I checked the fda website for any supplements approved by fda for f1cdx (p170019). There is no supplement related to lower dna input among 10 listed supplements (up to s102, some numbers are skipped). On f1cdx labeling (p170019c, retrieved from fda website on november 20, 2019), there are several places mentioning the required dna quantity: on page 2 of 36, test principle, "50-1000 ng of which will undergo; on page 18 of 36, analytical specificity / (started on page 16), "dna yield is sufficient to meet the standard processing requirement of dna isolation (? 55 ng)"; on page 24 of 36, dna extraction, "all average dna yields were significantly above the minimum requirement of 55 ng". To my understanding that as part of the validated f1cdx assay, a requirement of a minimum extracted dna quantity of 55 ng is critical and any changes, especially lowering the value, would need fda's approval. I'd like to find out if my understanding is correct and if yes, was there an adequate communications with the agency was made and what was agency's decision. Add'l comment, i understand that there other considerations for the benefit of pts that the specimens could be assayed even without a minimum amount of 55 ng dna extracted. But in this case, the final report should be marked clearly that the assay is no longer f1cdx. Fda safety report id# (b)(4).
Patient Sequence No: 1, Text Type: D, B5