Large-Scale Oligonucleotide Manufacturing

Development of Kilogram-Scale Convergent Liquid-Phase Synthesis of Oligonucleotides

“…We utilized the same standard chromatography and purity analyses for LPOS; therefore, discussion of the process development was focused on the common intermediate 10. Fragments 3−6 have free 3′-OHs that when converted into phosphoramidites 3a−6a couple with the 5′-OHs of fragment 2, 5-mer (7), 10-mer (8), and 14-mer (9) (Scheme 1c). Fragment 2 has a 3′ solubility determining group (SDG), which is a 3′-OH protecting group that imparts a defined solubility profile that can be manipulated to purify fragments via precipitation.…”

“…Oligonucleotide therapeutics alter cell protein expression by regulating mRNAs through degradation and splice modulating mechanisms and have proven effective in the treatment of rare diseases. − Recent clinical programs show promise of oligonucleotides in the treatment of more common diseases that afflict global patient populations in the millions, as indicated by approval of Leqvio, a cholesterol lowering drug, in Europe. , Currently, oligonucleotides are manufactured by a linear chain elongation on a solid support carried out in a specialized column by a process known as solid-phase oligonucleotide synthesis (SPOS). , The technology has been well developed to meet the demands of rare diseases. However, manufacturing a metric ton of an oligonucleotide drug annually would require ∼200 syntheses at the typical ∼1 mol scale (∼5 kg purified product), and while not impossible, the approach would be difficult to sustain long-term. , Scaling up SPOS would require the development of larger scale synthesizers and synthesis columns, as well as investments in specialized dedicated facilities.…”

“…However, manufacturing a metric ton of an oligonucleotide drug annually would require ∼200 syntheses at the typical ∼1 mol scale (∼5 kg purified product), and while not impossible, the approach would be difficult to sustain long-term. 8,9 Scaling up SPOS would require the development of larger scale synthesizers and synthesis columns, as well as investments in specialized dedicated facilities.…”

Scalable convergent synthesis of therapeutic oligonucleotides

“…A single strand of an ASO or siRNA typically contains 18 to 25 nucleotides and requires up to 100 separate chemical reactions to synthesize, as installation of each nucleotide proceeds via a four-reaction cycle. 7,23,24 To scale up the synthesis of therapeutic oligonucleotides, impurities must be controlled to very low levels in each isolated intermediate to avoid accumulation of impurities that cannot be separated from the full-length product (FLP) during purification. The majority of existing LPOS strategies require extensive purification of intermediates by precipitation, 25 extractions, 26 or chromatography.…”

“…In current clinical research, new oligonucleotides are showing great promise to treat diseases afflicting millions of people, including cardiovascular disease, and yearly demand for each drug could reach over a metric ton. 2 The current SPOS process at ~ 5 kg scale 7 would require ~200 batches to deliver 1000 kg. While it is conceivable that economies of scale may be realized in massive, specialized facilities, this approach has significant engineering and cost challenges 8 as well as a negative environmental impact.…”