Flag­ship Pio­neer­ing Launch­es Serif Bio­med­i­cines to Estab­lish Mod­i­fied DNA as a New Biotechnology

Fol­low­ing Flagship’s orig­i­na­tion of gen­er­a­tive pro­tein and mRNA plat­forms, Serif is pio­neer­ing Mod­i­fied DNA med­i­cines to pro­gram the foun­da­tion­al infor­ma­tion lay­er of biology

Serif to present data at an upcom­ing sci­en­tif­ic meet­ing demon­strat­ing tol­er­a­bil­i­ty in non-human pri­mates and sus­tained gene expres­sion with ther­a­peu­tic effects in pre­clin­i­cal mod­els after intra­venous (IV) administration

Com­pa­ny emerges fol­low­ing five years of plat­form devel­op­ment and with an ini­tial com­mit­ment of $50 mil­lion from Flag­ship Pioneering

CAM­BRIDGE, Mass., April 21, 2026 — Flag­ship Pio­neer­ing, a sci­en­tif­ic inno­va­tion engine for trans­for­ma­tive plat­forms and prod­ucts, today announced the launch of Serif Bio­med­i­cines, a biotech­nol­o­gy com­pa­ny pio­neer­ing Mod­i­fied DNA as a new class of med­i­cines. Mod­i­fied DNA brings togeth­er the best fea­tures of mRNA and gene ther­a­py, while mit­i­gat­ing their lim­i­ta­tions, by enabling med­i­cines that are pro­gram­ma­ble, scal­able, durable, and redos­able. Flag­ship has ini­tial­ly com­mit­ted $50 mil­lion to devel­op the company’s plat­form and advance its first drug dis­cov­ery programs.

Over the past sev­er­al decades, endur­ing biotech­nol­o­gy com­pa­nies have trans­formed stages of the cen­tral dog­ma of biol­o­gy into pow­er­ful ther­a­peu­tic plat­forms. Yet despite its cen­tral role as the code of life, DNA has not been trans­lat­ed into a ther­a­peu­tic modal­i­ty out­side of gene ther­a­py because of its immuno­genic­i­ty and inef­fi­cient access to the cell’s nucle­us. Address­ing these fun­da­men­tal bar­ri­ers, Serif has reshaped the struc­tur­al and chem­i­cal form of DNA, sim­i­lar to how typo­graph­ic ser­ifs sub­tly refine how writ­ten lan­guage is expressed. These refine­ments enable Serif’s Mod­i­fied DNA to, with­out alter­ing the cell’s genome, express genes safe­ly, durably, and pro­gram­ma­bly inside cells.

“When a foun­da­tion­al lay­er of biol­o­gy becomes engi­neer­able, new ther­a­peu­tic cat­e­gories are born that can rede­fine the pos­si­bil­i­ties for med­i­cine,” said Noubar Afeyan, Ph.D., Founder and CEO of Flag­ship Pio­neer­ing and Co-Founder of Serif Bio­med­i­cines. ​“Serif builds upon our expe­ri­ence in pri­or cat­e­go­ry-orig­i­nat­ing Flag­ship com­pa­nies to estab­lish Mod­i­fied DNA as a prac­ti­cal and broad­ly applic­a­ble ther­a­peu­tic platform.”

Serif is build­ing the com­plete tech­nol­o­gy stack to unlock non-viral DNA ther­a­peu­tics in a cap­i­tal-effi­cient man­ner, com­bin­ing Mod­i­fied DNA that min­i­mizes innate immuno­genic­i­ty, co-deliv­ered mRNA Co-fac­tors that enhance nuclear entry and gene expres­sion, opti­mized lipid nanopar­ti­cles for redos­ing and tar­get­ed tis­sue deliv­ery, AI-guid­ed DNA sequence design for cell-spe­cif­ic pro­gram­ma­ble gene expres­sion, and scal­able man­u­fac­tur­ing for acces­si­ble ther­a­peu­tics. Unlike RNA ther­a­pies that are lim­it­ed to tran­sient gene expres­sion, gene ther­a­pies that can­not be redosed, and genome engi­neer­ing strate­gies that rely on DNA inte­gra­tion, Mod­i­fied DNA enables a durable, redos­able, and poten­tial­ly safer ther­a­peu­tic pro­file that sup­ports broad med­ical appli­ca­tions with sig­nif­i­cant mar­ket oppor­tu­ni­ties. Serif’s ini­tial drug dis­cov­ery pro­grams focus on rare dis­eases and immune pro­gram­ming where Mod­i­fied DNA’s ther­a­peu­tic prop­er­ties offer clear advan­tages for ful­fill­ing mean­ing­ful unmet clin­i­cal needs. 

“More than 75 years after DNA was rec­og­nized as the key infor­ma­tion mol­e­cule in biol­o­gy, turn­ing DNA into a reli­able med­i­cine remains one of our industry’s biggest oppor­tu­ni­ties,” said Jacob Rubens, Ph.D., Co-Founder and Chief Exec­u­tive Offi­cer of Serif Bio­med­i­cines and Orig­i­na­tion Part­ner at Flag­ship Pio­neer­ing. ​“With Mod­i­fied DNA, we are intro­duc­ing a new ther­a­peu­tic modal­i­ty that can become an endur­ing biotech­nol­o­gy in the emerg­ing era of pro­gram­ma­ble medicines.”

Serif will present pre­clin­i­cal data sup­port­ing its Mod­i­fied DNA plat­form at an upcom­ing sci­en­tif­ic meet­ing. The data show that, fol­low­ing sys­temic IV admin­is­tra­tion, Serif’s Mod­i­fied DNA demon­strates tol­er­a­bil­i­ty in non-human pri­mate stud­ies and durable gene expres­sion result­ing in func­tion­al and ther­a­peu­tic effects in vivo. Serif’s Mod­i­fied DNA plat­form is pro­tect­ed by more than 20 patent fam­i­lies, includ­ing issued U.S. patents.

In addi­tion to Afeyan and Rubens, Serif was co-found­ed by Geof­frey von Maltzahn, Ph.D., Gen­er­al Part­ner at Flag­ship Pio­neer­ing and Board Chair of Serif; Eric Keen, Ph.D., Prin­ci­pal at Flag­ship Pio­neer­ing; and Louisa Helms, Ph.D., Prin­ci­pal at Flag­ship Pio­neer­ing. The company’s lead­er­ship team includes Pete Smith, Ph.D., Chief Sci­en­tif­ic Offi­cer, and Andy Oh, Chief Finan­cial Offi­cer. Serif’s Board of Direc­tors also includes Andrew Allen, M.D., Ph.D., for­mer Pres­i­dent and CEO of Grit­stone bio; Avak Kahve­jian, Ph.D., Pres­i­dent, Flag­ship Labs and Gen­er­al Part­ner, Flag­ship Pio­neer­ing; and Michael Holmes, Ph.D., Chief Sci­en­tif­ic Offi­cer at Tessera Therapeutics.

Strate­gic advi­sors to the com­pa­ny include John Maraganore, Ph.D., for­mer Chief Exec­u­tive Offi­cer of Alny­lam Phar­ma­ceu­ti­cals; Mike Nal­ly, Chief Exec­u­tive Offi­cer of Gen­er­ate: Bio­med­i­cines and CEO-Part­ner at Flag­ship Pio­neer­ing; and Rupert Vessey, Ph.D., Chief Sci­en­tist at Flag­ship Pio­neer­ing and for­mer Pres­i­dent of Research and Ear­ly Devel­op­ment at Bris­tol Myers Squibb.

About Serif Biomedicines

Serif Bio­med­i­cines is pio­neer­ing Mod­i­fied DNA as a new class of biotech­nol­o­gy. Found­ed in 2021 with­in Flag­ship Labs, the inno­va­tion foundry of Flag­ship Pio­neer­ing, Serif inte­grates nucle­ic acid chem­istry, syn­thet­ic biol­o­gy, deliv­ery sci­ence, and arti­fi­cial intel­li­gence to enable pro­gram­ma­ble, scal­able, durable, and redos­able DNA med­i­cines. The company’s ini­tial focus is on genet­i­cal­ly defined dis­eases and repro­gram­ming the immune sys­tem. For more infor­ma­tion, vis­it www​.ser​if​bio​med​i​cines​.com. 

About Flag­ship Pioneering

Flag­ship Pio­neer­ing invents and builds plat­form com­pa­nies, each with the poten­tial for mul­ti­ple prod­ucts that trans­form human health, sus­tain­abil­i­ty and beyond. Since its launch in 2000, Flag­ship has orig­i­nat­ed and fos­tered more than 100 sci­en­tif­ic ven­tures, oper­at­ing with $14 bil­lion of assets under its direc­tion as of its lat­est cap­i­tal raise, announced in July 2024. The cur­rent Flag­ship ecosys­tem com­pris­es more than 40 com­pa­nies, includ­ing Foghorn Ther­a­peu­tics, Gen­er­ate Bio­med­i­cines, Inari, Indi­go Agri­cul­ture, Lila Sci­ences, Mod­er­na, Sana Biotech­nol­o­gy, Tessera Ther­a­peu­tics and Valo Health. For more infor­ma­tion, vis­it www​.flag​ship​pi​oneer​ing​.com. 

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