Our Take
This is a capital event, not a product one—a well-connected founder raising money for an established drug class, not a technical breakthrough in RNAi itself.
Why it matters
RNAi remains an underfunded modality despite Alnylam's success, so capital flowing to specialists matters for the space. Maraganore's move signals confidence that there are still white-space indications beyond Alnylam's focus.
Do this week
RNAi program leads: track City's clinical trial timeline (NCT numbers, dosing data) before your next target selection, since positive human data will reshape the competitive landscape for future candidates.
City Therapeutics lands $100M in Series B
City Therapeutics, co-founded by John Maraganore (the longtime CEO of Alnylam Pharmaceuticals), has raised nearly $100 million in Series B funding (company-reported). The biotech is developing RNA interference (RNAi) drugs, a gene-silencing approach that sees limited clinical deployment outside Alnylam's portfolio.
The company has advanced a clotting disorder therapeutic into early human testing. A second candidate targeting Stargardt disease, a rare inherited retinal degeneration, is expected to enter trials soon.
RNAi remains sparsely capitalized
RNAi as a modality has struggled to attract sustained venture interest despite Alnylam's commercial validation. Alnylam went public in 2012 and now generates revenue from marketed drugs like patisiran and inclisiran, yet the space has remained thin on dedicated competitors. City's capital raise signals that founders and backers still see untapped opportunities in the RNAi toolbox.
Maraganore's involvement carries weight: he spent two decades building Alnylam's clinical and regulatory expertise before stepping down as CEO in 2021. His presence on a new RNAi venture suggests conviction that validated disease indications remain open, particularly in rarer genetic disorders where RNAi's specificity is an advantage.
Clinical data will reset the field
If City's clotting disorder drug produces clean, durable efficacy in Phase 2, it becomes the proof point for which other RNAi candidates will be benchmarked. Watch for trial readouts on tolerability and dosing schedule, not just efficacy. RNAi's clinical advantage is narrow—it wins on specificity and duration, not on speed. Any stumble on safety or convenience erodes the entire premise.
For biotech teams evaluating RNAi for your own candidates, City's trials are a forcing function: you have a window to design your program before clinical precedent narrows the acceptable risk profile. Once one drug succeeds, regulatory expectations harden.