Catena Biosciences is a Berkeley-born ADC platform that puts multiple payloads on a single antibody, and StoryHouse funded a Pre-Series A to hold position ahead of a much larger Series A into a preclinical asset the FDA has already cleared to advance toward the clinic. The core wedge is Catena's enzymatic conjugation chemistry, developed in the Francis and Doudna labs at UC Berkeley, which allows attachment of payloads well beyond the small molecules used in today's antibody-drug conjugates. Its lead asset is a Trop2-targeting dual-payload ADC that, per the founder's data, showed roughly 4x the preclinical therapeutic index of leading approved ADCs and eliminated tumors at a fraction of the dose in non-human primate and patient-derived models.
The validation signals are strong for the stage: a green light from the FDA on the pre-IND package covering manufacturing, pre-clinical, and first-in-human strategy, de-risked multi-liter scaleup at over 98% purity, and a team that pairs inventor-CEO Marco Lobba (Pomona, UC Berkeley PhD) and Nobel laureate scientific co-founder Jennifer Doudna with senior operators (ex-Amgen CSO Rick Kendall, ex-Merck/AstraZeneca CBO Saurabh Johri) and heavyweight advisors Ron Johnson (ex-CEO Spark Therapeutics) and John Maraganore (founder of Alnylam). StoryHouse committed $800,000 out of a $1.5M Pre-Series A round on an uncapped SAFE (20% discount if the Series A closes above $35M before 2026-05-01, otherwise 25%), alongside Civilization Ventures ($200K) and LongeVC ($500K), out of StoryHouse Fund II, with the stated intent to invest again in the priced Series A rather than merely bridge.
ADCs are the dominant growth engine in oncology, generating roughly $13.5B in 2025 revenue across 15 approved products and forecast toward $30B+ by 2035 (Web). Catena's lead asset addresses the collective ~$10B ADC oncology opportunity across lung (NSCLC, >$6B), gastric and esophageal (>$2B), and triple-negative breast (TNBC, >$4B) cancers, with dual-payload chemistry sitting on the frontier that big pharma is now paying premiums to acquire (Internal, 2025-10-29 note; Web).
| Player | Positioning | Funding / Stage | Edge vs. them |
|---|---|---|---|
| Catena Biosciences | Enzymatic conjugation platform; Trop2 dual-payload lead ADC | Preclinical / pre-IND; raising $30-60M Series A | — |
| Gilead (Trodelvy) | Approved single-payload Trop2 ADC (sacituzumab govitecan) | Marketed | Catena's lead eliminated tumors at ~1/4 the dose in preclinical models (Internal) |
| AstraZeneca / Daiichi Sankyo | Datopotamab (Dato-DXd), late-stage Trop2 ADC | Marketed / late-stage | Claimed ~4x preclinical therapeutic index vs leading ADCs (Internal) |
| Kelun-Biotech (KH815) | Most advanced Trop2 dual-payload ADC (Topo I + RNA Pol II) | Clinical-stage (China) | Clinically ahead; Catena claims superior head-to-head preclinical data (Web + Internal) |
| Sutro, Araris, Adcoris, CrossBridge | Early-stage dual-payload / next-gen conjugation platforms | Preclinical / early clinical | Catena's Berkeley (Francis/Doudna) IP and >98% purity scaleup (Web + Internal) |
Moat: A patented enzymatic conjugation platform out of the Francis and Doudna labs that attaches payloads beyond conventional small molecules, delivering a claimed 4x preclinical therapeutic index and de-risked >98%-purity manufacturing, and extensible from ADCs to enzyme replacement, gene delivery, and cell therapy.
The base case is a strategic acquisition of the platform and/or lead asset by a large-cap oncology player. The ADC deal market is unusually hot: Pfizer's $43B Seagen acquisition reset the benchmark, Gilead is acquiring Tubulis in a deal worth up to $5B ($3.15B upfront), and average ADC deal size climbed to roughly $1.5B by mid-2025 (Web). Named strategics already circling Catena include Amgen (follow-on interest), Samsung, Takeda, Daiichi, Pfizer, and Genentech (Internal, 2025-10-29); the founder cited Taiho's ~$400M-upfront acquisition of Aurora as a recent preclinical-ADC comp. Against a projected $30-60M Series A entry, even a mid-pack ADC exit implies a return well into the double digits (Internal + Web).
A short deal note logging an attached PDF with Catena's fundraising status across the various funds it is speaking with.
See attached PDF for fundraising status with the various funds.
Email from Marco confirming the board aligned on the terms discussed on the prior Monday's call, with counsel drafting a SAFE note reflecting the agreed discount structure.
Email update from Marco re: SAFE note.
Dear All, I hope you are enjoying time with your families. I am thrilled to report that the board is aligned with the terms proposed in our call from Monday. With that in mind, our corporate counsel has drafted up the attached SAFE note which modifies the standard discount clause to reflect a 20% discount if round close occurs prior to May 1st 2026 (total round size >$35M) and 25% discount if either round close is after that date, or the total amount is <$35M.
Otherwise the SAFE note remains vanilla. Please review to ensure the attached reflects the agreed terms. I need to get a signed board authorization before we can proceed with signing. I will launch that in parallel and let you know ASAP once that is complete. Have a wonderful holiday! Marco
A working call on the Pre-Series A and its structure. Catena wanted $1-1.5M to extend runway past an April cash-out; StoryHouse pushed for a cap while the board and lead co-investors favored an uncapped discount.
Summary: Marco knows they need the money and wants to make it happen. The board does not want a cap because it will set potential valuation expectations for the A investors. Currently Marco and the board do not really have leverage. StoryHouse made clear it would want a cap. He is sharing comp data. StoryHouse should wait a bit to let pressure build, potentially give an official offer at a $26M-$30M cap. No other investor is at the table right now, so no point agreeing to the discount as a cap is much better for StoryHouse.
Bridge round: Catena wants a $1-1.5M bridge to extend runway from the current April cash-out date. $1M provides three additional months (through July); $1.5M extends to September (preferred). Current burn is ~$300K/month. StoryHouse considering $800K-$1M (majority of round).
Valuation structure debate: StoryHouse proposed a $26M post-money cap (based on $25M post from the last round); board preference is a 20% discount, no cap. Shahram (Civilization Ventures) strongly favors the discount, as does Chin Maya (Social Impact Capital). Concern is that setting any valuation could create a floor for Series A negotiations. Marco's modeling shows a ~3x ownership difference in best-case scenarios (50 pre scenario: 1.35% vs 4.05% ownership delta).
Series A context: target $30-60M Series A; comparable valuations $30-45M pre-money for preclinical ADC companies (referenced Arda Therapeutics at $23M pre, Firefly Bio at $25M pre; Two Step Therapeutics raising ~$50-60M at $35-40M pre). Ron Johnson and John Maraganore advising on the Series A process; StoryHouse will invest in the Series A, not the bridge, to maintain negotiating credibility.
New advisory team: Ron Johnson (former CEO Orbital, sold to BMS for $1.5B; ex-CEO Spark Therapeutics) signed as advisor, converting to Executive Board Chair post-Series A. John Maraganore (founder of Alnylam ~20 years, partner at Arch Ventures) also advisor until Series A close; both uncompensated until then. An Arch Ventures meeting was arranged through Maraganore; a call with Christina Burrow happened, CDA in progress.
Conference insights: Marco presented at the Antibody Engineering & Therapeutics conference in San Diego; strong industry validation for dual-payload ADCs, with major pharma attendance (Daiichi, Takeda, Pfizer, Genentech). Next steps: Marco to send PitchBook comparable data; StoryHouse to discuss internally and possibly with Matt; possible call with Shahram to align on terms; no immediate timeline pressure identified.