AI Analysis · Q1 2026

Samsara BioCapital's Q1 2026 13F is a $1.03B, 22-position portfolio that is one of the most concentrated pure-biotech books in institutional data -- 19 of 22 positions (86.4%) are Healthcare or Unknown-sector biopharmaceutical names, and the portfolio has zero equity-sector diversification (no Technology, no Financials, no Consumer Cyclical, no Industrials). It is a classic biotech long/short or event-driven hedge-fund mandate focused on clinical-stage and small-cap biopharmaceutical companies. Total AUM rose from $969.3M in Q4 2025 to $1.03B in Q1 2026 (+$60.0M or +6.2%), the portfolio's first material AUM expansion in recent quarters, partially driven by mark-to-market appreciation in the anchor names and partially by中新 additions. Six anchors define the book: Scholar Rock HLDG ($339.1M, 32.9%, 6.90M shares, flat shares, +$35.2M or +11.6% mark-to-market from $303.8M) -- a secretome-and-growth-factor biotech focused on latent-TGF-β and myostatin inhibitors -- is the portfolio's anchor, 1/3 of AUM with flat shares signaling the manager's highest-conviction position; Mineralys Therapeutics ($159.0M, 15.5%, flat, -$54.0M or -25.3% mark-to-market from $213.1M); Alumis ($139.8M, 13.6%, +10.2% shares, +$83.6M mark-to-market appreciation from $56.2M despite the share increase, the portfolio's largest valued add); Septerna ($75.7M, 7.4%, flat, -$12.1M from $87.8M, -13.8%); Kalaris ($74.7M, 7.3%, flat); and Spyglass Pharma ($54.7M, 5.3%, NEW) -- the quarter's largest new opening. 25 total changes (4 new, 3 sold, 2 increased, 3 decreased, 13 unchanged) reflect a manager trimming Q4 winners and adding new asymmetric biotech opens. The four new opens: Spyglass Pharma ($54.7M) -- a clinical-stage biopharma focused on ophthalmology and retinal disease -- is the largest new position in Q1 and a major thematic add into ocular biotech; Aquestive Therapeutics ($10.4M) -- oral-film drug delivery -- re-opened after being SOLD in Q4 (a rapid round-trip suggesting the manager changed views within a single quarter); Agomab Therapeutics ($6.3M) -- a fibrosis-and-asthma biotech; and Coherus Oncology ($5.8M) -- biosimilar-and-oncology. Three sold: Aquestive Therapeutics (re-sold after the Q4 round-trip, same $16.2M position), Contineum Therapeutics ($0.83M, a de minimis loss), and Nuvation Bio (warrants, $41K). Two increases: Alumis ($84M-valued add on +10.2% shares, the portfolio's largest absolute value gain -- Alumis reported Phase 2 data in Q1 2026 for its autoimmune-disease candidate and the stock rallied sharply) and Sutro Biopharma (+419.7% shares, +$24.1M, from $2.4M to $26.5M -- an explosive conviction add into a clinical-stage ADC developer). Three decreased: Palvella (-63.3% shares, -$6.2M), Abivax (-25.0% shares, -$3.9M), and X4 Pharma (-6.5% shares, -$0.3M). The sector breakdown -- Unknown $674.4M (65.5%, primarily unclassified US micro-cap biotech with no GICS sector), Healthcare $354.8M (34.5%) -- reflects the pure-biotech identity. The 77.25 whaleScore on $1.03B reflects AUM. The portfolio's core identity is a concentrated long-biased biotech event fund with heavy exposure to clinical-stage names, latent-TGF-β inhibition (Scholar Rock), rare-disease metabolic disease (Mineralys), autoimmune oral therapies (Alumis), and GPCR-targeted dermatology (Septerna). The Q1 delta reflects a manager drawing down Q4 winners (Mineralys -$54.0M, Kalaris -35.1%-valued erosion), capturing mark-to-market gains in Alumis (+$83.6M) and Scholar Rock (+$35.2M), and using the gross proceeds to establish four new names with asymmetric clinical-event profiles (Spyglass, Agomab, Coherus, Aquestive). The +6.2% AUM growth is unusual for a biotech fund in a mixed quarter and may reflect new capital inflows or the Alumis rally lifting AUM materially.

The portfolio's defining structure: Scholar Rock HLDG ($339.1M, 32.9%, 6.90M shares, flat, +$35.2M or +11.6% from Q4's $303.8M) -- a clinical-stage biopharmaceutical company developing therapeutics based on its proprietary latent-TGF-β and myostatin inhibitor platform -- is the portfolio's largest position and its anchor. At 32.9% of AUM, Scholar Rock is the portfolio's defining conviction bet: the manager has accumulated 6.90M shares (nearly all float for a sub-$1B market-cap biotech) and held flat through Q1, signaling absolute conviction in Scholar Rock's latent-TGF-β-and-myostatin programs for muscular dystrophy, fibrosis, and oncology indications. Scholar Rock's stock rallied approximately +11.6% in Q1 2026 on positive clinical updates; the +$35.2M-valued appreciation is the portfolio's single largest mark-to-market gain. Mineralys Therapeutics ($159.0M, 15.5%, 5.87M shares, flat, -$54.0M or -25.3% from Q4's $213.1M) -- a clinical-stage biopharmaceutical company focused on rare and metabolic diseases -- is the portfolio's second-largest position and its most dramatically reduced name. The -25.3% mark-to-market erosion (from $213.1M to $159.0M) reflects a stock that declined significantly in Q1 -- possibly on clinical-trial disappointment or competitive news -- and the manager's decision to hold rather than sell suggests continued fundamental conviction despite the valuation hit.

Alumis ($139.8M, 13.6%, 6.35M shares, +10.2% shares, +$83.6M-market appreciation from $56.2M despite the share increase) -- an oral-small-molecule biopharmaceutical company developing treatments for autoimmune and inflammatory diseases -- is the portfolio's breakout story. The +$83.6M-valued appreciation on a modest +10.2% share increase means Alumis's stock rallied sharply in Q1 2026 -- likely on Phase 2 clinical-trial data or regulatory updates for its autoimmune lead candidate. The manager added 588K shares into strength, roughly doubling the position's value from ~$56.2M to ~$139.8M in a single quarter. Septerna ($75.7M, 7.4%, 3.15M shares, flat, -$12.1M from $87.8M, -13.8%) -- a clinical-stage GPCR-focused biopharmaceutical company developing treatments for dermatological and rare diseases -- is the portfolio's fourth-largest position and held steady despite the mark-to-market decline, reflecting conviction in the GPCR platform. Kalaris Therapeutics ($74.7M, 7.3%, 12.95M shares, flat) -- a clinical-stage biopharma -- held absolutely flat at 12.95M shares (a large share count relative to market cap, suggesting significant ownership percentage). Spyglass Pharma ($54.7M, 5.3%, 2.11M shares, NEW) -- the quarter's largest new position -- is a clinical-stage biopharmaceutical company focused on ophthalmology and retinal disease; the initial $54.7M position is among the largest first-time biotech opens in institutional data, signaling strong near-term clinical-event conviction (Phase 2/3 readouts expected within 12-18 months).

Quarter at a glance — Q1 2026

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