Octagon Capital Advisors LP In its 13F for Q1 2025 (holdings as of March 31, 2025, filed May 16, 2025), Octagon Capital Advisors LP reported 33 stock positions worth $460.1 million . Its top holding was Apellis Pharmaceuticals (APLS) at 10.0% of the portfolio, followed by Dianthus Therapeutics (DNTH, 9.2% ) and Arrivent Biopharma (AVBP, 8.3% ). Compared with Q4 2024, it opened 8 new positions, sold out of 5, added to 3 and reduced 9. The biggest buy was a new position in Trevi Therapeutics (TRVI) and the biggest sale Apellis Pharmaceuticals (APLS, shares −30% ).
Location NEW YORK, NY
CIK 0001839435
Portfolio Value $460.1M (Q1 2025) Holdings 33 stocks · $460.1M Holdings quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock % Of Portfolio ▼ Shares Held Total Value Change vs Q4 2024 APLS Apellis Pharmaceuticals Inc. 2,094,000 $45.8M Reduce -30.4% DNTH Dianthus Therapeutics Inc. 2,341,667 $42.5M Add +11.0% AVBP Arrivent Biopharma Inc. 2,059,387 $38.1M No change TRVI Trevi Therapeutics Inc. 3,322,000 $20.9M New CNTA Centessa Pharmaceuticals Ltd. 1,425,000 $20.5M Reduce -28.5% GOSS Gossamer Bio Inc. 18,350,000 $20.2M No change OCUL Ocular Therapeutix Inc. 2,425,000 $17.8M No change MIND MEDICINE MINDMED INC 3,018,000 $17.7M No change COGT Cogent Biosciences Inc. 2,763,000 $16.6M No change KALV Kalvista Pharmaceuticals Inc. 1,370,000 $15.8M No change TSHA Taysha Gene Therapies Inc. 10,700,000 $14.9M Add +2.4% NUVB Nuvation Bio Inc. 7,900,000 $13.9M Reduce -14.2% VRNA Verona Pharma Ltd. 217,264 $13.8M Reduce -62.0% TRML Tourmaline Bio Inc. 905,000 $13.8M New MRUS Merus NV 308,000 $13.0M No change PHVS Pharvaris NV 769,815 $12.1M Reduce -1.1% MLTX Moonlake Immunotherapeutics 296,000 $11.6M New SNDX Syndax Pharmaceuticals Inc. 904,000 $11.1M No change ATYR Atyr Pharma Inc. 3,552,000 $10.7M Add +294.7% SRRK Scholar Rock Holding Corp. 329,000 $10.6M Reduce -32.6% VSTM Verastem Inc. 1,720,000 $10.4M New RGLS Regulus Therapeutics Inc. 4,637,076 $8.1M Reduce -4.4% SPRY Ars Pharmaceuticals Inc. 625,000 $7.9M New ABVX Abivax SA-ADR 1,230,000 $7.7M New ERAS Erasca Inc. 5,136,795 $7.0M No change VRDN Viridian Therapeutics Inc. 450,000 $6.1M Reduce -48.3% CRBP Corbus Pharmaceuticals Holdi 1,115,000 $5.9M No change UNICYCIVE THERAPEUTICS INC 10,000,000 $5.7M No change MAZE Maze Therapeutics Inc. 468,000 $5.2M New CATX Perspective Therapeutics Inc. 2,250,000 $4.8M Reduce -2.4% KLRS Kalaris Therapeutics Inc. 481,000 $3.9M New NGNE Neurogene Inc. 303,000 $3.5M No change BBOT Bridgebio Oncology Therapeut filed as HELIX ACQUISITION CORP II 250,000 $2.8M No change
Options reported separately and not counted above: CNTA puts ($8.6M).
Other holdings (1): bonds, preferreds, convertibles and warrants · $48.1M (not counted above) Security Class Shares / Principal Value Change NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 27,330,800 $48.1M Add +8650.5%
Total filed on the 13F, all lines: $508.2M.
Portfolio Sells Q4 2024 → Q1 2025 Portfolio Sells quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock Change vs Q4 2024 % Of Portfolio Change To Portfolio ▲ APLS Apellis Pharmaceuticals Inc. Reduce -30.4% 9.95% −6.39 INSM Insmed Inc. Sold out 0.00% −3.90 DYN Dyne Therapeutics Inc. Sold out 0.00% −2.68 BBIO Bridgebio Pharma Inc. Sold out 0.00% −2.06 VRDN Viridian Therapeutics Inc. Reduce -48.3% 1.32% −1.52 VRNA Verona Pharma Ltd. Reduce -62.0% 3.00% −1.52 SRRK Scholar Rock Holding Corp. Reduce -32.6% 2.30% −1.29 CNTA Centessa Pharmaceuticals Ltd. Reduce -28.5% 4.45% −1.23 NUVB Nuvation Bio Inc. Reduce -14.2% 3.02% −1.15 ALLOVIR INC Sold out 0.00% −0.80 MERSANA THERAPEUTICS INC Sold out 0.00% −0.24 CATX Perspective Therapeutics Inc. Reduce -2.4% 1.04% −0.21 PHVS Pharvaris NV Reduce -1.1% 2.63% +0.09 RGLS Regulus Therapeutics Inc. Reduce -4.4% 1.76% +0.46
Portfolio Buys Q4 2024 → Q1 2025 Portfolio Buys quarter Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024 Q3 2024 Q2 2024 Q1 2024
Stock Change vs Q4 2024 % Of Portfolio Change To Portfolio ▼ TRVI Trevi Therapeutics Inc. New 4.54% +4.54 TRML Tourmaline Bio Inc. New 2.99% +2.99 MLTX Moonlake Immunotherapeutics New 2.51% +2.51 VSTM Verastem Inc. New 2.25% +2.25 ATYR Atyr Pharma Inc. Add +294.7% 2.33% +1.78 SPRY Ars Pharmaceuticals Inc. New 1.71% +1.71 ABVX Abivax SA-ADR New 1.67% +1.67 DNTH Dianthus Therapeutics Inc. Add +11.0% 9.23% +1.40 MAZE Maze Therapeutics Inc. New 1.12% +1.12 KLRS Kalaris Therapeutics Inc. New 0.84% +0.84 TSHA Taysha Gene Therapies Inc. Add +2.4% 3.23% +0.15
Options Activity Q4 2024 → Q1 2025 Security Type Change vs Q4 2024 Underlying Shares Value ▼ INSM Insmed Inc. call Sold out 250,000 $17.3Mbefore exit CNTA Centessa Pharmaceuticals Ltd. put Add +294.7% 600,000 $8.6M
Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.
Notes & Other Activity Q4 2024 → Q1 2025 Security Class Change vs Q4 2024 Shares / Principal Value ▼ NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 Add +8650.5% 27,330,800 $48.1M
Bonds, preferreds, convertibles and warrants; not part of the stock holdings or percentages above.
All Filings Quarter Positions 13F Reported Value Top Holdings Q2 2026 26 $1.1B DNTH, DFTX, ABVX, COGT, ALMS Q1 2026 29 $903.6M DNTH, COGT, ABVX, ALMS, DFTX Q4 2025 26 $798.8M ABVX, DNTH, COGT, TSHA, GOSS Q3 2025 25 $640.2M ABVX, DNTH, GOSS, COGT, AVBP Q2 2025 29 $455.3M DNTH, AVBP, VRNA, TSHA, SPRY Q1 2025 Amended 33 $460.1M APLS, DNTH, AVBP, TRVI, CNTA Q4 2024 30 $587.1M APLS, AVBP, DNTH, CNTA, VRNA Q3 2024 40 $623.9M APLS, VRNA, GPCR, DNTH, AVBP Q2 2024 44 $606.1M APLS, DNTH, GPCR, INSM, DYN Q1 2024 56 $822.6M APLS, ALPN, DNTH, VRNA, DYN