NEXTBio Capital Management LP — 13F Holdings & Portfolio

CIK 2038158 · latest 13F-HR filed 2026-08-14

NEXTBio Capital Management LP manages $217.4M in 13F-reported U.S. long-equity assets across 22 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are PTGX (12.37%), STTK (11.90%), CMPS (11.56%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 3 new positions and exited 5; 11 existing positions rose in reported value and 4 fell.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

Loading holdings…
AUM
$217.4M

Long-equity book

Holdings
22

Distinct positions

Period
2026-06-30

Filed 2026-08-14

Q/Q Activity
+3 / −5 / ↑11 / ↓4

vs 2026-03-31

Portfolio charts

Latest quarter's book, what changed, and how the portfolio has evolved across filings.

Portfolio map

Q2 26

Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.

Sector mix

% of 13F value

Sectors from each company's SIC code; funds and ETFs grouped separately.

Biggest buys and sells

Q1 26 → Q2 26

Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.

13F assets and positions

3 quarters

Total reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.

Top positions over time

reported value

The eight largest current positions, valued at each quarter end.

Concentration

top 10 = 77.7%

Cumulative share of the portfolio held in the largest N positions.

Firm Profile & Key People
Address
500 W 2ND STREET
SUITE 1900
AUSTIN, TX 78701
Phone
(650) 501-0882
Name Title / Status Ownership Type
KLEMM, RICHARD, DAVID ControlMANAGING PARTNER; CO-FOUNDER25–50%Individual
LU, HONGBO, (NMN) ControlMANAGING PARTNER; CO-FOUNDER50–75%Individual
Phan, Ky ControlCHIEF FINANCIAL OFFICERLess than 5%Individual

Quarter-over-quarter changes

Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.

NEXTBio Capital Management LP Holdings (2026-06-30)

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 PROTAGONIST THERAPEUTICS INC PTGX 74366E102 $26.9M 12.37% 219,333 SH
2 SHATTUCK LABS INC STTK 82024L103 $25.9M 11.90% 3,727,348 SH
3 COMPASS PATHWAYS PLC CMPS 20451W101 $25.1M 11.56% 1,775,759 SH
4 STRUCTURE THERAPEUTICS INC GPCR 86366E106 $16.8M 7.71% 312,496 SH
5 VOR BIOPHARMA INC VOR 929033207 $16.4M 7.53% 889,164 SH
6 RHYTHM PHARMACEUTICALS INC RYTM 76243J105 $14.6M 6.73% 131,758 SH
7 PALVELLA THERAPEUTICS INC NE PVLA 697947109 $13.7M 6.32% 89,909 SH
8 XENON PHARMACEUTICALS INC XENE 98420N105 $11.1M 5.09% 183,225 SH
9 ZENAS BIOPHARMA INC ZBIO 98937L105 $10.8M 4.98% 426,736 SH
10 ORIC PHARMACEUTICALS INC ORIC 68622P109 $7.6M 3.52% 706,124 SH
11 INVENTIVA SA IVA 46124U107 $6.8M 3.11% 1,787,984 SH
12 CRESCENT BIOPHARMA INC. CBIO G2545C104 $6.7M 3.09% 372,856 SH
13 VAXCYTE INC PCVX 92243G108 $6.2M 2.87% 107,223 SH
14 COGENT BIOSCIENCES INC COGT 19240Q201 $5.1M 2.33% 131,075 SH
15 VERASTEM INC VSTM 92337C203 $5.0M 2.30% 1,306,800 SH
16 DISC MEDICINE INC IRON 254604101 $3.9M 1.77% 52,655 SH
17 PHARVARIS N V PHVS N69605108 $3.7M 1.72% 108,055 SH
18 ZAI LAB LTD ZLAB 98887Q104 $3.5M 1.60% 183,362 SH
19 BIOAGE LABS INC BIOA 09077V100 $2.5M 1.14% 100,732 SH
20 LB PHARMACEUTICALS INC LBRX 50180M108 $2.2M 1.02% 68,249 SH
21 EVOMMUNE INC EVMN 30054Y107 $1.6M 0.73% 119,063 SH
22 ADICET BIO INC ACET 007002207 $1.4M 0.63% 157,827 SH
Filing History
Period Filed AUM Holdings Accession
2026-06-30 2026-08-14 $217.4M 22 0001172661-26-003533
2026-03-31 2026-05-14 $215.4M 24 0001172661-26-001957
2025-12-31 2026-02-13 $170.5M 23 0001172661-26-000761
Filer Information
Address
500 W 2ND STREET
SUITE 1900
AUSTIN, TX 78701
Phone
(650) 501-0882
Filing Manager
NEXTBio Capital Management LP
AUSTIN, TX
Signatory
KY PHAN
CHIEF FINANCIAL OFFICER