SELLAS Life Sciences Group, Inc.
US ˙ NasdaqCM ˙ US81642T2096

SecuritySLS / SELLAS Life Sciences Group, Inc.
InstitutionNorthern Trust Corp
Latest Disclosed Ownership1,275,984 shares
Latest Disclosed Value $ 5,397,412
Northern Trust Corp reports 37.09% increase in ownership of SLS / SELLAS Life Sciences Group, Inc.

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 1,275,984 shares of SELLAS Life Sciences Group, Inc. (US:SLS) valued at $5,397,412 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 930,750 shares of SELLAS Life Sciences Group, Inc.. This represents a change in shares of 37.09% during the quarter. The current value of the position is $11,534,895 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-14 2026-03-31 13F SELLAS LIFE SCIENCES GROUP I COM NEW 81642T209 1,275,984 345,234 37.09 5,397 53.85 0.0007
2026-02-17 2025-12-31 13F SELLAS LIFE SCIENCES GROUP I COM NEW 81642T209 930,750 199,575 27.30 3,509 198.05 0.0004
2025-11-14 2025-09-30 13F SELLAS LIFE SCIENCES GROUP I COM NEW 81642T209 731,175 32,682 4.68 1,177 -23.02 0.0002
2025-08-13 2025-06-30 13F SELLAS LIFE SCIENCES GROUP I COM NEW 81642T209 698,493 534,103 324.90 1,530 763.84 0.0002
2025-05-13 2025-03-31 13F SELLAS LIFE SCIENCES GROUP I COM NEW 81642T209 164,390 29,669 22.02 178 26.43 0.0000
2025-02-14 2024-12-31 13F SELLAS LIFE SCIENCES GROUP I COM NEW 81642T209 134,721 33,878 33.59 140 11.11 0.0000
2024-11-13 2024-09-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 100,843 0 0.00 126 5.00 0.0000
2024-08-14 2024-06-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 100,843 12,113 13.65 120 34.83 0.0000
2024-05-14 2024-03-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 88,730 26,293 42.11 90 34.85 0.0000
2024-02-13 2023-12-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 62,437 23,077 58.63 66 3.13 0.0000
2023-11-13 2023-09-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 39,360 0 0.00 65 4.92 0.0000
2023-08-11 2023-06-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 39,360 9,342 31.12 62 45.24 0.0000
2023-05-15 2023-03-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 30,018 -7,653 -20.32 43 -52.27 0.0000
2023-02-13 2022-12-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 37,671 0 0.00 89 15.79 0.0000
2022-11-14 2022-09-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 37,671 13,066 53.10 76 38.18 0.0000
2022-08-12 2022-06-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 24,605 -215 -0.87 55 -66.67 0.0000
2022-05-13 2022-03-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 24,820 215 0.87 165 21.32 0.0000
2022-02-08 2021-12-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 24,605 0 0.00 136 -39.56 0.0000
2021-11-15 2021-09-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 24,605 0 0.00 225 -17.58 0.0000
2021-08-13 2021-06-30 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 24,605 6,495 35.86 273 76.13 0.0000
2021-05-12 2021-03-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 18,110 1,878 11.57 155 64.89 0.0000
2021-02-11 2020-12-31 13F SELLAS LIFE SCIENCES GROUP I COM 81642T209 16,232 16,232 -10.37 94 -39.35 0.0000
2018-05-09 2018-03-31 13F GALENA BIOPHARMA COM 363256504 0 -39,865 -100.00 0 -100.00
2018-02-14 2017-12-31 13F GALENA BIOPHARMA COM 363256504 39,865 -43 -0.11 10 -28.57 0.0000
2017-11-13 2017-09-30 13F GALENA BIOPHARMA COM 363256504 39,908 0 0.00 14 -39.13 0.0000
2017-08-11 2017-06-30 13F GALENA BIOPHARMA COM 363256504 39,908 -88,862 -69.01 23 -70.89 0.0000
2017-05-12 2017-03-31 13F GALENA BIOPHARMA COM 363256504 128,770 25,008 24.10 79 -60.89 0.0000
2017-02-13 2016-12-31 13F GALENA BIOPHARMA COM 363256504 103,762 -1,937,871 -94.92 202 -71.75 0.0001
2016-11-09 2016-09-30 13F GALENA BIOPHARMA COM 363256108 2,041,633 131,185 6.87 715 -19.75 0.0002
2016-08-12 2016-06-30 13F GALENA BIOPHARMA COM 363256108 1,910,448 165,076 9.46 891 -62.47 0.0003
2016-08-19 2016-03-31 13F/A-1 GALENA BIOPHARMA COM 363256108 1,745,372 57,675 3.42 2,374 -4.31 0.0008
2016-05-13 2016-03-31 13F GALENA BIOPHARMA COM 363256108 1,745,372 2,374
2016-02-12 2015-12-31 13F GALENA BIOPHARMA COM 363256108 1,687,697 32,238 1.95 2,481 -5.12 0.0008
2015-11-12 2015-09-30 13F GALENA BIOPHARMA COM 363256108 1,655,459 27,676 1.70 2,615 -5.49 0.0009
2015-08-13 2015-06-30 13F GALENA BIOPHARMA COM 363256108 1,627,783 354,076 27.80 2,767 56.33 0.0019
2015-05-14 2015-03-31 13F GALENA BIOPHARMA COM 363256108 1,273,707 9,381 0.74 1,770 -7.28 0.0005
2015-02-12 2014-12-31 13F GALENA BIOPHARMA COM 363256108 1,264,326 -33,247 -2.56 1,909 -28.58 0.0006
2014-11-13 2014-09-30 13F GALENA BIOPHARMA COM 363256108 1,297,573 -6,591 -0.51 2,673 -33.01 0.0008
2014-08-14 2014-06-30 13F GALENA BIOPHARMA COM 363256108 1,304,164 -39,800 -2.96 3,990 18.75 0.0012
2014-05-14 2014-03-31 13F GALENA BIOPHARMA COM 363256108 1,343,964 -51,146 -3.67 3,360 -51.45 0.0011
2014-02-21 2013-12-31 13F/A-1 GALENA BIOPHARMA COM 363256108 1,395,110 199,104 16.65 6,920 153.85 0.0022
2014-02-12 2013-12-31 13F GALENA BIOPHARMA COM 363256108 1,395,110 6,920
2013-11-13 2013-09-30 13F GALENA BIOPHARMA COM 363256108 1,196,006 791,309 195.53 2,726 203.23 0.0010
2013-08-09 2013-06-30 13F GALENA BIOPHARMA COM 363256108 404,697 404,697 899 0.0003
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.