Cullinan Therapeutics, Inc. SEC Filings

Cullinan Therapeutics reported new early-stage clinical data for its T cell engager programs CLN-978 and velinotamig in autoimmune diseases. In Phase 1 OUTRACE RA, two heavily pre-treated rheumatoid arthritis patients showed robust responses, including one DAS28-ESR remission with a disease score falling from 4.0 to 2.2 by week eight. Initial multi-dose data in systemic lupus erythematosus show a favorable safety profile and support a planned Phase 2a expansion in lupus nephritis, expected to start in early 2027.

For velinotamig, the first two refractory SLE patients treated in a Phase 1b/2a study in China experienced rapid drops in SLEDAI-2K scores (from 16 and 14 to 0 and 2 at week eight) and achieved complete renal response, with no CRS or ICANS observed. Cullinan plans further CLN-978 data in RA in Q3 2026 and SLE in Q4 2026, additional velinotamig data in Q4 2026, and a Phase 1/2a trial in autoimmune cytopenias beginning in Q1 2027.

Cullinan Therapeutics reported initial Phase 1 data for CLN‑978, a CD19xCD3 T cell engager, in treatment‑refractory systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) from its OUTRACE trials. As of May 15, 2026, 29 patients had been evaluated across multiple step‑up and multi‑dose cohorts.

In SLE, among 14 patients with at least four weeks of follow‑up, 10 (71%) achieved a ≥4‑point hSLEDAI reduction and 5 reached DORIS remission. Peripheral B cells fell by more than 80% in 14 of 17 patients, with half of those at target doses ≥20 µg reaching depletion below the limit of quantification.

In RA, 5 of 7 patients (71%) showed improved disease activity, including one DAS28‑ESR remission at a 30 µg target dose. Deep, dose‑dependent B cell depletion was observed in blood, lymph node and synovial tissue, while autoantibody levels declined without affecting protective vaccine titers.

Across 10, 20 and 30 µg target doses, CLN‑978 was described as well tolerated. Cytokine release syndrome occurred in 11 of 29 patients, mostly Grade 1 after the initial 10 µg dose; one Grade 3 case followed a 45 µg dose, leading to discontinuation of that cohort. No ICANS events were reported. Cullinan will also discuss these data, first RA multi‑dose results, and initial velinotamig data at an Immunology Day on June 10.

Cullinan Therapeutics reported initial data from its Phase 1 OUTRACE Program testing CLN-978 in treatment‑refractory rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). As of a January 14, 2026 cutoff, 14 patients were dosed across RA (5 patients) and SLE (9 patients) cohorts.

Single subcutaneous step‑up and target doses of 10, 20, or 30 micrograms produced robust B cell depletion. After 10 micrograms, 9 of 11 patients showed more than 75% B cell reduction versus baseline; after 20 micrograms, three of six fell below quantification, with the others showing reductions of 98.5%, 77%, and 64%.

Among patients with at least four weeks of follow‑up, four of five RA patients had lower DAS28‑ESR scores, including four of four improving from high disease activity to moderate activity or remission. Five of six SLE patients had SLEDAI score reductions greater than four points. CLN‑978 was described as well tolerated with a favorable safety profile, and dose escalation is ongoing. Updated data will be presented at the EULAR Congress in June 2026.

Cullinan Therapeutics ownership update: A group of reporting persons led by Biotechnology Value Fund and affiliates reports shared beneficial ownership positions in the issuer's Common Stock as of 03/31/2026. The group holds Series A convertible preferred stock convertible into 4,819,890 shares, and an aggregate convertible position limited by a Conversion Blocker to 410,786 shares for conversion at that date. Reported beneficial holdings include 3,551,482 shares attributable to BVF, 2,272,849 shares to BVF2, and 224,641 shares to Trading Fund OS. The filing bases its percentages on 60,526,128 Shares outstanding as of 02/23/2026 and states BVF beneficially owned approximately 5.8% and BVF2 approximately 3.7% of outstanding shares.

Cullinan Therapeutics, Inc. reported a first‑quarter 2026 net loss of $49.661 million as it continued to invest heavily in autoimmune and oncology programs. Research and development expenses were $42.123 million and general and administrative expenses were $11.574 million.

Cash, cash equivalents, and short‑term investments totaled $351.9 million, with an additional $41.4 million in long‑term investments and interest receivable, which management believes can fund operations for at least twelve months. The company remains pre‑revenue and has an accumulated deficit of $637.8 million.

Pipelines advanced meaningfully. The U.S. FDA accepted a new drug application for zipalertinib in EGFR exon 20 insertion non‑small cell lung cancer, with a target action date of February 27, 2027, and a Phase 3 first‑line trial completed enrollment. Early immunology programs, including CLN‑978 and velinotamig, have multiple data readouts planned through 2026. Cullinan also established a $200.0 million at‑the‑market equity offering program to provide additional financing flexibility.

Cullinan Therapeutics reported first quarter 2026 results and highlighted key pipeline milestones in autoimmune disease and oncology. Cash, cash equivalents, investments and interest receivable were $393.3 million as of March 31, 2026, which the company expects will fund operations into 2029 under its current plan.

The company booked a net loss of $49.7 million, with research and development expenses of $42.1 million and general and administrative expenses of $11.6 million for the quarter. Cullinan’s partner-led NDA for zipalertinib in EGFR ex20ins NSCLC was accepted by the U.S. FDA, with a PDUFA target action date of February 27, 2027.

Cullinan Therapeutics Chief Scientific Officer Jennifer Michaelson reported an exercise-and-sell transaction in company stock. She sold a total of 8,000 shares of Common Stock in open-market transactions at weighted average prices of $14.60 and $15.58, with actual trade prices ranging from $14.24 to $15.60. These sales were executed pursuant to a pre-established Rule 10b5-1 trading plan dated August 7, 2025. On the same day, she exercised stock options for 4,000 shares of Common Stock at an exercise price of $4.30 per share, converting a derivative position into additional common shares while using part of her holdings for liquidity.

CGEM-related insider reported proposed sales. The filing lists multiple proposed and completed dispositions of Common stock, including 10b5-1 sales on 03/05/2026 for 8,000 shares at $125,453.60 and an exercise of stock options to sell 4,000 shares on 05/05/2026. The excerpt also shows 4,000 RSUs dated 02/22/2024.

Cullinan Therapeutics, Inc. has registered securities on a Form S-3 shelf and may sell up to $200,000,000 of its common stock through an at-the-market sales agreement with TD Securities (USA) LLC (TD Cowen). Sales may occur "from time to time" at market-determined prices under the sales agreement.

The prospectus covers multiple security types but the accompanying base prospectus and sales agreement specifically permit the company to offer common stock with proceeds to be used for general corporate purposes, including R&D, clinical trials, in-licensing and potential acquisitions.