Cullinan Oncology Inc SEC Filings

Cullinan Therapeutics, Inc. presented updated Phase 1 data for its bispecific antibody CLN-049 in patients with relapsed/refractory acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) at the ASH Annual Meeting. As of the August 2025 cutoff, 45 patients were enrolled across dose levels from 1.5 to 12 μg/kg, with 41 evaluable for efficacy. At the highest dose of 12 μg/kg (16 patients), the complete response/complete remission with partial hematologic recovery (CR/CRh) rate was 31% (5 of 16), and the composite complete response (CRc) rate was also 31%.

Across doses at or above 6 μg/kg (32 patients), the CR/CRh rate was 25% (8 of 32) and the CRc rate was 28% (9 of 32), with promising durability: 63% (5 of 8) of CR/CRh responders had responses lasting more than 16 weeks, and some proceeded to stem cell transplant. Among patients with bone marrow blasts under 5% at these doses, 30% were MRD negative, including one ongoing response beyond 36 weeks. In eight patients with high‑risk TP53‑mutated AML at 12 μg/kg, 50% achieved CR/CRh, with most responses lasting over 16 weeks. Safety data showed a favorable profile, with cytokine release syndrome mostly Grade 1–2, no Grade 3 CRS with two step‑up doses, and no CRS‑related treatment discontinuations. CLN-049 development will proceed under U.S. FDA Fast Track designation, with dose escalation ongoing and expansion cohorts planned in early 2026.

Cullinan Therapeutics, Inc. (CGEM)11/24/2025, the officer sold 4,000 shares of common stock at $12.3 per share in an open-market sale. After this trade, the officer beneficially owns 138,004 shares of Cullinan common stock. The filing notes that this sale was carried out under a pre-established Rule 10b5-1 trading plan adopted on August 7, 2025, which is designed to allow insiders to sell shares according to a preset schedule.

Cullinan Therapeutics, through its subsidiary Cullinan Amber Corp., is ending development of its CLN-617 cancer immunotherapy program. On November 18, 2025, the company notified the Massachusetts Institute of Technology that it is terminating their Exclusive Patent License Agreement covering the technology behind CLN-617, with the termination effective February 18, 2026. Under that agreement, MIT had granted Cullinan exclusive worldwide rights to develop the CLN-617 technology, which will now be returned to MIT. This move confirms CLN-617 will no longer be advanced within Cullinan’s pipeline.

Cullinan Therapeutics (CGEM) reported a Q3 2025 net loss of $50.6M as operating expenses rose with pipeline investment. Research and development was $41.97M and general and administrative was $13.63M, offset partly by $5.09M of interest income.

Liquidity remains strong with cash and cash equivalents of $103.3M, short‑term investments of $229.3M, and long‑term investments of $140.0M as of September 30, 2025. Management states these resources are sufficient to fund operations through at least the next twelve months. The company also has an at‑the‑market program with $85.6M capacity remaining.

Pipeline updates: Cullinan licensed velinotamig from Genrix with a $20.0M upfront fee recorded in R&D. Zipalertinib, co‑developed with Taiho, met the primary endpoint in a pivotal Phase 2b; following a positive Type B pre‑NDA meeting, Taiho plans a rolling NDA submission by year‑end 2025. Subsequent to quarter end, Cullinan decided not to pursue further development of CLN‑619 and CLN‑617. Common shares outstanding were 59,076,259 as of October 31, 2025.

Cullinan Therapeutics (CGEM) reported quarterly results and disclosed liquidity details. As of September 30, 2025, cash, cash equivalents, short- and long-term investments, and interest receivable totaled $475.5 million. The company stated its cash resources are expected to provide runway into 2029 under its new operating plan.

The press release with results was furnished as Exhibit 99.1. The disclosure was provided as supplemental information and designated as furnished, not filed, under the Exchange Act.

Cullinan Therapeutics reported new Phase 1 data for CLN-049 in relapsed/refractory AML and MDS, to be presented at the ASH Annual Meeting in December. As of the June 2025 cutoff, 40 patients were enrolled and 29 AML patients were efficacy evaluable.

In AML at target doses ≥6 μg/kg (n=23), CLN-049 showed a CRc rate of 30% and an ORR of 57%. At 12 μg/kg (n=13), the CRc rate was 31% and ORR was 69%. Among nine patients achieving bone marrow blasts <5%, three were MRD negative by flow cytometry; relapse was not observed in MRD-negative patients, and one patient has remained on study for >6 months. Responses were observed regardless of baseline genetic risk, including four responses (2 CRh, 2 MLFS) among five TP53‑mutated AML patients treated at 12 μg/kg.

Safety findings indicate a manageable profile in 40 patients: the most common TEAEs were CRS (40%) and infusion-related reaction (35%). All CRS events were Grade 1–2, with one Grade 1 ICANS; none led to discontinuation. Grade ≥3 TEAEs >10% included febrile neutropenia and white blood cell count decrease (17.5% each), and pneumonia (12.5%). Dose escalation is ongoing.

Cullinan Therapeutics (CGEM): Reporting persons associated with Lynx1 Capital Management disclosed an open‑market purchase of 165,667 shares of common stock on 10/28/2025 at a weighted average price of $8.4005, executed across multiple trades ranging from $8.035 to $8.50.

Following the transaction, they report 8,963,500 shares beneficially owned on an indirect basis through Lynx1 Master Fund LP. The filing notes a standard disclaimer of beneficial ownership except to the extent of pecuniary interest.

Cullinan Therapeutics (CGEM): Lynx1-affiliated reporting persons disclosed open‑market purchases of Common Stock across four days, increasing their indirect holdings. Following the most recent transaction, beneficial ownership stood at 8,797,833 shares, held indirectly through Lynx1 Master Fund LP as described in the filing.

• 10/14/2025: 15,032 shares at a weighted avg price of $7.587 (purchases ranged $7.50–$7.68).
• 10/15/2025: 51,500 shares at $7.9427 (range $7.88–$8.00).
• 10/16/2025: 150,000 shares at $8.855 (range $8.68–$9.22).
• 10/17/2025: 32,217 shares at $7.8395 (range $7.78–$7.85).

The filing lists the transactions as purchases and notes the indirect ownership structure via Lynx1 Capital Management LP and related entities.

Lynx1 Capital Management LP and affiliated reporting person Weston Nichols disclosed purchases of Cullinan Therapeutics, Inc. (CGEM) common stock across three days. On 10/08/2025 they bought 556,300 shares at a weighted average price of $6.46, increasing indirect holdings to 7,645,743 shares. On 10/09/2025 they acquired 626,043 shares at a weighted average of $6.6958, bringing holdings to 8,271,786 shares. On 10/10/2025 they purchased 277,298 shares at a weighted average of $7.3617, raising indirect holdings to 8,549,084 shares. The shares are held directly by Lynx1 Master Fund LP, for which Lynx1 Capital Management LP serves as investment manager; the filing disclaims beneficial ownership except to the extent of any pecuniary interest.