FDA halts new enrollment in MacroGenics (NASDAQ: MGNX) LINNET study
Filing Impact
Filing Sentiment
Form Type
8-K
Rhea-AI Filing Summary
MacroGenics, Inc. reported that the U.S. Food and Drug Administration has placed a partial clinical hold on its Phase 2 LINNET study of lorigerlimab in gynecologic cancers. Under this action, enrollment of new patients is paused, while existing participants may continue to receive the study drug.
The hold follows recent serious safety events in four patients, including Grade 4 thrombocytopenia in two cases, Grade 4 myocarditis in one case, and Grade 4 neutropenia with concurrent septic shock in one case that progressed to a Grade 5 event. To date, 41 participants have been dosed at 6 mg/kg every three weeks across platinum-resistant ovarian cancer and clear cell gynecologic cancer cohorts.
The LINNET trial uses a Simon two-stage design in platinum-resistant ovarian cancer, with a potential expansion from about 20 to 40 patients if a predefined activity threshold is reached, and includes up to 20 patients with clear cell gynecologic cancer. MacroGenics states it is committed to working closely with the FDA to resolve the partial hold and aims to resume enrollment as soon as conditions allow.
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- FDA partial clinical hold on key Phase 2 trial — New patient enrollment in the LINNET study is paused after serious safety events, including multiple Grade 4 toxicities and one Grade 5 event, creating material uncertainty around lorigerlimab’s risk–benefit profile in gynecologic cancers.
Insights
FDA partial hold on LINNET signals meaningful safety concerns for lorigerlimab.
The FDA’s partial clinical hold on the Phase 2 LINNET study means no new patients can enroll, although current participants may stay on lorigerlimab. This follows serious Grade 4 toxicities and one Grade 5 event among four patients at a 6 mg/kg every three weeks dose.
For an investigational immunotherapy targeting PD-1 and CTLA-4, such high-grade events raise questions about dose, schedule, and patient selection. The trial’s Simon two-stage design in platinum-resistant ovarian cancer and separate clear cell gynecologic cohort underpins lorigerlimab’s value in MacroGenics’ pipeline.
The company indicates it will work with the FDA to resolve the hold and intends to resume enrollment. Future regulatory feedback and any protocol changes for the LINNET study will be important to understand how the safety profile may affect ongoing development of lorigerlimab.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934
Date of report (Date of earliest event reported): February 23, 2026
(Exact Name of Registrant as Specified in Charter)
(State or Other Jurisdiction of Incorporation) | (Commission File Number) | (IRS Employer Identification No.) | |||||||||||||||
| (Address of Principal Executive Offices) | (Zip Code) | ||||||||||||||||
Registrant's telephone number, including area code: (301 ) 251-5172
Not applicable
(Former Name or Former Address, if Changed Since Last Report)
Securities registered pursuant to Section 12(b) of the Act:
| Title of each class | Trading Symbol(s) | Name of each exchange on which registered | ||||||
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
Emerging growth company ☐
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
| Item 8.01 | Other Events. | ||||||||||||||||
On February 23, 2026, MacroGenics, Inc. issued a press release announcing that the U.S. Food and Drug Administration (the “FDA”) has placed a partial clinical hold on its Phase 2 LINNET study of lorigerlimab, an investigational, bispecific DART® molecule that targets PD-1 and CTLA-4, in patients with gynecologic cancers.
A copy of the press release is attached to this Current Report on Form 8-K as Exhibit 99.1 and is incorporated by reference into this Item 8.01.
| Item 9.01 | Financial Statements and Exhibits | ||||||||||||||||
(d) Exhibits. | |||||||||||||||||
| Exhibit Number | Description of Exhibit | ||||||||||||||||
99.1 | Press Release dated February 23, 2026 | ||||||||||||||||
| 104 | Cover Page Interactive Data (embedded within the Inline XBRL document) | ||||||||||||||||
SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
Date: February 23, 2026 | MACROGENICS, INC. | |||||||||||||||||||||||||
By: /s/ Jeffrey Peters Jeffrey Peters Senior Vice President and General Counsel | ||||||||||||||||||||||||||
Exhibit 99.1
MacroGenics Announces Pausing of Enrollment of New Study Participants in LINNET Trial
FDA has placed partial clinical hold on LINNET study of lorigerlimab in gynecologic cancer
ROCKVILLE, MD., February 23, 2026 (GLOBE NEWSWIRE) — MacroGenics, Inc. (NASDAQ: MGNX), a clinical-stage biopharmaceutical company focused on developing innovative antibody-based therapeutics for the treatment of cancer, today announced that the U. S. Food and Drug Administration (FDA) has placed a partial clinical hold on its Phase 2 LINNET study of lorigerlimab, an investigational, bispecific DART® molecule that targets PD-1 and CTLA-4, in patients with gynecologic cancers. Under the partial clinical hold, no new patients will be enrolled in the LINNET study until the partial hold is lifted by the FDA. Current study participants may continue to receive study drug.
The FDA’s partial clinical hold was initiated following the Company’s recent notification to the FDA of a temporary pause in enrollment of new participants in the LINNET trial due to the occurrence of recent safety events. The safety events that prompted the enrollment pause occurred across four patients and included Grade 4 thrombocytopenia (N=2), Grade 4 myocarditis (N=1), and Grade 4 neutropenia and concurrent septic shock (N=1) which led to a Grade 5 event. To date, 41 study participants have been dosed at 6 mg/kg every 3 weeks across the platinum-resistant ovarian cancer (PROC) and clear cell gynecologic cancer (CCGC) cohorts.
“At MacroGenics, our top priority is patient safety,” said Eric Risser, President and CEO. “MacroGenics is fully committed to working closely with the FDA to resolve the partial clinical hold and we intend to resume study enrollment as soon as possible.”
About the LINNET Study
The LINNET study is evaluating lorigerlimab, an investigational, bispecific DART® molecule that targets PD-1 and CTLA-4, as monotherapy in a Simon two-stage trial in eligible patients with PROC who have received up to three prior lines of therapy. If a predefined activity threshold is met in the first stage — based on approximately 20 patients — the study may expand to enroll an additional 20 patients. The study was also designed to enroll up to 20 patients with CCGC who have received at least one prior line of therapy. The primary endpoint is objective response rate (ORR), with multiple secondary endpoints.
About MacroGenics, Inc.
MacroGenics (the Company) is a biopharmaceutical company focused on developing innovative monoclonal antibody-based therapeutics for the treatment of cancer. The Company generates its pipeline of product candidates primarily from its proprietary suite of next-generation antibody-based technology platforms, which have applicability across broad therapeutic
Exhibit 99.1
domains. The combination of MacroGenics' technology platforms and protein engineering expertise has allowed the Company to generate promising product candidates and enter into several strategic collaborations with global pharmaceutical and biotechnology companies. For more information, please see the Company's website at www.macrogenics.com. MacroGenics and the MacroGenics logo are trademarks or registered trademarks of MacroGenics, Inc.
Cautionary Note on Forward-Looking Statements
Any statements in this press release about future expectations, plans and prospects for MacroGenics (“Company”), including statements about the Company’s strategy, future operations, clinical development of and regulatory plans for the Company’s therapeutic candidates, expected timing of the release of clinical updates and safety and efficacy data for the Company’s ongoing clinical trials and other statements containing the words “subject to”, "believe", “anticipate”, “plan”, “expect”, “intend”, “estimate”, “potential,” “project”, “may”, “will”, “should”, “would”, “could”, “can”, the negatives thereof, variations thereon and similar expressions, or by discussions of strategy, including our ability to execute on our key strategic priorities for 2025 and 2026, constitute forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: the risk of delays or failure in reaching an agreement with the FDA regarding the release of a clinical hold, risks that TZIELD, lorigerlimab, ZYNYZ, or any other product candidate’s revenue, expenses and costs may not be as expected, risks relating to TZIELD, lorigerlimab, ZYNYZ, or any other product candidate’s market acceptance, competition, reimbursement and regulatory actions; future data updates, including timing and results of efficacy and safety data with respect to product candidates in ongoing clinical trials; our ability to provide manufacturing services to our customers; the uncertainties inherent in the initiation and enrollment of future clinical trials; the availability of financing to fund the internal development of our product candidates; expectations of expanding ongoing clinical trials; expectations for the timing and steps required in the regulatory review process; expectations for regulatory approvals; expectations of future milestone payments; the impact of competitive products; our ability to enter into agreements with strategic partners and other matters that could affect the availability or commercial potential of the Company's product candidates; business, economic or political disruptions due to catastrophes or other events, including natural disasters, terrorist attacks, civil unrest and actual or threatened armed conflict, or public health crises; costs of litigation and the failure to successfully defend lawsuits and other claims against us; and other risks described in the Company's filings with the Securities and Exchange Commission. In addition, the forward-looking statements included in this press release represent the Company's views only as of the date hereof. The Company anticipates that subsequent events and developments will cause the Company's views to change. However, while the Company may elect to update these forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so, except as may be required by law. These forward-looking statements should not be relied upon as representing the Company's views as of any date subsequent to the date hereof.
CONTACTS
Jim Karrels, Senior Vice President, CFO
Exhibit 99.1
1-301-251-5172
info@macrogenics.com
Argot Partners
1-212-600-1902
macrogenics@argotpartners.com
FAQ
What did MacroGenics (MGNX) announce regarding the LINNET study?
MacroGenics announced that the FDA placed a partial clinical hold on its Phase 2 LINNET study of lorigerlimab in gynecologic cancers. New patient enrollment is paused, but current participants may continue receiving study drug while the company works with regulators to address safety concerns.
Why did the FDA place a partial clinical hold on MacroGenics’ lorigerlimab trial?
The partial hold followed MacroGenics’ report of recent serious safety events in four patients. These included Grade 4 thrombocytopenia in two patients, Grade 4 myocarditis in one, and Grade 4 neutropenia with septic shock in one patient that progressed to a Grade 5 event.
Are patients currently in MacroGenics’ LINNET trial still receiving lorigerlimab?
Yes, patients already enrolled in the LINNET Phase 2 trial may continue to receive lorigerlimab under the partial clinical hold. The restriction applies only to enrolling new participants until the FDA lifts the hold following further review and potential trial modifications.
How many patients have been treated in the MacroGenics LINNET study so far?
The LINNET trial has dosed 41 study participants with lorigerlimab at 6 mg/kg every three weeks. These patients are enrolled across platinum-resistant ovarian cancer and clear cell gynecologic cancer cohorts, which together form the core population for evaluating the drug’s activity and safety.
What is the design and goal of MacroGenics’ LINNET Phase 2 study?
The LINNET study evaluates lorigerlimab as monotherapy in a Simon two-stage trial for platinum-resistant ovarian cancer, with an initial cohort of about 20 patients and possible expansion to 40. It also includes up to 20 clear cell gynecologic cancer patients, with objective response rate as the primary endpoint.
How does MacroGenics plan to address the FDA’s partial hold on LINNET?
MacroGenics states that patient safety is its top priority and that it is fully committed to working closely with the FDA. The company intends to resolve the partial clinical hold and resume enrollment in the LINNET study once regulators are satisfied with the safety measures and trial plan.
Filing Exhibits & Attachments
4 documents
Macrogenics Inc
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