Genmab (GMAB) Stock News

Genmab (Nasdaq: GMAB) reported updated Phase 1/2 RAINFOL-01 cohort B2 data for investigational rinatabart sesutecan (Rina-S) in advanced endometrial cancer.

At a median one-year follow-up, Rina-S 100 mg/m2 Q3W produced a 50.0% confirmed ORR including two complete responses; 63.6% of responders remain on treatment. Rina-S 120 mg/m2 showed a 44.1% ORR with one CR. Patients had a median of three prior lines. Grade ≥3 serious TEAEs occurred in 36.4% (100 mg/m2) and 52.4% (120 mg/m2). No ocular toxicity, neuropathy, or ILD signals reported. The U.S. FDA granted Breakthrough Therapy Designation and a Phase 3 trial in endometrial cancer is underway.

Genmab (Nasdaq: GMAB) has announced its plans to acquire Merus (Nasdaq: MRUS) in an all-cash transaction valued at approximately USD 8.0 billion, or USD 97.00 per share. The acquisition represents a 41% premium over Merus' closing price on September 26, 2025.

The strategic acquisition brings petosemtamab, a late-stage oncology asset with two FDA Breakthrough Therapy Designations for head and neck cancer, into Genmab's portfolio. The Phase 3 asset showed promising Phase 2 data at ASCO 2025, with superior overall response rates and progression-free survival compared to standard care. Genmab expects potential product launch in 2027, with projected annual sales of $1+ billion by 2029.

The transaction will be funded through cash and $5.5 billion in non-convertible debt. Genmab aims to achieve gross leverage below 3x within two years post-closing. The deal is expected to close by early Q1 2026 and become EBITDA accretive by end of 2029.

Genmab (NASDAQ: GMAB) announced updated results from its Phase 2 EPCORE® NHL-6 trial evaluating epcoritamab monotherapy in relapsed/refractory (R/R) DLBCL patients. The study demonstrated significant success in outpatient treatment, with 92% of patients receiving their first full dose in an outpatient setting.

Key efficacy results showed an overall response rate of 64.3% and complete response rate of 47.6% in patients treated after one prior line of therapy. For patients with two or more prior treatments, the response rates were 60.0% and 38.0% respectively. The safety profile remained consistent with previous studies, with manageable cytokine release syndrome (CRS) occurring in 40.2% of patients, primarily low-grade and resolving within a median of two days.

Genmab (NASDAQ: GMAB) announced that the FDA has granted Breakthrough Therapy Designation (BTD) to rinatabart sesutecan (Rina-S®) for treating adult patients with recurrent or progressive endometrial cancer who have disease progression after platinum-containing regimen and PD-(L)1 therapy.

The designation was supported by results from the Phase 1/2 RAINFOL™-01 trial, where 64 heavily pretreated patients with advanced or recurrent EC were treated with Rina-S. The drug is currently being evaluated as a single-agent treatment in the ongoing Phase 1/2 RAINFOL™-01 trial and will be further studied in a planned Phase 3 trial.

Rina-S is a folate receptor alpha-directed, TOPO1-inhibitor antibody-drug conjugate (ADC) that is also being evaluated in other clinical trials, including the Phase 3 RAINFOL-02 trial in ovarian cancer.

Genmab (NASDAQ: GMAB) announced positive results from its Phase 3 EPCORE® FL-1 trial for epcoritamab combined with rituximab and lenalidomide (R2) in treating relapsed/refractory follicular lymphoma. The trial met both primary endpoints with significant improvements in Overall Response Rate (95.7%, p<0.0001) and Progression-Free Survival (HR 0.21, p<0.0001), reducing disease progression risk by 79%.

The FDA has accepted a priority review for the supplemental Biologics License Application (sBLA) with a target action date of November 30, 2025. If approved, this combination would become the first bispecific antibody regimen available as a second-line treatment for R/R FL patients. The safety profile aligned with known individual regimens with no new safety signals observed.

Genmab (GMAB) announced promising results from the Phase 1b/2 EPCORE NHL-2 trial evaluating epcoritamab combination therapy in relapsed/refractory DLBCL patients. The study showed an impressive 87% overall response rate and 65% complete response rate when epcoritamab was combined with R-ICE in patients eligible for autologous stem cell transplantation. At six months, 81% of responses were ongoing, 74% of patients remained progression-free, and patient survival was 100%. The safety profile was manageable, with mainly low-grade adverse events. The therapy demonstrated particularly strong results in high-risk patients who progressed rapidly after initial treatment, achieving an 85% overall response rate. This investigational combination therapy shows potential as a bridge to ASCT, with 65% of patients proceeding to transplantation.

Genmab announced promising Phase 1/2 trial results for rinatabart sesutecan (Rina-S) in treating advanced endometrial cancer. The study showed a 50.0% confirmed objective response rate at 100 mg/m2 dosage, including two complete responses, in heavily pre-treated patients. The median duration of response was not reached after 7.7 months follow-up. The trial involved 64 patients who received either 100 mg/m2 (n=22) or 120 mg/m2 (n=42) doses. The 120 mg/m2 cohort showed a 47.1% response rate. Common side effects included diarrhea, shortness of breath, and urinary tract infection, with serious adverse events occurring in 31.8% of patients at 100 mg/m2 and 50.0% at 120 mg/m2. Notably, no ocular toxicities, neuropathy, or Interstitial Lung Disease were observed, which are typically common with antibody-drug conjugates.

Genmab (GMAB) will present new research data at the 2025 ASCO Annual Meeting from May 30 to June 3 in Chicago. Key highlights include:

- First disclosure of Phase 1/2 trial results for rinatabart sesutecan (Rina-S®), a novel antibody-drug conjugate, in patients with recurrent/advanced endometrial cancer

- Presentation of long-term follow-up data from the Phase 1/2 EPCORE™ NHL-1 study of epcoritamab in patients with relapsed/refractory DLBCL, focusing on patients maintaining complete response at 2 years

The company will host a virtual investor update on June 2 at 4:00 PM CDT to review the Rina-S data. The presentations demonstrate Genmab's commitment to developing alternative treatment options, particularly for endometrial cancer, which has rising mortality rates and limited treatment options.

Genmab (NASDAQ: GMAB) announced the presentation of 14 abstracts evaluating epcoritamab, their T-cell engaging bispecific antibody, at the 2025 European Hematology Association Congress. The presentations will showcase data across multiple treatment settings for diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). Key highlights include:

Two oral presentations will feature data from:

• EPCORE NHL-2 trial: evaluating epcoritamab plus R-ICE in relapsed/refractory DLBCL patients
• EPCORE NHL-5 trial: studying epcoritamab plus pola-R-CHP in previously-untreated DLBCL patients

Additional notable presentations include three-year follow-up data from the EPCORE NHL-1 and NHL-3 trials for epcoritamab monotherapy in R/R DLBCL and FL patients. The research will also be presented at the 18th International Conference on Malignant Lymphoma in Lugano, Switzerland.