Alec Stranahan

Brian Cheng

Charles Zhu

Dane Leone

Etzer Darout

Gregory Renza

Kaveri Pohlman

Lut Ming Cheng

Mara Goldstein

Tara Bancroft

Unknown Analyst

- Xencor, Inc. announced initial Phase 1 results for **XmAb819**, a first-in-class ENPP3 x CD3 bispecific T-cell engager for advanced clear cell renal cell carcinoma (ccRCC), on **October 24, 2025**.  **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:0]** 
- The study reported a **25% overall response rate (ORR)** and a **70% disease control rate (DCR)** in heavily pretreated patients within the target dose range.  **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:0]** **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:1]**  
- XmAb819 demonstrated a **well-tolerated safety profile**, with common adverse events being Grade 1 or 2 cytokine release syndrome (CRS), rash, and gastrointestinal toxicities.  **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:0]** **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:1]** 
- The company anticipates selecting a recommended Phase 3 dose (RP3D) in **2026** and initiating a pivotal study in advanced ccRCC in **2027**.  **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:0]** **[1326732_0001326732-25-000082_xncr-2025x1024xexx991.htm:7]** 
- Measures are being implemented to address prior dose preparation errors, including a new low concentration formulation expected in **1H 2026**.  **[1326732_0001326732-25-000082_xncr-20251024xexx992.htm:1]** **[1326732_0001326732-25-000082_xncr-2025x1024xexx991.htm:3]**

Xencor Announces Initial Phase 1 Results for XmAb819 in Advanced Clear Cell Renal Cell Carcinoma

- Xencor is advancing its lead T-cell engagers, **XmAb® 819** and **XmAb® 541**, with recommended Phase III doses expected to be established in **2026**.  **[0001326732_2202752_1]** **[0001326732_2202752_8]** **[0001326732_2202752_14]** 
- The Phase I study of **XmAb® 819** in heavily pretreated clear cell renal cell carcinoma (RCC) patients demonstrated a best overall response rate of **25%** and a disease control rate of **70%**, with the drug being well-tolerated and manageable adverse events.  **[0001326732_2202752_3]** **[0001326732_2202752_4]** **[0001326732_2202752_6]** 
- Xencor views **XmAb® 819** as a potential blockbuster drug in clear cell RCC, aiming to redefine the standard of care for second and third-line treatment, with global drug sales for RCC projected to reach **$12 billion by 2030**.  **[0001326732_2202752_6]** 
- Early data for **XmAb® 541**, a Claudin 6 targeting CD3, indicates active dose levels with **3 responders out of 9** patients (2 germ cell tumors, 1 ovarian cancer) and tumor reductions in 7 of 9 patients.  **[0001326732_2202752_8]**

Xencor Provides Update on XmAb® 819 and XmAb® 541 Clinical Programs

- Xencor's XmAb819, a T-cell engager for clear cell renal cell carcinoma, achieved a **25% best overall response rate** and **70% disease control rate** in evaluable, heavily pretreated patients (median of four prior systemic therapies) in its target dose range, surpassing the internal target of 20%.  **[0001326732_2203191_4]** **[0001326732_2203191_6]** 
- The XmAb819 program addressed initial dose prep dilution errors from early 2025 that caused elevated Grade 3 Cytokine Release Syndrome (CRS) in affected patients; mitigation efforts are in place, and a new low concentration drug product will be introduced in **H1 2026** to resolve the issue.  **[0001326732_2203191_3]** **[0001326732_2203191_11]** 
- Xencor expects to establish recommended phase III doses for both XmAb819 and XmAb541, a Claudin-6 targeting CD3, in **2026**.  **[0001326732_2203191_1]** **[0001326732_2203191_8]** **[0001326732_2203191_14]** 
- Early clinical data for XmAb541 shows anti-tumor activity, with **three responders out of nine** patients (two with germ cell tumors and one with ovarian cancer) at the most recent IV dose level.  **[0001326732_2203191_8]** 
- XmAb819 is viewed as a potential blockbuster drug in clear cell renal cell carcinoma, a market projected to reach **$12 billion in global drug sales by 2030**.  **[0001326732_2203191_6]**

Xencor Provides Update on XmAb819 and XmAb541 Clinical Programs

- Xencor reported positive initial Phase 1 dose escalation results for **XmAb819** in advanced clear cell renal cell carcinoma (RCC), demonstrating a best overall response rate of **25%** and a disease control rate of **70%** in heavily pretreated patients who had a median of four prior systemic therapies.  **[0001326732_2202770_3]** **[0001326732_2202770_7]** 
- **XmAb819** was well-tolerated, with a low rate of **4%** patient discontinuation due to adverse events and a **6%** Grade 3 Cytokine Release Syndrome (CRS) rate for patients receiving the intended priming dose.  **[0001326732_2202770_2]**  No cases of ICANS (Immune effector Cell-Associated Neurotoxicity Syndrome) of any grade were reported.  **[0001326732_2202770_2]** 
- The company is rapidly advancing **XmAb541**, its first-in-class Claudin-6 targeting CD3 T cell engager, having met its corporate goal to begin characterizing target dose range cohorts by year-end.  **[0001326732_2202770_7]**  Early antitumor activity includes **three responders out of nine patients** at the most recent IV dose level.  **[0001326732_2202770_7]** 
- Xencor aims to establish recommended phase three doses for both **XmAb819** and **XmAb541** during **2026**.  **[0001326732_2202770_0]** **[0001326732_2202770_7]**

Xencor Announces Positive Initial Phase 1 Results for XmAb819 and Progress for XmAb541

- Xencor announced **positive initial Phase I dose escalation results** for XmAb® 819 in advanced clear cell renal cell carcinoma, showing a **best overall response rate of 25%** and a **disease control rate of 70%** in heavily pretreated patients.  **[0001326732_2203182_4]** 
- The XmAb® 819 study population had a **median of four prior systemic therapies**, with **36% having prior HIF2α inhibitor therapy**.  **[0001326732_2203182_3]**  The drug demonstrated a **low rate of grade 3 CRS (6%)** with the intended priming dose, and no ICANS were reported.  **[0001326732_2203182_3]** **[0001326732_2203182_4]** **[0001326732_2203182_11]** 
- Xencor aims to establish a recommended Phase III dose for XmAb® 819 in **2026**, with plans to explore combination therapies and broaden its use to other ENPP3 expressing tumors.  **[0001326732_2203182_1]** **[0001326732_2203182_6]** **[0001326732_2203182_14]** 
- Xencor also provided an update on XmAb® 541, its Claudin 6 targeting CD3, reporting **three responders out of nine patients** (two germ cell tumors, one ovarian cancer) at its most recent IV dose level, with a recommended Phase III dose also targeted for **2026**.  **[0001326732_2203182_8]**

Xencor Reports Positive Initial Phase I Results for XmAb® 819 and XmAb® 541

- Xencor announced initial results from the ongoing Phase 1 dose-escalation study of **XmAb819**, a first-in-class ENPP3 x CD3 T-cell engaging bispecific antibody, for patients with advanced clear cell renal cell carcinoma (ccRCC).  **[1326732_231b6538d3584c3baceb1a9b8952c631_0]** 
- The study demonstrated a **25% overall response rate (ORR)** and a **70% disease control rate (DCR)** among 20 efficacy-evaluable patients treated within the target dose range.  **[1326732_231b6538d3584c3baceb1a9b8952c631_0]** **[1326732_231b6538d3584c3baceb1a9b8952c631_1]** 
- XmAb819 was **well-tolerated** in heavily pretreated patients, with common treatment-emergent adverse events (TEAE) primarily Grade 1 or 2 in severity.  **[1326732_231b6538d3584c3baceb1a9b8952c631_0]** **[1326732_231b6538d3584c3baceb1a9b8952c631_1]** 
- Xencor is on track to select a recommended Phase 3 dose during **2026** and initiate its first pivotal study in advanced ccRCC during **2027**.  **[1326732_231b6538d3584c3baceb1a9b8952c631_0]**

Xencor Presents Initial Phase 1 Data for XmAb819

- Xencor maintains a strong financial position with approximately **$663.8 million**.  **[0001326732_2202005:2]** 
- The company is advancing an optimized portfolio of XmAb drug candidates, with the **Phase 2 XENITH-UC study for XmAb942 (TL1A)** in ulcerative colitis having started in **2H'25**.  **[0001326732_2202005:3]** **[0001326732_2202005:10]** 
- Key clinical milestones expected in 2025 include initial Phase 1 data for **XmAb819 (ENPP3 x CD3)** in renal cell carcinoma planned for **Q4 2025**, and the planned **First-In-Human study for XmAb657 (CD19 x CD3)** in autoimmune diseases in **2H'25**.  **[0001326732_2202005:3]** **[0001326732_2202005:22]** **[0001326732_2202005:28]** 
- Xencor leverages its modular XmAb technology through **more than 15 technology license partnerships**, which have resulted in multiple commercialized XmAb antibodies such as Ultomiris® and Monjuvi®.  **[0001326732_2202005:2]** **[0001326732_2202005:4]**

Xencor (XNCR)