On May 6, 2026 Aptevo Therapeutics Inc. (Nasdaq:APVO) reported new clinical results from its RAINIER frontline acute myeloid leukemia (AML) trial. The Company is on track to complete the Phase 1b dose-optimization trial and select the recommended Phase 2 dose (RP2D) this year. As with the current study, the Phase 2 trial will dose mipletamig in combination with venetoclax and azacitidine.

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Across 31 evaluable frontline AML patients treated to date (includes data through RAINIER Cohort 5, plus 4 patients from the previously completed dose expansion trial), mipletamig in combination with venetoclax and azacitidine has demonstrated an 87% clinical benefit rate (CR/CRi/PR) and an 81% remission rate (CR/CRi), with results continuing to reflect a consistent profile of clinical activity and favorable safety as the dataset expands.

With Cohort 5 complete, dosing has progressed through all previously evaluated mipletamig dose levels. The trial has now entered its final stage, which includes:

Two final dose-level cohorts-Cohorts 6 and 7-representing the highest dose levels of mipletamig evaluated. Enrollment in Cohort 6 is nearing completion

Two groups of six additional patients will be enrolled at select dose levels, with the first enrolling concurrently with Cohort 6

These activities will complete the dataset required for RP2D selection and the planned Phase 2 regulatory interaction, with the trial on track for completion this year.

"With the completion of Cohort 5, we have evaluated mipletamig across all previously studied dose levels and have entered the final stage of the RAINIER trial," said Jeff Lamothe, President and Chief Executive Officer of Aptevo Therapeutics. "The data is compelling, the remaining work is clearly defined, and the study is on track for completion this year, with the dataset enabling selection of the Phase 2 dose and our advancement into Phase 2. The strength and consistency of the data as it expands gives us confidence in the path forward."

Among the evaluable frontline patient population treated to date (N=31), including 27 patients from the RAINIER trial through Cohort 5 and 4 patients from the completed dose-expansion trial, mipletamig in combination with venetoclax and azacitidine has demonstrated:

87% clinical benefit rate,*demonstrating broad anti-leukemia activity and blast reduction across response categories

81% achieved CR or CRi (remission), comparing favorably to the historical benchmark**.

65% achieved CR (complete remission), comparing favorably to the historical benchmark**

55% of patients who achieved CR/CRi had blast reductions that reached the important measurable residual disease-negative level, a result that is typically associated with stronger, more durable responses

36% of patients with remissions had the TP53 genetic mutation, a high-risk biomarker typically associated with poor prognosis in AML and for which most treatment options frequently fail

6 patients treated to date have proceeded to allogeneic stem cell transplant, which represents the best possible outcome in AML treatment and is rarely achieved in the older or unfit frontline patient population

No cytokine release syndrome reported

*Clinical benefit rate, including complete remission (CR), complete remission with incomplete hematologic recovery (CRi), and partial remission (PR)

**In the Phase 3 VIALE-A trial evaluating venetoclax plus azacitidine in frontline intent-to-treat AML patients who were ineligible for intensive induction chemotherapy, the reported composite CR/CRi rate was 66.4%, and the CR rate was 37% (DiNardo et al., New England Journal of Medicine, 2020).

Collectively, these data outperform the benchmark** and demonstrate mipletamig’s potential to meaningfully enhance frontline AML treatment in older and/or unfit patients by improving efficacy outcomes without materially increasing toxicity.

"Our results demonstrate a consistent pattern of clinical activity and favorable safety across patients treated to date," said Dirk Huebner, M.D., Chief Medical Officer of Aptevo Therapeutics. "As dose selection progresses, the focus is on identifying a Phase 2 dose that is supported by a complete and well-characterized dataset."

About the RAINIER Trial

RAINIER, a frontline AML study, is a Phase 1b/2 dose-optimization, multi-center, multi-cohort, open-label study. Subjects are adults aged 18 or older, newly diagnosed with AML, who are not eligible for intensive induction chemotherapy. RAINIER will be conducted in two parts: first, a Phase 1b dose-optimization study in frontline AML patients, followed by a Phase 2 study. The Phase 1b trial consists of 28-day cycles of treatment across multiple sequential cohorts.

About Mipletamig

Aptevo’s wholly owned lead proprietary drug candidate, mipletamig, being evaluated for the treatment of AML, is differentiated by design to redirect the immune system of the patient to destroy leukemic cells and leukemic stem cells expressing the target antigen CD123, which is a compelling target for AML due to its overexpression on leukemic stem cells and AML blasts. This antibody-like recombinant protein therapeutic is designed to engage both leukemic cells and T cells of the immune system and bring them closely together to trigger the destruction of leukemic cells.

Mipletamig is purposefully designed to reduce the likelihood and severity of CRS by use of the CRIS-7-derived CD3 binding pathway, an approach that differentiates Aptevo from competitors. Mipletamig has received orphan drug designation ("orphan status") for AML under the Orphan Drug Act. Orphan drug designation provides key advantages-including the opportunity to seek U.S. market exclusivity for a specific period of time upon approval, FDA fee reductions, and access to development and tax credits. Mipletamig has been evaluated in more than 120 patients over three trials to date.

(Press release, Aptevo Therapeutics, MAY 6, 2026, View Source [SID1234665215])

On May 6, 2026 Actinium Pharmaceuticals, Inc. (NYSE American: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, reported the upcoming presentation of three abstracts at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2026 Annual Meeting, taking place May 30-June 2, 2026, in Los Angeles, California.

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The presentations include two posters on ATNM-400, Actinium’s first-in-class Actinium-225 (225Ac) antibody radioconjugate, demonstrating its potential in prostate cancer and non-small cell lung cancer (NSCLC), as well as a third poster presenting preclinical radiochemistry data on chelator-to-antibody ratio (CAR) optimization that underpins ATNM-400 development. Together, the data underscore Actinium’s scientific leadership in next-generation alpha-emitting radioconjugates.

Sandesh Seth, Actinium’s Chairman and CEO, said, "Data to be presented at SNMMI 2026 further strengthen the profile of ATNM-400 as a first-in-class, radiotherapy with broad solid tumor applicability. In NSCLC, ATNM-400 demonstrates the ability to overcome key resistance mechanisms to both EGFR and KRAS mutations that limit current targeted therapies and support its development as a mutation agnostic agent. In prostate cancer, new data demonstrate its potential in the PSMA negative setting, in addition to promising data in PSMA-high and medium settings further supporting the differentiated profile of ATNM-400. Importantly, as we head toward clinical studies with ATNM-400, we showcase our efforts to maximize ATNM-400’s therapeutic index by utilizing our deep radiochemistry expertise to optimize the CAR. Together, the data to be presented support ATNM-400’s growing potential as a differentiated radiotherapy across multiple high-value solid tumor indications that represent some of oncology’s largest commercial opportunities."

ATNM-400 SNMMI 2026 Presentation Details

Abstract Title: ATNM-400: A First-in-Class Actinium-225 Antibody Radioconjugate Demonstrating Potent PSMA-Independent Efficacy in Prostate Cancer Models
Session: Oncology: Discovery & Translational Meet the Author Session
Date & Time: Tuesday, June 2, 2026 11:30am-12:15pm PT | Los Angeles, California

Abstract Title: ATNM-400: A First-in-Class Actinium-225 Antibody Radioconjugate Demonstrating Durable, Mutation-Agnostic Anti-Tumor Activity in Non-Small Cell Lung Cancer Models
Session: Oncology: Discovery & Translational Meet the Author Session
Date & Time: Tuesday, June 2, 2026, 11:30am-12:15pm PT | Los Angeles, California

Abstract Title: Optimizing Chelator-to-Antibody Ratio Improves Tumor Targeting and Pharmacokinetics of 225Ac-Labeled Antibodies
Session: MTA05 RPSC/CMIIT POPs and Science Pavilion Mixer
Date & Time: Sunday, May 31, 2026, 7:30-8:00pm PT | Los Angeles, California

(Press release, Actinium Pharmaceuticals, MAY 6, 2026, View Source [SID1234665214])

On May 6, 2026 Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of cancer and autoimmune diseases, reported financial results for the first quarter ended March 31, 2026.

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"Xencor continues to execute across our wholly owned clinical pipeline, with significant progress in both oncology and autoimmune disease. We look forward to presenting expansion cohort data from our Phase 1 study of XmAb819 for the treatment of advanced clear cell renal cell carcinoma at a medical meeting in the second half of 2026, which will help support the initiation of our first pivotal study planned for 2027," said Bassil Dahiyat, Ph.D., president and chief executive officer at Xencor.

"Our TL1A pipeline continues to advance with strong enrollment in the global Phase 2b XENITH-UC Study of XmAb942 in ulcerative colitis supported by investigator enthusiasm for its potential best-in-class profile in moderately to severely active ulcerative colitis. We expect to complete a blinded interim analysis around year-end 2026 and complete the primary endpoint analysis for the study’s 12-week induction period during the second half of 2027. We also look forward to initiating the first-in-human study of XmAb412, our novel TL1A x IL23p19 bispecific antibody, in the third quarter of 2026. XmAb412 utilizes our novel XenLock Fab domain platform, which enables multi-specific biologics designed to address the very stringent requirements for high potency, long half-life and low immunogenicity in the treatment of autoimmune and inflammatory disease."

Wholly Owned Pipeline Overview

XmAb819 (ENPP3 x CD3), a first-in-class, tumor-targeted T-cell engaging XmAb 2+1 bispecific antibody in development for patients with advanced clear cell renal cell carcinoma (ccRCC).

Xencor plans to present expansion cohort data from the ongoing Phase 1 study to define a recommended Phase 3 target dose at a medical conference in 2H26 and support initiation of a pivotal study of XmAb819 in ccRCC planned for 2027.
Tumor expansion cohorts in ENPP3+ colorectal cancer (CRC), non-small cell lung cancer (NSCLC) and papillary renal cell carcinoma (pRCC) are open to enrollment.
Xencor plans to initiate a sub-study in patients with advanced ccRCC who have not previously received treatment with a tyrosine kinase inhibitor (TKI) in 3Q26.
XmAb541 (CLDN6 x CD3), a first-in-class, tumor-targeted T-cell engaging XmAb 2+1 bispecific antibody in Phase 1 clinical development for patients with advanced gynecologic and germ cell tumors.

Xencor plans to present Phase 1 dose-escalation data to define a recommended Phase 3 target dose in 2H26 and evaluate plans for a pivotal study of XmAb541 during 2027.
Additionally, Xencor is initiating a new clinical study to evaluate the combination of XmAb541 and XmAb808 (B7H3 x CD28) for patients with CLDN6+ high-grade serous ovarian cancer. XmAb808 is a bispecific antibody designed to provide conditional co-stimulation of T cells. Xencor presented a poster characterizing preclinical combinations of XmAb808 with multiple CD3 T cell engaging bispecific antibodies, including XmAb541, at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting in April 2026.
XmAb942 (Xtend anti-TL1A), a potential best-in-class, high-potency, extended half-life antibody in development for patients with inflammatory bowel disease.

Xencor is conducting the XENITH-UC Study, a global Phase 2b study of XmAb942 in ulcerative colitis (UC). XENITH-UC is a randomized, double-blind, placebo-controlled trial in patients with moderately to severely active UC, whose disease has progressed after at least one conventional or advanced therapy.
Xencor presented final results from the Phase 1 dose-escalation study of XmAb942 in healthy participants at Digestive Disease Week (DDW) in May 2026. All dose levels and routes of administration were well tolerated. XmAb942’s immunogenicity profile supports best-in-class drug exposure, and no impacts of anti-drug antibodies on safety or tolerability or on the population pharmacokinetic model were observed. The estimated terminal half-life of 74 days supports the single subcutaneous injection 12-week dosing interval used during the maintenance treatment period in XENITH-UC.
Enrollment expectations support a XENITH-UC blinded interim analysis around year-end 2026 and reaching the primary endpoint of the 12-week induction period during the second half of 2027. The primary endpoint is percentage of patients achieving clinical remission defined by the modified Mayo score at week 12.
XmAb412 (TL1A x IL23p19), a novel bispecific antibody format using the XenLock platform for dual targeting of inflammatory pathways in autoimmune and inflammatory disease.

Xencor presented preclinical characterization of XmAb412 at DDW in May 2026. XmAb412 robustly suppresses both TL1A and IL-23 inflammatory pathways and is predicted to have a human half-life between 60 and 70 days. XmAb412 supports high-concentration, low viscosity and citrate-free formulation suitable for subcutaneous dosing.
Xencor plans to initiate a first-in-human study of XmAb412 in 3Q26.
Plamotamab (CD20 x CD3), a clinical-stage, B-cell depleting bispecific T-cell engager in Phase 1 development for patients with rheumatoid arthritis (RA), who have progressed through prior standard-of-care treatment.

Xencor plans to provide an update on progress achieved in the Phase 1b study of plamotamab in RA in 2H26.
XmAb657 (CD19 x CD3), a clinical-stage, potent, extended half-life B-cell depleting bispecific T-cell engager in Phase 1 dose escalation, enrolling healthy participants and patients with idiopathic inflammatory myopathies (IIM).

Xencor plans to provide an update on progress achieved in the Phase 1 study of XmAb657 in 2H26.
Financial Guidance: Based on current operating plans, Xencor expects to end 2026 with between $380 million and $400 million in cash, cash equivalents and marketable debt securities, and to have sufficient cash resources to fund research and development programs and operations into mid-2028.

Financial Results for the First Quarter Ended March 31, 2026

Cash, cash equivalents and marketable debt securities totaled $541.8 million as of March 31, 2026, compared to $610.8 million as of December 31, 2025.

Revenue for the first quarter ended March 31, 2026 was $4.5 million, compared to $32.7 million for the same period in 2025. Revenue earned in the first quarter of 2026 was primarily non-cash royalty revenue from Incyte and Alexion, compared to the same period in 2025, which was primarily non-cash royalty revenue from Alexion and Incyte and milestone revenue from Incyte and Vir. Revenue for the first quarter ended March 31, 2026 includes a one-time $6.6 million reduction due to royalties on disputed U.S. sales due from Alexion.

Research and development (R&D) expenses for the first quarter ended March 31, 2026 were $64.7 million, compared to $58.6 million for the same period in 2025. Increased R&D spending for the first quarter of 2026 compared to 2025 is primarily due to increased spending on pipeline programs, partially offset by reduced lower stock-based compensation expense.

General and administrative (G&A) expenses for the first quarter ended March 31, 2026 were $17.7 million, compared to $17.3 million for the same period in 2025. G&A spending for the first quarter 2026 compared to 2025 remained relatively consistent.

Other expense, net, for the first quarter ended March 31, 2026 was $50.8 million, compared to $5.1 million for the same period in 2025. Increased other expense, net, for the first quarter of 2026, compared to 2025, is primarily due to unrealized losses on an equity security.

Net loss attributable to Xencor for the first quarter ended March 31, 2026 was $128.9 million, or $(1.71) on a fully diluted per share basis, compared to net loss of $48.4 million, or $(0.66) on a fully diluted per share basis, for the same period in 2025.

Upcoming Investor Conference

Company management will present at the BofA Securities Health Care Conference on Tuesday, May 12, 2026 at 3:00 p.m. PDT. A live webcast of the presentation will be available under "Events & Presentations" in the Investors section of the Company’s website located at www.xencor.com. A replay of the event will be available on the Xencor website for at least 30 days following the presentation.

(Press release, Xencor, MAY 6, 2026, View Source [SID1234665211])

On May 6, 2026 Nona Biosciences ("Nona" or the "Company"), a global biotechnology company advancing biotherapeutic discovery through innovative technology platforms, reported the appointment of Dr. Josh Xiao as Chief Scientific Officer (CSO). Dr. Xiao will be based in both US and China and report directly to Dr. Di Hong, Chief Executive Officer of Nona Biosciences.

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In this role, Dr. Xiao will lead the development of Nona’s global scientific strategy and oversee the continued evolution of its technology platforms, especially Hu-mAtrIx, the AI-driven drug discovery platform, with the goal of strengthening the company’s long-term competitive advantage through integrated technological capabilities and ecosystem collaboration. He will also guide the direction of scientific innovation and support the advancement of novel therapeutic approaches across multiple disease areas. In addition, Dr. Xiao will provide leadership to Nona’s global Project Leaders (PLs), establishing a structured and scalable capability development framework to enhance project execution, deepen scientific insight into partner needs, and enable efficient integration of platform resources.

Dr. Xiao brings more than 25 years of experience in drug discovery and leadership across both large biopharmaceutical companies and emerging biotechnology start-ups. He earned his Ph.D. in Biochemistry from Louisiana State University and did his postdoctoral training at Columbia University. Most recently, Dr. Xiao served as an entrepreneur in residence at RA Ventures, the healthcare incubator of RA Capital and co-founder of Starfish Medicines. Prior to that, he held scientific team leadership roles at Amgen, Tularik (acquired by Amgen), and Millennium Pharmaceuticals (acquired by Takeda), and led drug discovery function at several start-ups. His expertise spans target discovery and validation, antibody discovery and engineering, translational medicines, and IND filing.

Dr. Di Hong, Chief Executive Officer of Nona Biosciences, commented, "We are very pleased to welcome Josh to Nona at a pivotal stage in our growth. His extensive experience in drug discovery and translational medicines, as well as his strong track record in building high-performing scientific teams will be instrumental as we continue to enhance our platform capabilities and global scientific leadership. We believe he will further strengthen our ability to deliver high-quality innovation and create long-term value for our partners."

"Nona Biosciences has been a leader in discovery and development of fully human antibodies and multi-specifics with its proprietary H2L2 Harbour Mice platform, HCAb Harbour Mice platform, and Hu-mAtrIx AI-driven drug discovery platform, enabling several new ‘antibody+’ therapeutics modalities," said Dr. Josh Xiao, Chief Scientific Officer of Nona Biosciences. "I am thrilled to join the Nona Biosciences team, and very excited to help strengthen and expand our technology platforms to help our partners succeed."

(Press release, Nona Biosciences, MAY 6, 2026, View Source [SID1234665210])

On May 6, 2026 CRISPR Therapeutics (Nasdaq: CRSP) reported that members of its senior management team will present at the Bank of America Securities 2026 Global Healthcare Conference on Tuesday, May 12, 2026 1:40 p.m. PDT.

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A live webcast of the fireside chat will be available on the "Events & Presentations" page in the Investors section of the Company’s website at View Source A replay of the webcast will be archived on the Company’s website for 14 days following the presentation.

(Press release, CRISPR Therapeutics, MAY 6, 2026, View Source [SID1234665209])