RAINIER Trial Data Update: Two Additional AML Patients Achieve Remission Within 30 Days of Treatment
Aptevo Therapeutics (NASDAQ:APVO) reported positive interim results from its RAINIER dose optimization trial for mipletamig in treating frontline AML patients. Two additional patients achieved remission within 30 days of treatment, bringing the total success rate to 9 out of 10 frontline patients across two trials.
The triplet combination of mipletamig + venetoclax + azacitidine achieved a 90% overall remission rate in frontline patients, significantly outperforming the 66% benchmark for the doublet therapy (venetoclax + azacitidine). The complete remission rate of 70% also surpasses the 36% rate from the Viale-A Pivotal trial.
In Cohort 2, which uses an 18mcg dosage level, three patients have been evaluated: two achieved remission within 30 days, while one progressed and passed away for unrelated reasons. Notably, no Cytokine Release Syndrome has been observed in the RAINIER trial, and all patients who achieved remission remain in remission.
Aptevo Therapeutics (NASDAQ:APVO) ha riportato risultati intermedi positivi dal suo trial di ottimizzazione della dose RAINIER per mipletamig nel trattamento dei pazienti con AML in fase iniziale. Due pazienti aggiuntivi hanno raggiunto la remissione entro 30 giorni dal trattamento, portando il tasso di successo totale a 9 su 10 pazienti in fase iniziale in due trial.
La combinazione tripla di mipletamig + venetoclax + azacitidina ha raggiunto un tasso di remissione complessivo del 90% nei pazienti in fase iniziale, superando significativamente il benchmark del 66% per la terapia doppia (venetoclax + azacitidina). Il tasso di remissione completa del 70% supera anche il tasso del 36% proveniente dal trial Viale-A Pivotal.
Nella Coorte 2, che utilizza un livello di dosaggio di 18mcg, sono stati valutati tre pazienti: due hanno raggiunto la remissione entro 30 giorni, mentre uno ha progredito ed è deceduto per motivi non correlati. È notevole che non sia stato osservato alcun Sindrome da Rilascio di Citochine nel trial RAINIER, e tutti i pazienti che hanno raggiunto la remissione rimangono in remissione.
Aptevo Therapeutics (NASDAQ:APVO) informó resultados interinos positivos de su ensayo de optimización de dosis RAINIER para mipletamig en el tratamiento de pacientes con LMA en primera línea. Dos pacientes adicionales lograron remisión dentro de los 30 días de tratamiento, llevando la tasa de éxito total a 9 de 10 pacientes en primera línea en dos ensayos.
La combinación triple de mipletamig + venetoclax + azacitidina logró una tasa de remisión general del 90% en pacientes en primera línea, superando significativamente el punto de referencia del 66% para la terapia doble (venetoclax + azacitidina). La tasa de remisión completa del 70% también supera la tasa del 36% del ensayo Viale-A Pivotal.
En la Cohorte 2, que utiliza un nivel de dosificación de 18mcg, se han evaluado tres pacientes: dos lograron remisión dentro de los 30 días, mientras que uno progresó y falleció por razones no relacionadas. Es notable que no se ha observado ningún Síndrome de Liberación de Citoquinas en el ensayo RAINIER, y todos los pacientes que lograron remisión permanecen en remisión.
Aptevo Therapeutics (NASDAQ:APVO)는 전방 AML 환자 치료를 위한 mipletamig의 RAINIER 용량 최적화 시험에서 긍정적인 중간 결과를 보고했습니다. 치료 후 30일 이내에 두 명의 추가 환자가 완전 관해에 도달했습니다, 이로 인해 두 개의 시험에서 전방 환자 10명 중 9명의 성공률이 달성되었습니다.
mipletamig + venetoclax + azacitidine의 삼중 조합은 전방 환자에서 90%의 전반적인 완전 관해율을 달성하여 이중 요법(venetoclax + azacitidine)의 66% 기준치를 크게 초과했습니다. 70%의 완전 관해율은 Viale-A Pivotal 시험의 36%를 초과합니다.
18mcg 용량 수준을 사용하는 코호트 2에서 세 명의 환자가 평가되었습니다: 두 명은 30일 이내에 완전 관해에 도달했으며, 한 명은 진행되어 비관련 사유로 사망했습니다. 특히, RAINIER 시험에서는 사이토카인 방출 증후군이 관찰되지 않았으며, 완전 관해에 도달한 모든 환자는 여전히 관해 상태를 유지하고 있습니다.
Aptevo Therapeutics (NASDAQ:APVO) a rapporté des résultats intermédiaires positifs de son essai d'optimisation de dose RAINIER pour le mipletamig dans le traitement des patients atteints de LMA en première ligne. Deux patients supplémentaires ont atteint la rémission dans les 30 jours suivant le traitement, portant le taux de succès total à 9 sur 10 patients en première ligne dans deux essais.
La combinaison triple de mipletamig + venetoclax + azacitidine a atteint un taux de rémission global de 90 % chez les patients en première ligne, dépassant de manière significative le seuil de 66 % pour la thérapie double (venetoclax + azacitidine). Le taux de rémission complète de 70 % dépasse également le taux de 36 % de l'essai Viale-A Pivotal.
Dans la Cohorte 2, qui utilise un niveau de dosage de 18mcg, trois patients ont été évalués : deux ont atteint la rémission dans les 30 jours, tandis qu'un a progressé et est décédé pour des raisons non liées. Il est à noter qu'aucun syndrome de libération de cytokines n'a été observé dans l'essai RAINIER, et tous les patients ayant atteint la rémission restent en rémission.
Aptevo Therapeutics (NASDAQ:APVO) berichtete über positive Zwischenresultate aus seiner RAINIER-Dosisoptimierungsstudie für mipletamig zur Behandlung von AML-Patienten in der Erstlinientherapie. Zwei zusätzliche Patienten erreichten innerhalb von 30 Tagen die Remission nach der Behandlung, was die Gesamterfolgsquote auf 9 von 10 Patienten in der Erstlinientherapie über zwei Studien erhöht.
Die Dreifachkombination aus mipletamig + venetoclax + azacitidin erzielte eine Gesamtremissionsrate von 90% bei Patienten in der Erstlinientherapie und übertraf damit deutlich den Benchmark von 66% für die Doppeltherapie (venetoclax + azacitidin). Die vollständige Remissionsrate von 70% übertrifft ebenfalls die 36% des Viale-A Pivotal-Tests.
In Kohorte 2, die ein Dosierungsniveau von 18mcg verwendet, wurden drei Patienten evaluiert: zwei erreichten innerhalb von 30 Tagen die Remission, während einer fortschritt und aus nicht zusammenhängenden Gründen verstarb. Bemerkenswert ist, dass im RAINIER-Test kein Zytokinfreisetzungssyndrom beobachtet wurde und alle Patienten, die eine Remission erreichten, weiterhin in Remission bleiben.
- 90% overall remission rate in frontline patients (9 out of 10)
- 70% complete remission rate, significantly higher than 36% benchmark
- No Cytokine Release Syndrome observed to date
- All patients maintaining remission status
- Two new patients achieved remission within 30 days
- One patient in Cohort 2 progressed after first cycle
Insights
Aptevo's latest RAINIER trial data demonstrates compelling efficacy for mipletamig in frontline AML patients unfit for intensive chemotherapy. The triplet combination therapy (mipletamig + venetoclax + azacitidine) has now achieved a 90% remission rate (9/10 patients) across two trials, substantially outperforming the
The absence of Cytokine Release Syndrome (CRS) - a common severe immune reaction with many CD3-targeting bispecifics - represents a significant safety advantage that could differentiate mipletamig from competitors. This safety profile potentially enables outpatient administration, expanding market accessibility and reducing treatment costs considerably.
While one patient in Cohort 2 progressed and died (unrelated to study drugs), the overall data strengthens mipletamig's clinical profile. As the second cohort nears completion at the established 18mcg dose level, Aptevo is building a consistent efficacy and safety narrative that positions mipletamig as a potential breakthrough in frontline AML therapy for this underserved elderly population.
The drug's unique CRIS-7 derived binding domain appears to be translating into real clinical differentiation, suggesting Aptevo's ADAPTIR platform may hold broader applications beyond this single indication.
Across two trials, 9 of 10 frontline AML patients achieved remission when treated with mipletamig in combination with the standard of care
Triplet Combination with mipletamig continues to outperform doublet combination benchmark
No Cytokine Release Syndrome (CRS) has been observed in the RAINIER trial to date
Cohort 2 enrollment nears completion
SEATTLE, WA / ACCESS Newswire / March 20, 2025 / Aptevo Therapeutics ("Aptevo") (NASDAQ:APVO), a clinical-stage biotechnology company developing novel bispecific immuno-oncology therapeutics based on its proprietary ADAPTIR® and ADAPTIR-FLEX® platform technologies, today announced two additional frontline AML patients have achieved remission* within 30 days of treatment in the Company's RAINIER dose optimization trial evaluating mipletamig in combination with standard of care for patients unfit for intensive chemotherapy. In total, 9 of 10 frontline patients across two trials achieved remission* when receiving the triplet combination of mipletamig + venetoclax + azacitidine (ven/aza). Notably, no CRS has been reported in the RAINIER trial to date.
The data builds on previously reported favorable outcomes from RAINIER's Cohort 1 and the completed dose expansion trial where
Cohort 2 will include six patients, dosed at the 18mcg level, the same dose used in combination with ven/aza in the completed expansion trial.
Three patients evaluable for efficacy achieved the following outcomes:
Two patients achieved remission withing 30 days of being dosed
One patient progressed after the first cycle and passed away for reasons unrelated to study drugs
Cohort 2 enrollment is nearing completion
"We're now past the halfway mark in Cohort 2 of the RAINIER trial and are thrilled by the continued, highly favorable remission results," said Dirk Huebner, MD, Chief Medical Officer of Aptevo. " This emerging pattern further supports mipletamig's impact on treatment outcomes in frontline AML patients who are not fit for intensive chemotherapy and who would otherwise receive ven/aza as the standard of care. One of our primary goals with the RAINIER trial is to demonstrate the contribution of mipletamig's unique mechanism of action when used in combination with venetoclax and azacitidine. By targeting AML this way, our approach has the potential to improve outcomes, particularly for elderly patients who have limited treatment options."
Mipletamig, a differentiated by design CD3 x CD123 bispecific antibody built on Aptevo's ADAPTIR platform and driven by a unique CRIS-7 derived binding domain, is being investigated as frontline therapy in combination with venetoclax and azacitidine, the current standard of care for AML patients who are unfit for intensive chemotherapy. These latest results further reinforce mipletamig's potential as a transformative treatment, supported by impressive efficacy, safety, and tolerability data from two prior clinical trials involving almost 100 patients.
*Remission = complete remission (CR) and, complete remission with blood markers that have not yet recovered (CRi).
About RAINIER
RAINIER, a frontline AML study, is a Phase 1b/2 dose optimization, multi-center, multi-cohort, open label study of up to 39 patients who are being treated across five dose levels ranging from 9 mcg - 140 mcg in combination with venetoclax and azacitidine (ven/aza). Subjects will be adults aged 18 or older, newly diagnosed with AML who are not eligible for intensive induction chemotherapy. Phase 1b consists of 28-day cycles of treatment in five sequential cohorts. Aptevo has partnered with Prometrika (https://www.prometrika.com/), a premier contract research organization for the trial. RAINIER will be conducted in two parts. First, a Phase 1b dose optimization study in frontline AML patients followed by a Phase 2 study.
Cohort 1 included 3 patients, dosed at the 9mcg level.
All patients achieved remission* within 30 days
Thus far, all patients who achieved remission remain in remission.
One CR patient had no minimal residual disease (MRD-negative status) and was positive for the TP53 genetic mutation, which is generally associated with poor prognosis due to chemotherapy resistance, genetic instability, and overall treatment challenges
About Mipletamig
Aptevo's wholly owned lead proprietary drug candidate, mipletamig, targeting AML, MDS and other leukemias, 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 a unique CD3 derived from CRIS-7 vs. the CD3 used by other competitors. Mipletamig has received orphan drug designation ("orphan status") for AML according to the Orphan Drug Act. Mipletamig has been evaluated in almost 100 patients over three trials to date. RAINIER, Aptevo's Phase 1b/2 frontline AML program, was initiated in 3Q24.
About Aptevo Therapeutics
Aptevo Therapeutics Inc. (NASDAQ:APVO) is a clinical-stage biotechnology company focused on developing novel bispecific immunotherapies for the treatment of cancer. The company has two clinical candidates. Mipletamig is currently being evaluated in RAINIER, a Phase 1b/2 trial for the treatment of frontline acute myeloid leukemia in combination with standard of care venetoclax + azacitidine. Mipletamig has orphan status for AML according to the Orphan Drug Act. ALG.APV-527, a bispecific conditional 4-1BB agonist that is only active upon simultaneous binding to 4-1BB and 5T4, is being co-developed with Alligator Bioscience and is being evaluated in a Phase 1 clinical trial for the treatment of multiple solid tumor types likely to express 5T4. Aptevo has three pre-clinical candidates with different mechanisms of action designed to target a range of solid tumors. All pipeline candidates were created from two proprietary platforms, ADAPTIR® and ADAPTIR-FLEX®. The Aptevo mission is to improve treatment outcomes and transform the lives of cancer patients. For more information, please visit www.aptevotherapeutics.com.
Safe Harbor Statement
This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including, without limitation, Aptevo's expectations about the activity, efficacy, safety, tolerability and durability of its therapeutic candidates and potential use of any such candidates, including in combination with other drugs, as therapeutics for treatment of disease, its expectations regarding the effectiveness of its ADAPTIR and ADAPTIR-FLEX platforms, statements related to the progress of Aptevo's clinical programs, including statements related to anticipated clinical and regulatory milestones, whether further study of mipletamig in a Phase 1b dose optimization trial focusing on multiple doses of mipletamig in combination with venetoclax + azacitidine on a targeted patient population will continue to show remissions, whether Aptevo's final remission data or trial results will vary from its earlier assessment, whether Aptevo's strategy will translate into an improved overall survival in AML, especially among patient subgroups with poor prognosis, whether further study of ALG.APV-527 across multiple tumor types will continue to show clinical benefit, the possibility and timing of future preliminary or interim data readouts for ALG.APV-527, statements related to the progress of and enthusiasm for Aptevo's clinical programs, statements related to Aptevo's ability to generate stockholder value, whether Aptevo will continue to have momentum in its business in the future, and any other statements containing the words "may," "continue to," "believes," "knows," "expects," "optimism," "potential," "designed," "promising," "plans," "will" and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based on Aptevo's current intentions, beliefs, and expectations regarding future events. Aptevo cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from Aptevo's expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement.
There are several important factors that could cause Aptevo's actual results to differ materially from those indicated by such forward-looking statements, including a deterioration in Aptevo's business or prospects; further assessment of preliminary or interim data or different results from later clinical trials; adverse events and unanticipated problems, adverse developments in clinical development, including unexpected safety issues observed during a clinical trial; and changes in regulatory, social, macroeconomic and political conditions. For instance, actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the uncertainties inherent in the results of preliminary or interim data and preclinical studies being predictive of the results of later-stage clinical trials, initiation, enrollment and maintenance of patients, and the completion of clinical trials, the availability and timing of data from ongoing clinical trials, the trial design includes combination therapies that may make it difficult to accurately ascertain the benefits of mipletamig, expectations for the timing and steps required in the regulatory review process, expectations for regulatory approvals, the impact of competitive products, our ability to enter into agreements with strategic partners or raise funds on acceptable terms or at all and other matters that could affect the availability or commercial potential of Aptevo's product candidates, business or economic disruptions due to catastrophes or other events, including natural disasters or public health crises such as the coronavirus (referred to as COVID-19), geopolitical risks, including the current war between Russia and Ukraine, war between Israel and Hamas, and macroeconomic conditions such as economic uncertainty, rising inflation and interest rates, continued market volatility and decreased consumer confidence. These risks are not exhaustive, Aptevo faces known and unknown risks. Additional risks and factors that may affect results are set forth in Aptevo's filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and its subsequent reports on Form 10-Q and current reports on Form 8-K. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from Aptevo's expectations in any forward-looking statement. Any forward-looking statement speaks only as of the date of this press release, and, except as required by law, Aptevo does not assume any obligation to update any forward-looking statement to reflect new information, events, or circumstances.
Aptevo Therapeutics
Miriam Weber Miller
Aptevo Therapeutics
IR@apvo.com or millerm@apvo.com
+1 (206) 859 6629
SOURCE: Aptevo Therapeutics
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