invIOs reports early APN401 Phase 1 findings, including disease stabilization in 5 of 10 evaluable patients with advanced solid tumors and preliminary safety data.
Written By: Malavatu Satvika, PharmD
Reviewed by: Pharmacally Editorial Team
invIOs GmbH has reported Phase 1 clinical findings for APN401, an investigational autologous cell therapy for patients with advanced, treatment-refractory solid tumors. Published in Molecular Therapy Oncology, the report describes findings from two Phase 1 studies involving 17 patients, including safety outcomes, disease stabilization, immune changes and the feasibility of decentralized manufacturing.
Preliminary Safety Findings in Heavily Pretreated Patients
A total of 17 patients received APN401 across three dose levels. Participants had advanced solid tumors and had received between two and eleven prior lines of systemic therapy.
According to the company, no dose-limiting toxicities, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), or grade 3 or higher treatment-related adverse events were reported. The highest evaluated dose, 4.5 × 10⁷ peripheral blood mononuclear cells (PBMCs) per kilogram, was selected as the recommended Phase 2 dose.
These findings provide preliminary safety information in a heavily pretreated population. However, the small cohort limits the ability to characterize uncommon adverse events or risks that may emerge with longer follow-up. Selection of a recommended Phase 2 dose also does not establish the optimal dose for clinical benefit.
Disease Stabilization and Exploratory Immune Changes
Disease stabilization was observed in five of the 10 patients evaluable according to the Response Evaluation Criteria in Solid Tumors (RECIST). The reported denominator is important: seven of the 17 treated patients were not included in this evaluable group, and the available announcement does not specify the reasons.
Stable disease indicates that patients did not meet the criteria for either sufficient tumor shrinkage to qualify as an objective response or sufficient worsening to qualify as progressive disease during the assessment period. It does not necessarily indicate tumor shrinkage or durable disease control.
Exploratory immune profiling identified systemic changes following treatment, including increased levels of cytotoxic mediators and expansion of specific T-cell populations. These changes were most pronounced in patients with stable disease.
The findings suggest a possible association between immune activation and disease stabilization. However, the small evaluable population and exploratory nature of the analyses prevent conclusions about causality or the ability of these immune changes to predict treatment response.
How APN401 Targets CBL-B
APN401 is an investigational autologous cell therapy manufactured from patients’ own PBMCs. Small interfering RNA (siRNA) is used to transiently silence CBL-B, an intracellular immune checkpoint that negatively regulates antigen receptor signaling and T-cell activation.
By temporarily reducing CBL-B activity, APN401 is designed to enhance immune-cell activity against tumors. The approach aims to strengthen immune responses that may otherwise be constrained by regulatory mechanisms within the tumor microenvironment.
Although the reported immune changes are consistent with this biological rationale, clinical evidence is still needed to establish whether CBL-B silencing translates into meaningful and durable antitumor activity.
Decentralized Manufacturing and Treatment Feasibility
APN401 is manufactured using invIOs’ proprietary EPiC point-of-care platform. The company reported a vein-to-vein time of less than 24 hours, reproducible manufacturing across sites and feasibility of repeated administration.
These findings address practical considerations for personalized cell therapies, in which manufacturing time and coordination between cell collection, processing and administration can influence treatment delivery. A shorter vein-to-vein interval may simplify treatment logistics, although the reported timeframe alone does not establish broader scalability or superiority over alternative manufacturing approaches.
Clinical Interpretation
The Phase 1 findings provide preliminary evidence that APN401 can be administered without the specified major safety signals in a small group of heavily pretreated patients. Disease stabilization in five of 10 RECIST-evaluable patients, alongside exploratory immune changes, supports further investigation but does not establish antitumor efficacy.
The selection of a recommended Phase 2 dose and the reported manufacturing feasibility support continued clinical development. Larger studies with clearly defined efficacy endpoints, adequate follow-up and more complete patient-level response assessments are needed to determine whether APN401 can produce durable clinical benefit. Further investigation must also establish whether the observed immune changes are associated with treatment outcomes and can help identify patients most likely to benefit.
Reference
invIOs publishes positive clinical data on CBL-B-silenced autologous cell therapy APN401 in peer-reviewed journal, invIOs GmbH, 15 October 2026
Alexander Dohnal et al, Phase I Evaluation of APN401, an Autologous CBL-B–Silenced PBMC Therapy, in Advanced Solid Tumors, Molecular Therapy Oncology, 2026, 201357, https://doi.org/10.1016/j.omton.2026.201357
About the Writer
Malavatu Satvika (Linkedin) is a Pharm.D professional and aspiring healthcare medical writer with clinical exposure and research experience. Her interests include medical writing, drug safety, pharmaceutical research, and evidence-based healthcare communication. She has contributed to two research publications in pharmaceutical journals and has gained practical experience in prescription review, patient counselling, medication review, adverse drug reaction monitoring, drug information services, literature review, and clinical documentation through regular hospital training.
She has completed certifications in clinical research, ICH-GCP E6(R3), data management for clinical research, and congenital hypothyroidism. With a strong foundation in pharmacy, clinical practice, and scientific research, she aims to translate complex medical and pharmaceutical information into accurate, clear, and evidence-based healthcare content. She is also preparing to pursue a PhD and further develop her expertise in medical writing and pharmaceutical research.