Tandem 2026: Key Advances in Cellular Therapy and Transplantation

Investigators and clinicians gathered in Salt Lake City for the 2026 Tandem Meetings amid rapid evolution in cellular therapy. Across lymphoma, leukemia, multiple myeloma, and transplant-related infectious complications, the most anticipated presentations reflected a consistent theme: moving beyond proof-of-concept toward platform refinement by improving safety, shortening manufacturing timelines, and expanding access to patients who have historically been unable to receive these therapies.

From next-generation CAR-T constructs delivering deep responses with markedly improved toxicity profiles to immune-cloaked allogeneic products designed to scale “off the shelf,” here are 6 clinically oriented abstracts that may shape near-term practice.

What to Watch in Aggressive B-Cell Lymphoma

Late-Breaking: EB-103 (ARTEMIS Platform)—A TCR-Mimetic CAR-T Approach With High Response Rates and Mostly Low-Grade Toxicity

Presentation: STARLIGHT-1 Phase 1 Trial (NCT06343311) by Nassim Esteghamat, MD

Among the most closely watched updates at Tandem were late-breaking phase 1 data for EB-103, a CD19-targeted cellular therapy built on a two-component platform designed to mimic physiologic T-cell receptor signaling.¹ At the recommended dose level, EB-103 produced a 100% overall response rate (ORR) and 100% complete response (CR) rate in evaluable patients at that dose level, alongside exclusively grade 1/2 cytokine release syndrome (CRS).

Across the broader evaluable cohort, responses remained encouraging, and all patients achieving CR remained in remission at data cutoff, with durations extending out to more than a year in some cases.

The enrolled population reflected real-world complexity: the median age was 67 years, with a meaningful subset aged 75 years or older; high-risk histologies included double-hit and double-expressor disease; bulky disease in roughly one-third; and prior autologous transplant exposure. Notably, the trial included a patient with primary central nervous system (CNS) lymphoma without an apparent signal of disproportionate toxicity, an especially relevant finding given historic concerns surrounding neurologic risk in CNS involvement.

Mechanistically, the ARTEMIS platform separates antigen recognition and costimulation into 2 distinct surface components, which may allow more tightly regulated activation while limiting tonic signaling and inflammatory cytokine release. Manufacturing was successful for all patients who underwent apheresis, with an average production time on the order of weeks.

Why it matters: If expanded cohorts confirm durable responses with consistently favorable CRS and immune effector cell-associated neurotoxicity syndrome (ICANS) profiles, this platform could broaden eligibility, particularly for older, frailer patients and select CNS lymphoma populations where toxicity concerns often limit CAR-T deployment.

What to Watch in B-Cell Lymphomas

KITE-753: Dual-Target CD19/CD20 CAR-T With Rapid Manufacturing and Minimal Severe Toxicity

Presentation: Phase 1 Study (NCT04989803) by Saurabh Dahiya, MD, FACP

Dual-targeting CAR-T constructs were a major theme at Tandem 2026, and KITE-753 stood out for its combination of efficacy, speed, and tolerability. In the phase 1 study, KITE-753—a dual-target CD19/CD20 product—achieved high complete response rates at the recommended dose level, while demonstrating no grade 3 or higher CRS and no grade 3 or higher ICANS events in reported cohorts.²

In CAR-naïve patients treated at the recommended dose (dose level 3), the ORR was 86%, with 79% achieving CR; all complete responders remained in CR at month 3. The median time to first response was 29 days, consistent with delayed but robust CAR-T kinetics.

KITE-753 employs a “DuoCore” configuration that pairs CD19 and CD20 targeting with distinct costimulatory domains (CD28 for CD19; 4-1BB for CD20) expressed within the same T cell. This architecture is intended to reduce antigen escape while modulating inflammatory signaling relative to traditional CD19-only approaches.

The trial also highlighted a key operational advance: rapid manufacturing, with a median 13-day leukapheresis-to-delivery timeline. If reproducible in broader rollouts, this could reduce bridging therapy needs and expand CAR-T feasibility for patients with rapidly progressive disease.

Why it matters: Rapid manufacturing plus low severe toxicity rates may shift how clinicians think about CAR-T candidacy, especially in older patients or those with comorbidities where toxicity risk and logistical delays currently limit access. Registrational studies in second- and third-line settings are underway.

What to Watch in CLL and Disease-Specific CAR-T Optimization

LV20.19 in Relapsed/Refractory CLL: Durable Disease Control With a Distinct IEC-HS Signal

Presentation: Phase 1/2 Trial (NCT04186520) by Nirav Shah, MD

CAR-T therapy in CLL continues to evolve toward disease-specific optimization, and phase 1 data for LV20.19 underscored why.³ In heavily pretreated patients (median of 4 prior lines; most were double-refractory to BTK inhibitors and BCL-2 inhibitors), LV20.19 delivered deep responses, including a 78% CR/CRi rate, high rates of minimal residual disease (MRD) negativity in assessed patients, and a reported median progression-free survival of 32 months with a 24-month overall survival rate of 79%.

However, the presentation also highlighted a critical toxicity pattern: immune effector cell–associated hemophagocytic syndrome–like syndrome (IEC-HS) occurred in roughly half of patients, with markedly elevated ferritin and a cytokine signature that differed from classic CRS, most notably with absence of IL-6 elevation. These features suggest a mechanistically distinct inflammatory syndrome that may not be adequately managed by tocilizumab (Actemra)-centered strategies alone, and investigators described using anakinra as a key next-line intervention.

In response to grade 3/4 toxicities at the initial dosing level, investigators reduced the CAR-T dose from 2.5 × 10⁶ cells/kg to 1 × 10⁶ cells/kg. At the lower dose, grade 3/4 CRS and ICANS were eliminated, IEC-HS severity decreased, and efficacy appeared to be preserved, including similar expansion kinetics and response rates.

Why it matters: These data reinforce that CAR-T dosing and toxicity mitigation should be tailored to disease biology. For CLL and related marrow-/blood-enriched malignancies, IEC-HS recognition and preplanned management pathways may be as essential as CRS/ICANS algorithms.

What to Watch in Multiple Myeloma and Off-the-Shelf Cellular Therapy

CB-011: Immune-Cloaked Allogeneic Anti-BCMA CAR-T Shows Deep Responses Without GVHD

Presentation: CaMMouflage Phase 1 Trial (NCT05722418) by Adriana Rossi, MD

Off-the-shelf CAR-T remains one of the most consequential frontiers in cellular therapy, and updated phase 1 data for CB-011 addressed several long-standing barriers: manufacturing delays, scalability, and graft-versus-host disease (GVHD).⁴ In the CaMMouflage trial, CB-011—an allogeneic anti-BCMA CAR-T product with multi-layer immune cloaking—achieved a 92% ORR with 75% CR or better rate at the recommended dose among patients with no prior BCMA-directed therapy, alongside no reported GVHD.

Responses were notable in clinically challenging subgroups, including patients with high-risk cytogenetics and extramedullary disease; presentations described clearance of extramedullary lesions, including true soft tissue plasmacytomas. Among evaluable patients, MRD negativity was frequent, and durable responses were observed, including a longest responder with an MRD-negative stringent CR extending beyond 21 months.

CB-011 incorporates multiple genetic modifications aimed at preventing host immune rejection (including MHC class I downregulation and NK inhibitory signaling). Importantly, correlative findings emphasized that lymphodepletion intensity still matters; stronger cyclophosphamide-based depletion was associated with improved CAR-T expansion and efficacy.

The safety profile featured mostly low-grade CRS and limited neurotoxicity signals, although a delayed Guillain-Barré syndrome case was reported, underscoring the need for continued monitoring as cohorts expand.

Why it matters: If durability and safety remain favorable in expansion cohorts, CB-011 could expand access for the majority of eligible patients who do not currently receive autologous CAR-T due to logistics, timing, and capacity constraints while potentially reducing prolonged immune suppression seen with continuously dosed bispecific antibodies.

What to Watch Beyond CAR-T: Innate Cellular Platforms

RB-1355: Intratumoral Autologous Macrophage Therapy Produces Systemic Activity With Minimal Toxicity

Presentation: First-in-Human Phase 1 Study by Paolo Strati, MD

Tandem also featured emerging innate immune cellular therapies aimed at patients who have exhausted T-cell–directed options. In a first-in-human phase 1 trial, RB-1355—an intratumoral therapy composed of autologous, repolarized M1 macrophages—demonstrated systemic antitumor activity across heavily pretreated B-cell and T-cell lymphomas, including in patients previously treated with CAR-T and bispecific antibodies.⁵

Across 13 patients (median 4 prior lines), there were complete responses in large B-cell lymphoma and responses in T-cell lymphoma subtypes. RB-1355 is notable for practical reasons: rapid manufacturing (about 1 week), no genetic modification, no requirement for lymphodepleting chemotherapy, and a favorable safety profile without dose-limiting toxicities.

Single-cell sequencing and correlative analyses suggested increases in intratumoral immune populations and trafficking into peripheral blood, offering mechanistic support for systemic responses.

Why it matters: Antigen-agnostic, low-toxicity cellular platforms may become essential salvage tools in the post–CAR-T and post-bispecific era, particularly for patients who are frail or those with antigen escape or pan-negative disease.

What to Watch in Supportive Care for Transplant and CAR-T Programs

Pritelivir: Phase 3 Data Suggest a New Standard for Refractory HSV in Immunocompromised Patients

Presentation: PRIOH-1 Phase 3 Trial (NCT03073967) by Genoveva Papanicolaou, MD

Cellular therapy success hinges on supportive care infrastructure, and phase 3 data for pritelivir addressed a major unmet need: refractory HSV in immunocompromised patients, where no FDA-approved therapies exist.⁶ In the PRIOH-1 trial, oral pritelivir (loading dose then daily dosing) achieved complete healing by day 28 in 62.7% of patients compared with 34% receiving investigator’s choice therapy—primarily intravenous foscarnet (Foscavir)—with statistically significant benefit.

Beyond efficacy, tolerability and feasibility were decisive: treatment completion was substantially higher with pritelivir, and discontinuation due to adverse events was far lower than in the comparator arm. Exposure-adjusted adverse event rates favored pritelivir, with fewer renal and electrolyte complications, which are key limitations of foscarnet-based regimens. Follow-up surveillance did not identify emergent pritelivir resistance when isolates were available.

Why it matters: A well-tolerated oral agent that outperforms intravenous salvage therapy could shift refractory HSV care from inpatient to outpatient settings, reducing toxicity, cost, and disruption to transplant or cellular therapy plans.

Looking Ahead

Across Tandem 2026, the most anticipated data converged on a central message: the field is shifting from bespoke innovation to implementation-ready refinement. Safety-optimized CAR-T designs challenge the idea that efficacy must come at the cost of severe CRS/ICANS, rapid manufacturing shortens the window where patients are lost to progression, disease-specific dosing frameworks (as in CLL) reinforce biology-driven deployment, immune-cloaked allogeneic CAR-T signals a plausible route to scalability, and supportive-care breakthroughs strengthen the foundation required to deliver these therapies safely.

As multiple programs advance through expansion cohorts and registrational pathways, the coming years may meaningfully broaden access to cellular therapies while improving real-world durability and tolerability.

References

1. Esteghamat N, Wang P, Zimdahl B, Liu C, Abedi M. Phase 1 study of CD19 ARTEMIS T cells (EB-103) in patients with aggressive B-cell non-Hodgkin lymphoma. Presented at: 2026 Tandem Meetings; February 4–7, 2026; Salt Lake City, UT. Presentation LBA-1.
2. Dahiya S, Ulrickson M, Yared J, et al. A phase 1 study of KITE-753 or KITE-363 in patients with relapsed/refractory B-cell lymphoma: initial safety and preliminary efficacy of KITE-753 and updated results of KITE-363. Presented at: 2026 Tandem Meetings; February 4–7, 2026; Salt Lake City, UT. Presentation 74.
3. Shah N, Murthy GSG, Atallah EL, et al. Dual targeted lentiviral transduced anti-CD20/anti-CD19 (LV20.19) CAR T cells for relapsed, refractory CLL. Presented at: 2026 Tandem Meetings; February 4–7, 2026; Salt Lake City, UT. Presentation 75.
4. Rossi A, Costa L, Clark WB, et al. CB-011, an allogeneic anti-BCMA CAR-T cell therapy with immune cloaking, for patients with relapsed/refractory multiple myeloma (r/r MM): dose escalation results from the CaMMouflage phase 1 trial. Presented at: 2026 Tandem Meetings; February 4–7, 2026; Salt Lake City, UT. Presentation LBA-2.
5. Strati P, Feldman T, Kidder K, et al. Intratumoral cellular therapy with autologous activated M1 Sirpα-low macrophages in non-hodgkin lymphoma: clinical results from a first-in-human phase 1 study. Presented at: 2026 Tandem Meetings; February 4–7, 2026; Salt Lake City, UT. Presentation 76.
6. Papanicolaou G, Avery R, Workowski K, et al. Pritelivir demonstrated superior efficacy compared to investigator’s choice treatment for refractory herpes simplex virus infections in immunocompromised patients: PRIOH-1, phase 3 safety and efficacy. Presented at: 2026 Tandem Meetings; February 4–7, 2026; Salt Lake City, UT. Presentation LBA-3.