Plain Language Summary of the KarMMa-3 study of ide-cel or standard of care regimens in people with relapsed or refractory multiple myeloma.

WHAT IS THIS SUMMARY ABOUT?: This plain language summary describes the results of a Phase 3 study called KarMMa-3. In this ongoing study, researchers looked at a relatively new treatment for people with multiple myeloma, a type of blood cancer, whose cancer got worse despite treatment (refractory) or had cancer that at first improved with treatment, but eventually stopped responding (relapsed). HOW WAS THIS STUDY CONDUCTED?: In the KarMMa-3 study, people with relapsed or refractory multiple myeloma received either a one-time infusion of a new treatment, named ide-cel, or one of the standard of care regimens currently available for patients with this cancer. People were treated with the standard of care regimens in weekly or monthly cycles until the cancer got worse, there were unacceptable side effects, or the person withdrew from the study. WHAT WERE THE RESULTS?: The results of this study showed that people receiving the one-time infusion of ide-cel lived longer without the cancer getting worse and had a greater reduction in cancer cells than patients receiving the standard of care regimen. A higher percentage of patients receiving ide-cel responded to treatment than patients receiving the standard of care regimen, and the response to treatment was better with idecel. These results show that ide-cel is a promising treatment for this challenging disease. Clinical Trial Registration: NCT03651128 (KarMMa-3 study).

Ide-cel or Standard Regimens in Relapsed and Refractory Multiple Myeloma.

BACKGROUND: Survival is poor among patients with triple-class-exposed relapsed and refractory multiple myeloma. Idecabtagene vicleucel (ide-cel), a B-cell maturation antigen-directed chimeric antigen receptor (CAR) T-cell therapy, previously led to deep, durable responses in patients with heavily pretreated relapsed and refractory multiple myeloma. METHODS: In this international, open-label, phase 3 trial involving adults with relapsed and refractory multiple myeloma who had received two to four regimens previously (including immunomodulatory agents, proteasome inhibitors, and daratumumab) and who had disease refractory to the last regimen, we randomly assigned patients in a 2:1 ratio to receive either ide-cel (dose range, 150×106 to 450×106 CAR-positive T cells) or one of five standard regimens. The primary end point was progression-free survival. Key secondary end points were overall response (partial response or better) and overall survival. Safety was assessed. RESULTS: A total of 386 patients underwent randomization: 254 to ide-cel and 132 to a standard regimen. A total of 66% of the patients had triple-class-refractory disease, and 95% had daratumumab-refractory disease. At a median follow-up of 18.6 months, the median progression-free survival was 13.3 months in the ide-cel group, as compared with 4.4 months in the standard-regimen group (hazard ratio for disease progression or death, 0.49; 95% confidence interval, 0.38 to 0.65; P<0.001). A response occurred in 71% of the patients in the ide-cel group and in 42% of those in the standard-regimen group (P<0.001); a complete response occurred in 39% and 5%, respectively. Data on overall survival were immature. Adverse events of grade 3 or 4 occurred in 93% of the patients in the ide-cel group and in 75% of those in the standard-regimen group. Among the 225 patients who received ide-cel, cytokine release syndrome occurred in 88%, with 5% having an event of grade 3 or higher, and investigator-identified neurotoxic effects occurred in 15%, with 3% having an event of grade 3 or higher. CONCLUSIONS: Ide-cel therapy significantly prolonged progression-free survival and improved response as compared with standard regimens in patients with triple-class-exposed relapsed and refractory multiple myeloma who had received two to four regimens previously. The toxicity of ide-cel was consistent with previous reports. (Funded by 2seventy bio and Celgene, a Bristol-Myers Squibb company; KarMMa-3 ClinicalTrials.gov number, NCT03651128.).

Local Delivery of OncoVEXmGM-CSF Generates Systemic Antitumor Immune Responses Enhanced by Cytotoxic T-Lymphocyte-Associated Protein Blockade.

Purpose: Talimogene laherparepvec, a new oncolytic immunotherapy, has been recently approved for the treatment of melanoma. Using a murine version of the virus, we characterized local and systemic antitumor immune responses driving efficacy in murine syngeneic models.Experimental Design: The activity of talimogene laherparepvec was characterized against melanoma cell lines using an in vitro viability assay. Efficacy of OncoVEXmGM-CSF (talimogene laherparepvec with the mouse granulocyte-macrophage colony-stimulating factor transgene) alone or in combination with checkpoint blockade was characterized in A20 and CT-26 contralateral murine tumor models. CD8+ depletion, adoptive T-cell transfers, and Enzyme-Linked ImmunoSpot assays were used to study the mechanism of action (MOA) of systemic immune responses.Results: Treatment with OncoVEXmGM-CSF cured all injected A20 tumors and half of contralateral tumors. Viral presence was limited to injected tumors and was not responsible for systemic efficacy. A significant increase in T cells (CD3+/CD8+) was observed in injected and contralateral tumors at 168 hours. Ex vivo analyses showed these cytotoxic T lymphocytes were tumor-specific. Increased neutrophils, monocytes, and chemokines were observed in injected tumors only. Importantly, depletion of CD8+ T cells abolished all systemic efficacy and significantly decreased local efficacy. In addition, immune cell transfer from OncoVEXmGM-CSF-cured mice significantly protected from tumor challenge. Finally, combination of OncoVEXmGM-CSF and checkpoint blockade resulted in increased tumor-specific CD8+ anti-AH1 T cells and systemic efficacy.Conclusions: The data support a dual MOA for OncoVEXmGM-CSF that involves direct oncolysis of injected tumors and activation of a CD8+-dependent systemic response that clears injected and contralateral tumors when combined with checkpoint inhibition. Clin Cancer Res; 23(20); 6190-202. ©2017 AACR.

Apo2L/TRAIL and the death receptor 5 agonist antibody AMG 655 cooperate to promote receptor clustering and antitumor activity.

Death receptor agonist therapies have exhibited limited clinical benefit to date. Investigations into why Apo2L/TRAIL and AMG 655 preclinical data were not predictive of clinical response revealed that coadministration of Apo2L/TRAIL with AMG 655 leads to increased antitumor activity in vitro and in vivo. The combination of Apo2L/TRAIL and AMG 655 results in enhanced signaling and can sensitize Apo2L/TRAIL-resistant cells. Structure determination of the Apo2L/TRAIL-DR5-AMG 655 ternary complex illustrates how higher order clustering of DR5 is achieved when both agents are combined. Enhanced agonism generated by combining Apo2L/TRAIL and AMG 655 provides insight into the limited efficacy observed in previous clinical trials and suggests testable hypotheses to reconsider death receptor agonism as a therapeutic strategy.

Combined therapy with the RANKL inhibitor RANK-Fc and rhApo2L/TRAIL/dulanermin reduces bone lesions and skeletal tumor burden in a model of breast cancer skeletal metastasis.

In bone metastases, tumor cells interact with the bone microenvironment to induce osteoclastogenesis, leading to bone destruction and the growth factor release.  RANK ligand (RANKL) is essential for osteoclast formation, function, and survival.  Tumor cell-mediated osteolysis is thought to occur ultimately via induction of RANKL within the bone stroma, and inhibition of RANKL in models of breast cancer bone metastases blocks tumor-induced osteolysis and reduces skeletal tumor burden.  In addition, the skeleton is co-opted by tumor cells and functions as a supportive tumor microenvironment.  Inhibition of RANKL, by reducing tumor-induced osteoclastogenesis, may reduce the local release of growth factors and calcium which may potentially enhance the anti-tumor activity of cytotoxic or direct tumor apoptotic agents.  Recombinant human Apo2 ligand/ TNF-related apoptosis-inducing ligand (rhApo2L/TRAIL/dulanermin) is a dual pro-apoptotic receptor agonist that preferentially induces apoptosis in cancer cells versus normal cells.  We therefore examined RANKL inhibition (using RANK-Fc) in combination with rhApo2L/TRAIL on tumor-induced osteolysis and skeletal tumor burden in a murine intracardiac injection model of MDA-MB-231 breast carcinoma bone metastasis.  rhApo2L/TRAIL treatment resulted in a rapid reduction of skeletal tumor burden. Treatment with RANK-Fc prevented osteolytic lesions and reduced skeletal tumor burden. Combining RANK-Fc with rhApo2L/TRAIL was superior to either rhApo2L/TRAIL or RANK-Fc alone at reducing skeletal tumor burden in the bone metastasis model.  Our findings show that RANKL inhibition effectively inhibits pathologic osteolysis induced by human breast adenocarcinoma MDA-MB-231 cells in animals with established tumors, and also enhances the ability of rhApo2L/TRAIL to reduce skeletal tumor burden in vivo.

Induction of transgene-specific cytotoxic T lymphocyte responses after transplantation of gene-modified CD34+ cells despite nonablative immunosuppressive conditioning.

In previous studies we showed that low-dose irradiation and immunosuppression with cyclosporine and mycophenolate mofetil prolonged in vivo persistence of gene-modified T cells but was unable to induce tolerance. We hypothesized that the lack of sustained antigen presentation because of the limited life span of the infused T cells might be responsible for the lack of tolerance induction. Thus, we examined whether tolerance could be induced by infusion of long-lived stem cells. Two baboons were transplanted with YFP/neo-transduced CD34+ cells. The transgene-marked cells disappeared completely within 5 weeks and CD8+ transgene-specific cytotoxic T lymphocytes were detected in both animals. Thus, this nonablative conditioning regimen did not provide sufficient immunosuppression for the induction of tolerance after infusion of gene-modified CD34+ cells.