Anti-BCMA CAR T-Cell Therapy for Multiple Myeloma

SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years. With the introduction of new combinations of antimyeloma agents in earlier lines of therapy, patients with Relapsed/Refractory myeloma often have disease that is refractory to multiple drugs. There is an urgent unmet medical need for agents with novel mechanisms of action that are safe and effective, for patients with aggressive and resistant disease.

Chimeric Antigen Receptor (CAR) T-cell therapy has been associated with long-term disease control in some hematologic malignancies and showed promising activity in a Phase 1 study involving patients with Relapsed or Refractory myeloma. B-cell Maturation Antigen (BCMA) is a member of the Tumor Necrosis Factor superfamily of proteins. It is a transmembrane signaling protein primarily expressed by malignant and normal plasma cells and some mature B cells. BCMA is involved in JNK and NF-kB signaling pathways that induce B-cell development and autoimmune responses. BCMA has been implicated in autoimmune disorders, as well as B-lymphocyte malignancies, Leukemia, Lymphomas, and Multiple Myeloma.

Anti-BCMA CAR T-Cell Therapy is a type of immunotherapy and consists of T cells collected from the patient’s blood in a leukapheresis procedure. These T cells are then stimulated by treating with interleukin 2 (IL-2) and anti-CD3 antibodies in vitro, so that they will actively proliferate and expand to large numbers. These T cells are then genetically engineered to produce special receptors on their surface called Chimeric Antigen Receptors (CAR), by transducing with a gene encoding the engineered CAR, via a retroviral vector such as lentiviral vector. These reprogrammed cytotoxic T cells with the Chimeric Antigen Receptors on their surface are now able to recognize a specific antigen such as BCMA on tumor cells. These genetically engineered and reprogrammed CAR T-cells are grown in the lab and are then infused into the patient. These cells in turn proliferate in the patient’s body and the engineered receptor on the cell surface help recognize and kill cancer cells that expresses that specific antigen such as BCMA. The patient undergoes lymphodepletion chemotherapy with Fludarabine and Cytoxan prior to the introduction of the engineered CAR T-cells. By depleting the number of circulating leukocytes, cytokine production is upregulated and reduces competition for resources, which in turn promotes the expansion of the engineered CAR T-cells.
Anti-BCMA-CAR-T-Cell-Therapy-for-Multiple-Myeloma
ABECMA® (Idecabtagene vicleucel) is the first FDA approved cell-based gene therapy for multiple myeloma and was based on results from the pivotal, open-label, single-arm, multicenter, multinational, Phase II study (KarMMa trial), in which the efficacy and safety of ABECMA® was evaluated in adults with Relapsed and Refractory multiple myeloma. In this study, 128 patients with persistent disease after at least three previous regimens including a Proteasome Inhibitor, an immunomodulatory agent, and an anti-CD38 antibody, received ABECMA® target doses of 150×106 to 450×106 CAR-positive (CAR+) T cells, after receiving lymphodepleting chemotherapy. Lymphodepletion therapy consisted of Fludarabine 30 mg/m2 IV and Cyclophosphamide 300 mg/m2 IV given on 3 consecutive days, followed by 2 days of rest before ABECMA® infusion. The median patient age was 61 years and the median time from diagnosis was 6 years. About 51% of patients had a high tumor burden (50% or more bone marrow plasma cells), 39% had extramedullary disease and 35% had a high-risk cytogenetic abnormalities, defined as del(17p), t(4;14), or t(14;16). Patients had received a median of 6 previous antimyeloma regimens and 94% had received previous Autologous Hematopoietic Stem Cell Transplants. The Primary end point was an Overall Response Rate (ORR) as assessed by an Independent Review Committee (IRC) and key Secondary end point was a Complete Response or better (comprising complete and stringent Complete Responses). Other efficacy endpoints include Time to Response, Duration of Response, Progression Free Survival (PFS), Overall Survival (OS), Minimal Residual Disease (MRD) evaluated by Next-Generation Sequencing (NGS) assay, and Safety.

At a median follow up of 13.3 months, the ORR was 73%, and 33% had a complete or stringent Complete Response. Of those with a complete or stringent Complete Response, 79% had MRD-negative status at a sensitivity level of 10−5, corresponding to 26% of the treated population. This benefit was consistently observed in most subgroups examined, including older patients, those who received bridging therapy, and those with aggressive disease features, including high-risk cytogenetics, triple or penta-refractory disease, a high tumor burden, and extramedullary disease. The median time to first response was 1.0 month and the median time to a Complete Response or better was 2.8 months. The estimated median Duration of Response was 10.7 months for all patients and 11.3 months among those receiving the highest target dose. The response duration increased with the depth of response. The median PFS was 8.8 months for all patients and 20.2 months in patients having a complete or stringent Complete Response. Data on Overall Survival are immature. Cellular kinetic analysis confirmed CAR+ T cells in 59% at 6 months and 36% at 12 months after infusion. Common toxicities included neutropenia, anemia and thrombocytopenia. Cytokine Release Syndrome was reported in 84% of patients including 5% Grade 3 or higher events. Neurotoxic effects developed in 18% of patients.

It was concluded that ABECMA® induced deep and durable responses in majority of heavily pretreated patients with Refractory and Relapsed myeloma, and fulfills a highly unmet need for this patient group. It should however be noted that although some subsets of patients may have sustained responses for long periods of time, most patients eventually relapse. This has been attributed to the loss of CAR T-cells, loss of antigen expression on the tumor cell surface, or to impaired activity of T cells in an immunosuppressive microenvironment. Studies are underway to overcome these shortcomings by optimizing CAR design, as well as preventing antigen escape and developing combination therapies.

Idecabtagene Vicleucel in Relapsed and Refractory Multiple Myeloma. Munshi NC, Anderson LD, Shah N, et al. N Engl J Med 2021; 384:705-716

Infection Risk in Multiple Myeloma Patients Receiving New Generation Therapies

SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients will eventually relapse, requiring multiple lines of therapy for disease control. The availability of newer agents has transformed Multiple Myeloma into a chronic disease. Patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.

Infection is a leading cause of morbidity and mortality in patients with Multiple Myeloma. In a study of over 3000 newly diagnosed Multiple Myeloma patients, approximately 50% of early deaths (deaths occurring in less than 6 months following diagnosis) were associated with infections (J Clin Oncol. 2005;23:9219-9226). The increased susceptibility to infection in this patient group has been attributed to disease-related deficits in the innate or adaptive immune system, including hypogammaglobulinaemia, qualitative and quantitative abnormalities of dendritic cells, T cells, and Natural Killer cells, as well as renal function impairment, and therapies administered at different stages of the disease. Further, the introduction of new therapeutic agents such as Proteasome Inhibitors (PIs), Immunomodulatory drugs and monoclonal antibodies, with novel mechanisms of action, for first and later lines of therapy, for both Hematopoietic Stem Cell Transplantation eligible and ineligible patients, has significantly improved survival, but has also changed the spectrum of infections in patients with Multiple Myeloma. The epidemiology and risks for infection with the use of new therapeutic agents however remains unclear. The present study was conducted to determine patterns, risks and outcomes of infections in patients with Multiple Myeloma, managed with new therapeutic agents and monoclonal antibodies.

In this study, patients with Multiple Myeloma treated with second generation therapies and other monoclonal antibodies were identified from pharmacy and clinical databases, collected from 2 major tertiary referral centers for Multiple Myeloma management in Australia. Agents considered new generation therapies included Pomalidomide, Carfilzomib, Isatuximab, Daratumumab and Elotuzumab. Following commencement of new generation therapy, 60% of the patient’s had previously received Autologous Stem Cell Transplantation and 93% of the patient’s had Relapsed or Refractory Multiple Myeloma. Patients were then followed for episodes of infection, from the commencement of therapy with any newer agents, until completion of treatment, death or end of study, which ever occurred first. Prophylaxis with antibiotics for bacterial infections was not routinely used, but antiviral prophylaxis with Valaciclovir was used when patients received therapy with Proteasome Inhibitors. Patients received prophylaxis with Trimethoprim/Sulfamethoxazole for Pneumocystis jirovecii pneumonia when steroid doses exceeded 16-20 mg of Prednisone equivalent per day.

Each episode of infection was classified as Microbiologically Defined (MDI) when pathogens were isolated on microbiological testing, Clinically Defined (CDI) when sites of infection were identified but no pathogens were isolated on microbiological testing, and Fever of Unknown Focus (FUF) when patients had febrile episodes with no pathogen or site identified. Univariate and multivariate analyses were performed to determine risk factors for infection.

A total of 148 patients with Multiple Myeloma were followed for a median of 13.2 months, and 345 infection episodes were identified. Of these, 29% (100 out of 345) were defined as Microbiologically Defined Infections, 58% (200 out of 345) were defined as Clinically Defined Infections, and 13% (45 out of 345) were defined as Fever of Unknown Focus. Of those with Microbiologically Defined Infections, 50% of infections were attributed to viruses, whereas 45% were attributed to bacterial infection. Respiratory Syncytial Virus was the most frequently isolated virus accounting for 24% of episodes, followed by Rhinovirus at 16% and Influenza virus at 14%. E. coli was the most frequently isolated bacteria at 20%, followed by Haemophilus influenza at 11%. The most common infection site was the respiratory tract (56.8%), hospital admission occurred in 41.7% of infection episodes, and the 30-day all-cause mortality rate was 5.4%. Treatment with Proteasome Inhibitors resulted in 16.8 times increased risk for infections, combination of IMiD and PI was associated with 13.44 times higher risk, monoclonal antibody combination therapy was associated with 10.44 times higher risk, and more than 4 lines of therapy was associated with 7.72 times higher risk for infections (P<0.05).

It was concluded from this study that majority of infections are caused by viruses, in patients with Multiple Myeloma treated with newer therapeutic agents. Treatment with a Proteasome Inhibitor and more than 4 lines of therapy were associated with higher risk for infection.

Epidemiology and Risks of Infections in Patients With Multiple Myeloma Managed With New Generation Therapies. Lim C, Sinha P, Harrison SJ, et al. Clinical Lymphoma, Myeloma & Leukemia. 2021;21:444-450.

Subcutaneous DARZALEX® Plus POMALYST® and Dexamethasone Improves Progression Free Survival in Relapsed or Refractory Multiple Myeloma

SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.

DARZALEX® is a human IgG1 antibody that targets CD38, a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation, by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy. DARZALEX® has activity as both a single agent and when combined with other standard regimens. POMALYST® (Pomalidomide) is a novel, oral, immunomodulatory drug which is far more potent than THALOMID® (Thalidomide) and REVLIMID® (Lenalidomide), and has been shown to be active in REVLIMID® and VELCADE® refractory patients. In the EQUULEUS Phase Ib study, intravenous DARZALEX® in combination with POMALYST® and Dexamethasone in heavily pretreated relapsed or refractory Multiple Myeloma, resulted in a Very Good Partial Response (VGPR) or better in 42% of patients.Mechanism-of-Action-of-Daratumumab

Recently published studies have concluded that the subcutaneous formulation of DARZALEX® resulted in non-inferior pharmacokinetics and efficacy compared to the current IV formulation, and also importantly offers the potential for a fixed-dose administration, shorter administration times and a lower rate of infusion-related reactions with improved safety profile.

APOLLO study is an open-label, randomized, multicenter, Phase III trial, conducted by the European Myeloma Network investigators, to evaluate SubCutaneous (SC) formulation of DARZALEX® in combination with POMALYST® and Dexamethasone (D-Pd; N=151) versus POMALYST® and Dexamethasone (Pd; N=153) alone, in relapsed/refractory Multiple Myeloma patients who have received one or more prior lines of therapy including REVLIMID® and a Proteasome Inhibitor. This study enrolled 304 patients with relapsed or refractory Multiple Myeloma, and prior treatment with anti-CD38 antibody or POMALYST® was not permitted. Treatment for all patients consisted of POMALYST® 4 mg orally daily plus Dexamethasone 40 mg orally on days 1, 8, 15, and 22 (20 mg for patients aged 75 years or older), given every 28 days. Patients in the D-Pd group additionally received DARZALEX® 1800 mg SC co-formulated with recombinant human hyaluronidase PH20 (rHuPH20; ENHANZE® drug delivery technology, Halozyme, Inc.), given weekly for cycles 1 to 2, every 2 weeks for cycles 3 to 6, and every 4 weeks thereafter. The median age was 67 years, and 35% had high cytogenetic risk (presence of del17p, t[14;16], or t[4;14]). The median prior lines of therapy were 2, approximately 80% of patients were refractory to REVLIMID®, 48% of patients were refractory to a Proteosome Inhibitor, and 42% of patients were refractory to both agents. Treatment was continued until disease progression or unacceptable toxicity. The median duration of treatment was 11.5 months with D-Pd, compared with 6.6 months with Pd. The Primary endpoint was Progression Free Survival (PFS). Secondary endpoints included Overall Response Rate (ORR), Very Good Partial Response (VGPR), Complete Response (CR), MRD negativity rate, Overall Survival (OS), and Safety.

The study met its Primary endpoint of improved PFS in the primary analysis at a median follow up of 16.9 months. The median PFS for the D-Pd group was 12.4 months versus 6.9 months for Pd group (HR=0.63; P=0.0018). This represented a 37% reduction in the risk of progression or death in patients treated with D-Pd. Among patients who were refractory to REVLIMID®, median PFS was 9.9 months in the D-Pd group versus 6.5 months in the Pd group. This benefit was seen across all subgroups of patients, regardless of age, stage, prior line of therapy, REVLIMID® refractoriness and cytogenetic risk. D-Pd regimen was also superior to Pd regimen in terms of other endpoints, including ORR (69% versus 46%), VGPR or better (51% versus 20%), CR (25% versus 4%), and MRD negativity (9% versus 2%). Survival data are immature and follow up is ongoing. Infusion-related events were rare, and seen in 6% of patients treated with D-Pd, and local injection-site reactions which were all Grade 1 were seen in 2% of patients in the D-Pd group. Treatment discontinuation due to treatment-related adverse events, were similar for the D-Pd and Pd groups (2% versus 3%).

It was concluded that Subcutaneous DARZALEX® given along with POMALYST® and Dexamethasone significantly reduced the risk of progression or death by 37% in patients with relapsed/refractory Multiple Myeloma, compared to POMALYST® and Dexamethasone alone. The infusion-related reaction rate was very low and median duration of injection administration was short at 5 minutes. Subcutaneous DARZALEX® thus has a high likelihood of changing clinical practice, increasing convenience for patients and decreasing treatment burden.

Daratumumab plus pomalidomide and dexamethasone versus pomalidomide and dexamethasone alone in previously treated multiple myeloma (APOLLO): an open-label, randomised, phase 3 trial. Dimopoulos MA, Terpos E, Boccadoro M, et al. Lancet Oncol. 2021;22:801-812. doi:10.1016/S1470-2045(21)00128-5

DARZALEX® with REVLIMID® and Dexamethasone Improves Overall Survival in Newly Diagnosed Multiple Myeloma

SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.

REVLIMID® (Lenalidomide) based regimens are often prescribed for patients with newly diagnosed, transplant-ineligible Multiple Myeloma. REVLIMID®, a thalidomide analogue has immunomodulatory, tumoricidal, and antiangiogenic properties, and synergizes with Dexamethasone to enhance anti-myeloma activity. DARZALEX® is a human IgG1 antibody that targets CD38, a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy. DARZALEX® has activity as both a single agent and when combined with other standard regimens. The primary analyses of several Phase III studies (ALCYONE, MAIA, and CASSIOPEIA) demonstrated superior clinical efficacy of DARZALEX® in combination with standard-of-care regimens, compared to standard of care alone, for patients with newly diagnosed multiple myeloma. The MAIA study compared the efficacy and safety of DARZALEX® plus REVLIMID® and Dexamathasone (D-Rd) with REVLIMID® and Dexamathasone (Rd), in transplant-ineligible newly diagnosed Multiple Myeloma patients.Mechanism-of-Action-of-Daratumumab

The MAIA study is a multicenter, international, open-label, phase III trial, which included 737 newly diagnosed Myeloma patients who were not candidates for high-dose chemotherapy and Autologous Stem Cell Transplant (ASCT), due to age 65 years or older or comorbidities. Patients were randomly assigned 1:1 to receive REVLIMID® 25 mg orally on days 1-21 of each 28-day cycle and Dexamethasone 40 mg once a week, with or without DARZALEX®. Patients assigned DARZALEX® (D-Rd regimen) received 16 mg/kg weekly for the first 8 weeks (cycles 1 and 2), every other week for 16 weeks (cycles 3 to 6), and then every 4 weeks (cycle 7 and beyond) until disease progression or unacceptable toxicity. Treatment groups were well balanced. The median patient age was 73 years, 99% of patients were 65 years or older and 44% of patients were 75-90 years old. Cytogenetic risk level could be determined in 642 patients of the total population. Eighty-six percent (86%) of these patients were standard risk and 14% were considered high risk. The Primary end point was Progression Free Survival (PFS). Key Secondary endpoints included Overall Survival (OS), Overall Response Rate (ORR), Minimal Residual Disease (MRD) negativity rate (10-5 sensitivity), and Safety.

In the primary analysis of the MAIA trial, D-Rd regimen reduced the risk of disease progression or death by 44%, compared to Rd. The authors now reported the updated efficacy and safety of D-Rd, compared to Rd, after almost 5 years of median follow up, in transplant-ineligible newly diagnosed Multiple Myeloma patients, from the prespecified interim OS analysis of MAIA.

After a median follow up of almost 5 years (56.2 months), the median OS was not reached (NR) in either treatment groups. The estimated 5-year OS rate was 66.3% with D-Rd and 53.1% with Rd (HR=0.68; P=0.0013). D-Rd reduced the risk of death by 32%. The updated median PFS was Not Reached with D-Rd versus 34.4 months with Rd. The estimated 5-year PFS rate was 52.5% with D-Rd and 28.7% with Rd (HR=0.53; P<0.0001). D-Rd reduced the risk of disease progression or death was reduced by 47%. The updated ORR was 92.9% with D-Rd versus 81.6% with Rd (P<0.0001).

The authors concluded that after almost 5 years of follow-up, the addition of DARZALEX® to REVLIMID® and Dexamethasone resulted in a significant improvement in Overall Survival, as well as significant reduction in the risk of disease progression or death, in newly diagnosed Multiple Myeloma patients, who are transplant-ineligible. The authors added that these results are more meaningful and support D-Rd as a new standard of care for this patient group, as this study population of elderly patients, never receive subsequent therapy.

OVERALL SURVIVAL RESULTS WITH DARATUMUMAB, LENALIDOMIDE, AND DEXAMETHASONE VERSUS LENALIDOMIDE AND DEXAMETHASONE IN TRANSPLANT-INELIGIBLE NEWLY DIAGNOSED MULTIPLE MYELOMA: PHASE 3 MAIA STUDY. Facon T, Kumar SK, Plesner T, et al. Presented at: European Hematology Association Annual Meeting; June 9-17, 2021; Virtual. Abstract LB1901.

ABECMA® (Idecabtagene vicleucel)

The FDA on March 26, 2021 approved ABECMA® for the treatment of adult patients with Relapsed or Refractory Multiple Myeloma after four or more prior lines of therapy, including an Immunomodulatory agent, a Proteasome Inhibitor, and an anti-CD38 monoclonal antibody. This is the first FDA-approved cell-based gene therapy for Multiple Myeloma. ABECMA® is a product of Bristol-Myers Squibb Company.

FDA Approves SARCLISA® Combination for Relapsed or Refractory Myeloma

SUMMARY: The FDA on March 31, 2021, approved SARCLISA® (Isatuximab-irfc) in combination with KYPROLIS® (Carfilzomib) and Dexamethasone, for the treatment of adult patients with Relapsed or Refractory multiple myeloma who have received one to three prior lines of therapy. Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.

CD38 is a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® (Daratumumab) is a human IgG1 antibody that targets CD38, and was approved for use in combination with KYPROLIS® and Dexamethasone in 2020, for the treatment of patients with multiple myeloma, who had received 1-3 prior lines of therapy. This was based on the CANDOR open label, Phase III trial, in which the triplet combination of DARZALEX®, KYPROLIS® and Dexamethasone resulted in a 37% reduction in the risk of progression or death, compared with KYPROLIS® and Dexamethasone. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation, by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy.

SARCLISA® is a CD38-targeting IgG1monoclonal antibody, similar to DARZALEX®, but unlike DARZALEX®, is not associated with complement activation, and can therefore be more readily given to patients with asthma or Chronic Obstructive Pulmonary Disease. Further, SARCLISA® targets a specific epitope on the CD38 receptor, and this distinction from DARZALEX® allows use of SARCLISA® in cases when DARZALEX® fails. Additionally, SARCLISA® infusions are less cumbersome.

The present FDA approval was based on IKEMA trial, which is a multicenter, randomized, open label, Phase III study, in which the efficacy and safety of SARCLISA® in combination with KYPROLIS® and Dexamethasone was evaluated among patients with relapsed and/or refractory multiple myeloma, who had received 1-3 prior lines of therapy. In this study, 302 eligible patients were randomized 3:2 to receive SARCLISA® plus KYPROLIS® and Dexamethasone (N=179) or KYPROLIS® and Dexamethasone alone (N=123). SARCLISA® was given at 10 mg/kg IV weekly for 4 weeks and then every 2 weeks. KYPROLIS® was given at 20 mg/m2 IV on days 1 and 2 and then at 56 mg/m2 IV thereafter twice weekly for 3 of 4 weeks and Dexamethasone was given at 20 mg twice weekly. Treatment was continued until disease progression or unacceptable toxicity. The median age was 64 years, 23% had 3 or more prior lines of therapy, 90% of patients had prior treatment with Proteasome Inhibitor, 78% had prior treatment with Immunomodulatory drug (IMiD) and 24% had high-risk cytogenetics. The Primary endpoint was Progression Free Survival as determined by an Independent Review Committee (IRC). Key secondary endpoints included Overall Response Rate (ORR), rate of Very Good Partial Response (VGPR) or better, Complete Response (CR) rate, Minimal Residual Disease (MRD) negativity rate (10-5 by NGS), and Overall Survival (OS).

At a prespecified interim analysis, and after a median follow up of 20.7 months, the PFS was Not Reached for SARCLISA® group versus 19.15 months for the KYPROLIS® and Dexamethasone group (HR=0.53; P=0.0007). This represented a 47% reduction in the risk of disease progression or death in patients treated with SARCLISA® plus KYPROLIS® and Dexamethasone, compared to those treated with KYPROLIS® and Dexamethasone. This benefit was seen across all patient subgroups including those with high risk cytogenetics. The Overall Response Rate did not differ significantly between the SARCLISA® combination and control groups (86.6% versus 82.9%), with Complete Response Rates of 39.7% versus 27.6% respectively. MRD negativity rate was 29.6% with SARCLISA® combination versus 13% in the KYPROLIS® and Dexamethasone group (P=0.0004). Overall survival data were not mature at the time of data cutoff.

It was concluded that the addition of SARCLISA® to KYPROLIS® and Dexamethasone, resulted in a superior, statistically significant improvement in PFS, with clinically meaningful improvement in depth of response. The authors added that SARCLISA® combination was well tolerated with manageable safety and a favorable benefit-risk profile, and represents a possible new standard of care treatment for patients with relapsed multiple myeloma.

Isatuximab Plus Carfilzomib and Dexamethasone Vs Carfilzomib and Dexamethasone in Relapsed/Refractory Multiple Myeloma (IKEMA): Interim Analysis of a Phase 3, Randomized, Open-Label Study. Moreau P, Dimopoulos MA, Mikhael J, et al. 2020 ASH Annual Meeting & Exposition. Abstract# 2316. Presented on December 6, 2020.

FDA Approves Anti-BCMA CAR T-Cell Therapy for Relapsed or Refractory Multiple Myeloma

SUMMARY: The FDA on March 26, 2021, approved ABECMA® (Idecabtagene vicleucel) for the treatment of adult patients with Relapsed or Refractory multiple myeloma after four or more prior lines of therapy, including an immunomodulatory agent, a Proteasome Inhibitor, and an anti-CD38 monoclonal antibody. This is the first FDA approved cell-based gene therapy for multiple myeloma. Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years. With the introduction of new combinations of antimyeloma agents in earlier lines of therapy, patients with Relapsed/Refractory myeloma often have disease that is refractory to multiple drugs. There is an urgent unmet medical need for agents with novel mechanisms of action that are safe and effective, for patients with aggressive and resistant disease.

Chimeric Antigen Receptor (CAR) T-cell therapy has been associated with long-term disease control in some hematologic malignancies and showed promising activity in a Phase 1 study involving patients with Relapsed or Refractory myeloma. B-cell Maturation Antigen (BCMA) is a member of the Tumor Necrosis Factor superfamily of proteins. It is a transmembrane signaling protein primarily expressed by malignant and normal plasma cells and some mature B cells. BCMA is involved in JNK and NF-kB signaling pathways that induce B-cell development and autoimmune responses. BCMA has been implicated in autoimmune disorders, as well as B-lymphocyte malignancies, Leukemia, Lymphomas, and Multiple Myeloma.Chimeric-Antigen-Receptor-T-Cell-Immunotherapy

Anti-BCMA CAR T-Cell Therapy ABECMA® is a type of immunotherapy and consists of T cells collected from the patient’s blood in a leukapheresis procedure. These T cells are then stimulated by treating with interleukin 2 (IL-2) and anti-CD3 antibodies in vitro, so that they will actively proliferate and expand to large numbers. These T cells are then genetically engineered to produce special receptors on their surface called Chimeric Antigen Receptors (CAR), by transducing with a gene encoding the engineered CAR, via a retroviral vector such as lentiviral vector. These reprogrammed cytotoxic T cells with the Chimeric Antigen Receptors on their surface are now able to recognize a specific antigen such as BCMA on tumor cells. These genetically engineered and reprogrammed CAR T-cells are grown in the lab and are then infused into the patient. These cells in turn proliferate in the patient’s body and the engineered receptor on the cell surface help recognize and kill cancer cells that expresses that specific antigen such as BCMA. The patient undergoes lymphodepletion chemotherapy with Fludarabine and Cytoxan prior to the introduction of the engineered CAR T-cells. By depleting the number of circulating leukocytes, cytokine production is upregulated and reduces competition for resources, which in turn promotes the expansion of the engineered CAR T-cells.

The FDA approval was based on results from the pivotal, open-label, single-arm, multicenter, multinational, Phase II study (KarMMa trial), in which the efficacy and safety of ABECMA® was evaluated in adults with Relapsed and Refractory multiple myeloma. In this study, 128 patients with persistent disease after at least three previous regimens including a Proteasome Inhibitor, an immunomodulatory agent, and an anti-CD38 antibody, received ABECMA® target doses of 150×106 to 450×106 CAR-positive (CAR+) T cells, after receiving lymphodepleting chemotherapy. Lymphodepletion therapy consisted of Fludarabine 30 mg/m2 IV and Cyclophosphamide 300 mg/m2 IV given on 3 consecutive days, followed by 2 days of rest before ABECMA® infusion. The median patient age was 61 years and the median time from diagnosis was 6 years. About 51% of patients had a high tumor burden (50% or more bone marrow plasma cells), 39% had extramedullary disease and 35% had a high-risk cytogenetic abnormalities, defined as del(17p), t(4;14), or t(14;16). Patients had received a median of 6 previous antimyeloma regimens and 94% had received previous Autologous Hematopoietic Stem Cell Transplants. The Primary end point was an Overall Response Rate (ORR) as assessed by an Independent Review Committee (IRC) and key Secondary end point was a Complete Response or better (comprising complete and stringent Complete Responses). Other efficacy endpoints include Time to Response, Duration of Response, Progression Free Survival (PFS), Overall Survival (OS), Minimal Residual Disease (MRD) evaluated by Next-Generation Sequencing (NGS) assay, and Safety.

At a median follow up of 13.3 months, the ORR was 73% and 33% had a complete or stringent Complete Response. Of those with a complete or stringent Complete Response, 79% had MRD-negative status at a sensitivity level of 10−5, corresponding to 26% of the treated population. This benefit was consistently observed in most subgroups examined, including older patients, those who received bridging therapy, and those with aggressive disease features, including high-risk cytogenetics, triple or penta-refractory disease, a high tumor burden, and extramedullary disease. The median time to first response was 1.0 month and the median time to a Complete Response or better was 2.8 months. The estimated median Duration of Response was 10.7 months for all patients and 11.3 months among those receiving the highest target dose. The response duration increased with the depth of response. The median PFS was 8.8 months for all patients and 20.2 months in patients having a complete or stringent Complete Response. Data on Overall Survival are immature. Cellular kinetic analysis confirmed CAR+ T cells in 59% at 6 months and 36% at 12 months after infusion. Common toxicities included neutropenia, anemia and thrombocytopenia. Cytokine Release Syndrome was reported in 84% of patients including 5% Grade 3 or higher events. Neurotoxic effects developed in 18% of patients.

It was concluded that ABECMA® induced deep and durable responses in majority of heavily pretreated patients with Refractory and Relapsed myeloma, and fulfills a high unmet need for this patient group.

Idecabtagene Vicleucel in Relapsed and Refractory Multiple Myeloma. Munshi NC, Anderson LD, Shah N, et al. N Engl J Med 2021; 384:705-716

FDA Approves PEPAXTO® for Relapsed or Refractory Multiple Myeloma

SUMMARY: The FDA on February 26, 2021, granted accelerated approval to PEPAXTO® (Melphalan flufenamide) in combination with Dexamethasone for adult patients with Relapsed or Refractory multiple myeloma, who have received at least four prior lines of therapy and whose disease is refractory to at least one Proteasome Inhibitor, one immunomodulatory agent, and one CD-38 directed monoclonal antibody.

Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years. With the introduction of new combinations of antimyeloma agents in earlier lines of therapy, patients with Relapsed/Refractory myeloma often have disease that is refractory to multiple drugs. There is an urgent unmet medical need for agents with novel mechanisms of action that are safe and effective, for patients with aggressive and resistant disease.

PEPAXTO® is a novel, first-in-class peptide-drug conjugate that links a peptide carrier to a cytotoxic agent, resulting in a highly lipophilic compound. The lipophilicity allows PEPAXTO® to readily diffuse across cell membranes and get distributed into cells. Through its passive uptake into cells, the conjugated agent circumvents the development of transporter-associated resistance. The drug compound then leverages aminopeptidases, which are overexpressed in multiple myeloma cells, resulting in the release of the cytotoxic alkylating payload, which irreversibly damages tumor DNA and induces apoptosis.

The HORIZON trial is a pivotal, single-arm, multicenter, Phase II study of PEPAXTO® plus Dexamethasone in heavily pretreated patients with Relapsed or Refractory multiple myeloma. This study included 157 patients with relapsed or refractory disease, of whom 97 patients were triple-class refractory to at least one Immunomodulatory agent, one Proteasome Inhibitor, and a CD38-directed monoclonal antibody, and had received at least four prior lines of therapy. Patients received PEPAXTO® 40 mg IV on day 1 and Dexamethasone 40 mg orally (20 mg for patients 75 years of age or older) on day 1, 8, 15 and 22 of each 28-day cycle, until disease progression or unacceptable toxicity. The Primary end point was Overall Response Rate (Partial Response or better) assessed by the investigator, and Secondary end points included Duration of Response, Progression Free Survival (PFS), Overall Survival (OS), and Safety.

The FDA approval was based on the efficacy in a subgroup of patients (N=97), who were triple-class refractory and had received at least four prior lines of treatment. The Overall Response Rate for the patients within this group of patients was 23.7 % and the Median Duration of Response was 4.2 months. Among these 97 patients, 41% had extramedullary disease (N=40), an aggressive and resistant characteristic associated with poor prognosis. The most common adverse reactions in 20% or more were fatigue, fever, nausea, diarrhea and respiratory tract infection. Most common laboratory abnormalities in 50% or more were cytopenias and increased creatinine.

It was concluded that PEPAXTO® is a novel and innovative therapeutic option for patients with refractory myeloma, and is an important addition to the myeloma treatment armamentarium, in an area of unmet medical need.

Melflufen and Dexamethasone in Heavily Pretreated Relapsed and Refractory Multiple Myeloma. Richardson PG , Oriol A, Larocca A, et al. J Clin Oncol. 2021; 39:757-767