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Purpose: Immune checkpoint inhibitors (ICI) in general have shown poor efficacy in bladder cancer. The purpose of this project was to determine whether photodynamic therapy (PDT) with bladder cancer–specific porphyrin-based PLZ4-nanoparticles (PNP) potentiated ICI. Experimental Design: SV40 T/Ras double-transgenic mice bearing spontaneous bladder cancer and C57BL/6 mice carrying syngeneic bladder cancer models were used to determine the efficacy and conduct molecular correlative studies. Results: PDT with PNP generated reactive oxygen species, and induced protein carbonylation and dendritic cell maturation. In SV40 T/Ras double-transgenic mice carrying spontaneous bladder cancer, the median survival was 33.7 days in the control, compared with 44.8 (P = 0.0123), 52.6 (P = 0.0054), and over 75 (P = 0.0001) days in the anti-programmed cell death-1 antibody (anti-PD-1), PNP PDT, and combination groups, respectively. At Day 75 when all mice in other groups died, only 1 in 7 mice in the combination group died. For the direct anti-tumor activity, compared with the control, the anti-PD-1, PNP PDT, and combination groups induced a 40.25% (P = 0.0003), 80.72% (P < 0.0001), and 93.03% (P < 0.0001) tumor reduction, respectively. For the abscopal anticancer immunity, the anti-PD-1, PNP PDT, and combination groups induced tumor reduction of 45.73% (P = 0.0001), 54.92% (P < 0.0001), and 75.96% (P < 0.0001), respectively. The combination treatment also diminished spontaneous and induced lung metastasis. Potential of immunotherapy by PNP PDT is multifactorial. Conclusions: In addition to its potential for photodynamic diagnosis and therapy, PNP PDT can synergize immunotherapy in treating locally advanced and metastatic bladder cancer. Clinical trials are warranted to determine the efficacy and toxicity of this combination.

Adoptive cell therapy with chimeric antigen receptor (CAR) immunotherapy has made tremendous progress with five CAR T therapies approved by the US Food and Drug Administration for hematological malignancies. However, CAR immunotherapy in solid tumors lags significantly behind. Some of the major hurdles for CAR immunotherapy in solid tumors include CAR T cell manufacturing, lack of tumor-specific antigens, inefficient CAR T cell trafficking and infiltration into tumor sites, immunosuppressive tumor microenvironment (TME), therapy-associated toxicity, and antigen escape. CAR Natural Killer (NK) cells have several advantages over CAR T cells as the NK cells can be manufactured from pre-existing cell lines or allogeneic NK cells with unmatched major histocompatibility complex (MHC); can kill cancer cells through both CAR-dependent and CAR-independent pathways; and have less toxicity, especially cytokine-release syndrome and neurotoxicity. At least one clinical trial showed the efficacy and tolerability of CAR NK cell therapy. Macrophages can efficiently infiltrate into tumors, are major immune regulators and abundantly present in TME. The immunosuppressive M2 macrophages are at least as efficient as the proinflammatory M1 macrophages in phagocytosis of target cells; and M2 macrophages can be induced to differentiate to the M1 phenotype. Consequently, there is significant interest in developing CAR macrophages for cancer immunotherapy to overcome some major hurdles associated with CAR T/NK therapy, especially in solid tumors. Nevertheless, both CAR NK and CAR macrophages have their own limitations. This comprehensive review article will discuss the current status and the major hurdles associated with CAR T and CAR NK therapy, followed by the structure and cutting-edge research of developing CAR macrophages as cancer-specific phagocytes, antigen presenters, immunostimulators, and TME modifiers.

Introduction: Multiple myeloma (MM) is a neoplastic proliferation of plasma cells. It is the second most common hematological malignancy in the US. Although it is associated with poor prognosis, newer therapies have improved outcomes in MM patients. This review aims to describe novel therapies used for the treatment of relapsed/refractory multiple myeloma (RRMM). Methods: A literature search was performed on Embase and clinicaltrials.gov using the keyword "Multiple Myeloma" from 1/1/2016 to 6/25/2020 for identifying ongoing clinical trials in the treatment of RRMM. After detailed scrutiny, we included 23 ongoing clinical trials (N=4362). We excluded case reports, case series, review articles, meta-analysis, and observational studies. Results: We summarized the interim results from ongoing clinical trials evaluating treatment of RRMM under following newer categories of drugs: Immunomodulatory drugs In a phase 1b/IIa trial (NCT02773030, N=51) evaluating the efficacy of a novel immunomodulators, iberdomide CC-220 + dexamethasone (Dex) yielded an overall response rate (ORR) of 31%, clinical benefit (CB) was seen in 51% of the patients, and disease control (DC) in 88% of the patients and it was well tolerated by RRMM patients. There are other ongoing clinical trials evaluating the efficacy of Avadomide (CC-122), CC-92480 in RRMM. Alkylating agents In a phase I/II trial (NCT01897714, N=45), melphalan-flufenamide (melflufan) + Dex yielded an ORR of 31%, it was well tolerated with 49% CB. Phase III OCEAN trial (NCT03151811, N=450) is currently ongoing to compare melflufen + Dex vs. pomalidomide (Pom) + Dex. Apoptotic agents A phase 3 trial BELLINI (NCT02755597, N=291) evaluated the efficacy of veneteclox (Ven, Bcl-2 inhibitor) by randomizing patients to either Ven or Placebo arm. With a median follow up of 28.6 months (m), progression free survival (PFS) was 23.2m in the Ven arm vs. 11.4m in placebo. The interim results from a phase I/II trial (NCT03314181, N=104) of Ven + daratumumab (Dara) + Dex showed ORR of 96% with ≥ very good partial response (VGPR) of 96%. The addition of Bortezomib (Bor) to VenDaraDex had a slightly low ORR of 92%, with ≥VGPR of 79%. Another phase I/II trial (NCT01794520, N=117) is in progress to assess the efficacy and safety of Ven as monotherapy. Monoclonal Antibodies (MoAb) A phase I/II trial (NCT01421186, N=91) evaluated the efficacy of MOR202, which is a novel MoAb. MOR202 was evaluated in three arms; MOR202 + Dex, MOR202 + Lenalidomide (Len) + Dex and MOR202 + Pom + Dex. The interim analysis showed the ORR of 65% with MOR202 + Len + Dex which was better than ORR of 48% with MOR202 + Pom + Dex, while the use of MOR202 + Dex yielded only 28% ORR. Antibody-drug conjugate (ADC) Four ongoing trials are evaluating the efficacy of ADC (belantamab mafodotin), and the interim results are available for two trials. In phase II DREAMM-2 trial (NCT03525678, N=221) evaluating 2 doses of GSK2857916, 2.5mg/kg dose yielded ORR of 31% while 3.4mg/kg showed ORR of 34%. Another phase I trial (NCT02064387, N=79) evaluated belantamab mafodotin in RRMM and other hematologic malignancies expressing B-cell maturation antigen (BCMA). The results were promising with ORR of 60%. Bispecific T-cell engagers (BiTE) Phase I trial of BiTE AMG 420 (NCT02514239, N=43) showed favorable results with ORR 70%, and CR 12%. The interim results from another phase I trial (NCT03486067, N=115) which evaluated the efficacy of BiTE CC-93269 showed 43% ORR and CR 17%. CAR-T Cell therapy CAR-T cell therapy is also being studied in RRMM with JNJ-68284528 directed against BCMA in a phase Ib trial (NCT03548207, N=118). The interim analysis of 29 response evaluable patients out of 118 reported 100% ORR with stringent CR 76%. PK13 Inhibitors In a phase I/II study (NCT00401011, N=84) evaluating perifosine + Bor +/- Dex, ORR of 41% was observed in Bor RR patients, and therapy was well tolerated with PFS of 6.4m and mOS of 25m. Conclusion: This review demonstrates novel and promising therapies which are currently in early phase clinical trials for the treatment of RRMM. Based on interim results, Iberdomide, melflufan, Ven, MoAb MOR202, ADC belantamab mafodotin, BiTE Molecule AMG 420, BCMA CAR-T cell therapy and perifosine have shown promising early activity and safety data in RRMM patients. Additional exploratory clinical trials are needed to confirm the efficacy and safety of these agents. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.

Introduction: Isatuximab (ISA) is an anti-CD38 monoclonal antibody that has shown benefit in patients with relapsed/refractory multiple myeloma (RRMM) in combination regimens. This study focuses on the clinical utility and tolerability of ISA based therapies in patients with ISS stage III disease. Methods: Literature search on PubMed, EmCare, Clinicaltrials.gov, Cochrane, and Google Scholar was performed from inception to July 1, 2020, for the use of ISA in MM patients. A total of five clinical trials, including phase Ib/II and phase III trials, were selected for a systematic review out of 109 studies (n=556 patients). Results: The median age was 61-71 years. The addition of ISA to pomalidomide-dexamethasone (PD) in previously treated patients was evaluated by Attal et al. (2019). International Staging System (ISS) stage III disease was present in 28% of the study population at baseline. Patients treated with ISA-PD had a meaningful increase in progression-free survival (PFS) (11.53 versus 6.47 months, P = 0.001, Hazard Ratio (HR): 0.596; 95% confidence interval (CI): 0.436-0.814. PFS benefit was maintained in subgroup analysis based on renal involvement, refractoriness to lenalidomide, and proteasome inhibitors. However, PFS benefit was not statistically significant in ISS stage III disease (HR: 0.64; CI: 0·36-1·11). Martin et al. (2017) evaluated the addition of ISA to lenalidomide and dexamethasone in 57 patients. 22% of the patients had ISS stage III disease. Mikeal et al. also included 9% and 37.1% of patients with ISS stage III MM in their phase Ib and II trials, respectively. All studies demonstrated a significant prolongation of PFS in patients refractory to lenalidomide with ISA administered at 10 mg/kg weekly/every two weeks. Iida et al. (2019) also reported statistically significant improvement in PFS with ISA monotherapy in heavily pretreated Japanese patients (PFS 4.7 months; 95% CI 3.75-NC). In patients with newly diagnosed MM, Ocio et al. (2017) showed encouraging results with an ISA based regimen in 17 patients. ISS stage III disease was present in 88% of the population. At the time of data cut-off, the overall response to treatment was 87%, and 82.4% continued to remain on treatment (see Table 1). Conclusion: ISA as monotherapy and in combination therapy improved surrogate endpoints without increased toxicity in patients refractory to previous lines of treatment. Limited data suggest an improvement in PFS for ISS stage III disease. Long-term results on efficacy in MM with high-risk cytogenetics are awaited. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.