Immunotherapy in Multiple Myeloma—Time for a Second Major Paradigm Shift

Multiple myeloma (MM) is a genetically heterogenous disease and remains mostly incurable with a small group of patients achieving long-term disease remission. The past decade witnessed enormous efforts to break the circulus vitiosus of tumor-induced immunosuppression and to re-engage the immune system to fight cancer. The first-in-class anti-CD38 monoclonal antibody, daratumumab, has shown unprecedented responses especially in combination with other novel agents in both newly diagnosed and relapsed MM. There has been great interest in harnessing the power of T cells with bispecific antibodies and chimeric antigen receptor T-cell therapies in hematologic malignancies including MM. These immune-based approaches have shown notable antimyeloma effects with deeper, durable responses in early clinical trials of heavily pretreated patients with MM with limited therapeutic options. Several trials are underway investigating both single and combinatorial immune therapies at different stages with a hope to bring major transformation in MM. In the current review, we summarize how an immunologic approach offers promise for the treatment of MM and is setting the stage for second major paradigm shift 2 decades after the emergence of thalidomide and novel therapeutics.

Efficacy and safety of atezolizumab (atezo) and bevacizumab (bev) in a phase Ib study of microsatellite instability (MSI)-high metastatic colorectal cancer (mCRC).

673 Background: Blockade of the PD-L1/PD-1 axis is a proven immunologic approach for treatment of many cancers; however, not all pts respond to monotherapy. Bev, an anti–VEGF-A antibody, has demonstrated clinical efficacy in mCRC and enhanced T-cell infiltration in tumors in preclinical studies. Thus, we postulated that combining atezo (anti-PD-L1) with bev would augment anti-tumor immune responses, resulting in improved and more durable clinical benefit. We report results from the first study of an anti-PD-L1 agent + VEGF-A blockade in MSI-high mCRC. Methods: A Ph Ib study (NCT01633970) investigated atezo + various chemotherapeutic/biologic regimens (eg, bev) in pts with advanced solid tumors, including mCRC. Pts received atezo 1200 mg q3w plus bev 15 mg/kg q3w (data cutoff, May 20, 2016). The primary objective was to evaluate the safety of atezo + bev. Secondary objectives included anti-tumor activity per RECIST v1.1. MSI status was tested locally. Results: Ten MSI-high mCRC pts were enrolled. Three pts had received 1 prior chemotherapy and 7 pts had received ≥ 2. Median age was 52.5 y. The minimum (range) of safety follow-up was 2.6 (2.6-20.3) mo. Median (range) treatment duration with atezo + bev was 10.1 (2-20) and 9.0 (2-19) mo, respectively. Efficacy results are shown below; the confirmed ORR per RECIST v1.1 was 30% (95% CI, 6.7%-65.3%). Median OS had not been reached with a median follow-up of 11.1 mo. Treatment-related all-grade AEs occurred in 80% of pts; 40% of pts had a related G3/4 AE. The most common related AE was proteinuria (40%; n = 3 G2 and n = 1 G3). No G5 events occurred. One AE led to discontinuation of atezo and 3 AEs led to discontinuation of bev. Biomarker data will be presented. Conclusions: Initial clinical activity was observed in heavily pretreated pts with MSI-high mCRC receiving atezo + bev; the disease control rate was 90%. This combination was well tolerated without unexpected toxicities. Further follow-up is ongoing. Clinical trial information: NCT01633970. [Table: see text]

Treating Hepatobiliary Cancer: The Immunologic Approach

Hepatobiliary cancer comprises a heterogeneous group of malignancies in which the standard treatments for advanced disease are minimally effective and evolve slowly over time. Like the majority of gastrointestinal cancers, with some notable exceptions, the impact of immune-based approaches is yet to be experienced. Notwithstanding this, the etiological background of hepatobiliary cancer - overlapping in almost every known causative or associated factor with inflammation - provides a strong clue that these approaches may have an impact on this group of diseases. This review seeks to put the management of hepatobiliary cancers in the context of its inflammation-based etiology, with the aim of pointing to the therapeutic opportunities in immune-based approaches currently entering the clinic or those that are about to do so.

Induction of Immunological Tolerance by Oral Anti-CD3

In recent years, our knowledge about immunoregulation and autoimmunity has significantly advanced, but nontoxic and more effective treatments for different inflammatory and autoimmune diseases are still lacking. Oral tolerance is of unique immunologic importance because it is a continuous natural immunologic event driven by exogenous antigen and is an attractive approach for treatment of these conditions. Parenteral administration of anti-CD3 monoclonal antibody is an approved therapy for transplantation in humans and is effective in autoimmune diabetes. Orally administered anti-CD3 monoclonal antibody is biologically active in the gut and suppresses experimental models of autoimmune diseases. Orally delivered antibody does not have side effects including cytokine release syndromes, thus oral anti-CD3 antibody is clinically applicable for chronic therapy. Here we review findings that identify a novel and powerful immunologic approach that is widely applicable for the treatment of human autoimmune conditions.

Impact of the lymphoma idiotype on in vivo tumor protection in a vaccination model based on targeting antigens to antigen-presenting cells

Trioma cell vaccination is a potent new immunologic approach for the therapy of malignant B-cell lymphoma. It is based on targeting tumor antigens to internalizing receptors on antigen-presenting cells (APCs). Tumor cells are fused to an APC-specific hybridoma, where they are converted to trioma cells that include potentially all lymphoma-derived antigens and that express the APC-binding arm. In this study, the mechanisms of trioma-mediated tumor immunity in immunocompetent mice were dissected, and it was shown in this model system that humoral anti-idiotypic immunity is indeed detectable after idiotype-specific immunization but that it does not reflect the degree of tumor protection obtained in vivo. Immunization against the idiotype alone was not sufficient for efficient tumor rejection in vivo. Targeting tumor antigens to APCs is only successful in terms of inducing tumor protection when designed as a polyvalent vaccination protocol.