Monomethyl Auristatin E (MMAE), a Payload for Multiple Antibody Drug Conjugates (ADCs), Demonstrates Differential Red Blood Cell Partitioning Across Human and Animal Species.

Background: Monomethyl auristatin E (MMAE) has been used as a payload for several Food and Drug Administration (FDA) approved antibody-drug conjugates (ADCs). It is known that MMAE is released from the ADC following binding, internalization and proteolytic degradation in target tissues. A striking discrepancy in systemic MMAE levels has been observed across species with 50-fold higher MMAE levels in human than that in rodents when normalized by ADC dose with unknown mechanism.Hypothesis and purpose: Multiple factors could affect systemic MMAE levels such as production and elimination of unconjugated MMAE following ADC dosing. In this study, we have explored whether MMAE displays differential red blood cell (RBC) partitioning across species that may contribute to the different MMAE levels seen between human and animals.Experiments: To determine MMAE RBC partitioning, tritium labeled MMAE ([3H]-MMAE) was incubated in whole blood from mice, rats, monkeys and humans in vitro, then RBC partitioning was determined and compared across species. To test whether MMAE released from the ADC would show any difference in RBC partitioning, pinatuzumab vedotin or polatuzumab vedotin was administered to mice, rats, and monkeys. MMAE levels were measured in both blood and plasma, and the ratios of MMAE levels were calculated as blood-to-plasma ratio (in vivo RBC partitioning).Results: Our in vitro data showed that unconjugated MMAE has a species-dependent RBC partitioning with strong RBC partitioning in mouse, rat, followed by monkey blood, whereas minimal RBC partitioning was seen in human blood. Incubation of 2 nM of MMAE in mouse blood resulted in a blood-to-plasma ratio of 11.8 ± 0.291, followed by rat, monkey, and human at 2.36 ± 0.0825, 1.57 ± 0.0250, and 0.976 ± 0.0620, respectively. MMAE RBC partitioning is also concentration-dependent, with an inverse relationship between RBC partitioning and MMAE concentration (higher RBC partitioning at lower concentration). In vivo dosing of pinatuzumab vedotin in mouse displayed systemic MMAE at about a 5-fold higher blood concentration compared to plasma concentration once MMAE reached a pseudo-equilibrium, while systemic MMAE from blood and plasma concentration showed a 1.65-fold difference in rat.Implication and conclusion: These data demonstrated that MMAE has a distinct RBC partitioning across different species, which may contribute to, at least in part, to the differential in the systemic MMAE levels observed in vivo between preclinical and clinical studies. These findings highlight the importance of fully characterizing the ADME properties of both the ADC and its payload, to enable better translation from animals to human for ADC development.

[Successful polatuzumab vedotin and rituximab therapy for post-CAR-T relapse of diffuse large B-cell lymphoma].

Relapse or progressive disease after chimeric antigen receptor T-cell (CAR-T) treatment remains a major issue for poor-risk aggressive large B-cell lymphoma. However, limited data are available on post-CAR-T use of polatuzumab vedotin. Here we describe the case of a patient with diffuse large B-cell lymphoma (DLBCL) who experienced relapse three months after CD19-directed CAR-T therapy with tisagenlecleucel. However, the relapsed lesions rapidly disappeared following treatment with polatuzumab vedotin and rituximab. Notably, long-term remission was achieved without severe cytopenia, infections or peripheral neuropathy, showing the therapeutic benefit of polatuzumab vedotin for CAR-T failure.

Polatuzumab vedotin, rituximab, and bendamustine combination in relapsed or refractory diffuse large B-cell lymphoma: a real-world data from Turkey.

Polatuzumab vedotin (Pola) with bendamustine and rituximab (BR) is a promising option for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). We analyzed the data of 71 R/R DLBCL patients who had been treated with Pola-BR in the named patient program from March 2018 to April 2021 from 32 centers in Turkey. All patients received up to six cycles of Pola 1.8 mg/kg, rituximab 375 mg/m2 on day 1, and bendamustine 90 mg/m2 on days 1-2 of each cycle. Median age at Pola-BR initiation was 55 (19-84). The overall response rate was 47.9%, including 32.4% CR rate when a median of 3 cycles was applied. With a median follow-up of 5 months, the median OS was 5 months. Grade 3-4 neutropenia and thrombocytopenia were the most common hematological toxicities. The real-world data from our cohort showed the Pola-BR is an effective option with a manageable toxicity profile.

Outcomes of polatuzumab vedotin-containing regimens in real-world setting of relapsed and or refractory diffuse large B-cell lymphoma patients: a matched-control analysis from the Thai Lymphoma Study Group (TLSG).

Relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) is a challenging condition to treat, and there is an unmet clinical need for effective therapies. Recently, polatuzumab vedotin (Pola), an anti-CD79b antibody-drug-conjugate (ADC), combined with bendamustine-rituximab (BR), has been approved for R/R DLBCL patients. However, real-world data on Pola-based regimens in R/R DLBCL patients, especially in Thailand, are limited. This study aimed to evaluate the efficacy and safety of Pola-based salvage treatment in R/R DLBCL patients in Thailand. Thirty-five patients who received Pola-based treatment were included in the study, and their data were compared to 180 matched patients who received non-Pola-based therapy. The overall response rate (ORR) in the Pola group was 62.8%, with complete remission and partial remission rates of 17.1% and 45.7%, respectively. The median progression-free survival (PFS) and overall survival (OS) were 10.6 months and 12.8 months, respectively. The study found a significantly higher ORR in Pola-based salvage treatments compared to non-Pola-based therapy (62.8% vs. 33.3%). The survival outcomes were also significantly superior in the Pola group, with longer median PFS and OS than the control group. Grades 3-4 adverse events (AEs) were mainly hematological, and they were tolerable. In conclusion, this study provides real-world evidence of the efficacy and safety of Pola-based salvage treatment in R/R DLBCL patients in Thailand. The results of this study are promising and suggest that Pola-based salvage treatment could be a viable option for R/R DLBCL patients who have limited treatment options.

Superiority of polatuzumab vedotin over other novel agents in previously untreated ABC-type diffuse large B-cell lymphoma: a network meta-analysis of 20 RCTs.

Because of lacking of head-to-head comparison among polatuzumab (Pola) vedotin and other novel agents for untreated diffuse large B-cell lymphoma (DLBCL), the optimal option remains undefined. We searched twelve relevant published reports, covering 8376 subjects. Interestingly, the PFS benefit with Pola-R-CHP over other regimens was found prominently in those B-cell-like type (ABC-type) patients. For those ABC-type patients, the PFS advantage with Pola-R-CHP was statistically significant, when compared to R-CHOP+Bort (HR: 0.52, P=0.02), R-CHOP+Ibru (HR: 0.43, P=0.001), R-CHOP+Lena (HR: 0.51, P=0.009), G-CHOP (HR: 0.46, P=0.008), and R-CHOP (HR: 0.40, P<0.001). Meanwhile, for those germinal center B-cell-like (GCB) type patients, no PFS advantage with Pola-R-CHP was found when compared to R-CHOP+Bort (HR: 1.18, P=0.46), R-CHOP+Lena (HR: 1.21, P=0.45), G-CHOP (HR: 1.39, P=0.14), R-CHOP-14 (HR: 0.94, P=0.82), and R-CHOP (HR: 1.00, P=1). The PFS advantage with Pola-R-CHP over other regimens might be confined to those patients of ABC-type DLBCL.

[Autologous stem cell transplantation after pola-BR regimen as a salvage therapy in relapsed diffuse large B-cell lymphoma].

A 57-year-old male patient with relapsed/refractory diffuse large B-cell lymphoma received 4 courses of Pola-BR (polatuzumab vedotin-bendamustine-rituximab). After treatment, stem cell collection with G-CSF and plerixafor successfully yielded 4.2×106 cells/kg of CD34-positive cells. The patient underwent autologous peripheral hematopoietic stem cell transplantation. Neutrophil engraftment was achieved on day 12 and the patient was followed up without progression. In this case, stem cell mobilization with G-CSF and plerixafor was effective even in patients who had received chemotherapy including bendamustine, which is known to sometimes complicate stem cell collection. Although bendamustine should generally be avoided in cases where stem cell collection is planned, there are cases in which the decision to perform transplantation is made after chemotherapy including bendamustine. We have reported a case in which we were able to perform stem cell collection after pola-BR regimen.

[Polatuzumab vedotin, bendamustine, and rituximab in patients with relapsed/refractory diffuse large B-cell lymphoma, including the outcome as a bridging treatment to CAR-T cell therapy or allogeneic hematopoietic stem cell transplant].

Pola-BR (polatuzumab vedotin, bendamustine, and rituximab) therapy received approval for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) in Japan in March 2021. There have been few reports on the efficacy and safety of Pola-BR therapy in Japanese clinical practice. A retrospective analysis was performed on twenty-nine patients with R/R DLBCL who received Pola-BR therapy at our institution (intent to cellular immunotherapy cohort: 20 patients, stand-alone treatment cohort: nine patients). The overall response rate was 69.0% (complete response 27.6%). The median progression-free survival was 5.1 months, with a 9.5-month median overall survival. In the intent to cellular immunotherapy cohort, 11 of 19 patients received chimeric antigen receptor T-cell (CAR-T) infusions, and one patient received allogeneic stem cell transplantation. Four patients received Pola-BR therapy, including bendamustine before leukapheresis, and all produced CAR-T products successfully. 3 of the 28 patients experienced grade3 or higher adverse events, and two required treatment discontinuation. Our single institution, a real-world cohort of R/R DLBCL patients showed high efficacy outcomes and a tolerable toxicity profile for Pola-BR therapy, which is comparable to previous studies. More cases are needed to determine its impact on CAR-T therapy and stem cell transplantation.

The molecular rationale for the combination of polatuzumab vedotin plus rituximab in diffuse large B-cell lymphoma.

Polatuzumab vedotin (Pola) is an antibody-drug conjugate that targets the B-cell antigen CD79b and delivers monomethyl auristatin E (MMAE). It is approved in combination with bendamustine and rituximab (Rit) for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). Understanding the molecular basis of Pola combination therapy with Rit, the key component for the treatment of DLBCL, is important to establish the effective treatment strategies against r/r DLBCL. Here, we examined the rationale for the combination of Pola with Rit using Pola-refractory cells. We found that treatment with Pola increased CD20 expression and sensitivity to Rit-induced complement-dependent cytotoxicity (CDC) in several Pola-refractory cells. Pola treatment increased phosphorylation of AKT and ERK and both AKT- and MEK-specific inhibitors attenuated the Pola-induced increase of CD20 and CDC sensitivity, suggesting that these phosphorylation events were required for this combination efficacy. It was revealed that anti-CD79b antibody increased the phosphorylation of AKT but inhibited the phosphorylation of ERK. In contrast, MMAE potentiated phosphorylation of ERK but slightly attenuated the phosphorylation of AKT. Pola also increased CD20 expression on Pola-refractory xenografted tumours and significantly enhanced antitumour activity in combination with Rit. In conclusion, these results could provide a novel rationale for the combination of Pola plus Rit.

United we stand: Double targeting of CD79B and CD20 in diffuse large B-cell lymphoma.

Polatuzumab vedotin is antibody-drug conjugate (ADC) targeting CD79B approved for the treatment of patients with relapsed/refractory diffuse large B-cell lymphoma when given in combination with bendamustine and rituximab. The report by Kawasaki et al. provide hints on what might be happening in lymphoma cells exposed to polatuzumab vedotin and to rituximab and on potential mechanism of resistance to the ADC. Commentary on: Kawasaki et al. The molecular rationale for the combination of polatuzumab vedotin plus rituximab in diffuse large B-cell lymphoma. Br J Haematol 2022;199:245-255.

Polatuzumab vedotin-based salvage immunochemotherapy as third-line or beyond treatment for patients with diffuse large B-cell lymphoma: a real-world experience.

Polatuzumab vedotin (PoV) has recently shown promising activity when combined with rituximab-bendamustine (BR) in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). However, few studies have described the prognostic factors predicting response. Here, we aimed to evaluate the efficacy and safety profile of PoV-based chemotherapy, including regimens other than BR, as third-line or beyond treatment for patients with R/R DLBCL and to explore prognostic factors. Overall, 40 patients, including 37 with de novo and 3 with transformed DLBCL, were enrolled. The overall response rate was 52.5%, and 25% and 27.5% of patients showed a complete response and partial response, respectively. With a median follow-up of 18.8 months, the median overall survival (OS) of the total cohort was 8.5 months, and that of those receiving subsequent hematopoietic stem cell transplantation (HSCT) was 24 months. Low/intermediate risk according to the revised International Prognostic Index score at diagnosis and before PoV treatment predicted better OS. Furthermore, a normal lactate dehydrogenase level and an absolute lymphocyte count/absolute monocyte count ratio > 1.5 were favorable OS prognostic factors. The most common adverse event was cytopenia, with 42.5% of patients developing febrile neutropenia. Grade 1-3 peripheral neuropathy associated with PoV was reported in 25% of patients and resolved in most patients after the cessation of treatment. In summary, we demonstrated that PoV combined with either BR or other intensive chemotherapy is an effective and well-tolerated salvage option for patients with R/R DLBCL. Subsequent HSCT has the potential to further improve survival outcomes in this high-risk population. Clinicaltrials.gov number: NCT05006534.

Polatuzumab vedotin plus bendamustine and rituximab in patients with relapsed/refractory diffuse large B-cell lymphoma in the real world.

OBJECTIVES: Polatuzumab vedotin with bendamustine and rituximab (Pola-BR) was approved for treatment of transplant-ineligible patients with relapsed/refractory DLBCL (R/R DLBCL). However, the number of patients treated in the GO29365 trial including the extension cohort was limited, and more data evaluating the efficacy of this treatment regimen is needed. METHODS: We analyzed 21 patients with R/R DLBCL to determine real-life efficacy and safety of Pola-BR regimen. Data of all patients entered the database of the NiHiL project (NCT03199066). RESULTS: Median overall survival was 8.7 months, and progression-free survival 3.8 months. The overall response rate was 33%. Grade 3-4 neutropenia was detected in 29%, thrombocytopenia in 38%, anemia in 19%, infections in 24% cases, and peripheral neuropathy in 5%. Discontinuation of treatment was caused by progression in 50%, adverse events in 31%, and intended bridging to CAR-T therapy in 19%. CONCLUSION: Although the outcome of patients is worse than in GO29365 trial, the use of Pola-BR regimen in the real world demonstrates tolerable toxicity profile and efficacy in transplant-ineligible patients with R/R DLBCL. Moreover, this regimen might represent a perspective option as a bridge to CAR-T therapy.

A phase 2 study of polatuzumab vedotin + bendamustine + rituximab in relapsed/refractory diffuse large B-cell lymphoma.

Polatuzumab vedotin (pola) is a CD79b-targeted antibody-drug conjugate delivering a potent antimitotic agent (monomethyl auristatin E) to B cells. This was an open-label, single-arm study of pola 1.8 mg/kg, bendamustine 90 mg/m2 , rituximab 375 mg/m2 (pola + BR) Q3W for up to six cycles in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who received ≥1 prior line of therapy and were ineligible for autologous stem cell transplantation (ASCT) or experienced treatment failure with prior ASCT. Primary endpoint was complete response rate (CRR) at the end of the treatment (EOT) by positron emission tomography-computed tomography (PET-CT) using modified Lugano Response Criteria. Secondary endpoints included efficacy, safety, and pharmacokinetics. Thirty-five patients (median age 71 [range 46-86] years) were enrolled. Twenty-three (66%) patients had refractory disease, and 23 (66%) had ≥2 prior lines of therapy. At a median follow-up of 5.4 (0.7-11.9) months, patients received a median of five treatment cycles. CRR was 34.3% (95% confidence interval [CI] 19.1-52.2) at EOT. Overall response rate was 42.9% at EOT, and median progression-free survival was 5.2 months (95% CI 3.6-not evaluable). Median overall survival was not reached. No fatal adverse events (AEs) were observed. Grade 3-4 AEs were mainly hematological: anemia (37%), neutropenia (31%), white blood cell count decreased (23%), thrombocytopenia/platelet count decreased/neutrophil count decreased (20% each), and febrile neutropenia (11%). Grade 1-2 peripheral neuropathy (PN; sensory and/or motor) was reported in 14% of patients; there were no ≥grade 3 PN events. This study (JapicCTI-184048) demonstrated the efficacy and safety of pola + BR in Japanese patients with R/R DLBCL who were ineligible for ASCT.

Challenges and Opportunities in the Management of Diffuse Large B-Cell Lymphoma in Older Patients.

Most patients with diffuse large B-cell lymphoma (DLBCL) are diagnosed at age 60 years or older. Challenges to effective therapy among older individuals include unfavorable biologic features of DLBCL, geriatric vulnerabilities, suboptimal treatment selection, and toxicities of cytotoxic chemotherapy. Wider application of geriatric assessments may help identify fit older patients who benefit from standard immunochemotherapy without unnecessary dose reductions. Conversely, attenuated regimens may provide a better balance of risk and benefit for selected unfit or frail patients. Supportive care with the use of corticosteroid-based prephase, prophylactic growth factors, and early institution of supportive and palliative care can help maximize treatment tolerance. Several novel or emerging therapies have demonstrated favorable toxicity profiles, thus facilitating effective treatment for elderly patients. In the relapsed or refractory setting, patients who are not candidates for stem cell transplantation can benefit from newly approved options including polatuzumab vedotin-based combinations or tafasitamab plus lenalidomide, which may have higher efficacy and/or lower toxicity than historical chemotherapy regimens. Chimeric antigen receptor T-cell therapy has been successfully applied to older patients outside of clinical trials. In the first-line setting, emerging immunotherapy options (bispecific antibodies) and targeted therapies (anti-CD20 antibodies combined with lenalidomide and/or B-cell receptor inhibitors) may provide chemotherapy-free approaches for DLBCL. Enrolling older patients in clinical trials will be paramount to fully examine potential efficacy and toxicity of these strategies. In this review, we discuss recent advances in fitness stratification and therapy that have expanded curative options for older patients, as well as future opportunities to improve outcomes in this population. IMPLICATIONS FOR PRACTICE: Management of diffuse large B-cell lymphoma in older patients poses challenges due to aggressive disease biology and geriatric vulnerability. Although R-CHOP remains standard first-line treatment, geriatric assessment may help evaluate patients' fitness for immunochemotherapy. Corticosteroid prephase, prophylactic growth factors, and early palliative care can improve tolerance of treatment. Novel salvage options (polatuzumab vedotin-based combinations, tafasitamab plus lenalidomide) or chimeric antigen receptor T-cell therapy should be considered in the relapsed or refractory setting for patients ineligible for stem cell transplantation. Emerging immunotherapies (bispecific antibodies) and targeted therapies provide potential first-line chemotherapy-free approaches, which need to be rigorously assessed in clinical trials that involve geriatric patients.

Real-life experience with the combination of polatuzumab vedotin, rituximab, and bendamustine in aggressive B-cell lymphomas.

Transplant-ineligible relapsed/refractory (rr) diffuse large B-cell lymphoma (DLBCL) patients represent an unmet medical need. Polatuzumab vedotin (Pola), an anti-CD79b antibody-drug-conjugate (ADG), with bendamustine- rituximab(BR) has recently gained approval for these patients, both in the USA and Europe, based on the GO29365 phase IIb trial. Real-life data with Pola are extremely limited. We report the outcomes of 61 Greek patients, who received Pola-(B)R mainly within a compassionate use program. Treatment was given for up to six 21-day cycles. Bendamustine was omitted in three cases due to previous short-lived responses. Fourty-nine rrDLBCL(efficacy cohort-EC) and 58 rr aggressive B-NHL (safety cohort-SC) patients received at least 1 Pola-BR cycle. Twenty-one (43%) patients of the EC responded with 12/49 (25%) CR and 9/49 (18%) PR as best response. Median progression-free survival, overall survival and duration of response were 4.0, 8.5, and 8.5 months respectively, while 55% of patients experienced a grade ≥3 adverse event, mainly hematologic. Treatment discontinuations and death during treatment were mainly due to disease progression. Twenty-two (41%) patients received further treatment; 11/22 are still alive, including one after CAR-T cells, and two after stem cell transplantation. Our data confirm that Pola-BR is a promising treatment for rrDLBCL patients, inducing an adequate response rate with acceptable toxicity. Pola-BR could be used as bridging therapy before further consolidative treatments.

Polatuzumab vedotin, an anti-CD79b antibody-drug conjugate for the treatment of relapsed/refractory diffuse large B-cell lymphoma.

Refractory/relapsed diffuse large B-cell lymphoma remains a major unmet medical need with poor outcome, especially for patients considered ineligible for stem cell transplant. Polatuzumab vedotin (PV) is a first-in-class anti-CD79b antibody-drug conjugate that contains the microtubule inhibitor monomethyl auristatin E. The development of PV is currently very active. This drug was US FDA approved in 2019 in combination with bendamustine and rituximab for the treatment of refractory/relapsed diffuse large B-cell lymphoma in third line and more, after demonstrating relevant efficacy and acceptable safety in a pivotal randomized Phase II trial. This review summarizes the features of this new drug with the primary focus on the clinical work supporting efficacy, relevance and tolerability of PV.

Safety and pharmacokinetics of polatuzumab vedotin in Japanese patients with relapsed/refractory B-cell non-Hodgkin lymphoma: a phase 1 dose-escalation study.

OBJECTIVE: A phase 1 dose-escalation study of polatuzumab vedotin (pola) was conducted to assess safety, pharmacokinetics and preliminary antitumor activity of pola in Japanese patients with relapsed/refractory B-cell non-Hodgkin lymphoma. METHODS: Patients received pola (1.0 or 1.8 mg/kg) intravenously every 21 days until disease progression or intolerance. Intra-patient dose escalation was prohibited. Tolerability was determined by the standard 3 + 3 rule. Blood sampling was performed to characterize pharmacokinetics. Antitumor activity was evaluated through computed tomography and bone marrow sampling. RESULTS: Four patients received pola 1.0 mg/kg; three received 1.8 mg/kg. Patients had follicular lymphoma (n = 4) or diffuse large B-cell lymphoma (n = 3), median age of 62 years, received a median of 3 prior therapies; six were female. Pola was well tolerated in both cohorts, with no dose-limiting toxicities observed. The most common adverse event was peripheral sensory neuropathy (n = 4). Grade 3 adverse events were cholecystitis and neutrophil count decreased (one each; both 1.0 mg/kg), and syncope and cataract (one each; both 1.8 mg/kg). The plasma half-life of antibody-conjugate monomethyl auristatin E was 4.43-7.98 days, and systemic exposure of unconjugated monomethyl auristatin E was limited in both cohorts. Four patients achieved objective responses (three complete, one partial) without disease progression during the study. CONCLUSIONS: This phase 1 dose-escalation study demonstrated that pola has an acceptable safety profile and offers encouraging antitumor activity to Japanese patients with relapsed/refractory B-cell non-Hodgkin lymphoma. Pola 1.8 mg/kg, the recommended phase 2 dose, was tolerable in Japanese patients.

Promising Immunotherapeutic Modalities for B-Cell Lymphoproliferative Disorders.

Over the last few years, treatment principles have been changed towards more targeted therapy for many B-cell lymphoma subtypes and in chronic lymphocytic leukemia (CLL). Immunotherapeutic modalities, namely monoclonal antibodies (mAbs), bispecific antibodies (bsAbs), antibody-drug conjugates (ADCs), and chimeric antigen receptor T (CAR-T) cell therapy, commonly use B-cell-associated antigens (CD19, CD20, CD22, and CD79b) as one of their targets. T-cell engagers (TCEs), a subclass of bsAbs, work on a similar mechanism as CAR-T cell therapy without the need of previous T-cell manipulation. Currently, several anti-CD20xCD3 TCEs have demonstrated promising efficacy across different lymphoma subtypes with slightly better outcomes in the indolent subset. Anti-CD19xCD3 TCEs are being developed as well but only blinatumomab has been evaluated in clinical trials yet. The results are not so impressive as those with anti-CD19 CAR-T cell therapy. Antibody-drug conjugates targeting different B-cell antigens (CD30, CD79b, CD19) seem to be effective in combination with mAbs, standard chemoimmunotherapy, or immune checkpoint inhibitors. Further investigation will show whether immunotherapy alone or in combinatory regimens has potential to replace chemotherapeutic agents from the first line treatment.

Emerging antibody-drug conjugates for treating lymphoid malignancies.

INTRODUCTION: Antibody-drug conjugates (ADC) are monoclonal antibodies (Mabs) attached to biologically active drugs through specialized chemical linkers. They deliver and release cytotoxic agents at the tumor site, reducing the likelihood of systemic exposure and therefore toxicity. These agents should improve the potency of chemotherapy by increasing the accumulation of cytotoxic the drug within or near the neoplastic cells with reduced systemic effects. Areas covered: A literature review was conducted of the MEDLINE database PubMed for articles in English examining Mabs, B-cell receptor pathway inhibitors and immunomodulating drugs. Publications from 2000 through April 2017 were scrutinized. Conference proceedings from the previous five years of the American Society of Hematology, European Hematology Association, American Society of Clinical Oncology, and ACR/ARHP Annual Scientific Meetings were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles. Expert opinion: Newer ADCs show promise as treatment for several hematologic malignancies, especially lymphoma, multiple myeloma, and leukemia. However, definitive data from ongoing and future clinical trials will aid in better defining the status of these agents in the treatment of these diseases.

Navigating between Scylla and Charybdis: A roadmap to do better than Pola-RCHP in DLBCL.

In treating diffuse large B-cell lymphoma (DLBCL), oncologists have traditionally relied on the chemotherapy backbone of R-CHOP as standard of care. The two dangers that the hematologist must navigate between are the aggressive disease (Charybdis that in the absence of therapy systematically destroys all the ships) and the toxicity of the therapies (Scylla with its six monstrous heads that devours six crew members at a time), and hematologists have to navigate very carefully between both. Therefore, three different strategies were employed with the goal of improving cure rates: de-escalating regimens, escalating regimens, and replacement strategies. With a replacement strategy, a breakthrough in treatment was identified with polatuzumab vedotin (anti-CD79B antibody/drug conjugate) plus R-CHP. However, this regimen still did not achieve the elusive universal cure rate. Fortunately, advances in genomic and molecular technologies have allowed for an improved understanding of the heterogenous molecular nature of the disease to help develop and guide more targeted, precise, and individualized therapies. Additionally, new pharmaceutical technologies have led to the development of novel cellular therapies, such as chimeric antigen receptor (CAR) T-cell therapy, that could be more effective, while maintaining an acceptable safety profile. Thus, we aim to highlight the challenges of DLBCL therapy as well as the need to address therapeutic regimens eventually no longer tethered to a chemotherapy backbone. In the intersection of artificial intelligence and multi-omics (genomics, epigenomics, transcriptomics, proteomics, metabolomics), we propose the need to analyze multidimensional biologic datato launch a decisive attack against DLBCL in a targeted and individualized fashion.

Disseminated tuberculosis after Polatuzumab-Vedotin based chemoimmunotherapy in a patient with Burkitt's lymphoma.

This report highlights the risk of latent tuberculosis (TB) reactivation after treatment with Polatuzumab Vedotin (PV), Rituximab, and Bendamustine (PBR protocol) despite appropriate chemoprophylaxis. A 48-year-old male with refractory Burkitt's lymphoma (BKL) was treated with PBR protocol. At baseline, the patient had a negative QuantiFERON test result, which turned out to be positive prior to starting PBR. He received chemoprophylaxis for 9 months and was compliant with treatment. One year later, he was admitted with COVID-19 pneumonia and was treated according to the protocol. His symptoms persisted for 1 month. Investigations yielded disseminated TB-infiltrated bone marrow and pleura. Downstream B-cell and T-cell depletion secondary to CD20 and CD79b antagonism may potentially explain the increased risk of TB reactivation associated with the combination of PV and rituximab. Further research is necessary to monitor the risk of TB reactivation among patients receiving a combination of PV and rituximab, especially in endemic areas with high prevalence and incidence of TB.