Background: Allogeneic Stem cell transplant (Allo-SCT) is a widely used treatment for multiple hematological malignancies, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Relapse after Allo-SCT depends on the disease status prior to SCT, intensity of conditioning regimen and donor type. Disease relapse after SCT tends to have a poor prognosis with low probability of long term remission. This systematic review aims to assess the efficacy and safety of salvage therapies for disease relapse after first Allo-SCT. Methods: A search was performed on PubMed, Cochrane, Embase, and Web of Science. We used the following mesh terms and Entree terms, "salvage therapy" AND "stem cell transplant" AND "acute myeloid leukemia" OR "myelodysplastic syndrome" from the inception of data till 06/20/2020. We screened 1,666 articles and included 4 clinical trials (N=134) and 18 observational studies (N=756) in this systematic review. We excluded case reports, case series, preclinical trials, review articles, meta-analysis and original studies not providing efficacy and safety of salvage therapy in AML/MDS patients relapsed after Allo-SCT. Results: Among 22 studies (N=888), the age range was 14-75 years (Table 1). In two observational studies (N=92) where second Allo-SCT was used as salvage therapy, complete response (CR) was seen in 74-84% of the patients. Stable CR was achieved in 15% of the participants, and 44% experienced disease relapse. Overall survival (OS) at 68 months was 14%. In the trial (N=8) evaluating, azacitidine in combination with sorafenib, CR rate was 50%, and 1-year OS was 31%. Hepatotoxicity was seen in these patients, none of the patients died or discontinued treatment due to treatment-related adverse events (TRAEs). Azacitidine monotherapy was associated with a CR rate of 13-32% (N=256). Overall response (ORR) of 15% and 56% was seen patients with hematological and molecular relapse, respectively. ≥Grade 3 TRAEs were infections, pneumonia, sepsis and hematological adverse events. Donor lymphocyte infusion (DLI) monotherapy (N=14) showed CR in 14% of the patients with a 2 yr OS of 42%. Decitabine in combination with DLI (N=36) led to CR in 17% of the patients with a median duration of response of 10 months. The incidence of acute and chronic graft vs. host disease (GvHD) was 19% and 5%, respectively. Similarly, azacitidine in combination with DLI (N=351) led to CR in 9.7-36% of the patients, with a 2-yr OS of 29-35%. In a retrospective study by Claiborne et al., 71% of patients experienced disease relapse at a median follow up of 6 months. Infections, neutropenia, and non-severe GI symptoms were attributed to azacytidine with DLI therapy. In a study on hypomethylating agents with lenalidomide (N=40), CR was seen in 21-36.4% of the patients, and 2-yr OS was 58%. Infections and neutropenia were reported in these patients. In 3 observational studies (N=48), venetoclax based regimens were associated with CR in 42-53% of the patients and 43% maintained the response for ≥3 months. More than 60% of patients died of infections in one of these studies. Conclusion: Azacytidine, decitabine, sorafenib, venetoclax, lenalidomide and DLI were well tolerated by patients with disease relapse after Allo-SCT. Hypomethylating agents (azacytidine and decitabine) were more effective in combination with DLI, lenalidomide and venetoclax rather than monotherapy. Among drug therapies, best efficacy outcomes were reported in studies on venetoclax based regimens. Additional multicenter randomized, double clinical trials are needed to confirm these results. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.

Introduction: Five year overall survival for acute myeloid leukemia (AML) is estimated to be less than 30%. Encouraging results seen with the tyrosine kinase inhibitors (TKIs), midostaurin and gilteritinib resulted in the approval of these molecular targeted therapies for patients with FLT3 Mutated AML. Other TKIs like sorafenib and quizartinib, have ongoing clinical trials. In this systematic review and meta-analysis, we assessed the efficacy and safety of TKIs for the treatment of newly diagnosed (ND) and relapsed refractory (R/R) AML. Methods: A search was performed on PubMed, Cochrane, Embase, and clinicaltrials.gov. We used the keywords "tyrosine kinase inhibitors" AND "acute myeloid leukemia" from the inception of literature till 07/10/2020. We screened 3245 articles and included 5 randomized clinical trials (RCTs) (N=1919) in this meta-analysis. We extracted data for efficacy (i-e, OS, CR, ORR, EFS) and safety (≥grade 3 treatment related adverse events (TRAE). We excluded case reports, case series, preclinical studies, review articles, meta-analysis, observational studies, and controlled clinical studies not providing any information about the efficacy or safety of TKI. We used the R programming language (version 4.0.2) to conduct a meta-analysis. Results: In the 5 RCTs (n=1919), the age range was 18-85 years. 1675 participants had FLT-3 mutation (Table 1). In 2 RCTs (N=738), two TKIs (gilteritinib and quizartinib) (N=492) were compared with salvage chemotherapy (N=246). Risk ratio (RR) of overall response rate (ORR) and complete remission (CR) was 2.43 (95% CI=1.97-3.00, I2=0) and 2.09 (95% CI=1.5-2.90, I2=48%), respectively in favor of TKIs. The hazard ratio (HR) for overall survival (OS) was 0.70 (95% CI=0.58-0.84, I2=0) in favor of TKIs. (Fig 1-3). The median OS was 6.2 months in the quizartinib group vs. 4.7 months in the chemotherapy group. Similarly, median OS was 9.3 months in the gilteritinib group vs. 5.6 months in the chemotherapy group. Grade 3 or higher TRAEs (anemia, infections, sepsis, febrile neutropenia, and liver toxicity) were reported more often in the TKI group vs. salvage chemotherapy group. (Fig 4-6). In 3 RCTs (N=1181), two TKIs (midostaurin and sorafenib) (N=597) were compared with placebo (N=582). In the RCT evaluating role of sorafenib in older patients (>60 years) (N=197), RR of CR was 0.75 (95% CI=0.58-0.96) in favor of placebo. Although more patients died in the sorafenib group than the placebo group (23 vs 10 within 60-day period), TRAEs were similar in the two groups. In the remaining 2 RCTs, sorafenib and midostaurin were compared with placebo in younger patients (<60 years old) (N=982). RR of CR was 1.07 (95% CI=0.96-1.19, I2=0) in favor of TKIs and the hazard ratio for OS was 0.80 (95% CI=0.66-0.96, I2=0) in favor of TKIs (Fig 7,8). Median event-free survival (EFS) was 21 months in the sorafenib group vs. 9 months in the placebo group. Similarly, median EFS was 8.2 months in the midostaurin group vs. 3 months in the placebo group. Grade 3 or higher TRAEs (anemia, liver toxicity, infections, and diarrhea) were more common in the TKI group as compared to the placebo group. (Fig 9,10) Conclusion: Gilteritinib and quizartinib were not only better tolerated but also more effective than salvage chemotherapy in patients with FLT-3 mutated AML. In older patients, sorafenib appeared to have lower efficacy and higher toxicity when compared with placebo. In contrast, for younger patients, sorafenib and midostaurin had better efficacy and lower toxicity than placebo. Additional multicenter double-blind randomized clinical trials are needed to confirm these results. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.:Honoraria, Research Funding, Speakers Bureau.

Background: Lenalidomide is an immune modulator, approved for use since 2005 for the treatment of multiple myeloma (MM) patients. Its use is associated with an increased risk of infections. Combination of lenalidomide with other drugs, monoclonal antibodies, proteasome inhibitors, dexamethasone, and alkylators, can enhance the risk of serious infections. We conducted a network meta-analysis to compare the incidence of ≥Grade 3 infections among lenalidomide based regimens used in MM that can help clinicians to monitor patients for the risk of infections. Methods: A search was performed on PubMed, Cochrane, Embase, and Web of Science. We used the following keywords, "lenalidomide" AND "multiple myeloma" from the inception of literature till 06/10/2020. We screened 14,684 articles and included 23 randomized clinical trials (RCT) (N=11,174) in network meta-analysis. We extracted the data for serious (≥Grade 3) infections in lenalidomide based regimens. We excluded case reports, case series, preclinical trials, non-randomized clinical trials, observational studies, review articles, meta-analysis, and RCTs not providing any information about ≥Grade 3 infections. We used the "netmeta" package by Rucker et al. in the R programming language (version 4.0.2) to conduct frequentist network meta-analysis. Results: In 23 RCTs, the median age was ≥65years in 11 RCTs (N=5585) and ≤65 in 12 RCTs (5589). 9 RCTs were performed on relapsed/refractory multiple myeloma (RRMM) patients (N=4254), while 13 RCTs were performed on newly diagnosed multiple myeloma (NDMM) patients (N=6920). Lenalidomide regimen was used as maintenance therapy in 8 RCT (N=4255). Table 1 reviews the baseline characteristics. The pooled incidence of high-grade infections in trials with a median age of ≥65 and ≤65 years is 1010/5585 and 634/5589, respectively. The incidence of high-grade infections is 693/4254 in RRMM patients, 951/6920 in NDMM patients, and 466/4255 in NDMM patients with maintenance therapy. P-score in table 2 represents the mean extent of certainty with which a regimen is better in terms of the incidence of high-grade infections, i.e., higher P-score means a lower risk of serious infections. According to P-score, lenalidomide with carfilzomib and dexamethasone is worst in terms of the incidence of infections. Indirect comparison of placebo with lenalidomide shows a risk ratio of high-grade infections of 2.87 (95% CI: 1.96; 4.23) in favor of placebo. Fig 1 outlines the indirect comparison of the incidence of high-grade infections with different lenalidomide based regimens vs. placebo. Table 3. shows the calculated indirect comparison of high-grade infections in each lenalidomide based regimen. Heterogeneity was not statistically significant. For serious infections, lenalidomide dexamethasone showed a risk ratio of 0.86, 0.70*, 0.76*, 0.78*, 0.77, and 0.77 in comparison with the combination of lenalidomide dexamethasone with bortezomib, carfilzomib, daratumumab, elotuzumab, ixazomib, and pembrolizumab respectively (*statistically significant). Conclusion: This network meta-analysis suggests an increase in the risk of high-grade infections with the addition of bortezomib, monoclonal antibodies, ixazomib, and carfilzomib to lenalidomide in multiple myeloma patients with the highest increase in risk with the addition of carfilzomib. Additional randomized clinical trials are needed on the toxicity of lenalidomide based regimens to confirm these results. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.

Background: Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma in the US. Lenalidomide (Len), an immunomodulator, is used in the treatment of multiple hematological malignancies. This systematic review and meta-analysis aimed to assess the efficacy and safety of Lenalidomide based regimens in Newly Diagnosed (ND) and Relapsed/Refractory (R/R) DLBCL. Methods : A search was performed on PubMed, Cochrane, Embase, and Web of Science. We used the following mesh terms and Emtree terms, "Lenalidomide" OR "Revlimid" AND "diffuse large B cell lymphoma" from the inception of literature till 06/20/2020. We screened 1640 articles and included 2 randomized clinical trials (N=72) and 21 single-arm clinical trials (N=860) in this meta-analysis. We excluded case reports, case series, preclinical trials, review articles, meta-analysis, observational studies, and clinical trials not providing any information about the lenalidomide efficacy or safety in DLBCL. We used the R programming language (version 4.0.2) to conduct a meta-analysis. Results : In 23 studies (N=932), Len based regimens were used in patients with age 19-92 years (range) Table 1. In 5 trials on R/R patients (N=252), Len was used as a maintenance therapy. Cumulative overall response rate (ORR) and cumulative complete response (CR) were 0.27 (95% CI 0.21; 0.33, I2=0%) (Fig1) and 0.10 (95% CI 0.07; 0.16, 8%) (Fig2), respectively. In one phase III trial, the ORR and CR were significantly improved in the Len arm vs investigator's choice drug. In 4 trials on R/R patients (N=207), Len with monoclonal antibodies (MoAb) was used. Cumulative ORR and CR were 0.40 (95% CI 0.28; 0.54, I2=71%) and 0.28 (95% CI 0.17; 0.42, I2=72%), respectively. In a trial on R/R patients (N=33), Len with Gemcitabine, Rituximab, and Oxaliplatin was used. Cumulative ORR and CR were 0.61 (95% CI 0.43; 0.76, I2=0%) and 0.39 (95% CI 0.24; 0.57, I2=0%), respectively. In a trial on R/R patients (N=15), Len with RICE was used with ORR and CR of 0.73 (95% CI 0.47; 0.90, I2=0%) and 0.60 (95% CI 0.35; 0.81, I2=0%), respectively. In a trial on R/R patients(N=55), Len with Everolimus was used. ORR and CR were 0.27 (95% CI 0.17; 0.40, I2=0%) and 0.07 (95% CI 0.03; 0.18, I2=0%), respectively. In a trial on R/R patients (N=19), Len with R-ESHAP was used. ORR and CR were 0.79 (95% CI 0.55; 0.92, I2=0%) and 0.47 (95% CI 0.27; 0.69, I2=0%), respectively. In a phase III trial on R/R patients (N=21), Len with Gemcitabine and Rituximab was used vs. placebo The ORR and CR were significantly improved in the Len arm vs placebo. In 4 trials on ND patients (N=158), Len with R-CHOP was used and the cumulative ORR and CR were 0.94 (95% CI 0.88; 0.97, I2=12%) and 0.81 (0.75; 0.87, I2=0%), respectively. In a trial on ND patients (N=15), Len with R-EPOCH was used with ORR and CR of 0.93 (95% CI 0.65; 0.99, I2=0%) and 0.87 (95% CI 0.59; 0.97, I2=0%), respectively. In 2 trials (N=103), Len with Ibrutinib and Rituximab was used. In R/R patients (N=45), cumulative ORR and CR were 0.38 (95% CI 0.25; 0.53, I2=0%) and 0.24 (95% CI 0.14; 0.39, I2=0%), respectively. In ND patients (N=58) has ORR and CR 0.86 (95% CI 0.75; 0.93, I2=0%), respectively. In 2 trials with a combination of ND and R/R patients (N=54), Len with Rituximab and Bendamustine was used. Cumulative ORR and CR were 0.63 (95% CI 0.49; 0.75, I2=0%) and 0.39 (95% CI 0.27; 0.52, I2=0%), respectively. The most common serious treatment-related adverse events (TRAE) were infection, thromboembolism, fatigue, sepsis, respiratory, neurological, cardiac (arrhythmias), gastrointestinal, rash, seizures, and hematological side effects (Table 1). Conclusion : Based on early phase trials, Len based regimens are well tolerated and effective in the treatment of both ND and R/R DLBCL patients. Combinations of lenalidomide with Tafasitamab and R-ESHAP have shown the highest response in R/R patients and combination with R-CHOP has shown the best response in ND patients. In randomized trials, lenalidomide has shown significant improvement in the survival of DLBCL patients as compared to placebo or physician's choice drug. Additional double-blind multicenter randomized clinical trials are needed to compare the efficacy and safety of lenalidomide based regimens in DLBCL patients. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.:Honoraria, Research Funding, Speakers Bureau.

Introduction: Stem cell transplantation (SCT) is used to treat multiple malignancies, but a major complication of the procedure is graft versus host disease (GvHD), which is a significant cause of morbidity and death in SCT patients. Methylprednisolone is the first-line therapy of GvHD. Ruxolitinib is a Janus kinase (JAK) inhibitor that can dampen the effect of inflammatory cytokines involved in GvHD and may be used in patients refractory to steroid treatment. In this systematic review and meta-analysis, we assessed the safety and efficacy of Ruxolitinib in steroid-resistant (SR) acute (a) and chronic (c) GvHD. Methods: We performed a search on PubMed, Cochrane, Embase, and Web of Science. We used the keywords, "Ruxolitinib" AND "Graft vs Host Disease" from the inception of literature till 7/10/2020. We screened 694 articles and included 1 randomized clinical trial (RCT) (N=309), 4 non-randomized trials (NRCT) (N=232), and 13 observational studies (N=481) in this meta-analysis. We extracted data for efficacy (i-e, OS, CR, ORR) and safety (≥grade 3 treatment related adverse events (TRAE). We excluded case reports, case series, review articles, meta-analysis, and preclinical trials. We used the R programming language (version 4.0.2) to conduct a meta-analysis. Results: In the 18 included studies (N=1022), Ruxolitinib was used in patients with the age range of 6 months to 70 years. 417 participants had grade III-IV acute GvHD, and 272 participants had moderate to severe chronic GvHD (Table 1). In an RCT (N=309), patients aged between 12-73 years with SR aGVHD were randomized 1:1 to receive either Ruxolitinib or physician's choice drug. Overall response rate (ORR) and complete response (CR) were significantly higher in the Ruxolitinib group as compared to the physician's choice drug. The results were consistent for all grades of GvHD. Grade 3 or higher treatment-related adverse events (TRAEs) were 78% in the two groups. 22% of the patients died of GvHD related adverse events in the Ruxolitinib group vs. 25% of the patients in the control group. In 12 clinical trials and observational studies, among SR GvHD patients (N=443), pooled ORR was 0.74 (CI=0.65-0.81, I2=61%) with Ruxolitinib treatment. Similarly, pooled CR was 0.45 (CI=0.34-0.68, I2=81%). The most common adverse events were cytopenias, viral reactivation, and infections. (Fig 1, 2) In 9 early phase trials and observational studies (N=282) in SR- chronic GvHD patients, pooled ORR and pooled CR were 0.75 (CI=0.64-0.83, I2=64%) and 0.11 (CI=0.08-0.16, I2=0), respectively. The most common adverse events were cytopenias and viral reactivation (Fig 3, 4). In a non-randomized trial (N=64), Ruxolitinib was used in combination with Etanercept for SR- acute GvHD patients. The ORR and CR were 87.5% and 72%, respectively. High rates of hematological adverse events and infections were reported in these patients. In an observational study (N=18), Ruxolitinib was used in combination with Extracorporeal Photopheresis (ECP). The combination was well-tolerated, and ORR and CR were 55% and 44%, respectively (Table 1). Conclusion: Ruxolitinib was well tolerated by patients with acute or chronic SR-GvHD. Ruxolitinib showed a higher efficacy compared to the physician's choice drug in SR acute GvHD. Ruxolitinib was also effective in SR cGvHD patients. The addition of etanercept to Ruxolitinib increased the efficacy in SR-acute GvHD patients but resulted in an increased incidence of infections. Ruxolitinib with ECP was effective and well tolerated in SR-acute GvHD. Additional multicenter, randomized, double-blind clinical trials are needed to confirm these results. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.