Seetharam, ­Mahesh

Although checkpoint inhibitors have been approved in multiple cancers, they are still under investigation in soft tissue sarcoma (STS). We conducted a retrospective review to report the safety, efficacy, and prognostic factors related to checkpoint inhibitors in STS. A sequential cohort of metastatic STS patients from four institutions treated with checkpoint inhibitors was assembled. Logistic and Cox regression models were applied to determine the effect of patient characteristics, prior treatment, and baseline factors on achieving the best overall response of complete response (CR), partial response (PR), or stable disease (SD) as determined by the treating physician. Eighty-eight patients with two median prior therapies received checkpoint inhibitors. Treatments included pembrolizumab in 47, nivolumab in 6, ipilimumab in 1, combination ipilimumab/nivolumab in 27, and other combination immunotherapies in 7 patients. Immunotherapy was discontinued in 54 patients—72.2% for progression, 16.7% for toxicity, and 11.1% for other reasons. Median progression-free survival (PFS) was 4.1 months and median overall survival was 19.1 months. One patient with undifferentiated pleomorphic sarcoma (UPS) achieved a CR, while 20 patients had a PR, including 7 UPS, 9 leiomyosarcoma (LMS), and 1 each with alveolar soft part sarcoma, fibroblastic sarcoma, sclerosing epithelioid fibrosarcoma, and myxofibrosarcoma. Forty-five percent (9 of 20) of LMS patients achieved a PR. Twenty-eight patients had SD. Our results confirm the activity and safety of anti-PD-1 therapy in metastatic STS. A notable response rate was observed in UPS and LMS subtypes. This study expands the knowledge base beyond what is currently available from clinical trials involving checkpoint inhibitors in metastatic STS.

e24114 Background: Pharmacogenomics (PGx) testing is used increasingly in cancer supportive care for drug and dose selection, and side effects prediction with antidepressants, antiemetics, and pain medications. Genetic variants in genes that encode for drug metabolizing enzymes (CYPs), transporters (SLC6A4) and drug receptors (HTR2A, OPRM1, etc) are well known for these medications. They contribute to inter-individual differences in medication safety and efficacy. We report on their frequency and effect on supportive care drugs in patients with solid tumors. Methods: Between 06/06/19 and 12/18/19, solid tumor cancer patients at Mayo Clinic Arizona were enrolled in a PGx prospective study. They were genotyped using a multi-gene panel, OneOme RightMed. The panel assessed 27 genes, including CYP2C9, CYP2C19, CYP2D6, CYP3A4, COMT, OPRM1, GRIK4, HTR2A, SLC6A4, associated with pain medications, antidepressants, and antiemetics. PGx pharmacist provided medication recommendations and dose adjustments based on PGx test results and concurrent medications. Results: 200 patients were swabbed and 196 patients were genotyped. The results were available within 5 days. All patients were also assessed for pheno-conversion (drug-drug-gene interactions) by a pharmacist. Recommendations were made based on predicted phenotype. Various solid tumor types were represented, including prostate (19.9%), colorectal (17.9%), melanoma (14.8%), and others (47.4%). Median age was 65 with 59.2% patients being male and 40.85% female. All had at least one actionable polymorphism related to these medications. The most significant findings were related to CYP2C19 and CYP2D6 genes. Of 196 patients, a total of 132 (67.3%) had other than normal CYP2D6 metabolizer phenotype and 112 (57.1%) had other than normal CYP2C19 metabolizer phenotype. Based on these genotypes, alternatives to pain medications were recommended for 37 patients, to ondansetron in 9 patients, and to anti-depressants in 51 patients. Conclusions: Genetic variants were commonly found that affect supportive care medications used in oncology practice and contribute to inter-individual differences associated with increased risk of adverse drug effects and reduced efficacy. PGx guided recommendation may help physicians in individualizing medication treatment outcomes for patients with different cancer types and with polypharmacy. PGx trained pharmacist can serve as a valuable asset in optimizing personalized medication management.

TPS11570 Background: Soft tissue sarcoma (STS) is a heterogenous malignancy of mesenchymal origin and includes more than 50 biologically distinct subtypes. Leiomyosarcoma (LMS), a neoplasm of smooth muscle origin, represents up to 20% of STS. The uterus is the most common site of origin in women. Advanced uterine LMS (uLMS) is initially treated with gemcitabine + docetaxel or anthracycline-based chemotherapy but overall survival remains < 24 mos. Besides recurrent alterations in RB1, TP53 and ATRX, insight into cancer biology of uLMS remains limited. Recently, whole exome and transcriptomic sequencing studies suggest uLMS harbors characteristic defects in the homologous recombination (HR) DNA repair pathway and thus features of BRCAness. HR-deficient cancers are unable to efficiently repair double-stranded DNA breaks and appear sensitive to treatment with poly ADP-ribose polymerase (PARP) inhibitors. In preclinical studies, the combination of temozolomide (T), an alkylating agent, and olaparib (O), a PARP inhibitor, was synergistic and markedly suppressed proliferation of uLMS models. A recent phase II study in small cell lung cancer defined the RP2D for T + O where the chief toxicity was myelosuppression. Methods: NCI Protocol #10250 is a single-arm, open-label, multi-center phase II clinical trial of T + O in patients with advanced uLMS. Eligible pts have ECOG PS ≤ 2, progression on ≥ 1 prior line of therapy and disease measurable by RECIST v1.1 and amenable to image-guided biopsy. Pts receive T 75 mg/m2 PO daily + O 200 mg PO BID on days 1-7 in 21-day cycles. The 1° endpoint is objective response rate (ORR). A one-stage binomial design is used to evaluate for an ORR ≤ 10% (null hypothesis) versus ≥ 35% (alternative hypothesis). The design calls for 22 patients. If 5/22 respond, the treatment is promising. This design yields 93% power and 1-sided type I error of 6%. 2° endpoints include progression free survival and safety. All pts undergo tumor biopsies pre-treatment and during cycle 2. Tissue is used for correlative analysis interrogating uLMS for features of BRCAness through (a) whole exome sequencing/RNAseq to evaluate for alterations in HR pathway component genes, (b) RAD51 foci formation by immunohistochemistry as a functional marker of HR pathway activity and (c) protein expression of Schlafen family member number 11 (SLFN11), an emerging biomarker for PARPi. Tumors are also evaluated for MGMT protein expression, a known determinant of sensitivity to T. The study opened to accrual 10/2019. Clinical trial information: NCT03880019.

AbstractBackgroundOutcomes data regarding advanced synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are limited, consisting primarily of retrospective series and post hoc analyses of clinical trials.MethodsIn this multi‐center retrospective study, data were abstracted from the medical records of 350 patients from nine sarcoma centers throughout the United States and combined into a registry. Patients with advanced/unresectable or metastatic SS (n = 249) or MRCL (n = 101) who received first‐line systemic anticancer therapy and had records of tumor imaging were included. Overall survival (OS), time to next treatment, time to distant metastasis, and progression‐free survival (PFS) were evaluated using the Kaplan‐Meier method and Cox regression.ResultsAt start of first‐line systemic anticancer therapy, 92.4% of patients with SS and 91.1% of patients with MRCL had metastatic lesions. However, 74.7% of patients with SS and 72.3% of patients with MRCL had ≥2 lines of systemic therapy. Median OS and median PFS from first‐line therapy for SS was 24.7 months (95% CI, 20.9‐29.4) and 7.5 months, respectively (95% CI, 6.4‐8.4). Median OS and median PFS from start of first‐line therapy for MRCL was 29.9 months (95% CI, 27‐44.6) and 8.9 months (95% CI 4.5‐12.0).ConclusionsTo the best of our knowledge, this is the largest retrospective study of patients with SS and MRCL. It provides an analysis of real‐world clinical outcomes among patients treated at major sarcoma cancer centers and could inform treatment decisions and design of clinical trials. In general, the survival outcomes for this selected population appear more favorable than in published literature.

TPS2621 Background: TKM-080301 is a lipid nanoparticle formulation of a small interfering RNA (siRNA) directed against PLK1, a serine/threonine kinase that regulates multiple critical aspects of cell cycle progression and mitosis. Anti-tumor activity, RNA interference and pharmacodynamic effects of PLK1 inhibition have been conclusively demonstrated in preclinical models. Demonstration of pharmacodynamic effects of PLK1 inhibition in patient biopsy samples is an exploratory objective of this first-in-human study. Methods: TKME080301 is being evaluated in an open-label, non-randomized, dose-escalation study in patients with advanced solid tumors or lymphoma. Sequential cohorts of 3 to 6 patients receive TKME080301 as a 30-minute intravenous infusion on Days 1, 8 and 15 of a 28-day cycle. Treatment can continue until disease progression, based on overall clinical benefit. Tumor response is determined according to RECIST criteria. Primary study objectives include determination of safety, maximum tolerated dose and dose limiting toxicities. Secondary objectives include characterization of pharmacokinetics and the preliminary assessment of anti-tumor activity. Five cohorts have been enrolled and a tentative Phase 2 dose has been identified. An expansion cohort of 10 patients began enrolling in February, 2013. The focus of the expansion cohort will be to collect additional safety and pharmacokinetic data at the tentative Phase 2 dose, as well as pharmacodynamic data from mandatory biopsy samples. Pre- and post-dose biopsy samples will be evaluated for potential evidence of PLK1 inhibition using 5’ RACE (rapid amplification of cDNA ends) polymerase chain reaction (to identify the predicted PLK1 mRNA cleavage product), histology (to assess for the presence of aberrant mitotic figures) and immunohistochemistry. An update on enrollment and pharmacodynamic evaluations will be presented. Clinical trial information: NCT01262235.

Abstract Introduction DLBCL is the most common lymphoid neoplasm in adults (Swerdlow 2016). While durable CRs are achieved in approximately 70% of patients (pts) with frontline RCHOP therapy (Pfreundschuh 2008), pts with high-risk features often experience disease resistance or relapse. In Part 1 of an ongoing study, pts with high-intermediate or high risk DLBCL by international prognostic index (IPI) scores, regardless of CD30 expression by IHC, were treated with 1.2 or 1.8 mg/kg brentuximab vedotin (BV) combined with RCHOP. After 3 of the first 10 pts treated at 1.8 mg/kg BV+RCHOP developed Grade 3 peripheral neuropathy (per Standardized MedDRA Query [SMQ]), all pts enrolled subsequently received treatment with 1.2 mg/kg BV+RCHOP. Following completion of enrollment in Part 1, the protocol was amended to enroll a non-randomized portion of the study (Part 2) evaluating the safety and efficacy of 1.8 mg/kg BV+RCHP (Yasenchak 2015), followed by an open-label, randomized portion comparing BV+RCHP to RCHOP (Part 3). Initial results from Part 2 and updated results from Part 1 are reported here. Methods For Part 2 of the study, pts with CD30-expressing high-intermediate and high-risk DLBCL were treated with up to 6 cycles of 1.8 mg/kg BV+RCHP (NCT01925612). Key inclusion criteria were CD30 expression by IHC performed by a local pathology lab and standard IPI scores of 3-5 or age-adjusted IPI (aaIPI) scores of 2-3 (high-intermediate/high risk). CD30 expression was confirmed by a central pathology lab, although CD30 expression by local pathology lab was required for eligibility. Disease response was evaluated with PET/CT per Cheson 2007. Results At the time of analysis for this ongoing study, 11 pts in Part 2 were treated with BV+RCHP (7 male, 4 female; 22-78 yrs). Of these pts, 9 had high-intermediate risk (IPI 3, aaIPI 2) and 2 had high risk disease (IPI 4-5, aaIPI 3), 6 had Stage IV disease, and 6 had an ECOG score of 2. At the end of treatment, the overall response rate was 91% (9 CR, 1 PR); 1 pt had PD after Cycle 4. The most frequent (>20%) treatment-emergent adverse events (AEs) were alopecia and nausea (73% each); fatigue (64%); constipation and peripheral sensory neuropathy (55% each); neutropenia and throat irritation (36% each); and chills, diarrhea, headache, and stomatitis (27% each). Grade 3 or 4 AEs occurred in 8 pts and 5 pts had serious AEs, which included febrile neutropenia, bacteremia, nausea, pneumocystis jiroveci pneumonia, pulmonary embolism, and vomiting. Peripheral sensory neuropathy occurred in 6 pts and all were Grade 1 or 2 events; no peripheral motor neuropathy AEs were reported. No AEs were fatal or led to discontinuation. One pt discontinued treatment after Cycle 4 due to disease progression. For the first 51 pts in Part 1, the progression-free survival (PFS) at 18 months for pts with CD30 expression (25 pts) or without detectable CD30 expression (24 pts) by IHC was 79% (95% CI: 57%, 91%) versus 58% (95% CI: 36%, 75%), respectively. Overall survival for pts was 92% (95% CI: 71%, 98%) versus 71% (95% CI: 48%, 85%), respectively. Ten pts had pre-existing peripheral neuropathy (per SMQ) at study entry. Treatment-emergent peripheral neuropathy (per SMQ) was observed in 75% of pts (38/51) who received BV+RCHOP; 55% of these pts (21/38) had resolution of all or some peripheral neuropathy events. Conclusions 1.8 mg/kg BV+RCHP is active as frontline treatment in CD30-expressing, high-intermediate/high risk DLBCL. When combined with RCHP, 1.8 mg/kg BV appears to be well-tolerated. The PFS and OS for pts with CD30-expression who received BV+RCHOP appear promising. The study is currently ongoing in pts with CD30-expressing high-intermediate/high risk DLBCL to assess the safety and activity of 1.8 mg/kg BV+RCHP versus standard RCHOP. Disclosures Halwani: Bristol Myers-Squibb: Research Funding; Kyowa Hakko Kirin: Research Funding; Takeda: Research Funding; Genentech: Research Funding; AbbVie: Consultancy, Other: Travel Expenses, Research Funding; Seattle Genetics: Consultancy, Research Funding; Immune Design: Research Funding; Miragen: Research Funding; Pharmacyclics: Consultancy; Amgen: Research Funding. Yasenchak:Seattle Genetics: Research Funding. Farber:Seattle Genetics: Research Funding. Burke:Pfizer: Consultancy; Janssen: Consultancy; Incyte: Consultancy; TG Therapeutics: Other: Travel Expenses; Millenium: Consultancy. Fayad:Seattle Genetics: Consultancy, Research Funding. Holkova:Seattle Genetics: Research Funding. Knapp:Insys Therapeutics, Inc.: Consultancy, Other: Travel, Accommodations, Expenses; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding. Kolibaba:Gilead: Consultancy, Research Funding; Celgene: Research Funding; TG Therapeutics: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; janssen: Research Funding; GSK: Research Funding; Genentech: Research Funding; Acerta: Research Funding. Patel-Donnelly:Seattle Genetics: Research Funding. Yimer:Ariad Pharmaceuticals: Consultancy; Biotheranostics: Consultancy; Bluebird Bio: Equity Ownership; Kite Pharma: Equity Ownership; Clovis Oncology: Equity Ownership; Juno Therpeutics: Equity Ownership; Seattle Genetics: Research Funding. Smith:Celgene: Consultancy, Speakers Bureau; Seattle Genetics: Research Funding. Levy:Janssen: Speakers Bureau; Amgen: Speakers Bureau; Takeda Pharmaceuticals International Co.: Speakers Bureau; Seattle Genetics: Research Funding; Actinium Pharmaceuticals, Inc.: Research Funding. Seetharam:Seattle Genetics: Research Funding. Belada:Seattle Genetics: Research Funding. Brooks:Seattle Genetics: Research Funding. Kingsley:Gilead: Equity Ownership; Pharmacyclics LLC, an AbbVie Company: Equity Ownership. Wagner-Johnston:Seattle Genetics: Research Funding. Ruffner:Forma Therapeutics: Consultancy; Sydnax: Consultancy; Seattle Genetics: Employment, Equity Ownership; Array Biopharma: Employment; Medivation: Employment. Bartlett:Gilead: Consultancy.

Abstract Introduction RCHOP is the standard frontline treatment for patients with DLBCL. However, for patients with high-intermediate or high-risk disease (IPI 3-5), outcomes are suboptimal, with an estimated 3-year PFS of about 55%. In addition to IPI, an additional factor associated with an increased risk include non-GCB cell of origin. Brentuximab vedotin, an ADC targeting CD30, has demonstrated single-agent activity in relapsed/refractory DLBCL patients. Of note, higher ORR and CR, as well as longer duration of PFS, were observed in those patients with CD30 detected on tumor cells by routine IHC. Methods This phase 2 study was designed to evaluate combination therapy using brentuximab vedotin (BV) and standard RCHOP chemotherapy as frontline treatment in patients with high-intermediate/high risk (standard IPI score 3-5 or age-adjusted IPI [aaIPI] score 2-3) DLBCL, regardless of CD30 expression (ClinicalTrials.gov NCT01925612). Patients were randomized to receive either 1.2 mg/kg BV+RCHOP or 1.8 mg/kg BV+RCHOP for up to 6 cycles of treatment. BV was given on Day 1 of every 21-day cycle. Response was assessed per investigator using Cheson 2007. AEs, physical examination findings, and laboratory testing were utilized to characterize safety. Tumor cell CD30 expression was measured by IHC and gene expression analysis; soluble CD30 was measured in plasma. Tumor microenvironment was also evaluated for frequency of immune-infiltrating cells. The primary endpoints for this study were the tolerability of each regimen and the CR rate at the end of treatment (EOT). Key secondary endpoints included progression-free survival (PFS). Additional exploratory endpoints included CD30 expression on tumor specimens (CD30- defined as <1% per IHC) and correlation of CD30 expression and response. Results Twenty-nine patients were treated with 1.2 mg/kg BV+RCHOP and 22 patients were treated with 1.8 mg/kg BV+RCHOP. Over half (63%) were high-intermediate risk (IPI 3, aaIPI 2) and 37% were high risk (IPI 4-5, aaIPI 3). Most had Stage IV disease (71%) and 27% had an ECOG score of 2. AEs in ≥50% of patients included peripheral sensory neuropathy (63%), fatigue (61%), nausea (55%), and diarrhea (53%). Grade 3 or higher events occurred in 76% of patients; the most frequent were neutropenia (33%) and febrile neutropenia (31%). The PET-negative CR rate was 69% overall; CD30+ patients had a CR rate of 76% (19/25) compared with 63% (12/19) in CD30- patients by IHC. Although PFS data are still immature (median follow up of 8 months), the estimated PFS rate at 12 months was 82% (95% CI: 58, 93) in CD30+ patients and 56% (95% CI: 32, 75) in CD30- patients. 60% (3/5) of patients with CD30- ABC-DLBCL progressed versus 27% (3/11) of CD30+ ABC-DLBCL patients. Four patients with EBV+ DLBCL were treated and all achieved CR; 3 EBV+ patients remain in remission after a median follow-up of 12 months. Within the microenvironment, a higher percentage of CD3+ T-cells was observed in patients with CR (23%; range, 4-80%) than in those with PR (14%; range, 10-15%) or PD (11%; range, 5-15%). Of the 32 patients who have not yet progressed, 50% had ≥20% CD3+ cells compared to 18% of patients with PD (2/11). Other factors, including soluble CD30 levels and infiltrating CD68+ cells, were not associated with clinical outcomes. Conclusions Interim results demonstrate that adding BV to RCHOP results in a high rate of CR in this population of IPI 3-5 DLBCL. Patients with CD30-expression in the tumor appear to have a higher CR rate and fewer early progression events than patients with CD30- DLBCL. Furthermore, subsets of patients who have a particularly poor prognosis (CD30+ ABC subtype and EBV+ DLBCL) appeared to have a favorable outcome with BV+RCHOP. Evaluation of the tumor microenvironment showed that higher frequencies of infiltrating CD3+ cells were observed in the CR group, suggesting possible immunologic correlates of response. However, CD30 expression appears to have greater prognostic significance in this study despite the relatively small sample size. These results are intriguing and merit further testing in a randomized trial. Disclosures Yasenchak: Seattle Genetics, Inc.: Research Funding. Off Label Use: Brentuximab vedotin is indicated in the US for treatment of patients with Hodgkin lymphoma after failure of autologous stem cell transplant or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates and for the treatment of patients with systemic anaplastic large cell lymphoma after failure of at least one prior multi-agent chemotherapy regimen. The drug is being evaluated in this study for use as frontline treatment in patients with high-intermediate/high risk DLBCL in combination with multiagent chemotherapy. . Halwani:Abbvie: Research Funding; Pharmacyclics: Other: Travel expenses, Research Funding; Takeda/Millenium: Research Funding; BMS: Research Funding; Seattle Genetics, Inc.: Other: Travel expenses, Research Funding; Roche/Genentech: Research Funding; Kyowa Hakko Kirin: Research Funding; Amgen: Research Funding. Advani:Seattle Genetics, Inc.: Research Funding; Genetech: Consultancy. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding. Budde:Merck: Research Funding; Ikara Inc: Patents & Royalties; Atara Biotherapeutics: Consultancy; Seattle Genetics, Inc.: Research Funding. Burke:Millenium/Takeda: Consultancy; Incyte: Consultancy; TG Therapeutics: Other: Travel expenses; Gilead: Consultancy; Janssen: Consultancy; Seattle Genetics, Inc.: Research Funding. Farber:Seattle Genetics, Inc.: Research Funding. Holkova:Seattle Genetics, Inc.: Research Funding. Kolibaba:GSK: Research Funding; Seattle Genetics, Inc.: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Gilead: Consultancy, Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; TG Therapeutics: Research Funding. Knapp:Celgene: Research Funding; Heron Pharmaceuticals: Other: Travel expenses, Research Funding; Merck: Research Funding; Seattle Genetics, Inc.: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Brystol-Myers Squibb: Research Funding; Genentech: Honoraria, Other: Travel expenses, Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; EMD Serono: Research Funding. Li:Seattle Genetics, Inc.: Employment, Equity Ownership. Manley:Seattle Genetics, Inc.: Employment, Equity Ownership. Patel-Donnelly:Seattle Genetics, Inc.: Research Funding. Seetharam:Seattle Genetics, Inc.: Research Funding. Yimer:Seattle Genetics, Inc.: Research Funding. Bartlett:Gilead: Consultancy, Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Millennium: Research Funding; Colgene: Research Funding; Medimmune: Research Funding; Kite: Research Funding; Insight: Research Funding; Seattle Genetics: Consultancy, Research Funding; MERC: Research Funding; Dynavax: Research Funding; Idera: Research Funding; Portola: Research Funding; Bristol Meyers Squibb: Research Funding; Infinity: Research Funding; LAM Theapeutics: Research Funding.

Abstract Background Outcomes for patients with DLBCL have improved over the past decade, with the addition of rituximab to CHOP or CHOP-like multi-agent chemotherapy regimens improving the 3-year overall survival (OS) of patients by 10-16% compared to multi-agent chemotherapy alone (Coiffier 2002; Pfreundschuh 2010). However, patients with high-intermediate or high-risk disease have relatively poor outcomes with the standard RCHOP regimen (Ziepert 2010); in a recent prospective trial of intermediate- and high-risk DLBCL patients, complete response (CR) rate for RCHOP alone was 26% (Hainsworth 2011). Brentuximab vedotin (ADCETRIS®) is an antibody-drug conjugate comprising the antibody cAC10, specific for human CD30, covalently attached to the microtubule-disrupting agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. Brentuximab vedotin has demonstrated compelling activity as a single agent in patients with relapsed or refractory DLBCL, even those with low CD30 expression (Bartlett 2013). This phase 2, randomized, open label study is designed to evaluate the antitumor activity and safety of brentuximab vedotin (1.2 or 1.8 mg/kg) when administered in combination with standard RCHOP chemotherapy (A+RCHOP) for the front-line treatment of patients with CD30-unselected high-intermediate/high-risk (standard IPI score 3–5 or age-adjusted IPI [aaIPI] score 2–3) DLBCL (ClinicalTrials.gov NCT01925612). Methods Patients were randomized to receive up to 6 cycles of either 1.2 or 1.8 mg/kg brentuximab vedotin administered IV on Day 1 of every 21-day cycle in combination with RCHOP; prednisone was administered orally on Days 1-5 of every 21-day cycle. Assessments included disease response per Cheson 2007, as evaluated by the investigator, surveillance of adverse events (AEs), physical examination findings, and laboratory testing. The primary endpoints for this study are the CR rate at the end of treatment (EOT) and the type, incidence, and severity of AEs. Key secondary endpoints include objective response rate (ORR), progression-free survival (PFS), and OS. Results At the time of the planned interim analysis, 33 patients were enrolled (17 patients, 1.2 mg/kg A+RCHOP; 16 patients, 1.8 mg/kg A+RCHOP). Median age for all patients was 66 years (range, 21 to 81). At baseline, 36% were high-risk (IPI 4-5, aaIPI 3) and 64% were high-intermediate risk (IPI 3, aaIPI 2). The majority of patients (73%) had Stage IV disease and 33% had an ECOG status of 2. At the time of interim analysis, a total of 12 patients (6 patients in each arm) had completed EOT. Across both dose levels, ORR was 92% (11/12), with 7 CRs (58%), 4 PRs (33%), and 1 PD. The patient with PD subsequently died. Patients with PR had a median reduction of baseline tumor size of 84% (range, 92% to 83%), as measured by SPD. The only patient with follow-up after EOT converted from PR to CR without subsequent therapy. Treatment-emergent AEs occurring in ≥30% of patients treated (26/33) were nausea, diarrhea, peripheral sensory neuropathy, fatigue, and decreased appetite. Grade 3 or higher events occurring in more than 2 patients were febrile neutropenia and neutropenia. Events of peripheral neuropathy occurred equally per arm (46%, 1.2 mg/kg A+RCHOP; 46% 1.8 mg/kg A+RCHOP) and were generally Grade 1 or 2 (15% and 23%, respectively); events were of similar grade across dose levels. The median time to onset of any grade of peripheral neuropathy was 6 weeks (range, 2 to 10 weeks). Five patients (19%) had dose reductions due to peripheral neuropathy and 3 patients (12%) had dose reductions due to febrile neutropenia. One patient who received 1.2 mg/kg A+RCHOP discontinued study drug due to an AE (thrombocytopenia). Conclusions At doses of 1.2 or 1.8 mg/kg, A+RCHOP exhibited manageable toxicity in the treatment of newly-diagnosed DLBCL; the incidence of peripheral neuropathy was similar to single-agent administration of brentuximab vedotin (Pro 2012, Younes 2012) and RCHOP alone (Rummel 2013, Flinn 2014). In 12 patients with response-assessable, high-intermediate and high-risk DLBCL, A+RCHOP showed encouraging antitumor activity, with an ORR of 92% and a CR rate of 58%. Disclosures Yasenchak: Seattle Genetics, Inc.: Research Funding. Off Label Use: Brentuximab vedotin is indicated in the US for treatment of patients with Hodgkin lymphoma after failure of autologous stem cell transplant or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates and for the treatment of patients with systemic anaplastic large cell lymphoma after failure of at least one prior multi-agent chemotherapy regimen. . Farber:Seattle Genetics, Inc.: Research Funding. Budde:Seattle Genetics, Inc.: Research Funding. Ansell:Seattle Genetics, Inc.: Research Funding. Advani:Takeda Pharmaceuticals International Co.: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding; Jansseen Pharmaceuticals: Research Funding; Genentech: Research Funding; Seattle Genetics, Inc.: Research Funding, Travel expenses Other. Holkova:Seattle Genetics, Inc.: Research Funding. Halwani:Seattle Genetics, Inc.: Research Funding. Knapp:Takeda Pharmaceuticals International Co.: Research Funding; EMD Serono: Research Funding; Bristol Myers Squibb: Research Funding; Celgene: Research Funding; Merck: Research Funding; Heron Pharmaceuticals: Research Funding, Travel expenses, Travel expenses Other; Genentech: Research Funding, Travel expenses, Travel expenses Other; Seattle Genetics, Inc.: Research Funding; Pharmacyclics: Research Funding. Fayad:Seattle Genetics, Inc.: Consultancy, Research Funding. Kolibaba:Genentech: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Seattle Genetics, Inc.: Research Funding. Patel-Donnelly:Seattle Genetics, Inc.: Research Funding. Seetharam:Seattle Genetics, Inc.: Research Funding. Manley:Seattle Genetics, Inc.: Employment, Equity Ownership. Bartlett:Genentech: Research Funding; ImaginAb: Research Funding; Celgene: Research Funding; MedImmune: Research Funding; Novartis: Research Funding; Pharmacyclics: Research Funding; Pfizer: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Seattle Genetics, Inc.: Research Funding, Travel expenses Other; Janssen: Research Funding; Astra Zeneca: Research Funding.

Abstract Trichoblastic carcinoma is an uncommon malignant neoplasm arising from follicular germinative cells. The high-grade trichoblastic carcinoma has been reported with lymphatic and hematogenous dissemination. The authors present a 59-year-old man with gluteal cleft trichoblastic carcinoma and highlight the useful role of serial 18F-FDG PET/CT examinations in the demonstration of initial and subsequent nodal metastasis in the inguina and pelvis.