ALBERT

Description: Introduction: 18Fluoro-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is one of the most widely used imaging techniques to detect multiple myeloma (MM). Intracellular FDG uptake depicts in vivo metabolic activity, which can be seen in both malignant and non-malignant cells, resulting in limited sensitivity and specificity. Our group showed preclinically that tracing MM dissemination using a CD38-directed human antibody, daratumumab, that is radioconjugated with copper-64 via the chelator DOTA (64Cu-DOTA-Dara), led to improved sensitivity and specificity over that of FDG (Caserta et al, Blood 2018). Herein, we report the results of a Phase 1 trial (NCT#03311828) designed to 1) assess the safety and feasibility of 64Cu-DOTA-Dara PET/CT and 2) to evaluate and characterize the ability of 64Cu-DOTA-Dara to accurately detect or exclude MM lesions compared with FDG PET/CT. Methods: Patients with biopsy-proven MM and/or a plasmacytoma received an FDG PET/CT scan within 60 days of enrollment. On Day 0, patients were infused with unlabeled ("cold") Dara at one of four dose levels (0 mg, 10 mg, 45 mg, 95 mg) to optimize biodistribution of radioconjugated 64Cu-DOTA-Dara, especially in the liver and the spleen. Within 6 hours of unlabeled Dara administration, patients received 64Cu-DOTA-Dara at a dose of 13.63-16.68 mCi (~5 mg). Whole-body PET scans were obtained at 24 hours and at 48 hours (the latter scan encompassing known tumors). 64Cu-DOTA-Dara standardized uptake values (SUV) were evaluated in MM lesions and normal organs, which were then compared with values from standard FDG PET/CT. Biopsies were performed on accessible discordant lesions. Results: A total of 10 Dara-naïve patients were imaged. Patients were treated with 0 (n=3), 10 (n=3), 45 (n=3), or 95 mg (n=1) of unlabeled Dara. Four patients had newly diagnosed disease, one had biochemical relapse, one had a recurrent plasmacytoma by MRI, and four had possible recurrence by standard PET/CT. No significant adverse events were observed from either cold or 64Cu-DOTA-Dara. With the exception of the one patient with a recurrent plasmacytoma, radiolabeled antibody was eliminated from systemic circulation in subjects analyzed at the first three dose levels within 30 min post injection. In the patient with a recurrent plasmacytoma, the radiolabeled antibody was elevated in the blood for over two days. One newly diagnosed patient had extensive disease by FDG PET and had a biopsy-proven target lesion in the sternum, which had an SUVmax of 14.7 on 64Cu-DOTA-Dara PET/CT vs. 3.3 onFDG PET/CT. A second biopsy from the same patient was taken from a discordant iliac crest lesion (positive for 64Cu-DOTA-Dara but negative for FDG PET/CT) that showed 20-30% MM cell infiltration. In another patient, an iliac crest lesion was 64Cu-DOTA-Dara positive and FDG-negative; biopsy revealed 6% plasmacytosis in the bone. A third patient had an FDG PET/CT positive pleural lesion with an SUVmax of 8.98 and negative on 64Cu-DOTA-Dara (Figure 1A). The lesion did not show recurrence upon biopsy. Furthermore, 64Cu-DOTA-Dara PET/CT yielded superior imaging of bone lesions in the calvarium (Figure 1B). Escalating doses of unlabeled Dara decreased liver and spleen uptake by 64Cu-DOTA-Dara. Conclusions: In this ongoing study, 64Cu-DOTA-Dara PET/CT imaging is to date safe and provides whole body imaging of MM. Further dose escalation of cold Dara (145 mg, 195 mg) is planned to optimize background interference. This modality has the potential to improve sensitivity and specificity over FDG PET/CT scanning in early-stage MM as well as in recurrent disease. Disclosures Krishnan: Celgene, Janssen, Sanofi, BMS: Consultancy; Sutro BioPharma, zPredicta: Consultancy; Amgen, Takeda: Speakers Bureau; Celgene, Z Predicta: Other: Stock Ownership; Takeda: Research Funding. Palmer:Gilead Sciences: Consultancy. Rosenzweig:Celgene, Takeda: Speakers Bureau. Wu:ImaginAb, Inc.: Consultancy, Other: Board Member.

Description: Background: Peripheral T cell lymphomas (PTCL) have a poor prognosis with current treatment regimens. High-dose chemotherapy followed by autologous stem cell transplant (ASCT) has been used as a consolidation strategy in remission states (CR1 or above) endorsed by the NCCN guidelines in appropriate patients. 5-year DFS is reported at 70% for alk -ve anaplastic large cell lymphoma (ALCL) and 30-40% for most other histologies (D'Amore et al, 2012, JCO). It is also performed in the relapsed settings if no previous ASCT performed and allogeneic transplant is not an option. CD25 is a targetable protein expressed differentially in PTCL and antibody based anti-CD25 therapies are efficacious in PTCL i.e denileukin diftitox (Foss et al Blood 2006, Dang et al, BJH 2006) , monoclonal antibody dacluzimab (Waldman et al 1995 Blood). Yttrium-90 (90Y) labeled chimeric antiCD25 antibody basiliximab emits beta particles and has been shown to inhibit the growth of human ALCL tumors and increase survival in SUDHL-1 xenograft mice (Zhang et al 2009 Cancer Biother Radiopharm). Previous investigations at COH by Raubitschek, Colcher et al established a safe does of Yttrium-90 (90Y) labeled basiliximab at 0.4mCi/kg in combination with BEAM. This is a phase 1 clinical trial of a novel conditioning regimen that includes the use of Yttrium-90 (90Y) labeled basiliximab with BEAM chemotherapy for PTCL patients eligible for ASCT. The trial utilizes a modified version of the rolling 6 design (Skolnik et al) to test 3 dose levels of Yttrium-90 (90Y) Basiliximab i.e 0.4mCi/kg, 0.5miC/kg and 0.6mCi/kg with the primary objective of evaluating the safety and tolerability of this combination and to establish the MTD. Secondary objectives include estimating incidence of relapse, OS, PFS, NRM at day 100, 1 year and 2 years post-transplant. Patients and Methods: Dose limiting toxicity (DLT) is defined according to the Bearman and CTCAE 4.03 scales, the latter for hematologic toxicity. The study/treatment schema is shown in Figure 1. Results: From 07/29/2015 to 06/10/2020, 20 patients underwent ASCT on this trial; n=4 at 0.4mCi/kg n=4 at 0.5mCi/kg and n=12 at 0.6mCi/kg. Median age at ASCT was 51 years (range: 18-76), and histologies included; PTCL-nos (n=10); alk-ve ALCL (n=5); angioimmunoblastic T-cell lymphoma (n=3); and intestinal T-cell lymphoma (n=2). Disease status at ASCT were CR1 in18, CR2 in 2 patients. Median number of prior therapies was 1 (range: 1-4). At a median follow-up of 17.1 months (range: 0.9-26.2), 12 patients remain in remission, 8 have relapsed out of which 5 have died of progressive lymphoma. OS was 100% (95% CI: N/A) at 100-days, and 83% (95% CI: 57-94) at 1 year. Non-relapse Mortality was 0% at both 100-days and 1-year. All patients successfully engrafted with the median days to ANC 〉= 500/ul was 10 (range: 10 - 21), and days to PLT 〉= 20,000/ul: 13 (12 - 92). Overall, no dose limiting toxicities were experienced. The most common/highest grade toxicity experienced (per Bearman Scale) was grade 2 stomatitis, which was seen in 3 patients at 0.4mCi/kg; 4 patients at 0.5 mCi/kg, and 7 at0.6mCi/kg. The only other toxicities seen were grade 2 GI in 2 patients at 0.4mCi/kg, and grade 2 bladder in one patient at 0.6mCi/kg dose.. Toxicities 〉grade 2 were not seen. Conclusion: aTac- BEAM appears to be safe as an ASCT conditioning regimen for PTCL with no increased toxicity as compared to the historical toxicities seen with BEAM alone in this patient population (D'Amore 2012 J of Clin Onc). The dose level 0.6mCi/kg will likely be the recommended phase II dose. An expanded phase is planned to evaluate the efficacy of this regimen followed by a randomized trial of BEAM alone plus a combination of aTac- BEAM. Figure 1 Disclosures Zain: Mundi Pharma: Research Funding; Seattle Genetics: Research Funding; Kyowa Kirin: Research Funding. Herrera:Gilead Sciences: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Immune Design: Research Funding; AstraZeneca: Research Funding; Karyopharm: Consultancy; Pharmacyclics: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Other: Travel, Accomodations, Expenses, Research Funding; Merck: Consultancy, Research Funding. Salhotra:Kadmon: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Nakamura:NapaJen Pharma: Consultancy; Celgene: Other: Support on seminar; Magenta Therapeutics: Other: Advisory board meeting; Viracor: Consultancy; Merck: Other: advisory board meeting; Alexion: Other: Support on a meeting presentation; Kyowa-Kirin: Other: Support on a meeting presentation; Kadmon Corporation: Other: Advisory board meeting. OffLabel Disclosure: Yittrium labelled Basiliximab