Teclistamab in combination with daratumumab and lenalidomide in multiple myeloma (MajesTEC-2 study)

Introduction: Combination of daratumumab (Dara) and lenalidomide (Len) may enhance the function of teclistamab (Tec), potentially resulting in improved antimyeloma activity in a broader population. We present initial safety and efficacy data of Tec-Dara- Len combination in patients with multiple myeloma (MM) in a phase 1b study (MajesTEC-2;NCT04722146). Method(s): Eligible patients who received 1-3 prior lines of therapy (LOT), including a proteasome inhibitor and immune-modulatory drug, were given weekly doses of Tec (0.72-or- 1.5 mg/kg with step-up dosing) + Dara 1800 mg + Len 25 mg. Responses per International Myeloma Working Group criteria, adverse events (Aes) per CTCAE v5.0, and for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) per ASTCT guidelines, were assessed. Result(s): 32 patients received Tec-Dara- Len (0.72 mg/kg, n = 13;1.5 mg/kg, n = 19). At data cut-off (11 July 2022), median follow-up (range) was 5.78 months (1.0-10.4) and median treatment duration was 4.98 months (0.10-10.35). Median age was 62 years (38-75);87.5% were male. Median prior LOT was 2 (1-3), 18.8% were refractory to Dara and 28.1% refractory to Len. CRS was most frequent AE (81.3% [n = 26], all grade 1/2), 95% occurred during cycle1. Median time to onset was 2 days (1-8), median duration was 2 days (1-22). No ICANS were reported. Frequent Aes (>=25.0% across both dose levels) were neutropenia (75.0% [n = 24];grade 3/4: 68.8% [n = 22]), fatigue (43.8% [n = 14];grade 3/4: 6.3% [n = 2]), diarrhoea (37.5% [n = 12];all grade 1/2), insomnia (31.3% [n = 10];grade 3/4: 3.1% [n = 1]), cough (28.1% [n = 9];all grade 1/2), hypophosphatemia (25.0% [n = 8];all grade 1/2), and pyrexia (25% [n = 8];grade 3/4: 6.3% [n = 2]). Febrile neutropenia frequency was 12.5% (n = 4). Infections occurred in 24 patients (75.0%;grade 3/4: 28.1% [n = 9]). Most common were upper respiratory infection (21.9% [n = 7]), COVID-19 (21.9% [n = 7]), and pneumonia (21.9% [n = 7]). Three (9.4%) had COVID-19 pneumonia. One (3.1%) discontinued due to COVID-19 infection and this patient subsequently died of this infection. Overall response rate (ORR, median follow-up) was 13/13 (8.61 months) at 0.72 mg/kg and 13/16 evaluable patients (less mature at 4.17 months) at 1.5 mg/kg. 12 patients attained very good/better partial response at 0.72 mg/kg dose, and response was not mature for 1.5 mg/kg group. Median time to first response was 1.0 month (0.7-2.0). Preliminary pharmacokinetic concentrations of Tec-Dara- Len were similar as seen with Tec monotherapy. Tec-Dara- Len- treatment led to proinflammatory cytokine production and T-cell activation. Conclusion(s): The combination of Tec-Dara- Len has no new safety signals beyond those seen with Tec or Dara-Len individually. Promising ORR supports the potential for this combination to have enhanced early disease control through the addition of Tec. These data warrant further investigation.

Preliminary results from phase 2 of CC-92480- MM- 001: Mezigdomide plus dexamethasone in relapsed/refractory multiple myeloma (RRMM)

In phase 1 of CC-92480- MM- 001 (NCT03374085), the recommended phase 2 dose (RP2D) of mezigdomide plus dexamethasone (MEZI-d) was selected at 1 mg once daily for 21/28 days. Here we report preliminary results from the MEZI-d dose-expansion cohort in patients with heavily pretreated RRMM. Key eligibility criteria were: RRMM;>=3 prior lines of therapy;disease progression <=60 days of last myeloma therapy;refractoriness to lenalidomide/pomalidomide, a proteasome inhibitor, a glucocorticoid, and an anti-CD38 monoclonal antibody. Oral mezigdomide 1 mg was given on days 1-21 of each 28-day cycle, plus weekly dexamethasone (40 mg;20 mg if >75 years of age). Primary objective was to evaluate efficacy (overall response rate [ORR]);secondary objectives included safety/tolerability and additional efficacy assessments. Pharmacodynamics was an exploratory objective. As of 16/Sep/2022, 101 patients had received MEZI-d at the RP2D. Median age was 67 (range 42-85) years, median time since initial diagnosis was 7.4 (1.1-37.0) years;39.6% of patients had plasmacytomas and 37/101 patients had high-risk cytogenetics (56/101 not evaluable). Median number of prior regimens was 6 (3-15);prior therapies included stem cell transplantation (77.2%) and anti-BCMA therapy (29.7%). All patients were refractory to last myeloma regimen and triple-class refractory. Median follow-up was 7.5 (0.5-21.9) months, with a median of 4 (1-20) cycles;10.0% of patients continued treatment;progressive disease was the main reason for discontinuation (60.4%). ORR was 40.6% for all patients. Whilst data are not mature yet, median PFS was 4.4 (95% CI 3.0-5.5) months and median duration of response was 7.6 (95% CI 5.4-9.5) months. ORR was 30.0% in patients with plasmacytomas (N = 40) and 50.0% in patients with prior anti-BCMA therapy (N = 30). Ninety-one (91.1%) patients experienced a grade 3/4 treatment-emergent adverse event (TEAE). Most frequent hematologic grade 3/4 TEAEs were neutropenia (75.2%), anaemia (35.6%), and thrombocytopenia (27.7%);34.7% of patients had grade 3/4 infections, including grade 3/4 pneumonia (15.8%) and COVID-19 (7.0%). Occurrence of other grade 3/4 non-hematologic TEAEs was generally low. Due to TEAEs, 76.2% and 29.7% of patients had mezigdomide dose interruptions and reductions, respectively;90.1% of patients discontinued mezigdomide. Mezigdomide induced substrate degradation and increases in activated and proliferating T cells in patients, including those directly refractory to pomalidomide-based therapies. MEZI-d had a manageable safety profile with encouraging efficacy in patients with triple-class refractory RRMM, including patients with prior BCMA-targeted therapies. These results strongly support the continued development of mezigdomide in MM, and especially in combination.

HIGH RESPONSES RATES WITH SINGLE AGENT BELANTAMAB MAFODOTIN IN RELAPSED SYSTEMIC AL AMYLOIDOSIS

Background: Systemic AL amyloidosis is an incurable relapsing plasma cell disorder. Despite therapeutic advances, there are no approved treatments for relapse disease. Treatment is often challenging due to underlying organ dysfunction. Belantamab mafodotin is an antibody-drug conjugate targeting B-cell maturation antigen with approval for relapsed refractory myeloma. In multiply pre-treated myeloma, the DREAMM-2 phase II trial showed an overall response rate of 32% for those with 2.5 mg/kg dose administered every three weeks with 2/3rd patients reporting keratopathy. A small case series of 6 patients with relapsed AL amyloidosis (Zhang et al , ASH 2021) was recently reported and a phase 2 trial is recruiting for patients with refractory amyloidosis (NCT04617925). Aims: We report our initial results using Belantamab monotherapy for the treatment of patients with AL amyloidosis with relapsed disease. Methods: Data for consecutive patients who were administered Belantamab at a specialist referral centre, National Amyloidosis Centre, University College London, was analysed. Results: Eleven patients were included 8 male, 3 female. Median age at Belantamab initiation was 65 (range 42-74) years. Eight patients had λ AL-type and three κ AL-type. At diagnosis, median involved free light-chain concentration was 534 (range 73-7181) mg/l. A median of two organs involved at baseline (range 1-3): 4 had cardiac involvement (half Mayo stage 2;half Mayo stage 3a) and 8 had renal involvement. The median prior lines of therapy was 3 (range 2-5) with all exposed to prior immunomodulatory drugs, proteasome inhibitors and 73% to anti-CD38 antibody treatments. Thirty-six percent had relapsed after melphalan-conditioned autologous stem cell transplantation. A median of 3 cycles of belantamab were delivered (range 1-8). The most frequent adverse event was ocular toxicity which was experienced in 8 patients (grade 1-3), necessitating dose modification of the three-weekly schedule. One patient developed transient grade 1 dyspnoea and liver dysfunction. No patients developed cytopenias, unlike previous reports (Zhang et al , 2021), nor infections beyond COVID (2 patients mild with no hospital admissions). The majority of the cohort required dose reduction either at initiation (patient 4, due to end stage renal failure;patient 11, post-renal transplant) or during therapy (n=5;three to 1.9mg/kg, two to 1.25mg/kg) due to ocular toxicity. Only one patient remained on the standard dose of 2.5mg/kg for >3 cycles. Ocular toxicity improved after treatment interruption (drug intervals 4-6 weeks) and no patients required complete treatment cessation. One patient is too early to assess response. Haematological responses (PR or better) were seen in 7 patients with 3 complete responses and two very good partial responses (VGPR) which are ongoing. Both renal patients (patients 4 and 11) commenced a dose of 1.25mg/kg and sustained a VGPR with no additional toxicity. Patient 3 had a 42% reduction in sFLC after two doses but then a prolonged gap due to keratopathy and has lost the response. There were no cardiac or renal toxicities observed. Summary/Conclusion: Belantamab mafodotin demonstrates significant activity in patients with heavily pre-treated AL amyloidosis with 70% achieving a ≥PR. Apart from keratopathy requiring dose modification, no other substantial toxicity was observed. Two patients with renal impairment (stage V CKD and ESRD) and one patient post-renal transplant tolerated treatment with no additional toxicity. Belantamab mafodotin shows promise in treatment of relapsed AL and needs further prospective trials.

Patients with plasma cell disorders retain their humoral response to COVID-19 vaccination following autologous stem cell transplant but falling titres emphasise the importance of re-vaccination

There is increased infection risk at the time of autologous stem cell transplantation (ASCT) including for patients with plasma cell disorders (PCD), therefore preventing infection with COVID-19 vaccination in this vulnerable group is key. However, patients with PCD have been shown to mount suboptimal responses to COVID-19 vaccination. A clinical audit of serological response to COVID-19 vaccination before and after ASCT was undertaken, to observe how antibody titres change during this period. Antibodies to the SARS-CoV-2 spike protein were measured using the Elecsys Anti-SARS-CoV-2S assay (Roche diagnostics) in 88 patients who underwent ASCT for PCD at the University College London Hospital NHS Foundation Trust between December 2020 and September 2021. Pre-ASCT antibody titres were measured following first or second vaccine and following ASCT. The majority ( n = 76) had no prior history of COVID-19 infection, and four of this cohort declined vaccination. In those who received one vaccine pre-ASCT ( n = 21), 76% seroconverted with a median titre of 11.3 3 U/ml (IQR 1.5-62.6). In those who received two doses pre-ASCT ( n = 51), 97% seroconverted with a median titre of 494 U/ml (IQR 190.5-1681). In those who received two doses pre-ASCT, anti-S antibodies were detected in the immediate post-ASCT setting, with titres of 373 U/ml (median, IQR 40.6-2326) measured less than or equal to 28 days (median 15 [6-25]) post-ASCT, and 170 U/ml (IQR 55-604) at more than 28 days (median 85 [32-125]) post-ASCT. Patients who received one dose pre-ASCT had lower median titres of 36.5 U/ml (IQR 12.6-1310) measured less than or equal to 28 days (median 15 [12-22] post-ASCT and 7.7 U/ml (IQR 2.9-23.8) at more than 28 days (median 85 [40-104] post-ASCT. Antibody levels declined over time, but patients who had received two vaccines pre-ASCT maintained higher titres post-ASCT compared to those who had received one dose, emphasising the importance of COVID-19 vaccination prior to ASCT. Our patients are advised to be re-vaccinated against COVID-19 3 months after ASCT, and antibody response following re-vaccination was measured in a subgroup ( n = 14). Those who were previously un-vaccinated did not seroconvert following one dose. However, antibody titres in those who had received either one or two vaccines ( n = 12) prior to ASCT increased from 32.4 U/ml (median, IQR 13.4-1082) post-ASCT to 431 U/ml (median, IQR 15.33-2500) following re-vaccination. Those who had received two vaccines pre-ASCT ( n = 2) achieved higher titres than those who had received a single dose. In conclusion, we demonstrated how protective titres fall during the patient's journey through ASCT and our repeated interactions with them. Despite this, patients vaccinated prior to ASCT maintain some level of measurable antibody immediately post-ASCT, which is encouraging as patients are considered most vulnerable to infection during this period. Titres were also boosted effectively after one dose of re-vaccination, compared to those never vaccinated. Current guidance is for adult patients who have undergone ASCT to be considered 'never vaccinated' against COVID-19, in line with pre-COVID-19 re-vaccination practice, and to receive a three-dose primary course followed by a booster vaccination post-ASCT. We must facilitate and encourage our patients to be vaccinated prior and after ASCT in this rapidly changing landscape, especially in context of the spread and evolution of a potentially more transmissible virus. (Table Presented).

Serological response to the BNT162B2 mRNA or ChAdOx-nCOV-19 COVID-19 vaccine after first and second doses in plasma cell disorder patients: Influence of host and disease factors

Background Plasma cell disorders (PCD) are at risk of inadequate immune responses to COVID-19 vaccines due to recognised humoral and cellular immune dysfunction which is multi-factorial and related to host and disease factors. With an estimated risk of 33% mortality from contracting COVID-19 in this population, protection with an anti-SARS-CoV-2 vaccination is critical. Initial extension to vaccination intervals in the United Kingdom to 12 weeks in December 2020 led to concerns that PCD patients would be left vulnerable for an extended period. Methods A clinical audit was performed on measured serological responses in PCD patients after first and second doses of the BNT162b2 and ChAdOx-1 nCoV-19 vaccines. Antibody levels were measured using Elecsys Anti-SARS-CoV-2S assay (Roche) for quantitative detection of IgG Abs, specific for the SARS-CoV-2 spike-protein. Positive cut-off of 0.80 U/mL defined serological response. Testing was performed at (or closest to) 4 and 8-weeks post-dose. Baseline nucleocapsid Ab results were available from previous screening in a subset of patients. All patients on CIT underwent 4-weekly swabs. Clinical information was retrieved from medical records. Results 188 PCD patients (155 multiple myeloma, 18 amyloid, 10 SMM/MGUS, other 5 PCD), median age 64 (range 32-84), had serological assessment after both vaccine doses. Fourteen with previous COVID-19 infection were excluded. Of 174 patients, 112 were tested after first dose. 88% (153) were on chemo-immunotherapy treatment (CIT). Seropositive rate after first dose was 63% (71/112);of those with available negative baseline antibody test, 62% (31/50) seroconverted. After second dose, 89% (154/174) were seropositive;of those with negative baseline antibody, 90% (61/68) seroconverted. Expectedly, paired median titres after second dose were significantly higher than post first dose (n=112, 3.245 U/mL (IQR 0.4-25.55) vs 518 U/mL (IQR 29.40-2187) p<0.0001) (Figure 1A). Of 41 patients seronegative after first dose, 25 (61%) seroconverted after second, though with lower titres than those only requiring one dose (Figure 1B). Active CIT, disease response less than PR, >=4 lines therapy, light-chain disease, male gender and not responding to first dose were significant factors for not responding to two vaccine doses. We explored <400 U/mL as sub-optimal response (in keeping with upcoming booster study eligibility, OCTAVE-DUO(1), also encompassing the lower quartile of reported healthy controls(2)), which included 43% (75/174) patients. Age 70 years, male gender, >=4 lines of treatment were independent predictors of less-than-optimal response (anti-CD38 CIT of borderline significance). Importantly, vaccine dosing intervals classified as =<42 vs >42 days (Figure 1C) or 28 +/- 14 days vs 84 +/- 14 days (excluding n=66 in neither) (Figure 1D) did not show difference in both definitions of response, neither did vaccine type. Fourteen with previous COVID-19 infection responded to one vaccine dose, median titres 2121 U/mL (IQR 23.48- 2500)) rising to median 2500 U/mL (IQR 2500-2500) after second dose (Figure 1E), significantly higher than those without previous infection. Conclusion Serological response to COVID-19 vaccine is lower in PCD patients than reported healthy controls at 63% after first dose, rising to 89% after second dose, despite extended dosing intervals. PCD patients should be prioritised for shorter intervals, as we show that patients seronegative after first dose, respond after second dose. Further work in PCD is needed to understand how Ab levels correlate to neutralisation capability, cellular responses, protection from infection and how long seroconversion lasts to better define correlates of protection. A booster vaccination or prophylactic passive antibody strategy may be required for those identified at risk, shown not to have responded to two vaccine doses or to have less-than-optimal response. Results from these trials will be eagerly awaited. (Figure Presented).

Daratumumab, Bortezomib and Dexamethasone (DVd) at First Relapse for Patients with Relapsed/ Refractory Multiple Myeloma (RRMM): A UK Myeloma Research Alliance (UK-MRA) Real-World Multicentre Analysis

Introduction: Daratumumab in combination with bortezomib and dexamethasone (DVd) demonstrated a superior overall response rates (ORR) and progression free survival (PFS) compared to Vd in the CASTOR phase 3 trial for patients with RRMM. On this basis, DVd was recommended in March 2019 for UK patients with RRMM that had 1 prior line (PL). Discrepancies in outcomes between patients treated in clinical trials compared to routine practice is well recognised due to a combination of patient, disease and treatment-related factors. In addition, bortezomib is often administered once-weekly in routine practice to minimise neuropathy, while CASTOR used bi-weekly bortezomib dosing. As a result, the real-world outcomes of patients treated with DVd are yet to be determined. The primary aims of this analysis was to assess the ORR and PFS for patients with RRMM with 1PL treated with DVd in routine practice. Secondary aims were to assess OS, time to next treatment (TTNT), and efficacy in different sub-groups (high risk cytogenetics, previous proteasome inhibitor (PI) exposure, refractoriness of prior therapies, bi-weekly vs weekly bortezomib schedule, and previous treatment free interval (TFI)). Methods: This was a retrospective analysis from 14 centres (academic and community hospitals;7 within the West Midlands Research Consortium (WMRC)) treated with DVd between March 2019 and June 2021. Patients received daratumumab (IV and then SC from June 2020) weekly in cycles 1-3, on day 1 of a 3-week cycle during cycles 4-8, and then monthly from cycle 9 to progression. SC Bortezomib was predominantly given weekly for cycles 1-8 although 5 centres used bi-weekly dosing for selected patients with aggressive disease. Adverse events were graded as per CTCAE criteria. Results: 288 patients were included, with a median age of 69 years (range 20-88) (Table 1). Patients received a median of 1 PL (range 1-2) with 93% (269) 1PL, 7% (18) 2 PL (due to COVID-19 measures). The majority had an ECOG performance status of 0-2 (98%) and most received weekly bortezomib (n=201). This population differed from those with 1PL treated on CASTOR in being older, more were ISS 3 (31% vs 19%, p=0.0145), and more had prior bortezomib exposure (71% vs 51%, p=0.0003), 4% were PI refractory, 9% had a GFR of <30ml/min (<20ml/min was an exclusion from CASTOR), and 2% had an ECOG performance status of ≥3. The ORR was 76%, with >VGPR in 54% (Table 2), with no significant difference in response between patients receiving biweekly vs weekly bortezomib (85% vs 83%;p=0.71). The median time to response was 1.6m. With a median follow up of 15m, the median PFS was 14m (95% CI 11.6-16). High cytogenetic risk patients had inferior outcomes: median PFS 10m (95% CI 6-14) for high risk vs not reached for standard risk (p=0.043);as did those with advanced ISS: median PFS was not reached, 15 and 12m for stage I, II and III respectively (p=0.05). For 15 patients with extramedullary disease (EMD), the median PFS was 3m (95% CI 1-5). Median PFS for patients who were PI refractory was shorter (10m vs 15m for PI sensitive patients (p=0.006)). There was no difference in median PFS for patients with prior PI exposure vs no prior PI (15 vs 13m;p=0.75), or according to weekly or bi-weekly bortezomib schedule (11 vs 15m;p=0.14). The median TTNT was 21m (95% CI 17-25). Overall, the median duration of treatment was 8m and 25 patients (9%) stopped treatment to receive a second autologous stem cell transplant. Those that had a prior TFI of >12m had a longer median PFS of 21m vs 10m (p=0.0004). The median OS has not been reached, with an estimated 2-year OS of 74%. For patients with high risk cytogenetics the median OS was 16m (95% CI 9-23;vs not reached for standard risk;p=0.0006), with estimated 2-year OS in the high risk group of 36%. There was no difference in OS for patients treated with biweekly vs weekly bortezomib (not reached for either;p=0.38). DVd was generally well tolerated with 6% stopping due to adverse events (CASTOR 9.5%). Grade 3 or 4 toxicity occurred in 62 (22%) most comm nly neutropenia and thrombocytopenia, with any grade infusion reactions reported in 27 (9%). Conclusions: These real-world data of DVd at 1 st relapse demonstrated good tolerability and high response rates with a weekly bortezomib schedule despite a more heterogenous population. However, high risk patients by cytogenetics, ISS or EMD had inferior outcomes as did those treated within 12 months from first line treatment. [Formula presented] Disclosures: Cook: Karyopharm: Consultancy, Honoraria;Pfizer: Consultancy, Honoraria;Sanofi: Consultancy, Honoraria;Takeda: Consultancy, Honoraria, Research Funding;Amgen: Consultancy, Honoraria, Research Funding;BMS: Consultancy, Honoraria, Research Funding;Oncopeptides: Consultancy, Honoraria;Roche: Consultancy, Honoraria;Janssen: Consultancy, Honoraria, Research Funding. Pratt: Binding Site: Consultancy;BMS/Celgene: Consultancy;Gilead: Consultancy;Janssen: Consultancy;Takeda: Consultancy;Amgen: Consultancy. Kishore: Celgene: Other: Attending fees;Jannsen: Other: Attending fees;Sanofi: Other: Attending fees;Takeda: Other: Attending fees. Yong: Amgen: Honoraria;Autolus: Research Funding;BMS: Research Funding;Janssen: Honoraria, Research Funding;Sanofi: Honoraria, Research Funding;GSK: Honoraria;Takeda: Honoraria. Popat: Abbvie, Takeda, Janssen, and Celgene: Consultancy;Takeda: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES;GlaxoSmithKline: Consultancy, Honoraria, Research Funding;AbbVie, BMS, Janssen, Oncopeptides, and Amgen: Honoraria;Janssen and BMS: Other: travel expenses.

Iberdomide (IBER) in Combination with Dexamethasone (DEX) in Patients (pts) with Relapsed/Refractory Multiple Myeloma (RRMM): Results from the Dose-Expansion Phase of the CC-220-MM-001 Trial

Introduction: Despite recent advances, MM remains incurable and new therapeutic options are needed, particularly for pts with RRMM. IBER is a novel, potent oral cereblon E3 ligase modulator (CELMoD ®) compound with enhanced tumoricidal and immune-stimulatory effects compared with immunomodulatory (IMiD ®) agents. Preclinically, IBER demonstrated marked synergy with DEX and with other standard myeloma treatments. CC-220-MM-001 (NCT02773030) is an ongoing phase 1/2 study evaluating IBER with different treatment combinations in independent cohorts of pts with RRMM;in phase 1, the recommended phase 2 dose of IBER, when given in combination with DEX, was determined at 1.6 mg (Lonial S, et al. Blood 2019;134[suppl 1]:3119). Here we report results from the dose expansion of IBER + DEX in pts with heavily pretreated, triple-class exposed (including ≥ 1 IMiD agent, ≥ 1 proteasome inhibitor [PI], and ≥ 1 anti-CD38 monoclonal antibody [mAb]) RRMM. Methods: Eligible pts had RRMM;had received ≥ 3 prior lines of therapy, including lenalidomide (LEN), pomalidomide (POM), a PI, a glucocorticoid, and an anti-CD38 mAb;had experienced disease progression within 60 days of last myeloma therapy;and were refractory to an IMiD agent, a PI, a glucocorticoid, and an anti-CD38 mAb. Pts with central nervous system involvement were not eligible. Pts who had received prior anti-BCMA therapy were excluded, but included in a supportive cohort for safety and preliminary efficacy assessment. IBER (1.6 mg) was given orally on days (D) 1-21, in combination with DEX (40 mg;20 mg if > 75 years of age) on D1, 8, 15, and 22 of each 28-day cycle. Thrombo-embolism prophylaxis was mandatory for all pts. Primary objective was to determine efficacy expressed as overall response rate (ORR). Secondary endpoints included additional efficacy and safety assessments. Exploratory endpoints included evaluation of health-related quality of life (HRQoL). Results: As of June 2, 2021, 107 pts had received IBER + DEX. Median age was 64 (44-83) years;median time since initial diagnosis was 6.9 (1.6-24.5) years. Extramedullary plasmacytomas were present in 25.2% of pts;29.9% of pts had high-risk cytogenetics. Median number of prior regimens was 6 (3-23). All pts were triple-class exposed;prior therapies included autologous stem cell transplantation (78.5%), PIs (100%), IMiD agents (LEN [100%] and POM [100%]), and anti-CD38 mAbs (100%);99.1% of pts were refractory to last myeloma regimen and 97.2% of pts were triple-class refractory. Median follow-up was 7.69 (0.5-17.5) months, with a median number of 4 (1-17) cycles received and 13 (12.1%) pts continuing treatment. Main reason for discontinuation was progressive disease (69.2%). ORR was 26.2%, with 1 (0.9%) stringent complete response, 8 (7.5%) very good partial responses, and 19 (17.8%) partial responses (Table);the clinical benefit rate (≥ minimal response) was 36.4% and disease control rate (≥ stable disease) was 79.4%. Median duration of response was 7.0 (4.5-11.3) months (Table), median progression-free survival was 3.0 (2.8-3.7) months, and median overall survival was 11.2 (9.0-not reached) months. Similar response rates were observed among a cohort of pts also exposed to BCMA therapies (N = 24, Table). Grade (Gr) 3-4 treatment-emergent adverse events (TEAEs) were reported in 88 (82.2%) pts. Most frequent (≥ 20% pts) hematologic Gr 3-4 TEAEs were neutropenia (44.9%;and 4.7% febrile neutropenia), anemia (28.0%), thrombocytopenia (21.5%), and leukopenia (20.6%). Gr 3-4 infections were reported in 27.1% of pts;Gr 3-4 pneumonia and COVID-19 occurred in 10.3% and 4.7% of pts, respectively. Occurrence of other Gr 3-4 non-hematologic TEAEs was generally low, including gastrointestinal disorders (5.6%), fatigue (2.8%), rash (1.9%). Fifty-six (52.3%) pts and 20 (18.7%) had IBER dose interruptions and reductions due to TEAEs, respectively. Five (4.7%) pts discontinued due to TEAEs. No pt discontinued IBER due to neutropenia. Overall, HRQoL was maintained in these pts. Conclusions: IBER + DEX demonst ated promising efficacy in pts with heavily pretreated, triple-class exposed and refractory RRMM, as well as in pts who had previously received anti-BCMA therapy;this combination was generally well tolerated and TEAEs were manageable with dose reductions and interruptions. These results support the further development of IBER in MM, including phase 3 trials in combination regimens. [Formula presented] Disclosures: Lonial: Abbvie: Consultancy, Honoraria;AMGEN: Consultancy, Honoraria;Takeda: Consultancy, Honoraria, Research Funding;GlaxoSmithKline: Consultancy, Honoraria, Research Funding;TG Therapeutics: Membership on an entity's Board of Directors or advisory committees;Merck: Honoraria;BMS/Celgene: Consultancy, Honoraria, Research Funding;Janssen: Consultancy, Honoraria, Research Funding. Popat: GlaxoSmithKline: Consultancy, Honoraria, Research Funding;Abbvie, Takeda, Janssen, and Celgene: Consultancy;Takeda: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES;AbbVie, BMS, Janssen, Oncopeptides, and Amgen: Honoraria;Janssen and BMS: Other: travel expenses. Hulin: Sanofi: Honoraria;Celgene/BMS: Honoraria;Janssen: Honoraria;Takeda: Honoraria;abbvie: Honoraria. Jagannath: Legend Biotech: Consultancy;Bristol Myers Squibb: Consultancy;Karyopharm Therapeutics: Consultancy;Janssen Pharmaceuticals: Consultancy;Sanofi: Consultancy;Takeda: Consultancy. Oriol: Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees;Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees;BMS/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Richardson: Karyopharm: Consultancy, Research Funding;Regeneron: Consultancy;AbbVie: Consultancy;Celgene/BMS: Consultancy, Research Funding;Oncopeptides: Consultancy, Research Funding;GlaxoSmithKline: Consultancy;Protocol Intelligence: Consultancy;Janssen: Consultancy;Secura Bio: Consultancy;Takeda: Consultancy, Research Funding;Sanofi: Consultancy;AstraZeneca: Consultancy;Jazz Pharmaceuticals: Consultancy, Research Funding. Weisel: Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Roche: Honoraria;Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Abbvie: Consultancy;Novartis: Honoraria;Pfizer: Honoraria. Minnema: Cilag: Consultancy;Janssen: Consultancy;Alnylam: Consultancy;Celgene: Other: Travel expenses;Kite/Gilead: Consultancy;BMS: Consultancy. Badros: J&J: Research Funding;Janssen: Research Funding;BMS: Research Funding;GlaxoSmithKline: Research Funding. Knop: BMS/Celgene: Consultancy, Honoraria, Research Funding;Amgen: Research Funding;Janssen: Consultancy;Oncopeptides: Consultancy;Pfizer: Consultancy;Sanofi: Consultanc . Stadtmauer: Janssen: Consultancy, Honoraria;Takeda: Consultancy, Honoraria;Abbvie: Consultancy, Honoraria;Amgen: Consultancy, Honoraria;Bristol Myers Squibb: Consultancy, Honoraria, Research Funding. Chen: Bristol Myers Squibb: Current Employment. Nguyen: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Amin: Bristol Myers Squibb: Current Employment. Kueenburg: Celgene a BMS company: Current Employment. Peluso: Celgene, a Bristol-Myers Squibb Company: Current Employment. van de Donk: BMS/Celgene: Consultancy, Honoraria;Janssen: Consultancy, Research Funding;Amgen: Consultancy, Research Funding;Cellectis: Research Funding;Takeda: Consultancy;Roche: Consultancy;Novartis /bayer/servier: Consultancy.

OAB-003: CARDAMON:Carfilzomib (K) maintenance following Autologous Stem Cell Transplant (ASCT) or carfilzomib-cyclophosphamide-dexamethasone (KCd) consolidation for newly diagnosed (NDTE) multiple myeloma (MM)

Background: The role of upfront ASCT for NDTE MM remains under evaluation with high MRD rates following novel induction and consolidation (cons) strategies. K maintenance represents an alternative strategy to lenalidomide maintenance. The CARDAMON trial investigated K maintenance following KCd induction plus either ASCT or KCd cons. Methods: NDTE pts received 4 x KCd induction (K 20/56 mg/m2 biweekly, C 500 mg D 1,8,15, d 40mg weekly) before 1:1 randomisation to ASCT or 4 x KCd cons followed by 18 cycles K maintenance (56mg/m2 D1,8,15). Flow cytometric MRD (10-5) was assessed post induction, pre-maintenance and at 6 months maintenance. Primary endpoints were ≥VGPR post induction and 2-year PFS from randomisation. Secondary endpoints included improvements in disease response and MRD conversion following ASCT/ cons and maintenance. Results: 281 patients were registered, with 218 randomised to either ASCT or cons. The median PFS for ASCT was not yet reached vs 3.4 years for cons, with cons failing to show non-inferiority (difference in 2-year PFS 6.5%, 70% CI 1.0% to 11.1%). 196 patients received K maintenance (99 ASCT, 97 cons), 17 remain on treatment. A median of 16 cycles (1-18) were given over a median of 15.9 months (0-21.5). COVID-19 led to maintenance treatment interruptions in 41 (8 ASCT, 6 Cons) and treatment discontinuation in 15 (9 ASCT, 6 Cons). The median K dose given was 50.6mg/m2 and was similar across both arms (51.2 vs 49.4mg/m2, p=0.03). K maintenance was discontinued for PD in 14.1% (ASCT) vs 22.7% (cons), and for adverse events (AEs) in 7.1% (ASCT) vs 4.1% (cons). Most common AEs were hypertension and infections and more ≥G3 AEs were noted in ASCT vs cons (p=0.01). Patient/ clinician withdrawals from maintenance were low but occurred more in the ASCT arm (9.1% vs 1%). MRD neg patients post ASCT/ Cons had a longer PFS than MRD pos (p=0.002);with a higher MRD neg rate in the ASCT arm (53.6% vs 35.1% in Cons, p=0.01). MRD neg patients at 6 months post maintenance also had longer PFS (p=0.004 cf MRD pos patients);again with higher MRD neg rates in the ASCT arm (58.1% ASCT vs 40.5% Cons, p=0.02). There was no difference in PFS for MRD neg patients according to treatment arm from PBSCH, post-ASCT/ Cons or 6 months maintenance timepoints. Overall, 27.8% of MRD pos patients converted to MRD neg post ASCT/ Cons with more converting with ASCT (39.1% ASCT vs 16.1%, p=0.004). 23.5% of MRD pos patients converted to neg during maintenance (30.6% ASCT, 17.8%: p=0.2). Maintenance of MRD negativity over the first 6 months was similar between ASCT and Cons arms (p=0.3). There was no evidence that the timing of achievement of MRD negativity impacted PFS. Conclusions: K maintenance at 56mg/m2 weekly was deliverable and tolerable, with continued higher MRD neg rates at 6 months post-ASCT compared to post-Cons. However more ≥G3 AEs and discontinuations for AEs/ patient choice were noted for K maintenance after ASCT.

Parent preference: Comparing telephone with face to face consultations during the COVID-19 pandemic

Background The Covid-19 pandemic led to a strong government response in attempts to limit spread of this virulent infectious disease. Societal measures included social distancing, hand hygiene with 'stay-at-home' advice, colloquially referred to as 'lockdown'. Medical practice had to respond quickly, respecting these measures whilst trying to offer ongoing patient services. Objectives There has been a proliferation of virtual appointments, offered either via telephone or video call. For a paediatrics department in a major district general hospital, phone consultations were the immediately available option. Our study objective was to implement an online survey questionnaire to explore family perceptions on virtual telephone appointments. Methods 168 families who participated in general paediatric follow up telephone consultations over a two-week period in May were contacted for consent to send them an online survey comparing telephone and face-to-face consultations. This group was targeted because they had at least one face-to-face appointment previously. The online survey consisted of 10 questions to compare different modes of consultations, including satisfaction rating using the Likert scale, and open text responses. Results 40 families (response rate 44%) of 92 who consented, completed the online survey. 4 (10%) parents had a strong preference for face-to-face appointments, with roughly 25% each slightly preferring telephone or face-toface appointments (9 and 12 respectively). 35% (14) did not mind either option. Despite this, if given the choice, 12 (30%) would choose face-to-face appointments in the future as opposed to 5 (12.5%) who would chose the telephone consultation. Parents rated convenience as greater for telephone appointments (33 responses, 85%). Some parents mentioned in feedback slightly better ability to remember information and ask questions. However, there was limited possibility for involving other adults and the child or young person. Positive comments about virtual clinics included not having to pay for parking (6, 15%). Parents gave constructive feedback, saying they could be asked to be ready to provide information, for example child's current weight. Few children were involved, and this needs to be borne in mind, especially as visual ques can be missed over telephone. 3 families (8%) however did report that children were happy not to be involved in the discussions. Conclusions Parents were grateful that some efforts had been made to maintain contact in difficult times, and responses may have been different in normal circumstances. There are some limitations to telephone consultations;mainly not being able to clinically examine or talk to children. Telephone consultations may result in silencing of the child's voice, with possible mental health and safeguarding issues. Some of these issues could be addressed with video calling. Interestingly despite convenience of telephone consultations, more parents indicated a preference for physical face-to-face consultations suggesting that, as the world returns to normal, whilst both options should be made available to them, we may not see significant changes in practice. Going forwards it may be beneficial to ask parents after initial consultation and if appropriate, if they would like a telephone or physical face-to-face appointment in the future.

Bcma-directed therapy in multiple myeloma: Effect of online education on clinician knowledge and confidence

Background: BCMA-directed modalities including CAR T-cell therapy, bispecific antibodies and antibody-directed cytotoxic agents are potentially transformative next steps in managing patients with multiple myeloma. However, beyond expert centres physicians have little experience of such agents to date. Aims: This study aimed to determine whether online continuing medical education could improve the knowledge and confidence of clinicians in their understanding of the rationale for and clinical aspects of different BCMA-directed therapies Methods: Three educational activities were launched for physicians outside the USA during 2020 to a target audience of hematologist/oncologists and ophthalmologists. Activities comprised a 30-minute video lecture, a 15-minute video collegial discussion, and a 30-minute online video panel discussion. Data were collected March to June 2020. For each activity educational effect was assessed with repeated-pairs pre-/ post-activity, where individual participants served as their own control. 3 multiple-choice, knowledge questions and 1 self-efficacy, 5-point Likert scale confidence question were analyzed. Data were subsequently combined and analyzed to provide a summative overview of the effect of the education across the combined knowledge-based learning objectives and confidence questions from the three programs. A McNemar's test was conducted to assess statistical significance of changes from pre- to post-assessment. Results: Between 66 and 103 hematologist/oncologists (combined total n=259) and 39-41 ophthalmologists (combined total n=121) completed pre- and post-activity questions. A statistically significant effect was observed for hematologist/oncologists across all 3 learning objectives (P<0.05-P<0.001) with a relative improvement in % of correct responses ranging from 10-44%. Furthermore, there was an overall improvement in confidence, with a 72% gain in confidence in those reporting increased confidence. The education had less impact on ophthalmologists;while some improvements were noted in individual activities, in the summative overview the greatest improvement was noted in knowledge of AEs associated with BCMA-directed therapies. The summative overview revealed that hematologists/oncologists demonstrated improvements in knowledge across the 3 learning objectives: 10% (P<0.05) regarding rationale and types of BCMA-directed therapies, 44% (P<0.001) regarding AEs associated with BCMAdirected therapies, and 29% (P<0.001) regarding BCMA clinical trials data. Ophthalmologists showed knowledge changes of -2% (NS) regarding knowledge of clinical data and the rationale and type of BCMA-directed therapy, and a 41% (P<0.05) improvement in knowledge of BMCA-therapy associated AEs. In combined self-assessed confidence questions, 51% of hematologist/oncologists had a measurable increase in and 46% maintained confidence. Thirty-three percent of ophthalmologists had a measurable increase in and 59% maintained confidence. All changes in confidence were significant (P<0.01 or P<0.001). At the individual activity level, ~50% of all participants stated that they would modify treatment plans and ~90% were committed to those changes. Summary/Conclusion: These three educational activities resulted in a considerable educational impact, particularly for hematologist/oncologists. Online medical education is valuable in improving knowledge and confidence, as well as identifying areas of continued educational need and potentially improving patient outcomes, of particular importance during the COVID-19 pandemic where in-person conference learning is inaccessible.

Development of antibody response to sarscov- 2 following asymptomatic infection in patients with plasma cell disorders on immunomodulatory therapy

Background: Plasma cell disorder (PCD) patients are extremely vulnerable to SARS-CoV-2 infection due to disease-related impaired humoral and cellular immunity as well as the receipt of immunosuppressive therapy. Reported mortality in a large cohort of patients with plasma cell disorders is 33%. The roll out of the COVID-19 vaccine is welcomed in this population, however there is concern of suboptimal antibody responses, from previous experience with the influenza vaccine. There is urgent need to understand the humoral response to SARSCoV- 2 infection in these patients, in the context of systemic anti-cancer therapy (SACT). Aims: We aimed to investigate the presence of SARS-CoV-2 antibodies in a cohort of PCD patients, the relationship with symptomatic infection, PCD characteristics and receipt of SACT. Methods: SARS-CoV-2 antibody screening with the Elecsys Anti-SARSCoV- 2 assay (Roche Diagnostics, Basel, Switzerland), a semi-quantitative assay of IgG and IgM against the nucleocapsid (N) antigen was introduced for PCD patients at our institution in July 2020. Clinical information was retrieved from the medical records. Patients with unexpected positive antibody tests were asked about possible past contacts and exposure to SARS-CoV-2. Results: We report on a six-month period of routine SARS-CoV-2 antibody screening. Two-hundred and forty-three PCD patients had one antibody test, 106 had serial samples. Total seroprevalence was 10.7% (26/243), of which 12 were patients with known PCR-swab positive COVID-19 disease. In a separate but overlapping cohort, 41 patients have had PCR confirmed COVID-19 disease;20 of these patients were tested, and 12 (60%) had seroconverted. Median time to testing from positive PCR test in the antibody positive patients was 86.5 days (range 22-256) and in antibody negative patients, 30.5 days (range 5-176 days). No PCD or COVID-19 disease factors were found to influence the likelihood of mounting an antibody response after PCR-confirmed COVID-19 disease in these 20 patients. In our screened cohort, 14 (6.3%) patients were unexpectedly antibody positive. Their clinical course is summarised in the included figure. The majority 85.7% (12/14) of patients described no COVID-19 symptoms. Seven (50%) patients were on SACT (including ixazomib, pomalidomide, lenalidomide and dexamethasone combinations) throughout the period from possible exposure to positive antibody test, with no interruption to their ongoing oral immunomodulatory treatment. Ten antibody positive patients had serial positive results at median 45 days (range 21-119) apart, demonstrating persistence, but some decline in titre over time. Summary/Conclusion: Our seroprevalence of 10.7% is lower but not dissimilar to that reported in the London population over a similar time period reflecting shielding behaviours in our patients but also the challenges of protecting them during high SARS-CoV-2 incidence in the community. Nevertheless, PCD patients retain the ability to seroconvert, even with asymptomatic COVID-19 disease and while on immunomodulatory therapy. Seroconversion rates following symptomatic infection appear lower however, with evidence of delay compared to the general population. These data support the advice for COVID-19 vaccination to be offered to all PCD patients although the suboptimal humoral response calls for close antibody monitoring of all vaccinated PCD patients and timely booster doses.