The introduction of CD38-targeting monoclonal antibodies (CD38 MoABs), daratumumab and isatuximab, has significantly impacted the management of patients with multiple myeloma (MM). Outcomes of patients with MM refractory to CD38 MoABs have not been described. We analyzed outcomes of 275 MM patients at 14 academic centers with disease refractory to CD38 MoABs. Median interval between MM diagnosis and refractoriness to CD38 MoAB (T 0) was 50.1 months. The median overall survival (OS) from T 0 for the entire cohort was 8.6 [95% C.I. 7.5-9.9] months, ranging from 11.2 months for patients not simultaneously refractory to an immunomodulatory (IMiD) agent and a proteasome inhibitor (PI) to 5.6 months for "penta-refractory" patients (refractory to CD38 MoAB, 2 PIs and 2 IMiDs). At least one subsequent treatment regimen was employed after T 0 in 249 (90%) patients. Overall response rate to first regimen after T 0 was 31% with median progression-free survival (PFS) and OS of 3.4 and 9.3 months, respectively. PFS was best achieved with combinations of carfilzomib and alkylator (median 5.7 months), and daratumumab and IMiD (median 4.5 months). Patients with MM refractory to CD38 MoAB have poor prognosis and this study provides benchmark for new therapies to be tested in this population.

A 72-year-old Caucasian woman who had recurrent sebaceous carcinoma of the right orbit with bilateral cervical lymph node involvement 24 months after orbital exenteration was treated with carboplatin (area under the curve of 5) and pembrolizumab (2 mg/kg) for 6 cycles, followed by maintenance pembrolizumab. She obtained a complete pathological remission and remains free of local, regional, and systemic disease at 15 months.

No abstract

A 74-year-old male with a long-standing history of chronic lymphocytic leukemia presented with dyspepsia. Upper endoscopy showed a subtle bluish 3-5-mm discoloration in the esophageal mucosa at approximately 20 cm from the incisors (Fig. 1). Biopsies demonstrated melanoma in situ and focal invasion into the superficial sub-mucosa, associated with melanosis, and consistent with primary esophageal melanoma (PMME, Fig. 2a, b). The cells stained positive for S-100 and MART-1a, which confirmed PMME.In an attempt to stage and treat the lesion, endoscopic mucosal resection (EMR) was done using the band and snare method. Pathology revealed an extensive in situ melanoma and a small cluster of invasive melanoma at one margin of excision within the sub-mucosa. A repeat EGD and biopsy demonstrated residual melanoma in situ at the margins of the resection. Repeat EMR was discussed; however, the patient wished to proceed with a transhiatal esophagectomy with cervical esophagogastric anastomosis. The surgical specimen revealed a 4.0×2.5-cm area of black-brown mucosal discoloration, located 1.5 cm form the proximal margin of resection. Microscopic sections showed extensive residual intramucosal melanoma involving the discolored area, the proximal cervical margin and random sections of mucosa away from the discolored area ( Fig. 3a, b). Thirty weeks after the surgery, the patient is clinically stable except for cervical dysphagia for which he is treated with dilatations.

Introduction Proteasome inhibitors (PIs) and immunomodulatory drugs (IMiDs) have significantly improved survival in patients with multiple myeloma (MM). Refractoriness to PIs and IMiDs results in poor outcomes with a median survival of about 13 months.Daratumumab and isatuximab are CD38-targeting monoclonal antibodies (MoABs) with remarkable activity in relapsed and refractory MM. The outcome of MM patients in US clinical practice who becomes refractory to CD38 MoABs is unknown. The aim of this multicenter, retrospective study is to investigate the natural history of patients with MM who become refractory to CD38 MoABs (Monoclonal Antibodies in Multiple Myeloma: Outcomes after Therapy Failure: MAMMOTH study). Methods We identified patients from 14 academic institutions in the US with diagnosis of active MM and refractory to daratumumab or isatuximab, administered alone or in combination. Patients were considered refractory to CD38 MoAB if treated with at least 4 weeks of therapy and had evidence of progressive disease (PD) while on therapy or within 60 days after last dose. The time when patients met the above criteria of progression was defined as time zero (T0). Data including patient-disease characteristics and all therapies administered before and after T0 were collected with an electronic platform and submitted to peer-based quality check for completeness and internal consistency. For survival outcome analysis, patients were classified into three groups: "Penta-refractory" (refractory to 1 CD38 MoAB + 2 PIs + 2 IMiDs), "Triple-refractory and quad-refractory" (refractory to 1 CD38 MoAB + 1 PI + 1/2 IMiDs, or 1 CD38 MoAB + 1/2 PIs + 1 IMiD), and "Not triple-refractory" (refractory to 1 CD38 MoAB, and not both of a PI and an IMiD). Responses were evaluated using the IMWG criteria. Results Two hundred and seventy-five patients were included in this study; median age at T0 was 65 years (range 27-90). Fifty five percent of patients were males, 52% had IgG isotype, 29% had ISS stage III disease, and 29% had high-risk cytogenetics at diagnosis. Median interval from diagnosis of MM to T0 was 50.1 months (mo) (range 2.5-230.1). Patients received a median of 4 lines of treatment (1-16) prior to the CD38 MoAB-containing regimen; 72% underwent prior autologous transplant. Daratumumab-refractory patients formed a majority (256, 93.1%) of this cohort. Most of the patients were refractory to lenalidomide (77%), pomalidomide (65%), bortezomib (68%), and carfilzomib (47%). Seventy patients (25.5%) were "penta-refractory" and 148 (53.8%) were "triple-refractory and quad-refractory". Median follow-up from T0 for survivors was 10.6 mo (range 1.9-42.3 mo). The median overall survival (OS) from T0 for the entire cohort was 8.6 mo (95% C.I. 7.2-9.9); OS for the groups based on refractoriness to prior treatments are shown (Figure). Two hundred and forty-nine patients (90.5%) received at least one line of treatment after T0, (median 2, range 1-10). The response rates and depth of responses to each line of treatment post T0 are shown (Table). Among patients who received ≥ 1 subsequent treatment, the median PFS and OS from T0 were 3.4 (95% C.I. 2.8-4.0) mo and 9.3 (95% C.I. 8.1-10.6) mo, respectively; the median OS for the 26 patients who received no further treatment was only 1.3 (95% C.I. 0.6-1.9) mo. By multivariate analysis, penta-refractoriness (HR 2.4, p <0.001), high-risk cytogenetics (HR 1.5, p=0.01), elevated LDH (HR 2, p<0.001) and creatinine > 2 (HR 2.4, p=0.01) at the onset of CD38-based therapy predicted inferior OS. Conclusions Patients with MM who become refractory to CD38 MoAB are increasingly less responsive to subsequent therapies. While survival is particularly dismal for penta-refractory patients, the outcomes are poor even for patients who are not refractory to other mainstream MM agents. The MAMMOTH study defines a MM population in urgent need for new therapies, and provides benchmark OS, PFS and response data for subsequent investigational therapies in this setting. Disclosures Malek: Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Paul:Bristol Myer Squibb: Other: Stock and pension plan (past employee). Neppalli:Amgen: Consultancy; Celgene: Consultancy. Liedtke:Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen/Onyx: Consultancy, Honoraria, Research Funding; BlueBirdBio: Research Funding; celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech/Roche: Research Funding; Caelum: Membership on an entity's Board of Directors or advisory committees. Hari:Amgen Inc.: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Spectrum: Consultancy, Research Funding; Kite Pharma: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Research Funding; Sanofi: Honoraria, Research Funding; Janssen: Honoraria; Takeda: Consultancy, Honoraria, Research Funding. Vij:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jansson: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Usmani:Abbvie, Amgen, Celgene, Genmab, Merck, MundiPharma, Janssen, Seattle Genetics: Consultancy; Amgen, BMS, Celgene, Janssen, Merck, Pharmacyclics,Sanofi, Seattle Genetics, Takeda: Research Funding. Kumar:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Costa:Karyopharm: Research Funding; Sanofi: Honoraria; Janssen: Research Funding; BMS: Research Funding; Abbvie: Research Funding; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding.