Randy A. Brown

Phase III Randomized Multicenter Study of a Humanized Anti-CD33 Monoclonal Antibody, Lintuzumab, in Combination With Chemotherapy, Versus Chemotherapy Alone in Patients With Refractory or First-Relapsed Acute Myeloid Leukemia

PURPOSE Lintuzumab (HuM195) is an unconjugated humanized murine monoclonal antibody directed against the cell surface myelomonocytic differentiation antigen CD33. In this study, the efficacy of lintuzumab in combination with induction chemotherapy was compared with chemotherapy alone in adults with first relapsed or primary refractory acute myeloid leukemia (AML). PATIENTS AND METHODS Patients with relapsed or primary resistant AML (duration of first response, zero to 12 months) were randomly assigned to receive either mitoxantrone 8 mg/m(2), etoposide 80 mg/m(2), and cytarabine 1 g/m(2) daily for 6 days (MEC) in combination with lintuzumab 12 mg/m(2), or MEC alone. Overall response, defined as the rate of complete remission (CR) and CR with incomplete platelet recovery (CRp), was the primary end point of the study, with additional analyses of survival time and toxicity. RESULTS A total of 191 patients were randomly assigned from November 1999 to April 2001. The percent CR plus CRp with MEC plus lintuzumab was 36% v 28% in patients treated with MEC alone (P = .28). The overall median survival was 156 days and was not different in the two arms of the study. Apart from mild antibody infusion-related toxicities (fever, chills, and hypotension), no differences in chemotherapy-related adverse effects, including hepatic and cardiac dysfunction, were observed with the addition of lintuzumab to induction chemotherapy. CONCLUSION The addition of lintuzumab to salvage induction chemotherapy was safe, but did not result in a statistically significant improvement in response rate or survival in patients with refractory/relapsed AML.

Two novel RUNX1 mutations in a patient with congenital thrombocytopenia that evolved into a high grade myelodysplastic syndrome

Here we report two new RUNX1 mutations in one patient with congenital thrombocytopenia that transformed into a high grade myelodysplastic syndrome with myelomonocytic features. The first mutation was a nucleotide base substitution from guanine to adenine within exon 8, resulting in a nonsense mutation in the DNA-binding inhibitory domain of the Runx1 protein. This nonsense mutation is suspected a de novo germline mutation since both parents are negative for the mutation. The second mutation identified was an in-frame six nucleotide base pair insertion in exon 5 of the RUNX1 gene, which is predicted to result in an insertion in the DNA-binding runt homology domain (RHD). This mutation is believed to be a somatic mutation as it was mosaic before allogeneic hematopoietic cell transplantation and disappeared after transplant. As no other genetic mutation was found using genetic screening, it is speculated that the combined effect of these two RUNX1 mutations may have exerted a stronger dominant negative effect than either RUNX1 mutation alone, thus leading to a myeloid malignancy.

A new model to predict remission status in AML patients based on day 14 bone marrow biopsy.

Although bone marrow evaluation on day 14 after initiation of induction chemotherapy (D14 BM) is a widely accepted practice in patients with acute myeloid leukemia (AML), it has suboptimal predictive value for predicting complete remission. We retrospectively analyzed pretreatment characteristics and post-induction response in a cohort of AML patients to determine if adding clinical and laboratory characteristics can improve the predictive value of the D14 BM evaluation. Among 297 patients treated for AML at the single institution 183 patients (61%) had leukemia-positive D14 BM. Of those, 94 were given reinduction chemotherapy and 89 were not. Of the 89 patients who did not receive reinduction, 32 (36%) subsequently achieved complete remission (CR) or complete remission with incomplete count recovery (CRi), and 57 (64%) had persistent disease. Persistent disease after positive D14 BM was more likely associated with higher percentage of D14 myeloblasts, a history of relapsed disease before induction, and higher risk disease compared to patients who subsequently achieved CR. Age, diagnostic white blood cell count, and the D14 BM cellularity did not influence the subsequent likelihood of achieving remission in patients with a positive D14 BM. A new mathematical equation was created and resulted in a positive predictive value of 83%, negative predictive value 90% and accuracy 88% for correctly identifying remission status after positive D14 BM in AML. The accuracy of predicting response using these additional parameters was significantly higher than without (0.88 vs. 0.80, P=0.002). Our new model provides better accuracy for predicting the likelihood of achieving remission and if validated in future studies may be useful for managing AML patients.

Effect of melphalan 140 mg/m2 vs 200 mg/m2 on toxicities and outcomes in multiple myeloma patients undergoing single autologous stem cell transplantation—a single center experience

Although melphalan at a dose of 140 mg/m2 (MEL140) is an acceptable conditioning regimen for autologous stem cell transplantation (ASCT) in multiple myeloma (MM) patients, very few studies compared it to the most commonly used dose of 200 mg/m2 (MEL200). A retrospective review of records of MM patients (2001–2010) identified 33 patients who received MEL140 and 96 patients who received MEL200. As expected, significantly higher percentage of patients in the MEL140 arm were >65 years or had cardiac ejection fraction <50%, had Karnofsky score <80, or had creatinine >2 at the time of ASCT (P≤.01). There were no significant differences in incidence of treatment related mortality and morbidity. At a median follow‐up of 74 months from ASCT, there were no significant differences in relapse free survival (RFS) and overall survival (OS) between the two groups. Similar proportion had myeloma status improve to ≥VGPR at 3 months post‐ASCT. Usage of post‐ASCT maintenance was similar. In multivariate cox proportional hazards model, only disease status of ≥VGPR at the time of ASCT significantly improved RFS (P=.024), but not OS (P=.104). In conclusion, MM patients who received MEL140 had similar long‐term outcomes to MEL200 patients despite their older age and co‐morbidities.

Abstract CT085: iCare 1: A prospective clinical trial to predict treatment response based on mutanome-informed computational biology in patients with AML and MDS

Hypomethylating agents (HMAs) (azacitidine (aza), decitabine (dec)) and lenalidomide (len) are approved agents and used to treat patients with myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML). Despite their widespread use, HMAs fail in the majority of these patients, and len fails in 75% of non-del(5q) MDS. Currently, no method exists to predict disease response, thus the management of MDS and AML patients is challenging. Methods: Patients with AML or MDS were recruited to a clinical trial (NCT02435550) designed to assess predictive values by comparing computer predictions of drug response to actual clinical response. Genomic profiling was conducted by cytogenetics, whole exome sequencing, and array CGH. Genomic results were inputted into a computational software (Cellworks), which generates disease-specific protein network maps using PubMed and other resources. Digital drug simulations were conducted by quantitatively measuring drug effect on a cell growth score (proliferation + viability + apoptosis). Each patient-specific protein network was screened for the extent by which aza, dec or len reduced disease growth in a dose-respondent manner. Treatment was physician’s choice of SOC. Clinical outcomes were prospectively recorded. IWG criteria were used to define response. Western blot assays were performed to validate the predicted protein network perturbations. Fisher’s exact test was used to compare prediction values of the genomics-informed computer method versus empiric drug administration. Results: 88 patients have had all molecular tests and computational modeling performed. Lab validation of computer-predicted, activated protein networks in 19 samples from 13 different patients showed correct prediction of 5 activated networks (Akt2, Akt3, PIK3CA, p38, Erk1/2) in 17 samples, with 89% accuracy. At the time of this report, 26/88 patients were eligible for efficacy evaluation. 8/26 patients showed clinical response to SOC therapy, 18/26 did not. 24/26 outcome predictions were correctly matched to their clinical outcomes, and 2/20 were incorrectly matched, resulting in 92% prediction accuracy, 80% PPV, 100% NPV, 100% sensitivity, and 89% specificity. The accuracy of the genomics-informed computer method was significantly greater than empiric drug administration (p=1.664e-05). New genomic signature rules were discovered to correlate with clinical response after aza, dec or len. Summary: A computational method that models multiple genomic abnormalities simultaneously showed high predictive value of protein network aberrations and clinical outcomes after SOC treatments. The network method uncovered molecular reasons for drug failure and highlighted resistance pathways that could be targeted to recover chemosensitivity. This technology could also be used to establish eligibility criteria for precision enrollment in drug development trials Citation Format: Leylah Drusbosky, Kimberly E. Hawkins, Shireen Vali, Taher Abbasi, Ansu Kumar, Neeraj Kumar Singh, Kabya Basu, Chandan Kumar, Amjad Husain, Caitlin Tucker, Randy A. Brown, Maxim Norkin, John Hiemenz, Jack Hsu, John Wingard, Christopher R. Cogle. iCare 1: A prospective clinical trial to predict treatment response based on mutanome-informed computational biology in patients with AML and MDS [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT085. doi:10.1158/1538-7445.AM2017-CT085