Endocrine Autoantibodies Determine Immune Checkpoint Inhibitor-induced Endocrinopathy: A Prospective Study.

CONTEXT: Incidence and awareness of endocrine-related adverse events (ERAE) associated with use of immune checkpoint inhibitors (ICI) has grown with increased ICI use, yet mechanisms for ERAE prediction, surveillance, and development are not well established. OBJECTIVE: We prospectively evaluated the impact of endocrine autoimmunity on ERAE development and overall survival (OS). METHODS: Adults ≥ 18 years of age prescribed ICI treatment for advanced or metastatic solid tumors and no known active/past endocrine disorders were eligible for enrollment. Thyroid, adrenal, and pancreatic antibodies as well as hormone levels were assessed prior to ICI treatment and at 8 to 9 weeks and 36 weeks after treatment for ERAE in relation to presence and changes in endocrine-specific antibodies, hormone levels, and OS. RESULTS: Sixty patients were enrolled and ERAE were detected in 14 (23.3%), with a median onset of 52 days (IQR, 38.5-71.5) after first ICI dose. Hypothyroidism occurred in 12 (20%) patients, and 2 (3.33%) patients developed hypophysitis. Diabetes and primary adrenal insufficiency were not observed. Antibodies were detected in 14 patients (11 at baseline, 3 developed during follow-up) and their presence was significantly associated with ERAE (R2 59.3%, P < 0.001). Thyroid peroxidase antibody (20%) and thyroid-stimulating immunoglobulin (3.3%) were most common, and anti-GAD was present in 1 patient. The presence of ERAE was associated with a more favorable OS (P = 0.001). CONCLUSION: Endocrine-specific autoantibodies play an important role in ERAE pathogenesis and may serve as predictive markers for early identification and treatment of ICI-induced endocrinopathies.

Phase 1-2a multicenter dose-escalation study of ezatiostat hydrochloride liposomes for injection (Telintra, TLK199), a novel glutathione analog prodrug in patients with myelodysplastic syndrome.

BACKGROUND: Ezatiostat hydrochloride liposomes for injection, a glutathione S-transferase P1-1 inhibitor, was evaluated in myelodysplastic syndrome (MDS). The objectives were to determine the safety, pharmacokinetics, and hematologic improvement (HI) rate. Phase 1-2a testing of ezatiostat for the treatment of MDS was conducted in a multidose-escalation, multicenter study. Phase 1 patients received ezatiostat at 5 dose levels (50, 100, 200, 400 and 600 mg/m2) intravenously (IV) on days 1 to 5 of a 14-day cycle until MDS progression or unacceptable toxicity. In phase 2, ezatiostat was administered on 2 dose schedules: 600 mg/m2 IV on days 1 to 5 or days 1 to 3 of a 21-day treatment cycle. RESULTS: 54 patients with histologically confirmed MDS were enrolled. The most common adverse events were grade 1 or 2, respectively, chills (11%, 9%), back pain (15%, 2%), flushing (19%, 0%), nausea (15%, 0%), bone pain (6%, 6%), fatigue (0%, 13%), extremity pain (7%, 4%), dyspnea (9%, 4%), and diarrhea (7%, 4%) related to acute infusional hypersensitivity reactions. The concentration of the primary active metabolites increased proportionate to ezatiostat dosage. Trilineage responses were observed in 4 of 16 patients (25%) with trilineage cytopenia. Hematologic Improvement-Erythroid (HI-E) was observed in 9 of 38 patients (24%), HI-Neutrophil in 11 of 26 patients (42%) and HI-Platelet in 12 of 24 patients (50%). These responses were accompanied by improvement in clinical symptoms and reductions in transfusion requirements. Improvement in bone marrow maturation and cellularity was also observed. CONCLUSION: Phase 2 studies of ezatiostat hydrochloride liposomes for injection in MDS are supported by the tolerability and HI responses observed. An oral formulation of ezatiostat hydrochloride tablets is also in phase 2 clinical development. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00035867.

A phase 2 study of rituximab in combination with recombinant interleukin-2 for rituximab-refractory indolent non-Hodgkin's lymphoma.

PURPOSE: The incidence of non-Hodgkin's lymphoma (NHL), the fifth most common malignancy in the United States, has increased over 70% in the last 30 years. Fifty percent to 75% of patients with low-grade or follicular NHL respond to rituximab therapy. However, responses are generally of limited duration, and complete responses are rare. Preclinical work suggests that human recombinant interleukin-2 (rIL-2; aldesleukin, Proleukin) enhances rituximab efficacy. Antibody-dependent cellular cytotoxicity (ADCC) is an important mechanism of action of rituximab. rIL-2 induces expansion and activation of Fc receptor (FcR)-bearing cells, thereby enhancing ADCC. Therefore, a large, multicenter phase 2 trial to assess the effects of rIL-2 on rituximab therapy in patients with rituxumab-refractory low-grade NHL was conducted. EXPERIMENTAL DESIGN: The combination of rituximab and rIL-2 was studied in 57 patients with rituximab-refractory low-grade NHL (i.e., patients must have received a single-agent course of rituximab and showed no tumor response, or had a response lasting <6 months). I.V. rituximab was given at 375 mg/m(2) (weeks 1-4). S.C. rIL-2 was given thrice a week at 14 MIU (weeks 2-5) and at 10 MIU (weeks 6-9). RESULTS: Rituximab plus rIL-2 combination therapy was safe and generally well tolerated, but responses were low. Fifty-seven patients were enrolled with 54 evaluable for response; however, only five responses (one complete and four partial) were observed. Correlative data indicate that rIL-2 expanded FcR-bearing cells and enhanced ADCC. However, other factors, such as FcgammaR polymorphisms in patients refractory to single-agent rituxumab and heterogeneous tumor biology, may have influenced the lack of clinical efficacy seen with this combination therapy. CONCLUSIONS: rIL-2 expands FcR-bearing cellular subsets in vivo and enhances in vitro ADCC of rituxumab. However, these findings do not directly translate into meaningful clinical benefit for patients with rituxumab-refractory NHL.

Prolonged follow-up after initial therapy with 2-chlorodeoxyadenosine in patients with indolent non-Hodgkin lymphoma: results of Cancer and Leukemia Group B Study 9153.

BACKGROUND: The objective of this study was to determine the efficacy and toxicity of 2-chlorodeoxyadenosine (2-CdA) in patients with untreated, indolent non-Hodgkin lymphoma (NHL). METHODS: For this multicenter, single-arm, Phase II study, 44 patients with treatment-naive, stage III or IV, indolent NHL (International Working Formulation subtypes A, B, and C) were enrolled. Patients received 0.14 mg/kg per day of 2-CdA as a 2-hour bolus infusion for 5 consecutive days every 28 days until maximal response or a total of 6 cycles. RESULTS: Thirty-eight patients were eligible for response evaluation. The overall response rate was 100% (95% confidence interval [95% CI], 90.8-100%), and the complete response rate was 31.6% (95% CI, 17.5-48.7%). In the intent-to-treat population, the median failure-free survival was 2.0 years (95% CI, 1.3-3.4 years), and the overall survival rate was 7.0 years (95% CI, 4.3-9.4 years). Six patients had sustained remissions that lasted a median of 8.7 years (range, from 5.9 years to > or =11 years). Although 68% of patients experienced at least 1 grade 3 or 4 event, consisting primarily of myelosuppression, severe infections were rare, with only 8 grade 3 infections. Four late malignancies (prostate adenocarcinoma, ductal carcinoma in situ, and myelodysplasia) and 4 patients with large cell transformation were reported. CONCLUSIONS: 2-CdA is an active, well-tolerated therapy for patients with untreated, indolent NHL.

Enhanced survival associated with vitiligo expression during maintenance biotherapy for metastatic melanoma.

Vitiligo, an autoimmune skin disorder, was evaluated in 49 metastatic melanoma patients treated with an immunotherapy regimen of maintenance biotherapy (mBT) following induction concurrent biochemotherapy (cBCT). Patients receiving mBT demonstrated a stable or better response to cBCT. The mBT regimen consisted of outpatient subcutaneous injections of low-dose IL-2 (1 MIU/m(2)) 5/7 days weekly, GM-CSF (125 mcg/m(2)) 14 days monthly, and high-dose pulses of in-patient continuous infusion decrescendo IL-2 (54 MIU/m(2)) over 48 hours monthly for the first 6 months and every 2 months thereafter. The majority of patients had poor prognostic features. Forty-nine patients were without evidence of vitiligo at the start of mBT. Of these, 21 patients (43%) developed vitiligo during mBT and had a median overall survival from the start of mBT of 18.2 months (95% CI, 12.3-N/A) compared to 8.5 months (95%CI <6.7-12.7) for 28 non-vitiligo patients (P=0.027). Six of 21 vitiligo patients (29%) expressed IgG antibody titers to tyrosinase-related protein-2 compared to four of 28 non-vitiligo patients (14%) (P=NS). The development of vitiligo in metastatic melanoma patients on cBCT/mBT immunotherapy correlates with a better therapeutic outcome.

Apoptosis, Bcl-2 antisense, and cancer therapy.

Apoptosis, or programmed cell death, is a complex process of cell turnover involved in both normal and pathologic processes in the body. Impairments in the apoptotic pathways contribute to tumorigenesis and the development of tumor resistance to chemotherapy. The proto-oncogene bcl-2 appears to serve a critical antiapoptotic function. Its broad expression in tumors coupled with its role in resistance to chemotherapy-induced apoptosis make bcl-2 a rational target for anticancer therapy. The Bcl-2 antisense drug oblimersen sodium (Genasense) enhances apoptosis alone and in combination with cytotoxic chemotherapy in vitro and in numerous xenograft models of solid tumors and hematologic cancers. Results from xenograft models of melanoma were especially encouraging, prompting melanoma to be identified as an initial human trial candidate. In a phase II trial in patients with advanced malignant melanoma resistant to first-line chemotherapy (including dacarbazine [DTIC-Dome]), three objective responses and three minor responses to oblimersen plus dacarbazine were observed among 14 patients. In a large randomized phase III trial, oblimersen plus dacarbazine showed a near doubling of response rate vs dacarbazine alone and a significant prolongation of progression-free survival. For the primary endpoint of overall survival, a significant benefit for the combination was not seen. The ability of oblimersen to modulate apoptosis suggests a new paradigm of anticancer therapy that has clinical potential in a variety of solid tumors and hematologic malignancies. Further, oblimersen is the first antisense molecule studied in clinical trials for its anticancer properties, opening up an entirely new direction for therapy.

Maintenance biotherapy for metastatic melanoma with interleukin-2 and granulocyte macrophage-colony stimulating factor improves survival for patients responding to induction concurrent biochemotherapy.

PURPOSE: A prospective Phase II study of a novel maintenance biotherapy regimen after induction biochemotherapy was conducted in patients with metastatic melanoma in efforts to maintain responses and improve survival. EXPERIMENTAL DESIGN: Thirty-three patients with poor prognosis metastatic melanoma who achieved a partial response (PR) or stable disease (SD) to induction concurrent biochemotherapy were treated with chronic low-dose interleukin (IL)-2 and granulocyte macrophage-colony stimulating factor, and intermittent pulses of intermediate/high-dose decrescendo IL-2 over a 12-month period. The outcome of these patients was compared with a control group of patients at our institution who were treated recently with induction biochemotherapy and achieved a PR or SD. RESULTS: Five patients (15%) achieved a complete response, and 4 patients (12%) maintained SD for at least 6 months on maintenance biotherapy. The median progression-free survival (PFS) and overall survival (OS) were 8.1 months and 18.5 months, respectively, compared with historical controls, which were PFS 5.9 months (P = 0.0015) and OS 9.3 months (P = 0.0004). Administration of maintenance biotherapy was a significant predictor of PFS (P = 0.0008) and OS (P = 0.0001) in multivariate and matched-pair analyses (P = 0.002). The maintenance biotherapy regimen was well tolerated with no dose-limiting acute or cumulative toxicities. CONCLUSION: In this single institution study, maintenance biotherapy with IL-2 and granulocyte macrophage colony-stimulating factor in patients achieving PR or SD to induction biochemotherapy improved PFS and OS compared with historical controls. A larger multicenter Phase II trial has been initiated in an effort to confirm these results.