Sotatercept (ACE-011) for the treatment of chemotherapy-induced anemia in patients with metastatic breast cancer or advanced or metastatic solid tumors treated with platinum-based chemotherapeutic regimens: results from two phase 2 studies.

PURPOSE: Sotatercept may represent a novel approach to the treatment of chemotherapy-induced anemia (CIA). We report the results from two phase 2 randomized studies examining the use of sotatercept for the treatment of CIA in patients with metastatic cancer. METHODS: In study A011-08, patients with metastatic breast cancer were randomized to 2:2:2:1 to receive sotatercept 0.1, 0.3, or 0.5 mg/kg, or placebo, respectively, every 28 days. In study ACE-011-NSCL-001, patients with solid tumors treated with platinum-based chemotherapy received sotatercept 15 or 30 mg every 42 days. The primary endpoint for both studies was hematopoietic response, defined as a hemoglobin (Hb) increase of ≥1 g/dL from baseline. RESULTS: Both studies were terminated early due to slow patient accrual. Among patients treated with sotatercept in the A011-08 and ACE-011-NSCL-001 studies, more patients achieved a mean Hb increase of ≥1 g/dL in the combined sotatercept 0.3 mg/kg and 15 mg (66.7 %) group and sotatercept 0.5 mg/kg and 30 mg (38.9 %) group versus the sotatercept 0.1 mg/kg (0 %) group. No patients achieved a mean Hb increase of ≥1 g/dL in the placebo group. The incidence of treatment-related adverse events (AEs) was low in both studies, and treatment discontinuations due to AEs were uncommon. CONCLUSIONS: Although both studies were terminated early, these results indicate that sotatercept is active and has an acceptable safety profile in the treatment of CIA.

Activin receptor antagonists for cancer-related anemia and bone disease.

INTRODUCTION: Antagonists of activin receptor signaling may be beneficial for cancer-related anemia and bone disease caused by malignancies such as multiple myeloma and solid tumors. AREAS COVERED: We review evidence of dysregulated signaling by activin receptor pathways in anemia, myeloma-associated osteolysis, and metastatic bone disease, as well as potential involvement in carcinogenesis. We then review properties of activin receptor antagonists in clinical development. EXPERT OPINION: Sotatercept is a novel receptor fusion protein that functions as a soluble trap to sequester ligands of activin receptor type IIA (ActRIIA). Preclinically, the murine version of sotatercept increased red blood cells (RBC) in a model of chemotherapy-induced anemia, inhibited tumor growth and metastasis, and exerted anabolic effects on bone in diverse models of multiple myeloma. Clinically, sotatercept increases RBC markedly in healthy volunteers and patients with multiple myeloma. With a rapid onset of action differing from erythropoietin, sotatercept is in clinical development as a potential first-in-class therapeutic for cancer-related anemia, including those characterized by ineffective erythropoiesis as in myelodysplastic syndromes. Anabolic bone activity in early clinical studies and potential antitumor effects make sotatercept a promising therapeutic candidate for multiple myeloma and malignant bone diseases. Antitumor activity has been observed preclinically with small-molecule inhibitors of transforming growth factor-ß receptor type I (ALK5) that also antagonize the closely related activin receptors ALK4 and ALK7. LY-2157299, the first such inhibitor to enter clinical studies, has shown an acceptable safety profile so far in patients with advanced cancer. Together, these data identify activin receptor antagonists as attractive therapeutic candidates for multiple diseases.

A phase II study of milataxel: a novel taxane analogue in previously treated patients with advanced colorectal cancer.

BACKGROUND: Milataxel is a novel taxane analog, with evidence of enhanced preclinical activity compared to paclitaxel and docetaxel, especially in cell lines that over express P-glycoprotein. Based on preclinical data that milataxel may be active in colorectal cancer (CRC), a phase II study was performed in patients with advanced previously treated CRC. PATIENTS AND RESULTS: Forty-four eligible patients were entered. Milataxel was administered intravenously every 3 weeks at the dose of 35 mg/m(2). No objective responses were noted, stable disease was seen in three patients. The median time to progression was 1.4 months (95% CI of 1.2-2.4 months). Three subjects developed neutropenic sepsis and two died. The most frequent grade 3/4 adverse events were neutropenia (57%), leukopenia (27%), dehydration (14%), neuropathy (16%), diarrhea (14%) and thrombocytopenia (14%). The pharmacokinetics of milataxel was assessed in five subjects. The mean milataxel elimination half-life was 64 h and the mean area under the plasma concentration-time curve was 1,708 ng h/ml. CONCLUSIONS: A syndrome of neutropenic sepsis and diarrhea can be life threatening and close surveillance is needed in patients treated with milataxel at the dose of 35 mg/m(2) every 3 weeks. Clinical activity was not demonstrated in patients with advanced previously treated CRC.

Clinical predictors of metastatic disease to the brain from non-small cell lung carcinoma: primary tumor size, cell type, and lymph node metastases.

PURPOSE: To retrospectively assess possible clinical predictors of metastatic disease to the brain in patients with non-small cell lung carcinoma (NSCLC). MATERIALS AND METHODS: Institutional review board approval was obtained, informed consent was waived, and data and other information were obtained prior to implementation of HIPAA. A review was performed of 264 patients (mean age, 65 years; 158 men and 106 women) with NSCLC who had undergone imaging studies of the chest and head. Hierarchical logistic regression was used to determine the predicted probability of metastatic disease to the brain as a function of patient age and sex and of size, cell type, peripheral versus central location, and lymph node stage of the primary NSCLC. RESULTS: Ninety-five (36%) patients had evidence of metastatic disease to the brain. Mean diameter of the primary tumors was 4.0 cm +/- 2.2 (standard deviation). Cell types included adenocarcinoma (136 [52%] patients), undifferentiated (68 [26%] patients), and squamous (47 [18%] patients), for which metastatic disease to the brain occurred in 43%, 41%, and 13% (P = .003) of patients, respectively. The predicted probability of metastatic disease to the brain correlated positively with size of the primary tumor (P < .001), cell type (adenocarcinoma and undifferentiated vs squamous, P = .001), and lymph node stage (P < .017) but did not correlate with age, sex, or primary tumor location. For primary adenocarcinoma without lymph node spread, the predicted probabilities of metastatic disease to the brain from 2- and 6-cm primary tumors were .14 (95% confidence interval: .06, .27) and .72 (95% confidence interval: .48, .88), respectively (P < .02). CONCLUSION: The probability of metastatic disease to the brain from primary NSCLC is correlated with size of the primary tumor, cell type, and intrathoracic lymph node stage.

Histologic assessment of non-small cell lung carcinoma after neoadjuvant therapy.

Chemotherapy or chemoradiation is often used in Stage IIIA non-small cell lung carcinoma before surgical resection (neoadjuvant therapy). In reviewing the histopathology of such tumors after resection, the recognition that the pathologic changes are related to prior therapy and the assessment of tumor regression are both of importance. To refine histologic parameters for tumor regression and describe patterns of tumor reaction to therapy, we identified 30 lobectomy or pneumonectomy specimens from 1996-2000 in which neoadjuvant therapy was received before surgical resection. Histologic patterns of treatment-induced tumor regression were analyzed semiquantitatively and included necrosis, fibrosis, mixed inflammatory infiltrate, foamy macrophages, and giant cells. To identify clinical and histologic parameters that correlate with treatment response, the 30 specimens were graded for tumor regression. No correlation was found between tumor regression and age, gender, or type of therapy (chemoradiation versus chemotherapy alone). Squamous cell carcinoma showed a significantly higher rate of response than adenocarcinoma (P =.04), with a significant number of adenocarcinomas in the nonresponder subgroup (P =.05). Tumor size reduction by radiologic assessment, when compared with histologic regression, did not reveal a statistically significant association. However, a positive correlation was found between extent of fibrosis and radiologic estimate of size reduction.