Single Agent Trilaciclib Prevents Multilineage Myelosuppression during Chemotherapy

SUMMARY: Chemotherapy remains one of the mainstays of cancer treatment. However, chemotherapy-induced damage of Hematopoietic Stem and Progenitor Cells (HSPC) causes multi-lineage myelosuppression. Currently, available therapies such as Granulocyte-Colony Stimulating Factors (G-CSF) and Erythropoiesis-Stimulating Agents (ESAs) prevent the myelosuppressive effects of chemotherapy in only one lineage. Therapeutic agents that lead to protection of multiple lineages simultaneously would be clinically meaningful.

Trilaciclib is a highly potent, selective, and reversible, intravenous, Cyclin-Dependent Kinase 4 and 6 (CDK 4/6) inhibitor, that transiently maintains G1 cell cycle arrest of Hematopoietic Stem and Progenitor Cells (HSPC), and protects them from damage by cytotoxic chemotherapy. Chemotherapy-induced damage of Hematopoietic Stem and Progenitor Cells (HSPC) causes multi-lineage myelosuppression. Trilaciclib proactively preserves HSPC and immune system function during chemotherapy (myelopreservation). Preclinical studies have demonstrated that Trilaciclib transiently maintains HSPC in G1 arrest and protects them from chemotherapy damage, leading to faster hematopoietic recovery. Additionally, Trilaciclib enhances immune response, and preserves immune system function.

Small Cell Lung Cancer (SCLC) was chosen as the testing platform, to explore the potential myelopreservation benefit of Trilaciclib for the following reasons: 1) Cytotoxic chemotherapy for SCLC is notable for its myelotoxicity. 2) SCLC tumor cells replicate independent of CDK4/6, through the obligate loss of Retinoblastoma (RB1), allowing assessment of Trilaciclib’s effects on the host, without any potential direct effects on the tumor. 3) SCLC is a chemosensitive tumor, and provides an optimal setting to demonstrate that Trilaciclib does not antagonize chemotherapy efficacy.

The authors in this publication, pooled data from three randomized, double-blind, placebo-controlled Phase II trials, in patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC), to understand the effects of Trilaciclib on specific myelosuppression endpoints, with greater statistical precision. Individual results from these three randomized trials have previously been reported. In this pooled analysis, 123 patients received Trilaciclib along with chemotherapy (N=123), and 119 patients received Placebo along with chemotherapy (N=119). The median age in both treatment groups was 64 years. The objectives of this pooled data analysis was to summarize the utilization of G-CSFs, ESAs and RBC transfusions, and hospitalizations due to Chemotherapy Induced Myelosuppression or sepsis, as well as explore the relationship between supportive care interventions and the myelopreservation benefits of Trilaciclib.

In the first study (NCT02499770), patients with newly diagnosed ES-SCLC received Trilaciclib 240 mg/m2 or Placebo IV, given daily on days 1 to 3, prior to chemotherapy, of each 21-day chemotherapy cycle with Etoposide and Carboplatin. In the second trial (NCT03041311), patients with newly diagnosed ES-SCLC received Trilaciclib 240 mg/m2 or Placebo IV, given daily on days 1 to 3, prior to chemotherapy, of each 21-day chemotherapy cycle with Etoposide, Carboplatin and Atezolizumab (TECENTRIQ®), followed by single-agent Atezolizumab alone, every 21 days. In the third study (NCT02514447), patients with previously treated ES-SCLC in the second or third line setting, received Trilaciclib 240 mg/m2 or Placebo IV daily, prior to Topotecan 1.5 mg/m2 IV given daily on days 1 to 5 of each 21-day cycle. The Primary outcome measures included percentage of patients with Severe (Grade 4) Neutropenia as well as duration of Severe Neutropenia. Supportive intervention endpoints included percentage of patients with RBC transfusions on or after week 5, and number of RBC transfusion events on or after week 5, as well as percentage of patients receiving ESAs. This study also explored the percentage of patients with hospitalizations due to Chemotherapy Induced Myelosuppression (neutropenia, anemia, thrombocytopenia) or sepsis, as well as incidence of hospitalizations due to Chemotherapy Induced Myelosuppression or sepsis, per 100 cycles.

It was noted that fewer patients receiving Trilaciclib had Severe Neutropenia (11.4% versus 52.9%) or Grade 3/4 anemia (20.3% versus 31.9%), compared to Placebo, respectively, and the use of supportive care interventions such as G-CSF and ESAs was significantly reduced. Hospitalizations due to Chemotherapy Induced Myelosuppression or sepsis occurred in significantly fewer patients and significantly less often among patients receiving Trilaciclib prior to chemotherapy, compared to those who received Placebo. Trilaciclib reduced the percentage of patients with Severe Neutropenia and duration of Severe Neutropenia, regardless of G-CSF administration. The proportion of patients receiving RBC transfusions was consistently lower with each cycle, among patients receiving Trilaciclib, whereas RBC transfusions in the Placebo group almost doubled over time.

It was concluded that Trilaciclib prior to chemotherapy significantly and meaningfully reduced Chemotherapy Induced Myelosuppression and the need for supportive care interventions, for the management of Severe Neutropenia and Grade 3/4 anemia, in patients with ES-SCLC. Chemotherapy-induced Severe Neutropenia was reduced with Trilaciclib, irrespective of G-CSF administration.

Trilaciclib Reduces the Need for Growth Factors and Red Blood Cell Transfusions to Manage Chemotherapy-Induced Myelosuppression. Ferrarotto R, Anderson I, Medgyasszay B, et al. Presented at: IASLC 2020 North America Conference on Lung Cancer; October 16-17, 2020.

FDA Approves IMFINZI® for Advanced Small Cell Lung Cancer

SUMMARY: The FDA on March 27, 2020 approved IMFINZI® (Durvalumab) in combination with Etoposide and either Carboplatin or Cisplatin as first-line treatment for patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC). The American Cancer Society estimates that for 2020 about 228,820 new cases of lung cancer will be diagnosed and about 135,720 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Small cell lung cancer (SCLC) accounts for approximately 13-15% of all lung cancers and is aggressive. Patients with extensive stage SCLC are often treated with a combination of Carboplatin or Cisplatin with Etoposide as first line treatment and the tumor response rates are as high as 60-80%. However, majority of the patients relapse within months of completing initial therapy, with a median Overall Survival (OS) of approximately 10 months. Patients often receive HYCAMTIN® (Topotecan) for recurrent or progressive SCLC (second-line treatment) and after failure on second-line therapy, treatment options are limited. The 5 year survival rate for Extensive Stage SCLC (ES-SCLC) is less than 5%, with a median survival of 9-10 months from the time of diagnosis.Unleashing-T-Cell-Function-with-PD-1-and-PD-L1-Antibodies

Based on the premise that SCLC has a high mutation rate, it was hypothesized that these tumors may be immunogenic and more recently immunotherapy with checkpoint inhibitors has demonstrated clinical activity in Extensive Stage SCLC. IMFINZI® (Durvalumab) is a selective, high-affinity, human IgG1 monoclonal antibody, that blocks the binding of Programmed Death Ligand 1 (PD-L1) to Programmed Death 1 (PD-1) receptor and CD80, thereby unleashing the T cells to recognize and kill tumor cells.

IMFINZI® is approved by the FDA for the treatment of patients with locally advanced, unresectable Stage III Non-Small Cell Lung Cancer, who have not progressed following chemoradiotherapy. Additionally, IMFINZI® is also approved for the treatment of patients with locally advanced or metastatic Urothelial carcinoma who have disease progression during or following Platinum-containing chemotherapy, or who have disease progression within 12 months of neoadjuvant or adjuvant treatment with Platinum-containing chemotherapy.

This present FDA approval was based on CASPIAN trial, which is a multicenter, randomized, controlled, open-label, Phase III study, in which the efficacy of IMFINZI® with or without CTLA-4 inhibitor Tremelimumab, in combination with Etoposide plus either Cisplatin or Carboplatin (Platinum-Etoposide), was compared to chemotherapy alone, in treatment-naive patients with ES-SCLC.
Patients were randomly assigned in a 1:1:1 ratio to IMFINZI® plus Platinum-Etoposide, IMFINZI® plus Tremelimumab plus Platinum-Etoposide, or Platinum-Etoposide alone. This study allocated 268 patients to the IMFINZI® plus Platinum-Etoposide group and 269 patients to the Platinum-Etoposide group. Treatment with Platinum-Etoposide consisted of Etoposide 80-100 mg/m2 IV on days 1-3 of each cycle with investigator’s choice of either Carboplatin AUC 5-6 mg/mL per min or Cisplatin 75-80 mg/m2 IV administered on day 1 of each cycle. Patients received up to four cycles of Platinum-Etoposide along with IMFINZI® 1500 mg IV with or without Tremelimumab 75 mg IV every 3 weeks, followed by maintenance IMFINZI® 1500 mg IV every 4 weeks in the immunotherapy treatment groups, or up to six cycles of Platinum-Etoposide IV every 3 weeks plus Prophylactic Cranial Irradiation (at the treating physicians discretion), in the Platinum-Etoposide control group. The median patient age was 62 years and 10% of the patients had CNS metastases. PCI was administered to 8% of patients in the Platinum-Etoposide group. The Primary endpoint was Overall Survival (OS). Additional efficacy outcome measures included Progression Free Survival (PFS) and Objective Response Rate (ORR). The authors reported the results for the IMFINZI® plus Platinum-Etoposide group, compared to the Platinum-Etoposide group, from a planned interim analysis.

The median OS was 13.0 months in the IMFINZI® plus chemotherapy group, compared with 10.3 months in the chemotherapy alone group (HR=0.73; P=0.0047), with a 27% reduction in the risk of death.
Approximately 34% of patients who received IMFINZI® were alive at 18 months as compared to 25% in the control arm of the trial. Additionally, IMFINZI® plus chemotherapy demonstrated a higher PFS rate at 12 months (17.5% versus 4.7%), a 10.3% increase in confirmed ORR (67.9% versus 57.6%), and improved Duration of Response at 12 months (22.7% versus 6.3%). The most common adverse reactions noted were nausea, fatigue, asthenia, and alopecia.

It was concluded that the addition of IMFINZI® to first line Platinum-Etoposide chemotherapy combination significantly improved Overall Survival in patients with Extensive Stage-Small Cell Lung Cancer, when compared to chemotherapy alone.

Durvalumab plus platinum-etoposide versus platinum-etoposide in first-line treatment of extensive-stage small-cell lung cancer (CASPIAN): a randomised, controlled, open-label, phase 3 trial. Paz-Ares L, Dvorkin M, Chen Y, CASPIAN investigators, et al. Lancet. 2019;394:1929-1939

IMFINZI® (Durvalumab)

The FDA on March 30, 2020 approved IMFINZI® in combination with Etoposide and either Carboplatin or Cisplatin as first-line treatment of patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC). IMFINZI® is a product of AstraZeneca.

TECENTRIQ® in Combination with Chemotherapy Improves Overall Survival in Extensive Stage Small-Cell Lung Cancer

SUMMARY: The American Cancer Society estimates that for 2019 about 228,150 new cases of lung cancer will be diagnosed and about 142,670 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Small cell lung cancer (SCLC) accounts for approximately 13-15% of all lung cancers and is aggressive. Patients with extensive stage SCLC are often treated with a combination of Carboplatin or Cisplatin with Etoposide as first line treatment and the tumor response rates are as high as 60-80%. However, majority of the patients relapse within months of completing initial therapy, with a median Overall Survival of approximately 10 months. Patients often receive HYCAMTIN® (Topotecan) for recurrent or progressive SCLC (second-line treatment) and after failure on second-line therapy, treatment options are limited. The 5 year survival rate for Extensive Stage SCLC is less than 5%, with a median survival of 9-10 months from the time of diagnosis.

Based on the premise that SCLC has a high mutation rate, it was hypothesized that these tumors may be immunogenic and could respond to immune-checkpoint inhibitors. TECENTRIQ® (Atezolizumab) is an anti PD-L1 monoclonal antibody that directly binds to PD-L1 expressed on tumor cells and tumor-infiltrating immune cells and blocks the interaction of PD-L1 with PD-1 and B7.1 receptors and thereby enables the activation of T cells and restores tumor-specific T-cell immunity. In a phase I trial, TECENTRIQ® monotherapy demonstrated durable responses, with an acceptable safety profile in patients with relapsed or refractory SCLC. A combination of checkpoint inhibition with cytotoxic chemotherapy was therefore studied, for synergy and improved efficacy.Unleashing-T-Cell-Function-with-PD1-and-PDL1-Antibodies

The IMpower133 trial is a multinational, randomized, double-blind, placebo-controlled Phase III trial which evaluated the benefit of TECENTRIQ® plus Carboplatin and Etoposide in chemo naïve patients with extensive-stage Small-Cell Lung Cancer. Enrolled patients were randomized in a 1:1 ratio and the induction phase consisted of four cycles of Carboplatin AUC 5 mg/ml/min IV on day 1 and Etoposide 100 mg/m2 IV on days 1-3 of each 21-day cycle, with either TECENTRIQ® 1200 mg IV day 1 of each cycle (N=201) or placebo (N=202). The induction phase was followed by a maintenance phase during which patients received either TECENTRIQ® or placebo (based on previous random assignment) and treatment was continued until disease progression or unacceptable toxicities. The median age was 64 yrs and PD-L1 testing was not a requirement. Prophylactic cranial irradiation was permitted during the maintenance phase of treatment but thoracic radiation therapy was not permitted. The Primary end points were Overall Survival (OS) and Progression Free Survival (PFS) and Secondary end points included Objective Response Rate (ORR) and Duration of Response. At a median follow up of 13.9 months, the median OS was 12.3 months in the TECENTRIQ® group compared to 10.3 months in the placebo group (HR=0.70; P=0.007). The median PFS which was a Coprimary endpoint was also longer in the TECENTRIQ® group than in the placebo group (5.2 months versus 4.3 months, HR=0.77; P=0.02). This data led to the approval of TECENTRIQ® for the first line treatment of extensive-stage Small-Cell Lung Cancer.

The authors now reported the Overall Survival (OS) outcomes after a follow up of more than 2 years. At a median follow up of 22.9 months, the median OS for the patients randomized to TECENTRIQ® persisted at 12.3 months versus 10.3 months in the placebo group (HR=0.76; P =0.01). The authors noted that there was no correlation between efficacy of the TECENTRIQ® combination and blood Tumor Mutational Burden level. Further, the OS benefit was not influenced by tumor tissue PD-L1 expression. There was no change in the Adverse Events rate noted, in this updated analysis.

It was concluded that with a follow up of close to 2 years, the addition of TECENTRIQ® to standard chemotherapy, for treatment of patients with extensive stage Small Cell Lung Cancer, continues to demonstrate improved Overall Survival, compared to chemotherapy alone. IMpower133: Updated Overall Survival (OS) analysis of first-line (1L) atezolizumab (atezo) + carboplatin + etoposide in extensive-stage SCLC (ES-SCLC). Reck M, Liu SV, Mansfield AS, et al. Presented at ESMO September 27-October 1, 2019; Barcelona, Spain. Abstract 17360.

FDA Approves KEYTRUDA® for Advanced Small Cell Lung Cancer

SUMMARY: The FDA on June 17, 2019 granted accelerated approval to KEYTRUDA® (Pembrolizumab) for patients with metastatic Small Cell Lung Cancer (SCLC) with disease progression on or after Platinum-based chemotherapy, and at least one other prior line of therapy. The American Cancer Society estimates that for 2019 about 228,150 new cases of lung cancer will be diagnosed and about 142,670 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Small cell lung cancer (SCLC) accounts for approximately 13-15% of all lung cancers, and is aggressive. Patients with SCLC are often treated with platinum based chemotherapy as first-line treatment, and the tumor response rates are as high as 60-80%. However, only 20% of patients with Limited Stage SCLC are cured, and majority of the patients relapse within months of completing initial therapy. Patients often receive HYCAMTIN® (Topotecan) for recurrent or progressive SCLC (second-line treatment) and after failure on second-line therapy, treatment options are limited. The 5 year survival rate for Extensive Stage SCLC is less than 5%, with a median survival of 9-10 months from the time of diagnosis.

KEYTRUDA® is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. It thereby reverses the PD-1 pathway-mediated inhibition of the immune response and unleashes the tumor-specific effector T cells.

The present FDA approval was based on pooled data from two Basket studies, KEYNOTE-158 (cohort G) and KEYNOTE-028 (cohort C1), which are two multicenter, multi-cohort, non-randomized, open-label trials, evaluating KEYTRUDA® in patients with SCLC, who had disease progression on or after platinum-based chemotherapy and at least one other prior line of therapy. In Basket trials, patients with different tumor histologies receive a single treatment and have a single biomarker. Among the 83 patients evaluated in both these studies for efficacy, 64% received two prior lines of therapy and 36% received three or more lines of therapy; 60% received prior thoracic radiation therapy; 51% received prior radiation therapy to the brain. Patients in the KEYNOTE-028 were required to have tumors expressing PD-L1, whereas PD-L1 positivity was not required for KEYNOTE-158. Patients in the KEYNOTE-028 study received KEYTRUDA® 10 mg/kg IV every 2 weeks (N=19), whereas those in KEYNOTE-158 received KEYTRUDA® 200 mg IV every 3 weeks (N=64). Treatment was continued until documented disease progression, unacceptable toxicity, or a maximum of 24 months. The major efficacy outcome measures included Objective Response Rate (ORR) and Duration of Response (DOR).

Treatment with KEYTRUDA® resulted in an Overall Response Rate of 19%, with a Complete Response Rate of 2% and a Partial Response Rate of 17%. Of the responding patients, 94% had a Duration of Response (DOR) of 6 months or longer, 63% had a DOR of 12 months or longer, and 56% had a DOR of 18 months or longer. Responses ranged from 4.1 to over 35.8 months. Adverse Events were similar to those occurring in patients with other solid tumors who received KEYTRUDA® as a single agent and the common adverse reactions included fatigue, decreased appetite, cough, nausea and constipation.

It was concluded that this new indication marks the first FDA approval for KEYTRUDA® in Small Cell Lung Cancer, and provides an additional treatment option for patients with advanced stage disease, based on clinical response rates. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pembrolizumab-metastatic-small-cell-lung-cancer

KEYTRUDA® (Pembrolizumab)

The FDA on June 17, 2019 granted accelerated approval to KEYTRUDA® for patients with metastatic Small Cell Lung Cancer (SCLC) with disease progression on or after platinum-based chemotherapy and at least one other prior line of therapy. KEYTRUDA® is a product of Merck.

TECENTRIQ® (Atezolizumab)

The FDA on March 18, 2019 approved TECENTRIQ® in combination with Carboplatin and Etoposide, for the first-line treatment of adult patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC). TECENTRIQ® is a product of Genentech Inc.

TECENTRIQ® in Combination with Chemotherapy Improves Overall Survival in Extensive Stage Small-Cell Lung Cancer

SUMMARY: Lung cancer is the second most common cancer in both men and women and accounts for about 14% of all new cancers and 27% of all cancer deaths. The American Cancer Society estimates that for 2018 about 234,030 new cases of lung cancer will be diagnosed and over 154,050 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Small cell lung cancer (SCLC) accounts for approximately 13-15% of all lung cancers and is aggressive. Patients with extensive stage SCLC are often treated with a combination of Carboplatin or Cisplatin with Etoposide as first line treatment and the tumor response rates are as high as 60-80%. However, majority of the patients relapse within months of completing initial therapy, with a median Overall Survival of approximately 10 months. Based on the premise that SCLC has a high mutation rate, it was hypothesized that these tumors may be immunogenic and could respond to immune-checkpoint inhibitors. This hypothesis was subsequently confirmed in patients with refractory or metastatic SCLC.

TECENTRIQ® (Atezolizumab) is an anti PD-L1 monoclonal antibody that directly binds to PD-L1 expressed on tumor cells and tumor-infiltrating immune cells and blocks the interaction of PD-L1 with PD-1 and B7.1 receptors and thereby enables the activation of T cells and restores tumor-specific T-cell immunity. In a phase I trial, TECENTRIQ® monotherapy demonstrated durable responses, with an acceptable safety profile in patients with relapsed or refractory SCLC. The authors in this study combined checkpoint inhibition with cytotoxic chemotherapy for synergy and improved efficacy. Unleashing-T-Cell-Function-with-Combination-Immunotherapy

The IMpower133 trial is a multinational, randomized, double-blind, placebo-controlled phase III trial which evaluated the benefit of TECENTRIQ® plus Carboplatin and Etoposide in chemo naïve patients with extensive-stage Small-Cell Lung Cancer. Enrolled patients were randomized in a 1:1 ratio and the induction phase consisted of four cycles of Carboplatin AUC 5 mg/ml/min IV on day 1 and Etoposide 100 mg/m2 IV on days 1-3 of each 21-day cycle, with either TECENTRIQ® 1200 mg IV day 1 of each cycle (N=201) or placebo (N=202). The induction phase was followed by a maintenance phase during which patients received either TECENTRIQ® or placebo (based on previous random assignment) and treatment was continued until disease progression or unacceptable toxicities. The median age was 64 yrs and PD-L1 testing was not a requirement. Prophylactic cranial irradiation was permitted during the maintenance phase of treatment but thoracic radiation therapy was not permitted. The Primary end points were Overall Survival (OS) and Progression Free Survival and Secondary end points included Objective Response Rate (ORR) and Duration of Response.

At a median follow up of 13.9 months, the median OS was 12.3 months in the TECENTRIQ® group compared to 10.3 months in the placebo group (HR=0.70; P=0.007). This suggested a 30% reduction in the risk of death when TECENTRIQ® was added to chemotherapy. The 1-year OS rate was 51.7% in the TECENTRIQ® group and 38.2% in the placebo group. The median Progression Free Survival was also longer in the TECENTRIQ® group than in the placebo group (5.2 months versus 4.3 months, HR=0.77; P=0.02). Survival benefits were consistently seen across patient subgroups. The safety profile of TECENTRIQ® plus Carboplatin and Etoposide was consistent with the previously reported safety profile of the individual agents, with no new findings observed in this trial.

It was concluded that in this multinational trial, the addition of TECENTRIQ® to chemotherapy in the first line treatment of extensive stage Small-Cell Lung Cancer resulted in significantly longer Overall Survival and Progression Free Survival, when compared to chemotherapy alone. First-Line Atezolizumab plus Chemotherapy in Extensive-Stage Small-Cell Lung Cancer. Horn L, Mansfield AS, SzczÄ™sna A, et al. for the IMpower133 Study Group. N Engl J Med 2018; 379:2220-2229

OPDIVO® (Nivolumab)

The FDA on August 16, 2018 granted accelerated approval to OPDIVO® for patients with metastatic Small Cell Lung Cancer (SCLC) with progression after platinum-based chemotherapy and at least one other line of therapy. OPDIVO® is a product of Bristol-Myers Squibb Company Inc.