Author: RR

FDA Approves Oral INQOVI® for Myelodysplastic Syndromes

RR

SUMMARY: The FDA on July 7, 2020, approved INQOVI®, an oral combination of Decitabine and Cedazuridine, for adult patients with MyeloDysplastic Syndromes (MDS), including previously treated and untreated de novo and secondary MDS with the following FAB subtypes – Refractory Anemia, Refractory Anemia with Ringed Sideroblasts, Refractory Anemia with Excess Blasts, Chronic MyeloMonocytic Leukemia (CMML), and Intermediate-1, Intermediate-2, and high-risk International Prognostic Scoring System (IPSS) groups.

It is estimated that in the US approximately 13,000 people are diagnosed with MyeloDysplastic Syndromes (MDS) each year. The prevalence has been estimated to be from 60,000 to 170,000 in the US. MyeloDysplastic Syndromes are a heterogenous group of stem cell disorders characterized by marrow failure resulting in cytopenias with associated cytogenetic abnormalities, and abnormal cellular maturation with morphologic changes in clonal cells. Majority of the individuals diagnosed with MDS are 65 years or older and die as a result of infection and/or bleeding, consequent to bone marrow failure. About a third of patients with MDS develop Acute Myeloid Leukemia (AML). CMML (Chronic MyeloMonocytic Leukemia) is a clonal hematopoietic malignancy characterized by accumulation of abnormal monocytes in the bone marrow and in blood. The incidence of CMML in the US is approximately 1,100 new cases per year. About 15-30% of patients with CMML develop AML. Patients with higher risk MDS and CMML are often treated with hypomethylating agents such as Decitabine (DACOGEN&reg) and Azacitidine (VIDAZA®). These agents are administered by IV infusion, or by large-volume subcutaneous injections.

INQOVI® is an orally-administered, unique fixed-dose combination of the DNA hypomethylating agent and DNA MethylTransferase (DNMT) inhibitor Decitabine, the active ingredient in Dacogen®, and the novel Cytidine deaminase inhibitor, Cedazuridine (35 mg Decitabine and 100 mg Cedazuridine). INQOVI® was designed to deliver Decitabine by oral administration. Cedazuridine prevents the degradation of Decitabine in the gut and liver by inhibiting Cytidine deaminase and the combination thereby permits the efficient delivery of Decitabine orally, at exposures that are equivalent to the approved intravenous form of Decitabine administered over 5 days.

The present FDA approval was based on data from two open-label, randomized, crossover clinical trials, ASTX727-01-B, which included 80 adult patients with MDS (IPSS Intermediate-1, Intermediate-2, or high-risk groups) or CMML, and ASTX727-02, which included 133 adult patients with MDS or CMML, including all FAB subtypes and IPSS Intermediate-1, Intermediate-2, or high-risk groups. In these two trials, patients were randomized 1:1 to receive INQOVI® orally in cycle 1 and Decitabine 20 mg/m2 intravenously in cycle 2 or the reverse order. Both oral INQOVI® and intravenous Decitabine were administered once daily on days 1 through 5 of a 28-day cycle. Starting with cycle 3, all patients received INQOVI® orally once daily on days 1 through 5 of each 28-day cycle, until disease progression or unacceptable toxicity. Both trials provided comparison of exposure and safety in the first two cycles between oral INQOVI® and IV Decitabine and description of disease response with INQOVI®. Comparison of disease response between the INQOVI® and IV Decitabine was not possible because all patients received INQOVI® starting from Cycle 3. The Primary endpoint was total 5-day AUC exposures of Decitabine following INQOVI® therapy compared with IV Decitabine, as measured across the first 2 cycles. Secondary endpoints included safety assessments, pharmacodynamic measurements, clinical responses, RBC transfusion independence, Leukemia-free survival, and Overall Survival.

ASTX727-01-B trial which included 80 patients demonstrated a Complete Response (CR) rate of 18% and median duration of CR of 8.7 months. Among the 41 patients who were dependent on RBC and/or platelet transfusions at baseline, 49% became transfusion independent during any consecutive 56-day post-baseline period. Of the 39 patients who were independent of both RBC and platelet transfusions at baseline, 64% remained transfusion independent during any consecutive 56-day post-baseline period.

ASTX727-02 trial, which included 133 patients, demonstrated a 99% geometric mean ratio of the 5-day cumulative Decitabine AUC following 5 consecutive once daily doses of the oral combination therapy, versus that of IV Decitabine, with a 90% Confidence interval between 93% and 106%. This confirmed equivalence of oral INQOVI® and IV Decitabine. Efficacy results demonstrated that 21% of patients achieved CR, and median duration of CR was 7.5 months. Among the 57 patients who were dependent on RBC and/or platelet transfusions at baseline, 53% became transfusion independent during any 56-day post-baseline period. Of the 76 patients who were independent of both RBC and platelet transfusions at baseline, 63% remained transfusion independent during any 56-day post-baseline period. The most common Adverse Events related to INQOVI® included fatigue, rash, dizziness, headaches, anorexia, nausea, diarrhea, constipation, mucositis, hemorrhage, myalgia, arthralgia, febrile neutropenia, and transaminase elevation.

It was concluded that INQOVI® which is a fixed-dose combination of Cedazuridine and Decitabine is a new treatment option for patients with MDS and CMML, and is an oral hypomethylating agent alternative to IV Decitabine.

https://www.fda.gov/drugs/drug-approvals-and-databases/fda-approves-oral-combination-decitabine-and-cedazuridine-myelodysplastic-syndromes

FDA Approves IO in Combination with Targeted Therapies for BRAF Positive Advanced Melanoma

RR

SUMMARY: The FDA on July 30, 2020, approved TECENTRIQ® (Atezolizumab), in combination with COTELLIC® (Cobimetinib) and ZELBORAF® (Vemurafenib), for patients with BRAF V600 mutation-positive unresectable or metastatic melanoma. It is estimated that in the US, approximately 100,350 new cases of melanoma will be diagnosed in 2020 and approximately 6,850 patients are expected to die of the disease. The incidence of melanoma has been on the rise for the past three decades. Surgical resection with a curative intent is the standard of care for patients with early stage melanoma, with a 5-year survival rate of 98% for Stage I disease and 90% for Stage II disease. Patients with locally advanced or metastatic melanoma historically have had poor outcomes. With the development and availability of immune checkpoint inhibitors and BRAF and MEK inhibitors, this patient group now has significantly improved outcomes.BRAF-and-MEK-Inhibition-in-MAPK-Pathway

The Mitogen-Activated Protein Kinase pathway (MAPK pathway) is an important signaling pathway which enables the cell to respond to external stimuli. This pathway plays a dual role, regulating cytokine production and participating in cytokine dependent signaling cascade. The MAPK pathway of interest is the RAS-RAF-MEK-ERK pathway. The RAF family of kinases includes ARAF, BRAF and CRAF signaling molecules. BRAF is a very important intermediary of the RAS-RAF-MEK-ERK pathway. BRAF mutations have been detected in 6-8% of all malignancies. The most common BRAF mutation in melanoma is at the V600E/K site and is detected in approximately 50% of melanomas, and result in constitutive activation of the MAPK pathway.

ZELBORAF® (Vemurafenib), a selective oral inhibitor of mutated BRAF, demonstrated significant improvement in Progression Free Survival (PFS) and Overall Survival (OS), compared to Dacarbazine. Squamous cell carcinomas were seen in about 6% of the patients treated with BRAF inhibitors. Paradoxical activation of the MAPK pathway in cells without a BRAF mutation has been implicated in the emergence of drug resistance and increased incidence of BRAF-inhibitor induced skin tumors. MEK gene is downstream from RAF in the MAPK pathway. The addition of a selective inhibitor of MEK gene such as COTELLIC® (Cobimetinib) to a BRAF inhibitor such as ZELBORAF® has addressed some of these limitations, in previously published studies, with improvement in Objective Response Rates (ORR) and decrease in the incidence of cutaneous secondary cancers. coBRIM is a multicenter, randomized, Phase III study in which the efficacy and safety of COTELLIC® combined with ZELBORAF®, was evaluated in previously untreated patients, with advanced BRAF-mutated melanoma. The final analysis of this trial evaluated the 5-year survival data, and the OS was over 30% in patients who received the combination therapy, with a Complete Response (CR) rate was about 20%.

TECENTRIQ® (Atezolizumab) is an anti PD-L1 monoclonal antibody, designed to directly bind to PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, thereby blocking its interactions with PD-1 and B7.1 receptors. PD-L1 inhibition may prevent T-cell deactivation and further enable the activation of T cells. The 5 year OS among patients receiving PD1 targeted immunotherapy is about 34%, with a median OS of 17-20 months. With the approval of multiple therapeutic options for the management of patients with BRAF-mutant melanoma, treatment decisions have become increasingly complex. In patients with limited disease burden, immunotherapy with checkpoint inhibitors is favored by most clinicians, based on the long term data supporting the durability of responses with immunotherapies, but response rates are lower. On the contrary, BRAF-targeted agents are utilized in patients with extensive, symptomatic disease and active brain metastases, as the response rates are higher but are short lived. The optimal sequence of these therapeutic strategies in order to improve long-term patient outcome, has remained unclear.

Preclinical studies suggested that combining these two targeted therapies with a checkpoint inhibitor might overcome the limitations of each class and potentially lead to more durable responses. The safety and efficacy of combining TECENTRIQ® with COTELLIC® (MEK inhibitor) and ZELBORAF® (BRAF inhibitor), in patients with BRAFV600-mutated metastatic melanoma, was evaluated in a Phase I study, with promising results, and a 28-day run-in period with COTELLIC® and ZELBORAF® was associated with an increase in proliferating CD4+ T-helper cells, without increasing the T-regulatory cells (Tregs). Tumor cells use Tregs as a shield to protect themselves against anti-tumor immune response and Tregs remain a hurdle in achieving the complete potential of anti-cancer therapies including immunotherapy. The aim of IMspire 150 trial was to determine if combining checkpoint inhibitor with two targeted therapies would improve efficacy.

IMspire150 is a pivotal, placebo-controlled, international, multicenter, double-blinded, Phase III trial, in which 514 treatment-naive patients with Stage IIIc and Stage IV, BRAF V600–mutant malignant melanoma were enrolled. Patients were randomly assigned 1:1 to treatment with the doublet combination or the triplet therapy. Doublet therapy given to the control group of patients consisted of ZELBORAF® 960 mg orally twice daily plus COTELLIC® at 60 mg orally, on days 1 to 21 of a 28 day cycle. In the experimental or triplet therapy group, there was a 28-day run-in with ZELBORAF® plus COTELLIC® alone, dosed similar to the control group (cycle 1), following which patients received TECENTRIQ® 840 mg IV on Days 1 and 15 of each 28 day cycle starting cycle 2, in combination with ZELBORAF® at a lower dose of 720 mg orally twice daily and COTELLIC® 60 mg orally once daily. Treatment was continued until disease progression, or unacceptable toxicity. Both treatment groups were well balanced, median patient age was 54 years, 58% were male and 94% of patients had Stage IV disease. The Primary endpoint was investigator-assessed Progression Free Survival (PFS). Secondary end points included Objective Response Rates (ORR), Duration of Response (DOR), and Overall Survival (OS).

The combination of immunotherapy with targeted therapies was significantly superior to targeted therapies alone. At a median follow up of 18.9 months, the median PFS with the triplet combination was 15.1 months versus 10.6 months with the doublet therapy (HR=0.78; P=0.025). This represented a 22% reduction in the risk of disease progression. This benefit was observed across all subgroups including age, disease burden, LDH level, and extent of tumor involvement by organ site. Although Objective Response Rates were similar in both treatment groups, the median Duration of Response was 21.0 months with triplet combination versus 12.6 months for the doublet therapy. The OS data were not mature at the time of this analysis, but interim analysis however showed a median OS of 28.8 months with the triplet combination versus 25.1 months with doublet therapy. Both treatment groups had comparable toxicities. Among those patients receiving triplet combination, the most common toxicities were rash, fever, fatigue, nausea, pruritus, stomatitis, musculoskeletal pain, hepatotoxicity, edema, hypothyroidism, and photosensitivity.

It was concluded that in treatment-naive patients with advanced BRAF V600-mutant malignant melanoma, TECENTRIQ® in combination with ZELBORAF® and COTELLIC® significantly and clinically improved Progression Free Survival, when compared to placebo in combination with ZELBORAF® and COTELLIC®.

Evaluation of atezolizumab (A), cobimetinib (C), and vemurafenib (V) in previously untreated patients with BRAFV600 mutation-positive advanced melanoma: Primary results from the phase 3 IMspire150 trial. McArthur GA, Stroyakovskiy D, Gogas H, et al. Presented at: the 2020 AACR Annual Virtual Meeting I; April 27-28, 2020. Abstract CT012.

TECARTUS®

RR

The FDA on July 24, 2020 granted accelerated approval to TECARTUS® (brexucabtagene autoleucel), a CD19-directed genetically modified Autologous T cell immunotherapy, for the treatment of adult patients with relapsed or refractory Mantle Cell Lymphoma (MCL). TECARTUS® is a product of Kite Pharma, a subsidiary of Gilead Sciences.

INQOVI® (Decitabine and Cedazuridine)

RR

The FDA on July 7, 2020 approved INQOVI® for adult patients with MyeloDysplastic Syndromes (MDS) including the following:
1) Previously treated and untreated, de novo and secondary MDS with the following French-American-British subtypes (Refractory Anemia, Refractory Anemia with Ringed Sideroblasts, Refractory Anemia with excess blasts, and Chronic MyeloMonocytic Leukemia [CMML])
2) Intermediate-1, Intermediate-2, and high-risk International Prognostic Scoring System groups.

INQOVI® is a product of Astex Pharmaceuticals, Inc.

The Transition to Biosimilars: Managing Payor Challenges

RR

Written by Dr. Robert Rifkin | Sponsored by Mylan Pharmaceuticals

Biologic agents have long played a vital role in oncology. Not only does this class of agents represent the best of science, but it also accounts for a tremendous increase in spend of the healthcare dollar. As the field of biologic therapies advances, the biosimilarity exercise has become relevant. The premise of biosimilarity is to decrease healthcare costs and improve access to care.1

This premise was first established with the affordable care act in the Biologics Price Competition and Innovation Act (BCPIA).2 Since its inception, a new pathway for approval of biosimilars was tested and implemented. The 351 (K) regulatory pathway was first tested with biosimilar filgrastim (filgrastim–sndz), or Zarxio.3 Initially, upon product launch, a modest discount of 15% was employed. (15%) The uptake was slow; however, when the market adjusted and uptake accelerated, an approximate 30% discount was in play.

Several other biosimilars have now entered the supportive care space. Specifically, in the case of short acting filgrastim, there are now competitors Nivestym (Filgrastim-aafi) with several additional biosimilar filgrastims under development. Within the pegfilgrastim arena, the position of the originator, Neulasta, has now been challenged by 3 other long-acting filgrastims: Fulphila (pegfilgrastim-jmdb), Udenyca (pegfilgrastim-cbqv), and Ziextenzo (pegfilgrastim-bmez).4 These original, early supportive care biosimilars have helped to define the marketplace, test regulatory mechanisms, and dispel any myths regarding their adoption.4

Herceptin (trastuzumab) also faces competition as new biosimilars enter space. Multiple biosimilars have now launched in addition to the originator molecule, including: Herzuma (trastuzumab-pkrb), Kanjinti (trastuzumab-anns), Ogivri (trastuzumab-dkst), Ontruzant (trastuzumab-dttb), and Trazimera (trastuzumab-qyyp).5 For the trastuzumabs, the large number of biosimilar options provides both competition in the marketplace in addition to a potential new source of significant confusion with distribution, supply chain, and inventory management. It is relatively unlikely that any payor or formulary will carry all five biosimilar trastuzumabs currently available in addition to any other biosimilar options slated for release over the next year.

Additionally, the rituximab space has become increasingly complex. Beyond the originator molecule, we can now choice to use Truxima (ritiximab abbs), or Ruxience (rituximab-pvvr), and several more launches are anticipated. The space is further complicated by the availability of a subcutaneous form of Rituxan Hycela (rituximab/hyaluronidase human), the only biosimilar available in subcutaneous injection. Unsurprisingly, this has created some from payors as all labeled indications are not initially the same for each product. Moving forward, rituximab biosimilar labels will soon be equivalent, and competition will then drive the marketplace.

In the real world, there still exist very real barriers to adoption including a clinical, ease of use, and economic barriers. It is likely payors will interpose themselves into each one of these. Multiple biosimilars are now being approved for each originator molecule. This will ultimately result in a decline in cost. Payors and other stakeholders will then be faced with complicated decisions of maintaining the originator on the formulary, deleting it and placing a biosimilar in its place, or perhaps carrying two versions of the same molecule, with preference being given to one. Most likely, most formularies will carry originator in addition to one or more biosimilars concurrently depending on the provider and payer landscape. the originator and a preferred biosimilar concurrently.

Several articles have reviewed the concept of switching between the biosimilar and the originator, and to date no significant safety signals have arisen.6 The payor landscape is impacted by product availability and opportunities to switch. This demonstrated safety of switching has incrementally impacted the payor landscape. Pharmacy Benefit Managers (PBM) have also been interwoven into the payor conundrum, with discounts and rebates providing an additional layer of complexity.

Not only is the transition to biosimilars complicated for payors, but the transition must also include all stakeholders involved in the ultimate selection of a therapeutic biologic. Providers and patients need to be very well educated regarding the concept of biosimilarity. Other stakeholders, including pharmacists, advanced practice providers, nurses, and admixture technologists, must be thoroughly educated. The electronic health record also needs to be updated to reflect the increasing numbers of biosimilars now available – including the preferred therapeutic agents in each circumstance.

Payors and clinicians alike will need to develop biosimilar teams, drug contracting strategies with and without GPO’s, and a thorough evaluation of clinical economics for each biosimilar. Biosimilars will assume an increasingly important role in the delivery of cancer care and it is important to approach this from a patient journey point of view (Fig. 1).

Figure 1: Patient Journey7

By tracing this from beginning to end, a formula for success may be developed.

The combination of clinical confidence, patient confidence, and operational excellence will be required to be sure that we are prepared for biosimilars and ensure patient access. The patient’s journey is complicated and increasingly influenced by the payor and other stakeholders . Providers, consideration of the revenue cycle, RN educators, pharmacists, admixture technologists, and infusion RNs all must play together to ensure the success of biosimilars. In alignment with the patient journey, diagnosis and treatment selection will be accomplished by the provider. This will be followed by insurance authorization, treatment education, treatment scheduling, treatment admixture, and finally the delivery of the drug to the well-educated patient. There are many potentials for success as well as failure (Fig. 2).

Figure 2: Drug Preparedness – Success vs. Failure7

The cornerstone for all to succeed, as well as all of the affected stakeholders managing paired challenges, remains education. This cannot be overstated. Numerous websites have now appeared, both branded and unbranded, to help deliver biosimilar education. Such websites may be found at the FDA8 and the Center for Biosimilars.9

In conclusion, as all the stakeholders become thoroughly educated, the many challenges outlined above will continue to present themselves in real-time. The success and adoption of current and future biosimilars will continue to depend on the sound education of all stakeholders, including payors, in addition to improved cost savings and access. Biosimilar usage will be important to ensure long-term sustainability on the market, and as biosimilar uptake increases, healthcare cost reduction and improvements to care access may be achieved.


Sources

1. Pittman WL, Wern C, Glode AE. Review of Biosimilars and Their Potential Use in Oncology Treatment and Supportive Care in the United States.
2. https://www.fda.gov/media/78946/download
3. U.S. Food & Drug Administration. Zarxio (filgrastim-sndz) Approval Letter. Published online March 6, 2015. Accessed June 19, 2020. https://www.accessdata.fda.gov/drugsatfda_docs/nda/2015/125553Orig1s000Approv.pdf
4. Rugo H, Rifkin RM, Deckerc P, Bair AH, Morgan G. Demystifying Biosimilars: Development, Regulation and Clinical Use. Future Oncology. 15(7):777-790, 2019
5. AmerisourceBergen. Approval and launch dates for US biosimilars. Published June 19, 2020. Accessed June 25, 2020. http://gabionline.net/Reports/Approval-and-launch-dates-for-US-biosimilars?ct=t%28GONL+V20F19-6%29&mc_cid=2821e641cc&mc_eid=%5BUNIQID%5D
6. Cohen HP, Blauvelt A, Rifkin RM, Danese S, Gokhale SB, Woollett G. Switching Reference Medications to Biosimilars: A Systematic Literature Review of Clinical Outcomes. Drugs 78(4): 463-78,2018.
7. Rifkin R, Busby L. Bringing Biosimilars to Community. Presented at McKesson Oncology University; 2019.
8. www.fda.gov
9. www.centerforbiosimilars.com/

ENHERTU® Improves Overall Survival in Previously Treated HER2-Positive Gastric Cancer

RR

SUMMARY: The American Cancer Society estimates that in the US, about 27,600 new cases of Gastric cancer will be diagnosed in 2020 and about 11,010 people will die of the disease. It is one of the leading causes of cancer-related deaths in the world. Several hereditary syndromes such as Hereditary Diffuse Gastric Cancer (HDGC), Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer) and Familial Adenomatous Polyposis (FAP) have been associated with a predisposition for stomach cancer. Additionally, one of the strongest risk factor for Gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium.

The Human Epidermal growth factor Receptor (HER) or erbB family of receptors, consist of HER1, HER2, HER3 and HER4. Approximately 15-20% of advanced Gastric and GastroEsophageal (GE) junction cancers, overexpress or have amplification of the HER2 oncogene. These patients often receive first line treatment with a combination of chemotherapy plus anti-HER2 antibody, Trastuzumab, as there is Overall Survival (OS) benefit with this combination regimen. Upon progression, Paclitaxel plus CYRAMZA® (Ramucirumab), an anti-VEGFR-2 antibody is recommended as second-line therapy, regardless of HER2 expression, based on OS and Progression Free Survival (PFS) data for this combination regimen. Trifluridine-tipiracil (LONSURF®) and Immune Checkpoint Inhibitors are treatment options for later lines of therapy and are associated with minimal prolongation in OS. Unlike treatment in metastatic breast cancer, re-treatment with Trastuzumab in combination with various different chemotherapy agents has not shown survival benefit in Gastric cancer. Further, Antibody-Drug Conjugate such as KADCYLA® (ado-trastuzumab emtansine), did not prolong median OS or improve Response Rates compared to chemotherapy, in patients with Gastric cancer who had progressed during or after treatment with Trastuzumab.Mechanism-of-Action-ENHERTU

ENHERTU® (Trastuzumab Deruxtecan) is an Antibody-Drug Conjugate (ADC) composed of a humanized monoclonal antibody specifically targeting HER2, with the amino acid sequence similar to Trastuzumab, a cleavable tetrapeptide-based linker, and a potent cytotoxic Topoisomerase I inhibitor as the cytotoxic drug (payload). ENHERTU® has a favorable pharmacokinetic profile and the tetrapeptide-based linker is stable in the plasma and is selectively cleaved by cathepsins that are up-regulated in tumor cells. Unlike KADCYLA®, ENHERTU® has a higher drug-to-antibody ratio (8 versus 4), released payload easily crosses the cell membrane with resulting potent cytotoxic effect on neighboring tumor cells regardless of target expression, and the released cytotoxic agent (payload) has a short half-life, minimizing systemic exposure.

DESTINY-Gastric01 is an open-label, randomized, multicenter, Phase II trial in which ENHERTU® was compared with chemotherapy in patients with HER2-positive advanced Gastric cancer. In this study 187 patients were randomly assigned in a 2:1 ratio to receive either ENHERTU® (N=125) or the treating physician’s choice of Irinotecan or Paclitaxel (N=62). Eligible patients had HER2-expressing advanced Gastric cancer or GastroEsophageal junction adenocarcinoma that had progressed after the receipt of at least two previous systemic therapies, which included a Fluoropyrimidine, a Platinum agent, and Trastuzumab (or approved biosimilar agent). Patients in the ENHERTU® group received the drug at a dose of 6.4 mg/kg as IV infusion every 3 weeks, whereas the physician’s choice group received either Irinotecan monotherapy 150 mg/m2 IV every 2 weeks, or Paclitaxel monotherapy 80 mg/m2 IV on days 1, 8, and 15 every 4 weeks. HER2 levels were documented as high if the score was 3+ on IHC, or 2+ on IHC with positive results on FISH, and documented as low if the score was 2+ on IHC with negative results on FISH, or a score of 1+ on IHC (negative). Treatment was continued until disease progression or unacceptable toxicities. Both treatment groups were well balanced. Approximately 72% of the patients had previously received CYRAMZA® (Ramucirumab), and 86% had received Taxanes. The median time since the last administration of Trastuzumab was 6.2 months. The Primary end point was the Objective Response Rate (ORR), according to Independent Central Review. Secondary end points included Overall Survival (OS), response duration, Progression Free Survival, and safety. The primary cohort consisted of patients with high-level HER2-positive disease, and was the focus of this analysis.

Treatment with ENHERTU® resulted in an ORR of 51%, compared to 14% in the physician’s choice group (P<0.001), according to Independent Central Review. An ORR lasting 4 weeks or more occurred in 43% of patients in the ENHERTU® group, as compared with 12% in the physician’s choice group. More than 80% of patients receiving ENHERTU® had a reduction in tumor size, compared with approximately half the patients receiving physician’s choice of chemotherapy. The median duration of confirmed objective response was 11.3 months in the ENHERTU® group, compared with 3.9 months in the physician’s choice group. Treatment with ENHERTU® resulted in a higher percentage of patients with confirmed disease control (86%), than physician’s choice of chemotherapy (62%). The ORR was higher among those with a HER2 score of 3+ on IHC, than among those with an IHC score of 2+ with positive results on FISH (58% versus 29%).
The Overall Survival was significantly longer in the ENHERTU® group compared to the physician’s choice group (median 12.5 months versus 8.4 months; HR=0.59; P=0.01). The estimated OS at 6 months was 80% in the ENHERTU® group and 66% in the physician’s choice group and at 12 months was 52% and 29%, respectively. In a prespecified subgroup analysis, OS benefit was greater with ENHERTU® compared to physician’s choice of chemotherapy, across most subgroups. The median PFS was 5.6 months in the ENHERTU® group and 3.5 months in the physician’s choice group (HR=0.47). The most common adverse events of Grade 3 or higher were cytopenias. ENHERTU® related Interstitial Lung Disease or pneumonitis was noted in 10% of patients and most events were Grade 1 or 2. Decrease in left ventricular ejection fraction or heart failure was not observed in either treatment groups.

It was concluded that treatment with ENHERTU® resulted in significant improvements in Objective Response Rates and Overall Survival, as compared with standard therapies, among patients with HER2-positive advanced Gastric or GastroEsophageal junction cancer. This benefit was seen even in patients who had disease progression while on Trastuzumab containing regimens.

Trastuzumab Deruxtecan in Previously Treated HER2-Positive Gastric Cancer. Shitara K, Bang Y-J, Iwasa S, et al. for the DESTINY-Gastric01 Investigators. N Engl J Med 2020; 382:2419-2430

XTANDI® Improves Overall Survival in Nonmetastatic Castration-Resistant Prostate Cancer

RR

SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 191,930 new cases of prostate cancer will be diagnosed in 2020 and 33,330 men will die of the disease.

The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer, and is the first treatment intervention. Androgen Deprivation Therapies have included bilateral orchiectomy or Gonadotropin Releasing Hormone (GnRH) analogues, with or without first generation Androgen Receptor (AR) inhibitors such as CASODEX® (Bicalutamide), NILANDRON® (Nilutamide) and EULEXIN® (Flutamide) or with second-generation, anti-androgen agents, which include ZYTIGA® (Abiraterone), XTANDI® (Enzalutamide), ERLEADA® (Apalutamide) and NUBEQA® (Darolutamide).

Approximately 10-20% of patients with advanced prostate cancer will progress to Castration Resistant Prostate Cancer (CRPC) within five years during ADT, and over 80% of these patients will have metastatic disease at the time of CRPC diagnosis (mCRPC). Among those patients without metastases at CRPC diagnosis, 33% are likely to develop metastases within two years. The estimated mean survival of patients with CRPC is 9-36 months. Progression to Castration Resistant Prostate Cancer (CRPC) often manifests itself with a rising PSA (Prostate Specific Antigen), and watchful waiting is often recommended in men with non-metastatic CRPC. However, those with a rapidly rising PSA on ADT (doubling time of less than 8-10 months), are at significantly greater risk of developing metastases and death.XTANDI-Mechanism-of-Action

XTANDI® (Enzalutamide) is an orally administered, second-generation, anti-androgen, with no reported agonistic effects. It competitively inhibits androgens and AR binding to androgens as well as AR nuclear translocation and interaction with DNA. It thus inhibits several steps in the AR signaling pathway and was designed to overcome acquired resistance to first-generation nonsteroidal anti-androgens. Previously published studies have shown that XTANDI® improved Overall Survival in metastatic CRPC, regardless of whether it was used before or after Docetaxel chemotherapy.

PROSPER trial is a multinational, double-blind, randomized, placebo-controlled Phase III study, conducted to assess the safety and efficacy of XTANDI® in patients with nonmetastatic CRPC. In this study, 1401 eligible patients were enrolled and randomized in a 2:1 ratio to receive XTANDI® 160 mg orally once daily (N=933) or placebo (N=468). Enrolled patients had rising PSA, with a PSA doubling time of 10 months or less, despite castrate levels of testosterone (0.50 ng/mL), while continuing to receive Androgen Deprivation Therapy (ADT) with either a gonadotropin-releasing hormone agonist or antagonist or with previous bilateral orchiectomy. A diagnosis of nonmetastatic CRPC was established based on conventional imaging such as CT scans, MRI and Bone scans. The median patient age was 73 years, and both treatment groups were well balanced. The Primary endpoint was Metastasis-Free Survival (MFS), defined as time from randomization to imaging-based progression, or time to death from any cause without evidence of imaging-based progression. Secondary endpoints included Overall Survival, time to PSA progression, PSA response rate and time to first use of a subsequent antineoplastic therapy, as well as health-related quality of life and frequency and severity of adverse events. At the primary analysis, the study met the Primary endpoint of MFS and treatment with XTANDI® significantly improved Metastasis-Free Survival. The authors in this publication reported results from the prespecified final analysis of Overall Survival.

The median Overall Survival was 67.0 months in the XTANDI® group and 56.3 months in the placebo group. XTANDI® plus Androgen Deprivation Therapy (ADT) lowered the risk of death by 27%, compared with placebo plus ADT (HR=0.73; P=0.001). This benefit was consistent across prespecified subgroups. XTANDI® was also associated with a delay in the use of a new subsequent antineoplastic therapy, and the median time to first use of new antineoplastic therapy was 66.7 months in the XTANDI® group and 19.1 months in the placebo group (HR=0.29). The most frequently reported Adverse Events with XTANDI® were fatigue and musculoskeletal events.

It was concluded that XTANDI® given along with Androgen Deprivation Therapy resulted in longer median Overall Survival, when compared with placebo plus ADT, among men with nonmetastatic, CRPC and a rapidly rising PSA level, with 27% lower risk of death. The authors however added that the classification of patients as having nonmetastatic disease may be impacted, with the availability of more sensitive imaging techniques, for earlier detection of metastasis.

Enzalutamide and Survival in Nonmetastatic, Castration-Resistant Prostate Cancer. Sternberg CN, Fizazi K, Saad F, et al. for the PROSPER Investigators. N Engl J Med 2020; 382:2197-2206

First Line KEYTRUDA® plus Chemotherapy Significantly Improves PFS in PD-L1-High Triple Negative Breast Cancer

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (13%) will develop invasive breast cancer during their lifetime. Approximately 276,480 new cases of invasive female breast cancer will be diagnosed in 2020 and about 42,170 women will die of the disease. Triple Negative Breast Cancer (TNBC) is a heterogeneous, molecularly diverse group of breast cancers and are ER (Estrogen Receptor), PR (Progesterone Receptor) and HER2 (Human Epidermal Growth Factor Receptor-2) negative. TNBC accounts for 15-20% of invasive breast cancers, with a higher incidence noted in young patients and African American females. It is usually aggressive, and tumors tend to be high grade, and patients with TNBC are at a higher risk of both local and distant recurrence and often develop visceral metastases. Those with metastatic disease have one of the worst prognoses of all cancers with a median Overall Survival of 13 months. The majority of patients with TNBC who develop metastatic disease do so within the first 3 years after diagnosis, whereas those without recurrence during this period of time have survival rates similar to those with ER-positive breast cancers. The lack of known recurrent oncogenic drivers in patients with metastatic TNBC, presents a major therapeutic challenge. Overall survival among patients with pretreated metastatic TNBC has not changed over the past 2 decades and standard chemotherapy is associated with low response rates of 10-15% and a Progression Free Survival (PFS) of only 2-3 months.

KEYTRUDA® (Pembrolizumab) 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 rationale for combining chemotherapy with immunotherapy is that cytotoxic chemotherapy releases tumor-specific antigens, and immune checkpoint inhibitors such as KEYTRUDA® when given along with chemotherapy can enhance endogenous anticancer immunity.

Single agent KEYTRUDA® in metastatic TNBC demonstrated durable antitumor activity in several studies, with Objective Response Rates (ORRs) ranging from 10% to 21% and improved clinical responses in patients with higher PD-L1 expression. When given along with chemotherapy as a neoadjuvant treatment for patients with high-risk, early-stage TNBC, KEYTRUDA® combination achieved Pathological Complete Response rate of 65%, regardless of PD-L1 expression. Based on this data, KEYTRUDA® in combination with chemotherapy was studied, for first-line treatment of triple-negative metastatic breast cancer.

KEYNOTE-355 is a randomized, double-blind, phase III study, which evaluated the benefit of KEYTRUDA® in combination with one of the three different chemotherapy regimens, nab-Paclitaxel, Paclitaxel, or the non-taxane containing Gemzar/Carboplatin, versus placebo plus one of the three chemotherapy regimens, in patients with previously untreated or locally recurrent inoperable metastatic TNBC. In this study, 847 patients were randomized 2:1 to receive either KEYTRUDA® 200 mg IV on day 1 of each 21-day cycle along with either nab-paclitaxel 100 mg/m2 IV on days 1, 8 and 15 of each 28-day cycle, Paclitaxel 90 mg/m2 IV on days 1, 8 and 15 of each 28-day cycle, or Gemcitabine 1000 mg/m2 IV plus Carboplatin AUC 2 IV on days 1 and 8 of each 21-day cycle (N= 566) or placebo along with one of the three chemotherapy regimens (N= 281). This study was not designed to compare the efficacy of the different chemotherapy regimens. Treatment was continued until disease progression. Patients were stratified by chemotherapy, PD-L1 tumor expression (CPS of 1 or higher versus CPS of less than 1), and prior treatment with the same class of neoadjuvant/adjuvant chemotherapy (yes vs no). The baseline characteristics of treatment groups were well-balanced. The co-Primary end points of the trial were Progression Free Survival (PFS) and Overall Survival (OS) in patients with PD-L1-positive tumors, and in all patients. Secondary end points were Objective Response Rate (ORR), Duration of Response, Disease Control Rate, and safety. The median follow up for patients assigned to receive KEYTRUDA® was 17.5 months and 15.5 months for the placebo group. The authors reported the results from an interim analysis conducted by an Independent Data Monitoring Committee (IDMC).

KEYTRUDA® in combination with chemotherapy, significantly improved PFS in patients with CPS (Combined Positive Score) of 10 or greater. The median PFS was 9.7 months for KEYTRUDA® plus chemotherapy, compared with 5.6 months for placebo plus chemotherapy (HR=0.65, P=0.0012). This represented a 35% reduction in the risk of disease progression. Among patients with CPS of 1 or greater, the median PFS was 7.6 months for KEYTRUDA® plus chemotherapy, compared with 5.6 months for the placebo plus chemotherapy arm (HR= 0.74; P=0.0014). This however based on prespecified statistical criteria, was not considered statistically significant. Among the entire Intention-To-Treat (ITT) population, the median PFS was 7.5 months in the KEYTRUDA® plus chemotherapy group, compared with 5.6 months for chemotherapy plus placebo group (HR=0.82). Formal statistical significance was not tested in the ITT population. Overall Survival data are pending. Adverse Events (AEs) were similar in both treatment groups, although immune-related AEs occurred at a higher incidence in the KEYTRUDA® arm.

It was concluded that KEYTRUDA® in combination with several chemotherapy regimens, showed a statistically significant and clinically meaningful improvement in PFS, compared with chemotherapy alone, in patients with previously untreated locally recurrent, inoperable or metastatic TNBC, whose tumors expressed PD-L1 with a Combined Positive Score (CPS) of 10 or more. This data may be particularly relevant for patients who may have received a taxane in the adjuvant setting within a year, and could be more appropriately treated with a non-taxane regimen, in combination with KEYTRUDA®.

KEYNOTE-355: Randomized, double-blind, phase III study of pembrolizumab + chemotherapy versus placebo + chemotherapy for previously untreated locally recurrent inoperable or metastatic triple-negative breast cancer. Cortes J, Cescon DW, Rugo HS. et al. J Clin Oncol 38: 2020 (suppl; abstr 1000)

PSMA-Targeted Imaging for Biochemically Recurrent Prostate Cancer

RR

SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 191,930 new cases of prostate cancer will be diagnosed in 2020 and 33,330 men will die of the disease.

The major source of PSA (Prostate Specific Antigen) is the prostate gland and the PSA levels are therefore undetectable within 6 weeks after Radical Prostatectomy. Similarly, following Radiation Therapy, there is a gradual decline in PSA before reaching a post treatment nadir. A detectable PSA level after Radical Prostatectomy, or a rising PSA level following Radiation Therapy, is considered PSA failure or biochemical recurrence. Approximately 35% of the patients with prostate cancer will experience PSA only relapse within 10 years of their primary treatment and a third of these patients will develop documented metastatic disease within 8 years following PSA only relapse.Defining-Biochemical-Recurrence

Rising PSA is therefore a sign of recurrent disease and identifying the site of recurrence can be of immense value for the clinician and can help determine the best course of therapy. The diagnostic accuracy of standard imaging tests, for the identification of sites of recurrence in patients with biochemical recurrence, is low. Almost 90% of the standard imaging tests such as CT/MRI and Bone Scan may be negative. More accurate non-invasive imaging techniques for the detection of recurrent tumor is therefore an unmet need. Prostascint, a Single Photon Emission Computerized Tomography (SPECT) radiopharmaceutical agent, was approved in 1999 for the diagnostic imaging of post-prostatectomy patients with a rising PSA. PET (Positron Emission Tomography) scans have largely superseded this study. FluDeoxyGlucose F18 (FDG), a glucose analogue is the most widely used PET radiotracer, but is not generally used as an imaging agent in prostate cancer. This is because good and reliable quality images are not feasible due to indolent growth of prostate cancers and the high urinary excretion of FDG. The other PET radiotracer that is available, Choline C11, has been shown to improve cancer detection in men with biochemical recurrent prostate cancer, but this agent has a short half life of 20 minutes, requires greater patient preparation including 6 hours of fasting prior to administration of Choline C11, delivers higher radiation dose to patients and image quality is poor. The FDA in 2016 approved AXUMIN® (Fluciclovine F18), a novel molecular radiopharmaceutical diagnostic agent, for PET imaging in men with suspected prostate cancer recurrence, based on elevated PSA levels, following prior treatment. This study however is less likely to be positive with PSA less than 1 ng/mL, unless the doubling time is rapid. There is also higher false positive rate within the intact or treated prostate gland, and uptake may be absent in densely sclerotic lesions. Current imaging modalities are therefore inadequate for localizing and characterizing occult disease in men with biochemically recurrent prostate cancer.

F-18 DCFPyL is a novel PET imaging agent that binds selectively with high affinity to Prostate-Specific Membrane Antigen (PSMA), which is overexpressed in prostate cancer cells. CONDOR is a prospective, multicenter, randomized, Phase III trial, conducted to evaluate the diagnostic performance of PET/CT imaging with F-18 DCFPyL, a radiopharmaceutical targeting the extracellular domain of PSMA. This study enrolled 208 men at 14 sites in the US and Canada, with a rising PSA level after definitive therapy and negative or equivocal standard-of-care imaging (eg, CT, MRI, bone scintigraphy). PET/CT imaging was performed 1-2 hours following administration of a single dose of F-18 DCFPyL. The median age was 68 yrs and the median time from diagnosis was 71 months. Approximately 50% of all patients had undergone Radical Prostatectomy, 35% underwent Radical Prostatectomy and Radiation Therapy, 15% had only received RadioTherapy, and 28% received at least one systemic therapy for their prostate cancer. Approximately 74% of patients had a total Gleason score below 8. All enrolled patients had biochemically recurrent metastatic Castration-Resistant Prostate Cancer, and a PSA of at least 0.2 ng/mL following radical prostatectomy, or at least 2 ng/mL over the nadir following prior Radiation Therapy, Cryotherapy or systemic therapy. The median PSA was 0.8 ng/mL, (PSA level at which most decisions about subsequent salvage focal or systemic therapies are made) and 31% of patients had a PSA of at least 2.0 ng/mL. All enrolled patients had no previous radiologic findings. The Primary endpoint was Correct Localization Rate of occult disease, as determined by three independent reviewers, and the Secondary endpoint was the impact of F-18 DCFPyL PET/CT imaging results on management of enrolled patients in this study.

The study met its Primary endpoint and the Correct Localization Rate of occult disease or the Positive Predictive Value ranged from 84.8% to 87% for the three independent reviewers. The Correct Localization Rate of occult disease was maintained regardless of PSA values and the F-18 DCFPyL PET/CT imaging detected disease even at the lowest of PSA values. Regarding the Secondary endpoint of impact of F-18 DCFPyL PET/CT imaging on treatment, 64% of patients had a change in management due to findings noted on the imaging study, of which 78% were attributable to positive findings on the imaging study, and 21.4% to negative findings on F-18 DCFPyL PET/CT imaging study. Specific changes in the treatment management included change in the goal of patients disease management from a noncurative approach to a curative salvage local therapy in 21% of patients, 28% changed from receiving salvage local therapy to systemic therapy or added systemic therapy, 23.9% changed from observation status to initiation of therapy and 4.4% changed from planned treatment to observation alone.

It was concluded that PSMA-targeted F-18 DCFPyL PET/CT imaging detected and localized occult disease in most men with biochemical recurrence, presenting with negative or equivocal findings on conventional imaging. Further, F-18 DCFPyL PET/CT imaging provided actionable information that led to change in treatment plans for the majority of patients, thus providing evidence that PSMA PET imaging may be valuable in men with recurrent or suspected metastatic prostate cancer.

Impact of PSMA-targeted imaging with 18F-DCFPyL-PET/CT on clinical management of patients (pts) with biochemically recurrent (BCR) prostate cancer (PCa): Results from a phase III, prospective, multicenter study (CONDOR). Morris MJ, Carroll PR, Saperstein L, et al. DOI: 10.1200/JCO.2020.38.15_suppl.5501 Journal of Clinical Oncology 38, no. 15_suppl (May 20, 2020) 5501-5501.