Rare Cancer Treatments and the Power of Checkpoint Inhibitors Among Hot Topics at ASCO
With the books closed on another American Society of Clinical Oncology (ASCO) meeting, it’s clear to see that checkpoint inhibitors keep showing a promise in additional indications and that more progress is being made in the treatment of rare cancers.
Checkpoint inhibitors have become cornerstones in the oncology pipelines of companies like Merck, AstraZeneca and Bristol-Myers Squibb (BMS). The importance of the class of drugs was underscored last year when the Nobel Prize in Medicine was awarded to two oncology pioneers who first broke ground in the use of checkpoint inhibitors.
At ASCO, checkpoint inhibitor leaders continued to show their strengths during the annual conference. In various presentations, the companies noted that the checkpoint inhibitors extended the lives of patients in multiple forms of cancer. BMS demonstrated the further power of its checkpoint inhibitor Opdivo (nivolumab) in metastatic melanoma. Alone and in combination with Yervoy, the drug showed efficacy in long-term quality of life study in patients with previously treated or untreated advanced melanoma. The drug company demonstrated a five-year survival of 57% for the combination treatment. Even after ceasing treatment, 56% of patients survived for at least three years, the company announced. AstraZeneca’s Imfinzi flexed its muscle in lung cancer.
A post-hoc analysis of a Phase III study showed longer overall survival evidence in patients in unresectable, Stage III non-small cell lung cancer. The additional year of follow-up data showed Imfinzi provided consistent efficacy, maintaining a 31% reduction in the risk of death vs. placebo after concurrent chemoradiation therapy. Merck also demonstrated the longevity of its star PD-L1 inhibitor, Keytruda. The company showcased five-year data in metastatic non-small cell lung cancer that demonstrated the efficacy of treating patients who have tumors with a high percentage of PD-L1 protein.
Rare cancer treatments were also highlighted at the conference. While rare cancers only account for a small percentage of all cancer diagnoses, there have been some significant advances made over the past few years, including the January approval of Novartis’ Lutathera for the treatment of somatostatin-receptor positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs), an orphan disease. Treatment with Lutathera lowered the risk of disease progression by 79% for these patients. Typically, patients with these kinds of tumors and distant metastases have a 5-year survival probability of 35%.
Daiichi Sankyo also showed off its promising therapy pexidartinib that showed increased tumor response rate in patients with tenosynovial giant cell tumor (TGCT). Also known as giant cell tumor of the tendon sheath, TGCT is a debilitating tumor of the joint or tendon sheath for which there is no approved systemic therapy. Pexidartinib showed an overall response rate of 39.3%, which led to ASCO recognizing the treatment as one of five significant advancements in rare disease treatment. ASCO called pexidartinib the first promising investigational therapy for TGCT. Also, Bayer’s sorafenib was shown to improve progression-free survival in patients with desmoid tumors for the first time. Desmoid tumors are rare sarcomas that are estimated to occur in approximately 1,000 people each year in the United States.
Increased survivability for breast cancer patients was also a hot topic at ASCO. Novartis showed off data for a hard-to-treat form of breast cancer. The Swiss company said Kisqali plus endocrine therapy extended the life of women with human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer. Overall survival rates in the intent-to-treat population at 42 months were 70.2% for Kisqali combination therapy compared to 46% for endocrine therapy alone. At the time of data cut-off, 35% of women taking Kisqali combination therapy were continuing the treatment. Novartis also showed off data from its recently approved Piqray, the first and only treatment specifically for patients with a PIK3CA mutation in HR+/HER2- advanced breast cancer.