Ovarian Cancer Drugs: Advancements and New Treatments

Ovarian cancer is one of the deadliest forms of cancer among women. According to the American Cancer Society, over 21,000 women in the United States are diagnosed with ovarian cancer each year and it leads to over 14,000 deaths annually. However, advancements in ovarian cancer drugs and treatments over the past few decades have led to improved survival rates and management of the disease. This article discusses some of the major drug developments for ovarian cancer.

Platinum-Based Chemotherapy
Platinum-based chemotherapy drugs have been a mainstay of first-line ovarian cancer treatment for decades. The two most commonly used drugs in this class are cisplatin and carboplatin. These drugs work by damaging the DNA of cancer cells, which leads to their death. Extensive research has shown that platinum-based drugs can significantly improve outcomes when used along with surgery for ovarian cancer.

While cisplatin is generally more effective, carboplatin tended to have fewer side effects and was less toxic. As a result, carboplatin increasingly became the standard first-line treatment for ovarian cancer through the 1990s and remains so today. Researchers continue working to enhance the effectiveness of platinum drugs. For example, combining them with other chemotherapy agents or adding them to maintenance therapy has led to improved progression-free and overall survival rates.

Immunotherapy Drugs
Immunotherapy has emerged as a promising new approach for treating various cancers, including ovarian cancer. These drugs work to boost the body's own immune system and enable it to better identify and destroy cancer cells. In recent years, the immunotherapy drug bevacizumab (Avastin) was approved as a treatment option for recurrent ovarian cancer. Avastin, which is an anti-VEGF antibody, helps control tumor growth by blocking angiogenesis or the formation of new blood vessels.

Another exciting development is the use of PD-1 and PD-L1 inhibitors. These drugs target checkpoints that cancer cells use to evade detection by the immune system. Keytruda (pembrolizumab) and Opdivo (nivolumab) are PD-1 inhibitors approved to treat various cancers. Ongoing clinical trials are exploring their potential as treatments for recurrent, refractory ovarian cancer either alone or in combination with other therapies. Early results indicate these immunotherapy drugs may improve survival. As further research progresses, they may lead to more durable responses for women with this disease.

PARP Inhibitors
Poly (ADP-ribose) polymerase or PARP inhibitors target DNA damage repair pathways and have emerged as an important class of targeted therapy drugs for ovarian cancer. Lynparza (olaparib) was the first PARP inhibitor approved for use in late-stage ovarian cancer with BRCA gene mutations. These mutations impair the ability to repair double-strand DNA breaks, rendering cancer cells more susceptible to PARP inhibition.

More recently, two additional PARP inhibitors, Rubraca (rucaparib) and Zejula (niraparib), earned FDA approval. They are also used for recurrent ovarian cancer with BRCA mutations who have received two or more prior chemotherapy regimens. Ongoing research aims to expand the use of PARP inhibitors to additional patient subgroups including those with other homologous recombination repair gene mutations. PARP inhibitors are generally well-tolerated and can potentially offer women multiple years of remission or stable disease.

Angiogenesis Inhibitors
Blocking blood vessel growth or angiogenesis within tumors is another strategy several drugs employ. As mentioned earlier, Avastin targets VEGF signaling to inhibit angiogenesis. Another agent, Vitrakvi (larotrectinib), received accelerated approval for solid tumors with NTRK gene fusions including ovarian cancer. These gene fusions stimulate tumor growth by activating metabolic and angiogenic pathways. Vitrakvi treats this rare molecular subset of cancer. Researchers continue identifying genetic biomarkers to refine use of targeted drugs like angiogenesis inhibitors.

Remaining Challenges and Future Outlook
Despite major advancements, ovarian cancer remains challenging to treat and most patients will eventually experience disease recurrence or progression. Important remaining challenges include overcoming platinum drug resistance, finding predictive biomarkers, and addressing metastasis. Combination regimens that pair different classes of drugs are an area of active exploration. Ultimately, immuno-oncology combinations, better screening methods, and earlier detection hold promise to significantly improve survival rates in the years to come. With sustained research efforts, women coping with ovarian cancer now have far more treatment options than in the past, offering renewed hope for managing this disease.

In conclusion, this article discussed several key drug developments for ovarian cancer treatment over the past few decades. Platinum drugs have long been standard first-line treatment while new immunotherapies, PARP inhibitors and other targeted agents offer additional options. Combination regimens continue advancing the field. With ongoing clinical research, we anticipate more personalized, effective therapies for women suffering from this disease.