Immunotherapy may be efficacious in patients with HIV-associated Kaposi's sarcoma

September 7, 2018, American Association for Cancer Research

Among a small cohort of patients with HIV-associated Kaposi's sarcoma treated with immune checkpoint inhibitors, more than 65 percent had partial or complete remission.

The study is published in Cancer Immunology Research, a journal of the American Association for Cancer Research, by Natalie Galanina, MD, oncologist at Moores Cancer Center at UC San Diego Health.

"Despite the successful and prevalent use of antiretroviral medications to treat human immunodeficiency virus (HIV)-positive , about 15 percent of this population still develops Kaposi's sarcoma, which is an incurable malignancy with significant morbidity," said Galanina. "Due to a paucity of novel therapeutic options for this disease in recent decades, we wanted to investigate if immune inhibition was effective in treating this virally mediated cancer."

The standard of care for patients with Kaposi's sarcoma is liposomal doxorubicin, a type of chemotherapy. While roughly half of patients respond to this therapy, most suffer relapses and require repeated treatments, noted Galanina. Because the standard of care is not curative, and Kaposi's sarcoma can persist in patients with an undetectable viral load, new treatments for this disease represent a clinically unmet need, she explained.

Galanina and colleagues analyzed data from nine men with Kaposi's sarcoma treated with anti-PD-1 immune checkpoint inhibitors at Moores Cancer Center between August 2013 and December 2017. All patients had received retroviral therapy and a median of one prior line of for Kaposi's sarcoma. Eight patients were treated with nivolumab (Opdivo), while one patient was treated with pembrolizumab (Keytruda).

In addition to survival data, the researchers utilized next-generation sequencing data from tissue and circulating tumor DNA to analyze tumor mutational burden (TMB) and PD-L1 expression levels, biomarkers for anti-PD-1 treatment.

Following treatment with immune checkpoint inhibition, five patients had a partial response, three patients had stable disease, and one patient had complete remission. All patients remained on treatment, and no patient had shown disease progression at 6.5 months of follow-up.

PD-L1 expression was negative in all four evaluable patients. Furthermore, all three evaluable patients had low TMB (between 1-4 mutations per megabase).

"Typically, checkpoint blockade immunotherapy is more effective in patients with high TMB and/or high expression of PD-L1, yet we saw many patients who responded to treatment without these characteristics," said Galanina. "It is possible that the viral immunogenomic mutanome is sufficient to induce changes to the immune system, enabling a response to treatment with checkpoint inhibition."

While treatment with standard chemotherapy can have significant side effects, patients treated with PD-1 inhibitors experienced limited toxicity in this study, noted Galanina. "Importantly, treatment with PD-1 inhibitors did not cause myelosuppression, which is an important finding in this patient population," she added.

Furthermore, seven patients treated with PD-1 inhibitors had an increase in both CD4+ and CD8+ T cell levels, although not statistically significant.

"Based on these results, we think that PD-1 checkpoint blockade may present a promising, novel therapeutic option for HIV-associated Kaposi's with high efficacy and low toxicity," said Galanina.

Limitations of the study include a small sample size and the paucity of available archival tissue material to corroborate PD-L1 expression findings.

Explore further: Research team develops predictor for immunotherapy response in melanoma

More information: Cancer Immunology Research, DOI: 10.1158/2326-6066.CIR-18-0121

Related Stories

Research team develops predictor for immunotherapy response in melanoma

August 20, 2018
In a new study, researchers developed a gene expression predictor that can indicate whether melanoma in a specific patient is likely to respond to treatment with immune checkpoint inhibitors, a novel type of immunotherapy. ...

Enhancing immune checkpoint inhibitor therapy using treatment combination

September 5, 2018
A combination of a novel inhibitor of the protein CK2 (Casein kinase 2) and an immune checkpoint inhibitor has dramatically greater antitumor activity than either inhibitor alone, according to research from The Wistar Institute ...

Older melanoma patients have better response to immune checkpoint blockade therapy

June 13, 2018
Patient age correlates with response to immunotherapy in melanoma and depleting regulatory T cells in young patients may have a therapeutic potential to enhance response in younger patients, according to research from The ...

Study finds melanoma biomarkers predicting checkpoint blocker response

July 18, 2018
Scientists at Dana-Farber/Brigham and Women's Cancer Center (DF/BWCC) have identified biomarkers in melanoma that could help tailor immunotherapy treatments to maximize the benefits for patients while reducing the likelihood ...

In melanoma, radiosurgery may combine well with immunotherapy, especially PD-1 inhibitors

June 25, 2018
Doctors often treat melanoma with drugs that unblind the immune system to cancer. And brain metastases associated with melanoma are often treated with precisely targeted radiation known as radiosurgery. Now a University of ...

New immunotherapy combination shows promise for patients with advanced melanoma

April 5, 2017
Treatment with a combination of ipilimumab (Yervoy) and Coxsackievirus A21 (CVA21; Cavatak) led to durable responses in a number of patients with advanced melanoma, including some whose melanoma had progressed despite prior ...

Recommended for you

Cancer immunotherapy might benefit from previously overlooked immune players

September 20, 2018
Cancer immunotherapy—efforts to boost a patient's own immune system, allowing it to better fight cancer cells on its own—has shown great promise for some previously intractable cancers. Yet immunotherapy doesn't work ...

What can salad dressing tell us about cancer? Think oil and vinegar

September 20, 2018
Researchers led by St. Jude Children's Research Hospital scientists have identified another way the process that causes oil to form droplets in water may contribute to solid tumors, such as prostate and breast cancer. The ...

Novel biomarker found in ovarian cancer patients can predict response to therapy

September 20, 2018
Despite months of aggressive treatment involving surgery and chemotherapy, about 85 percent of women with high-grade wide-spread ovarian cancer will have a recurrence of their disease. This leads to further treatment, but ...

Testing fluorescent tracers used to help surgeons determine edges of breast cancer tumors

September 20, 2018
A team of researchers with members from institutions in The Netherlands and China has conducted a test of fluorescent tracers meant to aid surgeons performing tumor removal in breast cancer patients. In their paper published ...

New way to target advanced breast cancers

September 20, 2018
A cytokine signature found in certain kinds of breast cancer cells can not only serve as a diagnostic tool for HER2-negative cancers but also offer an effective treatment target.

Understanding epilepsy in pediatric tumors

September 20, 2018
Pediatric brain tumors are characterized by frequent complications due to intractable epilepsy compared to adult brain tumors. However, the genetic cause of refractory epilepsy in pediatric brain cancer has not been elucidated ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.