Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Cancer immunotherapy
Table title:
FDA-approved antibodies
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Antibody </th><th colspan=1 rowspan=1 > Brand name </th><th colspan=1 rowspan=1 > Type </th><th colspan=1 rowspan=1 > Target </th><th colspan=1 rowspan=1 > Approval date </th><th colspan=1 rowspan=1 > Approved treatment(s) </th></tr>
<tr> <td colspan=1 rowspan=1 > Alemtuzumab </td><td colspan=1 rowspan=1 > Campath </td><td colspan=1 rowspan=1 > humanized </td><td colspan=1 rowspan=1 > CD52 </td><td colspan=1 rowspan=1 > 2001 </td><td colspan=1 rowspan=1 > B-cell chronic lymphocytic leukemia (CLL) </td></tr>
<tr> <td colspan=1 rowspan=1 > Atezolizumab </td><td colspan=1 rowspan=1 > Tecentriq </td><td colspan=1 rowspan=1 > humanized </td><td colspan=1 rowspan=1 > PD-L1 </td><td colspan=1 rowspan=1 > 2016 </td><td colspan=1 rowspan=1 > bladder cancer </td></tr>
<tr> <td colspan=1 rowspan=1 > Avelumab </td><td colspan=1 rowspan=1 > Bavencio </td><td colspan=1 rowspan=1 > human </td><td colspan=1 rowspan=1 > PD-L1 </td><td colspan=1 rowspan=1 > 2017 </td><td colspan=1 rowspan=1 > metastatic Merkel cell carcinoma </td></tr>
<tr> <td colspan=1 rowspan=1 > Ipilimumab </td><td colspan=1 rowspan=1 > Yervoy </td><td colspan=1 rowspan=1 > human </td><td colspan=1 rowspan=1 > CTLA4 </td><td colspan=1 rowspan=1 > 2011 </td><td colspan=1 rowspan=1 > metastatic melanoma </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Ofatumumab </td><td colspan=1 rowspan=1 > Arzerra </td><td class="highlighted"  colspan=1 rowspan=1 > human </td><td class="highlighted"  colspan=1 rowspan=1 > CD20 </td><td colspan=1 rowspan=1 > 2009 </td><td colspan=1 rowspan=1 > refractory CLL </td></tr>
<tr> <td colspan=1 rowspan=1 > Nivolumab </td><td colspan=1 rowspan=1 > Opdivo </td><td colspan=1 rowspan=1 > human </td><td colspan=1 rowspan=1 > PD-1 </td><td colspan=1 rowspan=1 > 2014 </td><td colspan=1 rowspan=1 > unresectable or metastatic melanoma, squamous non-small cell lung cancer, Renal cell carcinoma, colorectal cancer, hepatocellular carcinoma, classical hodgkin lymphoma </td></tr>
<tr> <td colspan=1 rowspan=1 > Pembrolizumab </td><td colspan=1 rowspan=1 > Keytruda </td><td colspan=1 rowspan=1 > humanized </td><td colspan=1 rowspan=1 > PD-1 </td><td colspan=1 rowspan=1 > 2014 </td><td colspan=1 rowspan=1 > unresectable or metastatic melanoma, squamous non-small cell lung cancer (NSCLC), Hodgkin's lymphoma, Merkel-cell carcinoma (MCC), primary mediastinal B-cell lymphoma (PMBCL), stomach cancer, cervical cancer </td></tr>
<tr> <td colspan=1 rowspan=1 > Rituximab </td><td colspan=1 rowspan=1 > Rituxan, Mabthera </td><td colspan=1 rowspan=1 > chimeric </td><td colspan=1 rowspan=1 > CD20 </td><td colspan=1 rowspan=1 > 1997 </td><td colspan=1 rowspan=1 > non-Hodgkin lymphoma </td></tr>
<tr> <td colspan=1 rowspan=1 > Durvalumab </td><td colspan=1 rowspan=1 > Imfinzi </td><td colspan=1 rowspan=1 > human </td><td colspan=1 rowspan=1 > PD-L1 </td><td colspan=1 rowspan=1 > 2017 </td><td colspan=1 rowspan=1 > bladder cancer non-small cell lung cancer </td></tr>
</table>
Question:
What is Ofatumumab used for?
Answer:
The Ofatumumab is a human antibody that binds to CD20.